Microbiology and Immunology via MedWorm.com

The prevalence of plasmid-mediated quinolone resistance determinants among clinical isolates of ESBL or AmpC-producing Escherichia coli from Chinese pediatric patients

Microbiology and Immunology — Fri, 26 Feb 2010 16:41:16 +0100

Three kinds of PMQR determinants (qnr genes, aac(6')-Ib-cr, and qepA) have been discovered and shown to be widely distributed among clinical isolates. To characterize the prevalence of PMQR determinants in ESBL or AmpC-producing E. coli clinical isolates in Chinese children, a total of 292 ESBL or AmpC-producing E. coli clinical isolates collected from five children's hospitals in China from 2005 to 2006 were screened for PMQR determinants by PCR. Twenty (6.8%) of the 292 isolates were positive for PMQR determinants. A total of 12 (4.1%) isolates were positive for qnr genes, comprising three positive for qnrA (1.0%), three for qnrB (1.0%), and six for qnrS (2.1%). Twenty-four (8.2%) isolates were positive for aac(6')-Ib, of which 10 (3.4% of 292) had the [ndash]cr variant. There was no qep...

Differential recruitment of CD63 and Rab7-interacting-lysosomal-protein to phagosomes containing Mycobacterium tuberculosis in macrophages

Microbiology and Immunology — Thu, 25 Feb 2010 00:00:00 +0100

M.tb is an intracellular pathogen which survives within the phagosomes of host macrophages by inhibiting their fusion with lysosomes. Here, it has been demonstrated that a lysosomal glycoprotein, CD63, is recruited to the majority of M.tb phagosomes, while RILP shows limited localization. This is consistent with the author's findings that CD63, but not RILP, is recruited to the phagosomes in macrophages expressing the dominant negative form of Rab7. These results suggest that M.tb phagosomes selectively fuse with endosomes and lysosomes to escape killing activity while acquiring nutrients. (Source: Microbiology and Immunology)

Prevalence of integrons and a new dfrA17 variant in Gram-negative bacilli which cause community-acquired infections

Microbiology and Immunology — Thu, 25 Feb 2010 00:00:00 +0100

A hundred and eleven Gram-negative bacilli from community-acquired infections were characterized by antimicrobial susceptibility testing, screened for class 1 and 2 integrons, and statistically evaluated for the association between antibiotic profile and the presence of integrons. The frequency with which integrons were harbored was 28.8%. Three E. coli strains contained a dfrA17 variant inserted in a class 1 integron. Results of PFGE indicated that some E. coli strains carrying integrons were clonally related. Carriage of gene cassettes was significantly associated with resistance to certain antibiotics (P < 0.05). (Source: Microbiology and Immunology)

Presence of multiple copies of capsulation loci in invasive Haemophilus influenzae type b (Hib) strains in Japan before introduction of the Hib conjugate vaccine

Microbiology and Immunology — Thu, 25 Feb 2010 00:00:00 +0100

We examined 24 Hib strains from Japanese children with invasive diseases due to Hib. Although all strains showed the same capb sequence, Southern blot analysis showed that four strains (16.7%) harbored multiple copies (more than two) of the capb locus. Careful analysis of the locus in circulating Hib strains is necessary now that the Hib vaccine has been introduced into Japan. (Source: Microbiology and Immunology)

Stability of Chlamydophila pneumoniae in a harsh environment without a requirement for acanthamoebae

Microbiology and Immunology — Mon, 25 Jan 2010 17:37:40 +0100

The effect of actual interactions between Chlamydophila pneumoniae and amoebae (Acanthamoeba) on the survival of C. pneumoniae was investigated. C. pneumoniae and amoebae were detected in 75 soil samples by IFU assay and PCR. Although C. pneumoniae could not be cultured, the DNA prevalence of C. pneumoniae and amoebae in natural soil was 20% and 92% (no correlation between the prevalence of DNA was observed). The viability of C. pneumoniae spiked in autoclaved soil was assessed by IFU assay and RT-PCR. Although the number of infective progeny decreased for three days, transcripts of C. pneumoniae were detected for up to 98 days independently of amoebae. The stability of C. pneumoniae in liquid medium was also assessed by IFU assay and transmission electron microscopy. The bacteria could su...

Protection of red sea bream Pagrus major against red sea bream iridovirus infection by vaccination with a recombinant viral protein

Microbiology and Immunology — Fri, 22 Jan 2010 00:00:00 +0100

In this study the immunogenicity of crude subunit vaccines against infection by the Megalocytivirus RSIV was investigated. Three capsid proteins, 18R, 351R and a major capsid protein, were selected for use as crude subunit vaccines. High homology among Megalocytivirus types was found in the initial sequence examined, the 351R region. Red sea bream (Pagrus major) juveniles were vaccinated by intraperitoneal injection of recombinant formalin-killed Escherichia coli cells expressing these three capsid proteins. After challenge infection with RSIV, fish vaccinated with the 351R-recombinant bacteria showed significantly greater survival than those vaccinated with control bacteria. The 351R protein was co-expressed with GAPDH from the bacterium Edwardsiella tarda in E. coli; this also protected ...

Non-opsonic phagocytosis of homologous non-toxigenic and toxigenic Corynebacterium diphtheriae strains by human U-937 macrophages

Microbiology and Immunology — Thu, 24 Dec 2009 16:01:45 +0100

In conclusion, human macrophages in the absence of opsonins may not be promptly effective at killing diphtheria bacilli. The presence of the tox gene influences the susceptibility of C. diphtheriae to human macrophages and the outcome of non-opsonic phagocytosis. C. diphtheriae strains exhibit strategies to survive within macrophages and to exert apoptosis and necrosis in human phagocytic cells, independent of the tox gene. (Source: Microbiology and Immunology)

Reviewers

Microbiology and Immunology — Mon, 30 Nov 2009 00:00:00 +0100

(Source: Microbiology and Immunology)

Relationship between regulatory and type 1 T cells in dogs with oral malignant melanoma

Microbiology and Immunology — Fri, 20 Nov 2009 00:00:00 +0100

In conclusion, the percentage of Treg increases with the tumor stage in the peripheral blood of dogs with oral malignant melanoma. In dogs, Treg appears to suppress Type 1 immunity, which may be responsible for anti-tumor responses. (Source: Microbiology and Immunology)

Lipoteichoic acids on Lactobacillus plantarum cell surfaces correlate with induction of interleukin-12p40 production

Microbiology and Immunology — Fri, 20 Nov 2009 00:00:00 +0100

Heat-killed cells of Lactobacillus plantarum L-137 are potent inducers of IL-12 in vitro as well as in vivo and have been shown to have antiallergic, antitumor, and antiviral effects through this induction, which leads to a Th1 type immune response. To determine why L-137 cells induce much greater IL-12 production than the type strain Lactobacillus plantarum JCM1149, we examined the differences in their CW components. The L-137 CW was found to have a higher alanine content and IL-12p40 induction was significantly greater in comparison with JCM1149 CW, whereas peptidoglycans isolated from both strains did not cause IL-12p40 induction. Because in purified CW preparations from gram-positive bacteria, the presence of LTA, the major proinflammatory structure on these bacteria, has been known to...

Full genomic amplification and subtyping of influenza A virus using a single set of universal primers

Microbiology and Immunology — Fri, 20 Nov 2009 00:00:00 +0100

Influenza A virus has eight-segmented RNA molecules as a genome and, among all strains of the virus, both ends of each segment have 13 and 12 nucleotide sequences conserved. In the present study, a simple RT-PCR method to amplify all eight segments of the virus and determine the HA and NA subtype using a single primer set based on the conserved terminal sequences has been established. This method is also capable of detecting subgenomic defective interfering RNA of the influenza A virus. Since the primers used here cope with each and every RNA segment of influenza A virus, this simple RT-PCR method is valuable not only for cloning each gene of the virus, but also for identifying subtypes, including subtypes other than 16 HA and 9 NA subtypes. (Source: Microbiology and Immunology)

A novel anti-prion protein monoclonal antibody and its single-chain fragment variable derivative with ability to inhibit abnormal prion protein accumulation in cultured cells

Microbiology and Immunology — Fri, 20 Nov 2009 00:00:00 +0100

mAbs T1 and T2 were established by immunizing PrP gene ablated mice with recombinant MoPrP of residues 121[ndash]231. Both mAbs were cross-reactive with PrP from hamster, sheep, cattle and deer. A linear epitope of mAb T1 was identified at residues 137[ndash]143 of MoPrP and buried in PrPC expressed on the cell surface. mAb T1 showed no inhibitory effect on accumulation of PrPSc in cultured scrapie-infected neuroblastoma (ScN2a) cells. In contrast, mAb T2 recognized a discontinuous epitope ranged on, or structured by, residues 132[ndash]217 and this epitope was exposed on the cell surface PrPC. mAb T2 showed an excellent inhibitory effect on PrPSc accumulation in vitro at a 50% inhibitory concentration of 0.02 [mu]g/ml (0.14 nM). The scFv form of mAb T2 (scFv T2) was secreted in neuroblast...

Amino acid substitutions at positions 242, 255 and 268 in rabies virus glycoprotein affect spread of viral infection

Microbiology and Immunology — Fri, 20 Nov 2009 00:00:00 +0100

Rabies virus Nishigahara strain kills adult mice after intracerebral inoculation, whereas the derivative RC-HL strain does not. It has previously been reported by us that the R(G 242/255/268) strain, in which amino acids at positions 242, 255 and 268 on the G protein have been replaced by those from the Nishigahara strain in the genetic background of the RC-HL strain, kills adult mice. This indicates that these three amino acids of G protein are important for pathogenicity of the Nishigahara strain. In order to obtain insights into the mechanism by which these amino acids affect pathogenicity, in this study spread of viral infection and apoptosis-inducing ability of the attenuated RC-HL strain and the virulent R(G 242/255/268) strain were compared. RC-HL infection spread less efficiently i...

Immunogenicity of an inactivated adjuvanted whole-virion influenza A (H5N1, NIBRG-14) vaccine administered by intramuscular or subcutaneous injection

Microbiology and Immunology — Fri, 20 Nov 2009 00:00:00 +0100

The immunogenicity and safety profile of an inactivated whole-virion influenza A (H5N1, NIBRG-14) vaccine with alum adjuvant that was administered by IM or SC injection in a phase I clinical study involving 120 healthy Japanese men aged 20[ndash]40 years is described. The serological response of the IM group was stronger than that of the SC group. Local adverse events were less severe with IM injection than with SC injection, while similar systemic adverse events were seen in both groups. These results indicate that, when administering an inactivated whole virion vaccine with alum adjuvant for pandemic influenza, IM injection may achieve better immunogenicity and safety than SC injection. (Source: Microbiology and Immunology)

The carboxy-terminal tail of Aeromonas sobria serine protease is associated with the chaperone

Microbiology and Immunology — Sun, 01 Nov 2009 00:00:00 +0100

ASP is the only bacterial protease in the kexin group of the subtilisin family. Previous studies have revealed that the ORF2 protein encoded at the 3' end of the asp operon is required for ASP to change from a nascent form into an active form in the periplasm. However, the mechanism by which ORF2 makes contact and interacts with ASP in the maturation process remains unknown. The present study examined the effect of mutations in the carboxy-terminal region of ASP on the ASP maturation process. Both deletion-mutation and amino acid-substitution studies have demonstrated that the histidine residue at position 595 (His-595), the sixth residue from the carboxyl terminus of ASP, is highly involved in the generation of active ASP molecules. An analysis by pull-down assay revealed that mutation at...

Dual specificity phosphatase16 is a negative regulator of c-Jun NH2-terminal kinase activity in T cells

Microbiology and Immunology — Tue, 27 Oct 2009 00:00:00 +0100

Activation of MAPK is negatively regulated by DUSP, which dephosphorylate the phosphothreonine and phosphotyrosine residues. We have identified a novel JNK-specific DUSP, DUSP16, from murine macrophages. Its involvement in T cells has not yet been defined. In the present study, we found expression of DUSP16 in thymocytes and activated T cells but not in naive T cells. To elucidate the roles of DUSP16 in T cells, transgenic mice expressing a dominant negative form of DUSP16 specifically in T cells were generated (dnDUSP16 Tg). JNK activity was selectively augmented in the thymocytes of these dnDUSP16 Tg mice. CD4 T cells in dnDUSP16 Tg mice showed normal levels of proliferation and IL-2 production after TCR triggering, while they produced increased IFN-[gamma] but reduced Th2 cytokines comp...

Recombinant human progranzyme 3 expressed in Escherichia coli for analysis of its activation mechanism

Microbiology and Immunology — Tue, 27 Oct 2009 00:00:00 +0100

Gr3 is reported to play an important role in defense against viral infection. Although it is known that Gr3 is synthesized as a proenzyme and activated in the cytotoxic granules of NK cells and CTL, the activation mechanism is not clearly understood. In an attempt to analyze the activation mechanism of human Gr3, a recombinant pro-Gr3 was expressed in the periplasm of E. coli and purified to homogeneity. On SDS-PAGE the recombinant pro-Gr3 showed a slightly higher molecular weight than the enzymatically active Gr3, because the former possesses a small propeptide at its N-terminal. The recombinant pro-Gr3 was enzymatically inactive. It could be activated by treatment with cathepsin C, which concomitantly decreased the molecular weight to that of active Gr3. The proteolytic reaction of cathe...

Inhibitory effects of soluble MD-2 and soluble CD14 on bacterial growth

Microbiology and Immunology — Tue, 27 Oct 2009 00:00:00 +0100

The effects of the soluble forms of the endotoxin receptor molecules sMD-2 and sCD14 on bacterial growth were studied. When Escherichia coli and Bacillus subtilis were incubated at 37°C for 18 hr with either sMD-2 or sCD14, growth of these bacteria was significantly inhibited as evaluated by viable cell counts and NADPH/NADH activity. A mutant of sCD14 (sCD14d57-64) lacking a region essential for LPS binding did not inhibit the growth of E. coli, whereas this mutant did inhibit the growth of B. subtilis. Addition of excess PG to the bacterial culture reversed the inhibitory effect of sMD-2 on the growth of B. subtilis, but not on the growth of E. coli. Furthermore, when evaluated by ELISA, both sMD-2 and sCD14 bound specifically to PG. Taken together, these results indicate that sMD-2 and...

Bifidobacterium suppresses IgE-mediated degranulation of rat basophilic leukemia (RBL-2H3) cells

Microbiology and Immunology — Tue, 27 Oct 2009 00:00:00 +0100

Sixteen heat-killed bifidobacteria isolated from human intestine and a probiotic strain Lactobacillus GG were tested for their ability to influence IgE-mediated degranulation of rat basophilic leukemia (RBL-2H3) cells in vitro. The bifidobacteria suppressed IgE-mediated degranulation of RBL-2H3 cells by 1.6[ndash]56.4% in a strain-dependent manner. Bifidobacteria from healthy infants expressed high inhibitory effects on IgE-mediated degranulation (41[ndash]55%), while those from allergic infants varied greatly in their effects against degranulation. Bifidobacteria taxonomically identified as Bifidobacterium bifidum exhibited much stronger inhibitory effects against IgE-mediated degranulation than those taxonomically identified as B. adolescentis (P < 0.05).These results indicate that the i...

Mycobacterium paraterrae sp. nov. recovered from a clinical specimen: novel chromogenic slow growing mycobacteria related to Mycobacterium terrae complex

Microbiology and Immunology — Tue, 27 Oct 2009 00:00:00 +0100

A previously unidentified, slowly growing scotochromogenic Mycobacterium was isolated from a Korean patient with symptomatic pulmonary infection. Phenotypically, this strain was generally similar to Mycobacterium terrae complex strains, however it uniquely produced orange pigmentation. Unique mycolic acid profiles and phylogenetic analyses based on three alternative chronometer molecules, 16S rRNA gene, hsp65 and rpoB, confirmed the taxonomic status of this strain as a novel species. These results support that this strain represents a novel Mycobacterium species. The name Mycobacterium paraterrae sp. nov. is proposed. The type strain is 05-2522 (= DSM 45127 = KCTC 19556). (Source: Microbiology and Immunology)

Protective effects of affinity-purified antibody and truncated vaccines against Pseudomonas aeruginosa V-antigen in neutropenic mice

Microbiology and Immunology — Fri, 23 Oct 2009 15:28:34 +0100

Virulent P. aeruginosa strains express PcrV, one of the translocational components of the type III secretion system. PcrV has been reported to be a protective antigen against lethal P. aeruginosa infection. The PcrV region, which contributes to protective immunity against P. aeruginosa infection, was investigated by using genetically engineered, truncated PcrV proteins and affinity-purified anti-PcrV antibodies against the truncated PcrV proteins. The efficacy of active and passive immunization against PcrV was tested in mice with cyclophosphamide-induced immunosuppression by intraabdominal challenge of P. aeruginosa. Active immunization with either full-length PcrV1-294 or PcrV139-294 significantly improved the survival of mice infected with P. aeruginosa, while PcrV139-258, PcrV139-234, ...

T cell activation in abnormal perinatal events

Microbiology and Immunology — Mon, 19 Oct 2009 00:00:00 +0100

The aim of this study was to determine the percentage of CD45RO+ T cells in umbilical cord blood from neonates born at less than 37 weeks of gestation. Fifty-nine patients were enrolled in this study, including 49 with preterm and 10 with term deliveries. Preterm deliveries were divided into two categories; spontaneous (Group A, n= 31) and indicated (Group B, n= 18). Perinatal infection was categorized as C-CAM, H-CAM and neonatal infection. The percentage of CD45RO+ T cells in the umbilical cord was assessed using flow cytometry. IL-6 was measured using ELISA. In Group A, the percentage of CD45RO+ T cells and concentrations of IL-6 in patients with perinatal infection (n= 18) were significantly higher than in those without perinatal infection (n= 13). A significant correlation between per...

A new antimicrobial peptide isolated from Oudneya africana seeds

Microbiology and Immunology — Mon, 19 Oct 2009 00:00:00 +0100

Oudneya africana R. Br. (Brassicaceae), a wild-growing plant in the arid region of Tunisia, is used in ethno-medicinal treatment of microbial infections. Validation of ethno-therapeutic claims pertaining to the plant was sought by investigating its antimicrobial activity. A proteinaceous extract of the seeds, called AS-3000, showed activity against various organisms including L. monocytogenes, E. coli, B. subtilis, E. hirae, P. aeruginosa, S. aureus and C. albicans. Extract AS-3000 exhibited a synergistic effect against L. ivanovii when combined with vancomycin or chloramphenicol. The post-antibiotic inhibitory effect of the ampicillin/AS-3000 combination was 2.3-fold greater than for the antibiotic alone. The mode of action of AS-3000 on Listeria and Escherichia was visible using SEM. The...

Effect of the extract made from Cochinchina momordica seeds on the humoral immune responses of mice to a commercial foot-and-mouth disease vaccine (serotypes O and Asia 1)

Microbiology and Immunology — Mon, 05 Oct 2009 00:00:00 +0100

The extract from ECMS was investigated for its effect on the humoral immune responses to foot-and-mouth disease vaccination. Fifty-six mice were randomly divided into seven groups with eight animals in each. Mice in groups 5 to 7 were subcutaneously (s.c.) injected with 0.5 mg DEX daily for 4 days to induce immunosuppression. The animals were then orally given ECMS (200 [mu]g in 250 [mu]l saline) in groups 3 and 6 or 250 [mu]l saline in group 2, or s.c. injected with ECMS (50 [mu]g in 100 [mu]l saline) in groups 4 and 7 or 100 [mu]l saline in group 5. After that, the animals in groups 2 to 7 were s.c. immunized twice with 100 [mu]l of commercial oil-adjuvanted bivalent FMDV vaccine (serotypes O and Asia 1) at intervals of 21 days. Mice in group 1 received injection of 100 [mu]l saline only...

A novel DNA vaccine containing multiple TB-specific epitopes cast in a natural structure elicits enhanced Th1 immunity compared with BCG

Microbiology and Immunology — Thu, 24 Sep 2009 18:02:49 +0100

Vaccination is expected to make a major contribution to the goal of eliminating tuberculosis worldwide by 2050. Because the protection afforded by the currently available tuberculosis vaccine, BCG, is insufficient, new vaccine strategies are urgently needed. Protective immunity against MTB depends on generation of a Th1-type cellular immune response characterized by secretion of IFN-[gamma] from antigen-specific T cells. Epitope-driven vaccines are created from sub-sequences of proteins (epitopes) derived by scanning the protein sequences of pathogens and selecting epitopes with patterns of amino acids which permit binding to human MHC molecules. Guided by the crystal structure of HSP65 and its characteristics, four functional T cell epitopes elaborately elicited from ESAT-6, Ag85A, CFP-10...

Non-structural and nucleocapsid proteins of Punta Toro virus induce apoptosis of hepatocytes through both intrinsic and extrinsic pathways

Microbiology and Immunology — Fri, 18 Sep 2009 00:00:00 +0100

Punta Toro virus (PTV; family Bunyaviridae, genus Phlebovirus) causes severe hepatic damage through brisk apoptosis of hepatocytes. In the present study, two viral proteins encoded by the S segment of the viral genome, non-structural (NSs) and nucleocapsid protein (N), were examined for their roles in apoptosis. Expression of NSs in HepG2 cells led to apoptosis in 45% of transfected cells, and with N, 28%, on average. These levels represent a four- to an eightfold increase over cells transfected with the mutated protein vectors. Caspase-3, -8 and -9 activities were increased by N protein when compared with the control NC (P < 0.05), and by NSsA and NSsB, as compared to control NSsC (P < 0.01). Treatment of the transfected cells with caspase-8 or -9 inhibitors markedly decreased apoptosis. ...

Characteristics of stork feces-derived H5N1 viruses that are preferentially transmitted to primary human airway epithelial cells

Microbiology and Immunology — Fri, 18 Sep 2009 00:00:00 +0100

Avian influenza viruses are a possible threat to human health as they may cause an influenza pandemic. Asian open-bill storks are migratory birds that brought H5N1 viruses into Thailand during the 2004[ndash]2005 epidemic. However, to date, there are no reports of direct transmission of stork-derived H5N1 viruses to Thais. Therefore, we questioned whether or not H5N1 viruses secreted in the feces of infected storks could directly infect cells derived from the human respiratory tract. To answer this question, we used primary NHBE cells as a model. We found that H5N1 viruses from two of the three cloacal swabs rapidly replicated and caused severe structural damage to the infected NHBE cells within the early phase of infection. Viruses from the remaining swab replicated poorly and caused no d...

Epitope mapping of canine distemper virus phosphoprotein by monoclonal antibodies

Microbiology and Immunology — Fri, 18 Sep 2009 00:00:00 +0100

The gene for phosphoprotein (P) of CDV encodes three different proteins, P, V, and C. The P protein is involved in viral gene transcription and replication. In the present study, we produced MAbs against a unique domain of the CDV-P protein, from aa 232 to 507, and determined their antigenic sites. By immunizing BALB/c mice with the recombinant P protein-specific fragment, we obtained six MAbs. Competitive binding inhibition assays revealed that they recognized two distinct regions of the P protein. Western blot analysis and immunofluorescence assays using deletion mutants of the unique C-terminus of the CDV-P protein revealed that all MAbs recognized a central short region (aa 233[ndash]303) of the CDV-P protein. In addition, linear and conformational epitopes have been determined, and at...

Broad-spectrum antiviral effect of Agrimonia pilosa extract on influenza viruses

Microbiology and Immunology — Tue, 08 Sep 2009 00:00:00 +0100

Influenza virus continues to emerge and re-emerge, posing new threats for humans. Here we tested various Korean medicinal plant extracts for potential antiviral activity against influenza viruses. Among them, an extract of Agrimonia pilosa was shown to be highly effective against all three subtypes of human influenza viruses including H1N1 and H3N2 influenza A subtypes and influenza B virus. The EC50 value against influenza A virus, as tested by the plaque reduction assay on MDCK cells, was 14[ndash]23 [mu]g/ml. The extract also exhibited a virucidal effect at a concentration of 160[ndash]570 ng/ml against influenza A and B viruses when the viruses were treated with the extract prior to plaque assay. In addition, when tested in embryonated chicken eggs the extract exhibited a strong inhibi...

Diverse effects of bacterial cell wall components on mast cell degranulation, cysteinyl leukotriene generation and migration

Microbiology and Immunology — Tue, 08 Sep 2009 00:00:00 +0100

Nowadays there is more and more evidence that mast cells take part in antibacterial defence. Mast cells have the ability to kill bacteria via phagocytose-dependent or phagocytose-independent ways and express antimicrobial peptides that can directly kill pathogens at their site of entry. What is more, mast cells are capable of processing bacterial antigens for presentation through class I and II MHC molecules. Some data indicate that these cells can release various proinflammatory mediators in response to activation with bacteria and/or their products, however this information is still far from complete. Therefore, in this study we examined the ability of PGN from Staphylococcus aureus, LPS from Eschericha coli and LAM from Mycobacterium smegmatis to stimulate mature rat mast cell degranula...

Mechanisms of action of acriflavine: electron microscopic study of cell wall changes induced in Staphylococcus aureus by acriflavine

Microbiology and Immunology — Mon, 24 Aug 2009 13:42:10 +0100

The antimicrobial action of acriflavine, a quaternary ammonium compound, on Staphylococcus aureus was studied by electron microscopic observation. The bactericidal activity of acriflavine was dose-dependent over the 4 hr of exposure time. Scanning electron micrographs showed a wavy wrinkled cell surface following treatment with acriflavine. Transmission electron micrographs showed thickened cell walls following treatment with acriflavine. Acriflavine-induced cell wall thickness seemed to affect both the peripheral and cross walls, but was reversible after treatment removal. These findings indicate that cell wall thickness is a characteristic phenotype of S. aureus exposed to acriflavine. It is therefore believed that cell wall thickness plays an important role in the mechanism of action of...

Possible circulation of H5N1 avian influenza viruses in healthy ducks on farms in northern Vietnam

Microbiology and Immunology — Fri, 21 Aug 2009 00:00:00 +0100

To estimate the prevalence of influenza A subtype H5N1 viruses among domestic ducks in the period between October and November 2006 when H5N1 outbreaks had been absent, 1106 healthy ducks raised in northern Vietnam were collected. Inoculation of all throat and cloacae samples into embryonated eggs resulted in the isolation of subtype H3N8 in 13 ducks, but not H5N1 viruses. Serological analyses demonstrated that five ducks (0.45%) solely developed H5N1 subtype-specific hemagglutinin-inhibiting and neuraminidase-inhibiting antibodies together with anti-non-structural protein 1 antibodies. The results suggested that the ducks were naturally infected with H5N1 viruses when obvious H5N1 outbreaks were absent. (Source: Microbiology and Immunology)

Intraspecies transmission of L-type-like bovine spongiform encephalopathy detected in Japan

Microbiology and Immunology — Fri, 21 Aug 2009 00:00:00 +0100

It has been assumed that the agent causing BSE in cattle is a uniform strain (classical BSE); however, different neuropathological and molecular phenotypes of BSE (atypical BSE) have been recently reported. We demonstrated the successful transmission of L-type-like atypical BSE detected in Japan (BSE/JP24 isolate) to cattle. Based on the incubation period, neuropathological hallmarks, and molecular properties of the abnormal host prion protein, the characteristics of BSE/JP24 prion were apparently distinguishable from the classical BSE prion and closely resemble those of bovine amyloidotic spongiform encephalopathy prion detected in Italy. (Source: Microbiology and Immunology)

Serum antibody responses to Wolbachia surface protein in patients with human lymphatic filariasis

Microbiology and Immunology — Fri, 21 Aug 2009 00:00:00 +0100

Wolbachia surface protein (WSP), which is the most abundantly expressed protein of Wolbachia from the human filarial parasite Brugia malayi, was chosen for the present study. B-cell epitope prediction of the WSP protein sequence indicates a high antigenicity, surface probability and hydrophilicity by DNA STAR software analysis. ProPred analysis suggests the presence of HLA class II binding regions in the WSP protein that contribute to T-cell responses and isotype reactivity. In order to validate these findings, the gene coding for endosymbiont WSP was PCR-amplified from the genomic DNA of the human filarial parasite Brugia malayi and cloned in T-7 expression vector pRSET-A. Western blot and ELISA at the total IgG level with recombiant WSP indicated a significantly elevated reactivity in CP...

Enhanced immune response to pneumococcal infection in malnourished mice nasally treated with heat-killed Lactobacillus casei

Microbiology and Immunology — Thu, 20 Aug 2009 23:00:00 +0100

The present study analyzed whether nasal administration of viable and non-viable Lactobacillus casei CRL 431 to immunocompromised mice was capable of increasing resistance against Streptococcus pneumoniae. Weaned mice were malnourished after consuming a PFD for 21 days. Malnourished mice were fed a BCD for 7 days or BCD for 7 days with viable or non-viable L. casei nasal treatments on day 6 and day 7 (BCD+LcV and BCD+LcN, respectively). The MNC group received PFD whereas the WNC mice consumed BCD. MNC mice showed greater lung colonization, more severe lung injuries, impaired leukocyte recruitment and reduced antibodies and cytokine production when compared with WNC mice. Administration of L. casei increased the resistance of malnourished mice to the infection. Both BCD+LcV and BCD+LcN trea...

N-linked glycan-dependent interaction of CD63 with CXCR4 at the Golgi apparatus induces downregulation of CXCR4

Microbiology and Immunology — Mon, 10 Aug 2009 23:00:00 +0100

Efficient downregulation of CXCR4 cell surface expression by introduction of the CD63 gene has previously been reported by us. In the present study, it was found that CD63 and its mutant efficiently interact with CXCR4 in live cells and that CD63-induced downregulation and interaction are significantly abrogated by the N-linked glycosylation inhibitor, TM. Furthermore, the downregulation and interaction were clearly attenuated by alternation of all three N-linked glycosylation sites in CD63. Either CD63 or CD63[Delta]N formed a complex with CXCR4 at the Golgi apparatus and the late endosomes, while CD63 GD mutants lost the ability to form a complex with CXCR4 exclusively at the Golgi apparatus. These findings suggest that CD63 interacts with CXCR4 through the N-linked glycans-portion of th...

Archetype JC virus efficiently propagates in kidney-derived cells stably expressing HIV-1 Tat

Microbiology and Immunology — Mon, 10 Aug 2009 23:00:00 +0100

Pathogenic JCV with rearranged regulatory regions (PML-type) causes PML, a demyelinating disease, in the brains of immunocompromised patients. On the other hand, archetype JCV persistently infecting the kidney is thought to be converted to PML-type virus during JCV replication in the infected host under immunosuppressed conditions. In addition, Tat protein, encoded by HIV-1, markedly enhances the expression of a reporter gene under control of the JCV late promoter. In order to examine the influence of Tat on JCV propagation, we used kidney-derived COS-7 cells, which only permit archetype JCV, and established COS-tat cells, which express HIV-1 Tat stably. We found that the extent of archetype JCV propagation in COS-tat cells is significantly greater than in COS-7 cells. On the other hand, C...

Covalent bonded Gag multimers in human immunodeficiency virus type-1 particles

Microbiology and Immunology — Mon, 10 Aug 2009 23:00:00 +0100

The oligomerization of HIV-1 Gag and Gag-Pol proteins, which are assembled at the plasma membrane, leads to viral budding. The budding generally places the viral components under non-reducing conditions. Here the effects of non-reducing conditions on Gag structures and viral RNA protection were examined. Using different reducing conditions and SDS-PAGE, it was shown that oligomerized Gag possesses intermolecular covalent bonds under non-reducing conditions. In addition, it was demonstrated that the mature viral core contains a large amount of covalent bonded Gag multimers, as does the immature core. Viral genomic RNA becomes sensitive to ribonuclease in reducing conditions. These results suggest that, under non-reducing conditions, covalent bonded Gag multimers are formed within the viral ...

Characterization of integrons and antimicrobial resistance genes in clinical isolates of Gram-negative bacteria from Palestinian hospitals

Microbiology and Immunology — Mon, 10 Aug 2009 23:00:00 +0100

In this study various types of antibiotic resistance genes have been identified in Gram-negative bacteria from Palestinian hospitals, many of which are reported in the Middle East area for the first time. (Source: Microbiology and Immunology)

Dynamics of fecal microbiota in hospitalized elderly fed probiotic LKM512 yogurt

Microbiology and Immunology — Thu, 23 Jul 2009 12:13:41 +0100

The comprehensive dynamics of intestinal microbiota including uncultured bacteria in response to probiotic consumption have not been well studied. The aims of this study were twofold: firstly to analyze the impact on intestinal microbiota of yogurt fermented by Bifidobacterium animalis subsp. lactis LKM512, Lactobacillus delbrueckii subsp. bulgaricus LKM1759, and Streptococcus thermophilus LKM1742 (LKM512 yogurt) and placebo fermented by these lactic acid bacterial strains without LKM512; and secondly to investigate the changes in intestinal microbiota that influence the concentration of PA, one of the beneficial metabolites produced by bacteria in the intestine. The LKM512 yogurt/placebo trial was performed in six hospitalized elderly patients (three men and three women with an average ag...

Study of human metapneumovirus-associated lower respiratory tract infections in Egyptian adults

Microbiology and Immunology — Sun, 12 Jul 2009 23:00:00 +0100

There is a deficiency in the data concerning the role of hMPV in lower respiratory tract infections in adults, and until now there has been no data available regarding the prevalence of hMPV in adults in our region. In the present study the association of hMPV with varieties of lower respiratory tract disorders in immunocompetent adult patients, either alone or with bacterial pathogens, has been highlighted. Eighty-eight patients were included in the study. They included 46 males and 42 females with an age range of 38[ndash]65 years. Patients presented with lower respiratory tract infections associated with acute exacerbation of asthma (67%), pneumonia (17%), and acute exacerbation of chronic obstructive lung diseases. Sputum and nasopharyngeal samples were obtained from the patients and s...

Isolation and characterization of bacteriophages specific for Campylobacter jejuni

Microbiology and Immunology — Sun, 12 Jul 2009 23:00:00 +0100

In this study, six C. jejuni-specific bacteriophages (CPS1[ndash]6) were isolated by the spot-on-the-lawn technique from chicken samples in Korea and characterized for potential use as biocontrol agents. All isolated bacteriophages exhibited a high specificity, being able to lyse only C. jejuni, but not other Gram[ndash]negative bacteria, including C. coli, Escherichia coli, Salmonella spp., and Gram[ndash]positive bacteria. Bacteriophages contain an icosahedral head and a contractile tail sheath in transmission electron microscopy, and possess ds-DNA with an average genome size of approximately 145 kb; therefore, all bacteriophages are categorized into the Myoviridae family. Bacterial lysis studies in liquid media revealed that CPS2 could be used to control the growth of C. jejuni. (Sourc...

Differential response of Vibrio cholerae planktonic and biofilm cells to autoinducer 2 deficiency

Microbiology and Immunology — Sun, 28 Jun 2009 23:00:00 +0100

The formation of biofilm communities enhances the persistence of Vibrio cholerae in aquatic environments. Biofilm production is repressed by the quorum-sensing regulator HapR in response to the accumulation of CAI-1 and AI-2. CAI-1 is the strongest input signal activating HapR, whereas the role of AI-2 remains ill-defined. In the present study, we show that a V. cholerae luxS (AI-2-defective) mutant made increased biofilm. Interestingly, cells in the biofilm were more responsive to AI-2 deficiency than cells from the planktonic population. (Source: Microbiology and Immunology)

Antiviral treatments reduce severity of diabetes in Ljungan virus-infected CD-1 mice and delay onset in diabetes-prone BB rats

Microbiology and Immunology — Sun, 28 Jun 2009 23:00:00 +0100

The effects of LV in two different species, CD-1 mice, without a genetic disposition for diabetes, and BB rats prone to T1D were examined. Male CD-1 mice that had been exposed to LV in utero developed a type 2-like diabetes with increased blood glucose, insulin levels and epididymal fat at the age of 10[ndash]15 weeks. Combination therapy including LV-antiserum and an antiviral drug, Pleconaril, significantly reduced the levels of blood glucose and insulin and the amount of abdominal fat. In BB rats, LV has been found in both prediabetic- and diabetic diabetes-prone rats, as well as in diabetes-resistant rats. To evaluate whether the presence of LV has any influence on the onset of T1D, prediabetic BB rats were treated with an antiserum against LV or a combination of the antiviral drugs Pl...

Adrenomedullin treatment reduces intestinal inflammation and maintains epithelial barrier function in mice administered dextran sulphate sodium

Microbiology and Immunology — Mon, 22 Jun 2009 23:00:00 +0100

Hyperactivation and hyperpermeability of the intestinal epithelium is a hallmark of IBD. AM has been shown to reduce the severity of colitis in the acetic acid and TNBS-induced colitis model, however the mechanism of the therapeutic effect of AM against the colitis has not been clarified. Here, we show that the protective capability of AM is associated with suppression of inflammation and maintenance of the intestinal epithelial barrier function. In the DSS-induced colitis model, intra-rectal AM-treated mice showed a reduction in loss of body weight and severity of colitis. AM-treatment suppressed phosphorylation of STAT1 and STAT3 in the colonic epithelium, and altered the cytokine balance in the intestinal T cells, with lower levels of IFN-[gamma] and TNF-[alpha] but higher levels of TGF...

A host-vector system for molecular study of the intracellular growth of Mycobacterium tuberculosis in phagocytic cells

Microbiology and Immunology — Mon, 22 Jun 2009 23:00:00 +0100

In this study it has been shown that, in contrast with M. smegmatis strain mc2155 which has been widely used for molecular analysis, M. smegmatis strain J15cs is able to survive even at day 6 post-infection in a murine macrophage cell line, J774. The survivability of J15cs was found to depend on the culture medium used for the bacteria prior to infection. Bacteria precultured on nutrient agar medium showed a high survivability and a characteristic cell wall ultrastructure. A plasmid vector, pYT923hyg, was developed from an Escherichia coli- mycobacterium shuttle vector pYT923 (previously constructed in our laboratory) to obtain three drug resistant genes (amp-, hyg- and km-resistant gene) and cloning sites in the km resistant gene. The vector pYT923hyg exerted no influence on in vitro grow...

Evolution of HIV-1 in a patient population failing multiple-drug therapy

Microbiology and Immunology — Mon, 15 Jun 2009 23:00:00 +0100

To understand the evolutionary pathway of the multi-drug-resistant virus HIV-1 under drug-induced selection pressure, plasma from seven patients from baseline to different intervals post-treatment failure were used in RT-PCR protocols. Multiple clones were sequenced for each time point. Drug-resistant mutations were detected in five patients. Phylogenetic analysis showed that at different time points, viral sequences clustered separately and formed independent lineages. Genetic diversity decreased from 1.59 to 0.55, whereas non-synonymous/synonymous mutation ratios increased from 0.067 to 0.118, respectively. These data suggest that the virus population changed dynamically and clustered in a time point-specific manner whereas genetic diversity decreased consistently. (Source: Microbiology ...

Change of specific T cells in an emerging neonatal infectious disease induced by a bacterial superantigen

Microbiology and Immunology — Mon, 15 Jun 2009 23:00:00 +0100

We present three diagnostic categories of NTED. Fifty patients (66.7%) were included in the category 'definitive NTED'. It is important to demonstrate an increase of V[beta]2+ T cells in the following phase in cases of 'probable NTED' or 'possible NTED'. (Source: Microbiology and Immunology)

Inhibitory effect of serotonin antagonists on JC virus propagation in a carrier culture of human neuroblastoma cells

Microbiology and Immunology — Mon, 15 Jun 2009 23:00:00 +0100

Human polyomavirus, JCV, causes fatal demyelinating disease, progressive multifocal leukoencephalopathy (PML). It has been shown that 5HT2AR acts as a cellular receptor for JCV on human glial cells. In the current study, we examined the inhibitory effects of 5HT2AR antagonists, ketanserin and ritanserin, both on JCV infection and on propagation by using human neuroblastoma cells IMR-32 and JCI, which continuously produce JCV. Transcriptional analysis revealed that 5HT2AR was constitutively expressed in JCI cells. Treatments with 5HT2AR antagonists led to a significant reduction in the titers of progeny viruses and the population of infected JCI cells. In addition, the amount of JCV genomic DNA was decreased in JCI cells in the presence of 5HT2AR antagonists. These results indicate that 5HT...

Effect of Lactobacillus rhamnosus GR-1 and Lactobacillus reuteri RC-14 on the ability of Candida albicans to infect cells and induce inflammation

Microbiology and Immunology — Mon, 15 Jun 2009 23:00:00 +0100

In conclusion, L. reuteri RC-14 alone and together with L. rhamnosus GR-1 have the potential to inhibit the yeast growth and their CFS may up-regulate IL-8 and IP-10 secretion by VK2/E6E7 cells, which could possibly have played an important role in helping to clear VVC in vivo. (Source: Microbiology and Immunology)

Development of a broadly reactive nested reverse transcription-PCR assay to detect murine noroviruses, and investigation of the prevalence of murine noroviruses in laboratory mice in Japan

Microbiology and Immunology — Tue, 02 Jun 2009 23:00:00 +0100

A broadly reactive nested RT-PCR assay to detect MNV was developed and subsequently used to investigate the prevalence of MNV in laboratory mice in Japan. MNV were detected in 8 (22%) of 37 murine stool specimens by second-round PCR, although no positive band was obtained from any specimen by first-round PCR. Genetic analysis of the second round PCR products showed that MNV sequences detected in this study were closely matched (97.2 [sim] 99.1%) to that of MNV-3 (DQ223042). This is the first report demonstrating the prevalence of MNV in Japan. (Source: Microbiology and Immunology)

Human leukocyte antigen profile in HIV-1 infected individuals and AIDS patients from Chongqing, China

Microbiology and Immunology — Tue, 02 Jun 2009 23:00:00 +0100

In this study, we performed 4-digit resolution HLA-A, B, DRB1 genotyping of 759 HIV-1 seropositive individuals using PCR-SSO methods. Six alleles were found at more than 10% high frequency: A*1101, A*0201, A*2402, B*4601, B*4001 and DRB1*0901. The most common 2- and 3-locus haplotypes were A*0201-B*4601, A*1101-B*4001, A*1101-B*4601, A*3303/1-B*5801, A*0201-B*4601-DRB1*0901, A*1101-B*4601-DRB1*0901 and A*3303/1-B*5801-DRB1*0301. 690 HIV-1 seropositive individuals with records of CD4 counts were divided into two groups: an AIDS patient group comprising 216 subjects with AIDS-defining symptoms and CD4 counts below 200 cells/mm3 and an asymptomatic, HIV seropositive group of 474 subjects with a stable CD4 count of no less than 200 individuals. In the AIDS patient group, A*3303/1 and B*5801 al...

Classification of OprD sequence and correlation with antimicrobial activity of carbapenem agents in Pseudomonas aeruginosa clinical isolates collected in Japan

Microbiology and Immunology — Sun, 31 May 2009 23:00:00 +0100

A total of 99 clinical isolates of metallo-ß-lactamase-negative Pseudomonas aeruginosa collected in Japan between 1998 and 2001 were studied for their susceptibilities to carbapenem agents and corresponding oprD gene mutations. The OprD sequence of each strain was grouped into two major classes, based on the pattern of alterations. Eighty strains (80.8%) were so-called 'full length type', whose OprD proteins were fully encoded. The remaining 19 strains (19.2%) were so-called 'defective type', which possessed deletions or major alterations that might cause conformational changes in the OprD porin protein. The changes in 'defective type' strains led to 15-, 17- and 23-fold increases in the geometric mean MIC for imipenem, meropenem and biapenem compared with 'full length type' strains, resp...

Characterization of the orf1-tolQRA operon in Pseudomonas aeruginosa

Microbiology and Immunology — Sun, 31 May 2009 23:00:00 +0100

The tol-pal genes play important roles in maintaining outer membrane integrity, transmembrane transportation, and cell division in Gram-negative bacteria. In Pseudomonas aeruginosa, an important human opportunistic pathogen, the tol-oprL genes are organized uniquely in three operons, orf1-tolQRA, tolB and oprL-orf2, and are regulated by iron availability. Similarity between TolQRA and the iron transport system ExbBD-TonB also exists in P. aeruginosa and they can replace each other imperfectly. It is of importance to investigate the regulation and functions of this membrane complex. In the present study, we characterized the promoters and expression profiles of the orf1-tolQRA operon and investigated the function of Orf1. Primer extension was carried out by using both isotope-labeled and fl...

Interleukin-1 deficiency in combination with macrophage depletion increases susceptibility to Pseudomonas aeruginosa bacteremia

Microbiology and Immunology — Mon, 27 Apr 2009 23:00:00 +0100

We evaluated the role of IL-1 during Pseudomonas aeruginosa bacteremia by intravenously injecting P. aeruginosa strain D4 into IL-1-deficient and WT mice. The two strains showed equivalent mortality rates. However, when the mice were pretreated with cyclophosphamide, bacteremia-induced mortality was significantly greater in the IL-1-deficient mice than in the WT mice (P < 0.01). We then investigated the role of neutrophils and macrophages in protecting IL-1-deficient mice from bacteremia by administering anti-Gr-1 antibody or liposomes containing dichloromethylene diphosphonate, respectively. After P. aeruginosa inoculation survival was significantly lower in the macrophage-depleted IL-1-deficient mice than in the WT mice. In contrast, neutrophil depletion did not have this effect. Compare...

Differentiated implication of Lactobacillus GG and L. gasseri TMC0356 to immune responses of murine Peyer's patch

Microbiology and Immunology — Mon, 27 Apr 2009 23:00:00 +0100

Lactobacillus GG and L. gasseri TMC0356 were examined for their potential to alter the immune responses of murine PP cells in vitro and in vivo. Lactobacillus GG and L. gasseri TMC0356 characteristically stimulated the production of IL-12, IL-6, IFN-[gamma] and IgA from isolated PP cells in vitro. Anatomical analysis indicated uptake of these bacteria by the PP tissue after giving orally in mice. Isolated PP cells exposed to Lactobacillus GG in vivo secreted more IFN-[gamma], IL-6 and total IgA, whereas those exposed to L. gasseri TMC0356 in vivo did not exhibit altered immune responses in terms of cytokine and IgA production. Therefore, these two bacteria might exhibit different immunodulatory effects in host animals by strain-dependent interaction with gut-associated lymphoid tissues in ...

Increase of regulatory T cells in the peripheral blood of dogs with metastatic tumors

Microbiology and Immunology — Mon, 27 Apr 2009 23:00:00 +0100

It is well known that lymphocytes from patients with advanced-stage cancer have impaired immune responsiveness and that type1 T lymphocyte subsets in tumor bearing hosts are suppressed. Treg have been reported to comprise a subgroup which inhibits T cell mediated immune responses. In the present study, the percentage of Treg, Th1 and Tc1 in the peripheral blood of tumor bearing dogs with or without metastases was evaluated. The percentages of Th1 and Tc1 in dogs with metastatic tumor were significantly less, and that of Treg was significantly greater, than those of dogs without metastatic tumor. The percentage of Treg showed an inverse correlation with that of Th1 and Tc1 in tumor bearing dogs. It was concluded that an increase in Treg in the peripheral blood of dogs with metastatic tumor ...

Study of the immunological profile towards Mycobacterium bovis antigens in naturally infected cattle

Microbiology and Immunology — Mon, 27 Apr 2009 23:00:00 +0100

A number of studies have determined the contribution of Th1 and Th2 responses to the protective immunity and pathology of Mycobacterium bovis infection. However, much of that information is derived from experimentally infecting cattle with M. bovis and few data from naturally infected animals are available. The aim of this study was to characterize the immunological profile towards M. bovis antigens of naturally infected cattle by measurement of cytokine mRNA expression in PBMC, and to determine which lymphocyte subsets are involved in recall responses of PBMC from M. bovis infected cattle to M. bovis antigens. Consistent with data from cattle experimentally infected with M. bovis, naturally infected animals were found to display a Th1 cytokine profile in response to M. bovis PPDB stimulat...

Characteristics of dengue virus-infected peripheral blood mononuclear cell death that correlates with the severity of illness

Microbiology and Immunology — Mon, 27 Apr 2009 23:00:00 +0100

In conclusion, our data highlight the adverse effect of apoptosis induced by DENV and by pro-inflammatory cytokines during natural DENV infection. (Source: Microbiology and Immunology)

Analysis of herpesvirus host specificity determinants using herpesvirus genomes as bacterial artificial chromosomes

Microbiology and Immunology — Mon, 27 Apr 2009 23:00:00 +0100

Almost all mammalian alphaherpesviruses can grow in cells derived from several types of animals in vitro. However, FHV-1 can only infect feline cell lines. For this reason, FHV-1 should be a good model to investigate species barriers to herpesviruses in vivo. To apply bacterial mutagenesis of FHV-1, we cloned the FHV-1 genome as a BAC. Using [lambda] and flp recombinations, we introduced a monomeric red fluorescence protein into the C-terminus of glycoprotein D. Although GFP in the constructed recombinant FHV-1, a transfectant of the bacmid of FHV-1 that possessed the GFP, acted in non-feline cell lines, the virus could not enter non-feline cell lines, demonstrating that the host specificity of FHV-1 was restricted in an early step of infection. The host range of canine herpesvirus is limi...

Human plasmacytoid dendritic cells express an atrial natriuretic peptide receptor, guanylyl cyclase-A

Microbiology and Immunology — Mon, 27 Apr 2009 23:00:00 +0100

We examined GC-A expression on blood pDC and found that GC-A was not expressed on fresh pDC but was induced after stimulation with CpG-oligodeoxynucleotide AAC-30, IL-3, or interleukin-3 plus CD40 ligand. Activated pDC responded to ANP with an increase in cGMP production, indicating that GC-A expressed on pDC was functional. We investigated whether tonsillar pDC express GC-A by immunohistochemistry and immunofluorescence staining. We found that GC-A+ HLA-DR+ cells were present in the T-cell areas and the perivascular areas. Flow cytometric analysis with tonsillar cells confirmed that lineage[minus] CD123high pDC express GC-A. These results indicate that the ANP/GC-A system is involved in immune regulation through pDC in secondary lymphoid organs. (Source: Microbiology and Immunology)

Rapid, sensitive and simple detection method for koi herpesvirus using loop-mediated isothermal amplification

Microbiology and Immunology — Mon, 27 Apr 2009 23:00:00 +0100

New methods were developed for the detection of koi herpesvirus (KHV, CyHV-3) by LAMP, which were compared with the PCR for specificity and sensitivity. We designed two primer sets targeting a specific sequence within the 9/5 PCR amplicon (9/5 LAMP) and the upper region of the SphI-5 PCR amplicon (SphI-5 LAMP), including a sequence highly conserved among the strains. The amplification was monitored in real-time based on the increase in turbidity, with magnesium pyrophosphate as the by-product. The reactions were carried out under isothermal conditions at 65°C for 60 min. The detection limit of both LAMP was six copies, equal to the modified SphI-5 PCR. No cross-reactivity with other fish pathogenic viruses and bacteria was observed. SphI-5 LAMP was found to have a quicker response in term...

Development of recombinant OmpA and OmpB proteins as diagnostic antigens for rickettsial disease

Microbiology and Immunology — Mon, 27 Apr 2009 23:00:00 +0100

In this study the diagnostic potential of Rickettsia conorii recombinant antigens was analyzed. For this, site-specific PCR primers were used to clone the OmpA and OmpB genes of R. conorii into pMAL-c2X plasmids. Six fragments of OmpA and four of OmpB were expressed as fusion proteins with maltose-binding protein in Escherichia coli. OmpA1350-1784, OmpB801-1269, and OmpB1227-1634 regions from truncated proteins were selected as diagnostic candidate antigens by ELISA using control sera. ELISA results of three antigens were compared to the results obtained by using a commercial ELISA kit which contained whole OmpA and OmpB antigens from R. conorii. For this analysis, 40 serum samples taken from febrile patients and uninfected controls were tested. Of the 20 R. conorii test results which were...

Interaction between superantigen and T-cell receptor Vβ element determines levels of superantigen-dependent cell-mediated cytotoxicity of CD8+ T cells in induction and effector phases

Microbiology and Immunology — Mon, 06 Apr 2009 23:00:00 +0100

Specific superantigens activate different T-cell fractions with distinct TCR V[beta] elements in association with MHC class II molecules and also induce SDCC against MHC class II+ target cells. In the present study, to determine whether the responsiveness of each CD8+ T-cell fraction expressing a different TCR V[beta] element is primarily determined by the TCR V[beta], we compared the levels of proliferation and SDCC in V[beta]3+ and V[beta]11+ T cells upon stimulation with SEA. Upon stimulation with SEAwt, the levels of proliferation were higher in V[beta]3+ T cells than in V[beta]11+ T cells. The levels of SDCC were also higher for the combination of V[beta]3+ T cells and SEAwt than for the combination of V[beta]11+ T cells and SEAwt during both the induction phase and the effector phase...

Effect of GM-CSF on cytokine induction by soluble β-glucan SCG in vitro in β-glucan-treated mice

Microbiology and Immunology — Mon, 06 Apr 2009 23:00:00 +0100

SCG is a 6-branched 1,3-[beta]-d-glucan, which are major cell wall structural components in fungi. Leukocytes from DBA/1 and DBA/2 mice are highly sensitive to SCG, producing cytokines such as GM-CSF, IFN-[gamma], TNF-[alpha] and IL-12p70, but not IL-6. GM-CSF plays a key biological role in this activity. In the present study, we examined the effect of giving i.p. SCG to DBA/2 mice on cytokine production in vitro. SCG was given i.p. to DBA/2 mice on day 0. Splenocytes were prepared on day 7 and cultured in the presence of SCG in vitro. The levels of cytokine production induced by SCG in vitro were lower in the cells from SCG-treated mice than in control mice. Expression of the [beta]-glucan receptor, dectin-1, in SCG-treated mice was comparable with that shown in control mice. However, the...

Improved cellular immune response elicited by a ubiquitin-fused ESAT-6 DNA vaccine against Mycobacterium tuberculosis

Microbiology and Immunology — Mon, 06 Apr 2009 23:00:00 +0100

The present study evaluated the immune response elicited by a ubiquitin-fused ESAT-6 DNA vaccine against Mycobacterium tuberculosis. BALB/c mice were vaccinated with plasmid DNA encoding ESAT-6 protein, ubiquitin-fused ESAT-6 DNA vaccine (UbGR-ESAT-6), pcDNA3-ubiquitin and blank vector, respectively. ESAT-6 DNA vaccine immunization induced a Thl-polarized immune response. The production of Thl-type cytokine (IFN-[gamma]) and proliferative T-cell responses was enhanced significantly in mice immunized with UbGR-ESAT-6 fusion DNA vaccine, compared to non-fusion DNA vaccine. This fusion DNA vaccine also resulted in an increased relative ratio of IgG2a to IgGl and the cytotoxicity of T cells. Thus, the present study demonstrated that the UbGR-ESAT-6 fusion DNA vaccine inoculation improved antig...

Distinct genotype and antigenicity among genogroup II sapoviruses

Microbiology and Immunology — Mon, 16 Mar 2009 00:00:00 +0100

SaV, a pathogen of acute gastroenteritis, is divided into five genogroups, GI to GV. However, the relation between SaV antigenicity and genetic clusters is not fully understood. We have recently identified two GII SaV strains, Mc10 and C12, which are grouped into the same cluster based on the polymerase but are grouped into distinct clusters based on the capsid. To evaluate the difference in antigenicity between these two strains, VLP were expressed in mammalian cells. An antigen ELISA demonstrated for the first time that strains in the same GII SaV genogroup, but within different clusters, have distinct antigenicities. (Source: Microbiology and Immunology)

Association between antibody response against cytomegalovirus strain-specific glycoprotein H epitopes and HLA-DR

Microbiology and Immunology — Mon, 16 Mar 2009 00:00:00 +0100

The gH of CMV is a major target for strain-specific neutralizing antibodies. To verify whether there is a correlation between HLA-DR type and strain-specific antibodies, antibodies against CMV gH in potential donors and recipients for renal transplantation were investigated. Among 471 subjects, 404 (86%) showed reactivity to CMV gH, but no antibodies against gH were detected in 67 (14%) subjects. The positive rates were over 80% in most HLA subpopulations. Fewer subjects with HLA-DR10 and DR11 had antibodies to CMV gH than did those without HLA-DR10 and DR11. HLA-DR10 and DR11 may be associated with fewer/non-responders for strain-specific neutralizing antibodies. (Source: Microbiology and Immunology)

Seroepidemiological study of norovirus infection in Aichi Prefecture, Japan

Microbiology and Immunology — Mon, 16 Mar 2009 00:00:00 +0100

The serological prevalence of IgG antibody to seven NoV strains (GI.1, GI.4, GII.3, GII.4, GII.10, GII.12 and GII.15) among inhabitants aged 1[ndash]62 years of Aichi Prefecture, Japan was studied. Age-related seroprevalence was measured by ELISA using baculovirus-expressed recombinant VLP antigens. Seropositive rates for all seven VLP antigens gradually increased with age. Among the tested antigens, the highest seropositive rate was for the GII.4 strain. This result is consistent with the recent epidemic of NoV infection due to GII.4 strain in Japan. (Source: Microbiology and Immunology)

Screen of multifunctional monoclonal antibodies against hepatitis B core virus-like particles

Microbiology and Immunology — Mon, 16 Mar 2009 00:00:00 +0100

In this study, a multifunctional mAb was produced using a novel research strategy. A truncated HBc-VLP bone vector with a special conformation was used as an immunogen and the target hybridoma cell lines were screened by a series of tests; including ELISA, Western blot, and cellular immunofluorescence based on the epitope presentation system. The screened monoclonal antibody was used to identify the HBc-VLP vector, a fusion HBc-VLP vaccine, and intracellular HBV capsids. The new strategy facilitated acquisition of the desired mAbs and will serve as a reference for other VLP-related research. (Source: Microbiology and Immunology)

Leuconostoc citreum HJ-P4 (KACC 91035) regulates immunoglobulin E in an ovalbumin-induced allergy model and induces interleukin-12 through nuclear factor-kappa B and p38/c-Jun N-terminal kinases signaling in macrophages

Microbiology and Immunology — Mon, 16 Mar 2009 00:00:00 +0100

In conclusion, the current study demonstrated that L. citreum is able to regulate serum IgE generation at the induction and effector phases of allergic response through overall control over antibody production and that its involvement of IL-12 production was mediated through NF-[kappa]B and p38/JNK. Taken together, the use of L. citreum can be useful in preventing the development and progression of IgE production. (Source: Microbiology and Immunology)

Suppression of anti-Candida activity of macrophages by a quorum-sensing molecule, farnesol, through induction of oxidative stress

Microbiology and Immunology — Thu, 12 Mar 2009 00:00:00 +0100

Farnesol is well known as a quorum-sensing molecule of Candida albicans. To assess the pathological function of farnesol, its effects on macrophage viability and functions including growth inhibitory activities against C. albicans were examined in vitro. Murine macrophages, when cultured in the presence of 56[ndash]112 [mu]M of farnesol for 1[ndash]2 hr, decreased their activity inhibiting the mycelial growth of C. albicans and lost their viability. This suppression of macrophage function by farnesol was neutralized by the coexistence of the anti-oxidants probucol and trolox. Macrophages cultured in the presence of farnesol for 2 hr displayed morphological change of nuclei and DNA fragmentation, which suggested apoptosis of the cells. Intracellular production of ROS in the farnesol-treated...

Occurrence of the African subgroup (Ia) of BK polyomavirus in younger Japanese children

Microbiology and Immunology — Thu, 12 Mar 2009 00:00:00 +0100

BK polyomavirus (BKV) is ubiquitous among humans, usually infecting them asymptomatically during childhood. BKV persists in renal tissue of individuals and their progeny are excreted in urine, particularly in immunocompromised patients. JC virus, another human polyomavirus, has been considered to be transmitted from parents to children during prolonged cohabitation. However, BKV has been supposed to be transmitted not only within but also outside the family. In the present study, to clarify this possibility, we analyzed phylogenetically 35 BKV which were excreted in the urine by Japanese children and adults undergoing stem cell transplantation. Subtypes I, III and IV were detected in 15, two and one children and in 15, one and one adults, respectively. Among 15 subtype I isolates from chil...

Identification of novel putative virulence factors, adhesin AIDA and type VI secretion system, in atypical strains of fish pathogenic Edwardsiella tarda by genomic subtractive hybridization.

Microbiology and Immunology — Sun, 01 Mar 2009 05:00:00 +0100

Authors: Sakai T, Matsuyama T, Sano M, Iida T Edwardsiella tarda, which is known to be the causative agent of edwardsiellosis in freshwater and marine fish, has two motility phenotypes. Typical strains exhibiting motility are isolated mainly from freshwater fish and Japanese flounder. Atypical strains exhibiting non-motility are isolated mainly from marine fish, with the exception of Japanese flounder. Subtractive hybridization was performed to identify genomic differences between these two phenotypes. Two fragments which showed homology to potential virulence factors were isolated from atypical strains: the autotransporter adhesin AIDA and a component of T6SS. We analysed DNA sequences of about 5 kbp containing these fragments and identified two partial ORF, and ORF encoding for other...

Analysis of cis-regulatory elements in the 5' untranslated region of murine leukemia virus controlling protein expression.

Microbiology and Immunology — Sun, 01 Mar 2009 05:00:00 +0100

Authors: Yamamoto N, Takase-Yoden S It has previously been reported by us that high-level expression of the Env protein of Fr-MLV clone A8 in brains is crucial for induction of spongiform neurodegeneration, and that the 0.3-kb fragment containing the R, U5, and the 5' leader sequence of A8 is responsible for neuropathogenicity. In the present study, the role of the 5' untranslated region in protein expression was investigated. Luciferase expression vectors containing the LTR (R-U3-U5) and 5' leader sequence of A8 and non-neuropathogenic 57 Fr-MLV, designated gl-A8 and gl-57, and their chimeric vectors, were constructed, and transfected into rat glial cells F10. Replacement of the region containing the 3' half of R, U5, and 5' leader sequence of gl-A8 with that of 57 showed a reduction ...

Real-time polymerase chain reaction as a rapid and efficient alternative to estimation of picornavirus titers by tissue culture infectious dose 50% or plaque forming units.

Microbiology and Immunology — Sun, 01 Mar 2009 05:00:00 +0100

Authors: Jonsson N, Gullberg M, Lindberg AM Quantification of viral infectious units is traditionally measured by methods based on forming plaques in semisolid media (PFU) or endpoint dilution of a virus-containing solution (TCID(50)), methods that are laborious, time-consuming and take on average 3-7 days to carry out. Quantitative real-time PCR is an established method to quantify nucleic acids at high accuracy and reproducibility, routinely used for virus detection and identification. In the present study, a procedure was developed using a two-step real-time PCR and the SYBR Green detection method to study whether there are correlations between TCID(50)/ml, PFU/ml and Ct values generated by real-time PCR enabling rapid and efficient calculation of titer equivalents when working with...

Identification of multiple sites suitable for insertion of foreign genes in herpes simplex virus genomes.

Microbiology and Immunology — Sun, 01 Mar 2009 05:00:00 +0100

Authors: Morimoto T, Arii J, Akashi H, Kawaguchi Y Information on sites in HSV genomes at which foreign gene(s) can be inserted without disrupting viral genes or affecting properties of the parental virus are important for basic research on HSV and development of HSV-based vectors for human therapy. The intergenic region between HSV-1 UL3 and UL4 genes has been reported to satisfy the requirements for such an insertion site. The UL3 and UL4 genes are oriented toward the intergenic region and, therefore, insertion of a foreign gene(s) into the region between the UL3 and UL4 polyadenylation signals should not disrupt any viral genes or transcriptional units. HSV-1 and HSV-2 each have more than 10 additional regions structurally similar to the intergenic region between UL3 and UL4. In the...

Engagement of Penicillium marneffei conidia with multiple pattern recognition receptors on human monocytes.

Microbiology and Immunology — Sun, 01 Mar 2009 05:00:00 +0100

Authors: Srinoulprasert Y, Pongtanalert P, Chawengkirttikul R, Chaiyaroj SC P. marneffei is a thermal dimorphic fungus which causes penicilliosis, an opportunistic infection in immunocompromised patients in South and Southeast Asia. Little is known about the innate immune response to P. marneffei infection. Therefore, the initial response of macrophages to P. marneffei conidia was evaluated by us. Adhesion between monocytes from healthy humans and fungal conidia was examined and found to be specifically inhibited by MAbs against PRR, such as MR, (TLR)1, TLR2, TLR4, TLR6, CD14, CD11a, CD11b, and CD18. To study the consequences of these interactions, cytokines were also examined by ELISA. Binding of P. marneffei conidia to monocytes was significantly inhibited, in a dose-dependent manner...

Immunolocalization and serum antibody responses to Brugia malayi pepsin inhibitor homolog (Bm-33).

Microbiology and Immunology — Sun, 01 Mar 2009 05:00:00 +0100

Authors: Krushna NS, Shiny C, Dharanya S, Sindhu A, Aishwarya S, Narayanan RB cDNA coding for Brugia malayi pepsin inhibitor homolog (Bm-33) from the human filarial parasite was cloned in pRSET for large-scale expression and functional characterization. The pRSET-B cloned gene did not yield recombinant protein expression and the reason was attributed to the presence of an N-terminal signal peptide. The gene was subcloned in pRSET-A without a signal peptide and the 33 kDa histidine-tagged recombinant protein was purified by IMAC. All individuals from an endemic area generated IgG responses against Bm-33 in the order MF>CP>EN. Isotype analysis indicated an elevated IgG4 reactivity in the order MF>EN>CP. Bm-33-specific IgE levels were elevated in MF, CP and EN compared to non-...

Phenotypic characteristics and pathogenic ability across distinct morphotypes of Burkholderia pseudomallei DT.

Microbiology and Immunology — Sun, 01 Mar 2009 05:00:00 +0100

Authors: Chen YS, Lin HH, Hung CC, Mu JJ, Hsiao YS, Chen YL Burkholderia pseudomallei DT is unusual as it exhibits six distinct colony morphotypes. Types III and V show stronger motility, whereas type VI exhibits the highest levels of bacterial association with peritoneal exudate cells. Although the bacterial loads in the organs are not significantly different for infections by the six distinct morphotypes, higher mortality (100% and 89%, respectively) and larger areas of abnormal liver debris (20.6% and 22.4%, respectively) are found with types I- and III-infected mice compared to the others. These morphotypes sometimes undergo switching to a mucoid type in the body of mice, but the reverse has never been observed. PMID: 19302529 [PubMed - in process] (Source: Microbiology and Imm...

Mitogen-activated protein kinases are involved in tumor necrosis factor alpha production in macrophages infected with Orientia tsutsugamushi

Microbiology and Immunology — Wed, 18 Feb 2009 00:00:00 +0100

In conclusion, our data indicate that MAPK signaling is required to induce maximal TNF-[alpha] production in macrophages during Orientia infection. (Source: Microbiology and Immunology)

Characterization of vaginal lactobacilli coaggregation ability with Escherichia coli.

Microbiology and Immunology — Sun, 01 Feb 2009 05:00:00 +0100

Authors: Ekmekci H, Aslim B, Ozturk S The coaggregation abilities of probiotic strains might enable it to form a barrier that prevents colonization by pathogenic bacteria. In the present study, the characterization of the coaggregation ability of 19 vaginal lactobacilli was studied. Coaggregation ability of all lactobacilli with Escherichia coli ATCC 11229 was positive. Only the highest coaggregation percentage of Lactobacillus acidophilus S1 was obtained with E. coli ATCC 11229 under both aerobic (71%) and anaerobic conditions (62%). The coaggregation abilities of strains occurred higher at acidic pH than at basic pH values. Moreover, the coaggregation abilities of tested strains against E. coli decreased after heat treatment (70 or 85 degrees C). Also, the relationship between hydrop...

Effects of Clinacanthus siamensis leaf extract on influenza virus infection.

Microbiology and Immunology — Sun, 01 Feb 2009 05:00:00 +0100

Authors: Wirotesangthong M, Nagai T, Yamada H, Amnuoypol S, Mungmee C Ethanolic extracts of 20 medicinal plants were screened for influenza virus NA inhibition and in vitro antiviral activities using MDCK cells in an MTT assay. The vaccine proteins of influenza virus A/New Caledonia/20/99 (H1N1), mouse-adapted influenza virus A/Guizhou/54/89 (A/G)(H3N2) and mouse-adapted influenza virus B/Ibaraki/2/85 (B/I) were used in the NA inhibition assay, and mouse-adapted influenza viruses A/PR/8/34 (H1N1), A/G and B/I were used in the in vitro antiviral assay. The results of the in vitro antiviral assay indicated that the A/G virus was the most susceptible and an extract of the leaf of CS possessed the highest in vitro anti-A/G virus activity (41.98%). Therefore, the A/G virus and the CS extrac...

Neutralizing antibody against severe acute respiratory syndrome (SARS)-coronavirus spike is highly effective for the protection of mice in the murine SARS model.

Microbiology and Immunology — Sun, 01 Feb 2009 05:00:00 +0100

Authors: Ishii K, Hasegawa H, Nagata N, Ami Y, Fukushi S, Taguchi F, Tsunetsugu-Yokota Y We evaluated the efficacy of three SARS vaccine candidates in a murine SARS model utilizing low-virulence Pp and SARS-CoV coinfection. Vaccinated mice were protected from severe respiratory disease in parallel with a low virus titer in the lungs and a high neutralizing antibody titer in the plasma. Importantly, the administration of spike protein-specific neutralizing monoclonal antibody protected mice from the disease, indicating that the neutralization is sufficient for protection. Moreover, a high level of IL-6 and MCP-1 production, but not other 18 cytokines tested, on days 2 and 3 after SARS-CoV infection was closely linked to the virus replication and disease severity, suggesting the importan...

Differences in clinical manifestations of influenza-associated encephalopathy by age.

Microbiology and Immunology — Sun, 01 Feb 2009 05:00:00 +0100

Authors: Wada T, Morishima T, Okumura A, Tashiro M, Hosoya M, Shiomi M, Okuno Y Data from patients in Japan was analyzed to examine the age distribution and differences by age in the clinical manifestations of influenza-associated encephalopathy. Between 1998 and 2002, 472 cases of influenza-associated encephalopathy in patients aged 15 years or younger were reported to the Collaborative Study Group on Influenza-Associated Encephalopathy. These cases were divided into two groups by age: 0-5 and 6-15 years. The differences between the groups were estimated based on the data for those aged 0-5 years, and the odds ratios and 95% confidence intervals calculated. Distribution was inversely correlated with age, with a peak at 1-2 years old. In comparison with patients aged 0-5, those aged 6-...

The context of tetanus toxoid application influences the outcome of antigen-specific and self-directed humoral immune response.

Microbiology and Immunology — Sun, 01 Feb 2009 05:00:00 +0100

Authors: Stojanović M, Zivković I, Inić-Kanada A, Petrusić V, Mićić M, Dimitrijević L Results are presented concerning our attempts to create a suitable model system for studying the connection between microbial antigen (micAg), autoimmunity and autoimmune disease on the basis of hyper-immunization and application of micAg in different contexts. Our research was focused on tetanus toxoid (TTd) as a model micAg. Non-pretreated and complete Freund's adjuvant pretreated BALB/c mice were immunized with high doses of TTd mixed with glycerol or aluminum hydroxide as adjuvants. The main aims of the experiments were to evaluate the properties of induced humoral immune responses, evaluate the pathological potential of induced immune responses and determ...

Presence of a novel Ehrlichia sp. in Ixodes granulatus found in Okinawa, Japan.

Microbiology and Immunology — Sun, 01 Feb 2009 05:00:00 +0100

Authors: Takano A, Ando S, Kishimoto T, Fujita H, Kadosaka T, Nitta Y, Kawabata H, Watanabe H Ehrlichia-specific DNA fragments of Ehrlichia omp-1 and groEL genes were found in two I. granulatus ticks which had been collected from wild small mammals in a subtropical zone in Japan. The DNA sequences of groEL and 16SrDNA of the suspected Ehrlichia were clustered into a group of E. chaffeensis, E. muris, and Ehrlichia sp. HF565 found in I. ovatus, but were distinctly different. Therefore the Ehrlichia strain was designated as a novel Ehrlichia sp. 360. The Ehrlichia sp. 360 was detected in I. granulatus but not in any other ticks. This suggests that I. granulatus is a probable vector of Ehrlichia sp. 360 in Japan. PMID: 19291093 [PubMed - in process] (Source: Microbiology and Immunolog...

Prevalence of antimicrobial resistance among serotypes of Campylobacter jejuni isolates from cattle and poultry in Japan.

Microbiology and Immunology — Sun, 01 Feb 2009 05:00:00 +0100

Authors: Harada K, Ozawa M, Ishihara K, Koike R, Asai T, Ishikawa H Penner serotypes of C. jejuni in a total of 601 isolates from apparently healthy cattle, layer and broiler chickens in Japan were examined between 2001 and 2006. Predominant serotypes were B (O: 2, 19.1%), D (O: 4, 13.5%), Y (O: 37, 7.3%) and G (O: 8, 5.8%), whereas the remaining serotypes made up less than 5% of the total isolates. The frequency of ampicillin resistance in serotype G (65.6%) was significantly higher than in serotypes D (12.5%), B (11.2%), and Y (0%). Our results suggest that serotype is one factor contributing to the prevalence of ampicillin resistance in C. jejuni isolates. PMID: 19291094 [PubMed - in process] (Source: Microbiology and Immunology)

New ITS genotype of Cryptococcus gattii isolated from an AIDS patient in Brazil.

Microbiology and Immunology — Sun, 01 Feb 2009 05:00:00 +0100

Authors: Kang Y, Tanaka H, Moretti ML, Mikami Y Based on combinations of nine variable nucleotides at nine different base positions in the ITS1-5.8S-ITS2 region, Cryptococcus gattii strains were classified into six genotypes. A new genotype of C. gattii, designated as ITS type 8, was isolated from an AIDS patient in Brazil. The ITS type 8 strain is closely related to the ITS type 4 strain, which has been frequently isolated in Brazil and the USA, but which shows ITS-signatured nucleotide difference at each nucleotide position. The ITS type 8 strain is also differentiated from all heretofore reported ITS types of C. gattii strains in the RAPD band patterns and IGS sequence information. PMID: 19291095 [PubMed - in process] (Source: Microbiology and Immunology)

Comparison of different methods for detecting methicillin resistance in MRSA isolates belonging to international lineages commonly isolated in the American continent.

Microbiology and Immunology — Sun, 01 Feb 2009 05:00:00 +0100

Authors: Silva-Carvalho MC, Teixeira LA, Ferreira FA, Ribeiro A, Ferreira-Carvalho BT, Figueiredo AM The aim of the present paper was to compare different methods for detecting methicillin resistance in Staphylococcus aureus. Among the isolates analyzed, 52 belonged to MRSA international lineages commonly detected in the American continent and 14 to sporadic MRSA clones. Both 30 mug-cefoxitin disk and PBP2a had 100% sensibility/specificity when the low-level heterogeneous isolates were tested and, thus, are highly recommended. PMID: 19291096 [PubMed - in process] (Source: Microbiology and Immunology)

Activation of mitogen-activated protein kinases is involved in the induction of interferon beta gene in macrophages infected with Orientia tsutsugamushi.

Microbiology and Immunology — Sun, 01 Feb 2009 05:00:00 +0100

In conclusion, our data indicate that MAPK pathways are required to induce maximal IFN-beta gene expression in macrophages during Orientia infection. PMID: 19291097 [PubMed - in process] (Source: Microbiology and Immunology)

Generation of drug-resistant mutants of Helicobacter pylori in the presence of peroxynitrite, a derivative of nitric oxide, at pathophysiological concentration.

Microbiology and Immunology — Thu, 01 Jan 2009 05:00:00 +0100

Authors: Kuwahara H, Kariu T, Fang J, Maeda H In the present study it has been shown that the reactive nitrogen species, peroxynitrite, can cause at least a 7.1-fold increase in the frequency of occurrence of drug-resistant mutants of Helicobacter pylori at a pathophysiological concentration (e.g. 1.0 muM) and in the presence of CLR. Furthermore, the CLR MIC of these resistant H. pylori strains increased by at least 250 times or higher in CLR susceptibility. In the 45 resistant strains, the modification of 23S rRNA A2142G was the predominant mutation (22/45), followed by A2143G (17/45) within the sequences of 23S rRNA. The other mutants were one each (1/45) in A2142T, and T2269G, and two each (2/45) in C2695G and T1944C, respectively. These results show that the inflammatory host react...

Fusion protein consisting of the first immunoglobulin-like domain of porcine nectin-1 and Fc portion of human IgG1 provides a marked resistance against pseudorabies virus infection to transgenic mice.

Microbiology and Immunology — Thu, 01 Jan 2009 05:00:00 +0100

Authors: Tomioka Y, Morimatsu M, Amagai K, Kuramochi M, Watanabe Y, Kouda S, Wada T, Kuboki N, Ono E Nectin-1 is a Ca(2+)-independent Ig-like cell-cell adhesion molecule and an alphaherpesvirus receptor that binds to virion glycoprotein D by the first Ig-like domain. We have investigated the antiviral potentials of soluble forms of porcine nectin-1 to PRV infection by generating transgenic mice expressing different types of fusion protein. Previously, we reported that mice transgenic for a chimera that carried the entire ectodomain of porcine nectin-1 fused to the Fc portion of porcine IgG1 were more resistant than those transgenic for a chimera that carried the first Ig-like domain fused to the Fc portion. Recently, we generated transgenic mice expressing a fusion protein made of the ...

Genetic stability (in vivo) of the attenuated oral rabies virus vaccine SAD B19.

Microbiology and Immunology — Thu, 01 Jan 2009 05:00:00 +0100

Authors: Beckert A, Geue L, Vos A, Neubert A, Freuling C, Müller T The distribution of oral rabies vaccine baits containing replication-competent live viruses poses certain environmental safety risks; among others, the possibility of reversion to or an increase in virulence. Hence, the genetic stability of the complete genome of the most widely used oral rabies vaccine virus, SAD B19, was examined after four and 10 serial i.c. passages in foxes and mice, respectively. It was shown that the consensus strain of SAD B19 was extremely stable in vivo. After 10 consecutive passages in mice not a single mutation was observed. In foxes, seven single nucleotide exchanges were found between the first and fourth passage, of which only one resulted in an amino acid exchange at position 9240 o...

Multiplex real-time PCR for the simultaneous detection of herpes simplex virus, human herpesvirus 6, and human herpesvirus 7.

Microbiology and Immunology — Thu, 01 Jan 2009 05:00:00 +0100

Authors: Wada K, Mizoguchi S, Ito Y, Kawada JI, Yamauchi Y, Morishima T, Nishiyama Y, Kimura H A simultaneous detection system to quantify HSV, HHV-6, and HHV-7 DNA via multiplex real-time PCR using different fluorochromes was developed. The minimum quantitative level established via this multiplex assay was four copies per reaction for HSV type 1, four copies for HHV-6, and three copies for HHV-7, respectively. The dynamic range encompassed at least six orders of magnitude. The system was specific and reproducible even in the presence of large amounts of other viral DNA. We then applied this multiplex real-time PCR assay to 105 CSF specimens obtained from subjects less than 15 years old in whom a diagnosis of viral encephalitis/encephalopathy was suspected on clinical grounds. The det...

IL-4-dependent induction of IgE basophils in peripheral blood and IgE B cells in spleen as respective indicators of allergen sensitization and a precursor of cells secreting allergen-specific IgE antibody.

Microbiology and Immunology — Thu, 01 Jan 2009 05:00:00 +0100

Authors: Miyoshi-Higashino M, Hirano M, Ogita-Nakanishi H, Yamamoto-Kimoto Y, Sakurai K, Tashiro-Yamaji J, Nomi H, Takahashi T, Miura-Takeda S, Takenaka H, Kubota T, Yoshida R It was recently reported by us that either primary i.n. or i.p. injection of cedar pollen extract into BALB/c mice, or a second s.c. injection of the allergen into i.v. or s.c. sensitized mice, causes an IL-4-dependent increase in total IgE serum antibody to produce allergen-specific IgE antibody upon further s.c. sensitization. To determine the biology of total IgE antibody, in the present study IgE(+) cells in peripheral blood or lymphoid tissues of allergen-sensitized BALB/c mice have been characterized. In peripheral blood, mice sensitized one to three times with the allergen produced a 2.5- to 4-fold increas...

Candida auris sp. nov., a novel ascomycetous yeast isolated from the external ear canal of an inpatient in a Japanese hospital.

Microbiology and Immunology — Thu, 01 Jan 2009 05:00:00 +0100

Authors: Satoh K, Makimura K, Hasumi Y, Nishiyama Y, Uchida K, Yamaguchi H A single strain of a novel ascomycetous yeast species belonging to the genus Candida was isolated from the external ear canal of an inpatient in a Japanese hospital. Analyses of the 26S rDNA D1/D2 domain, nuclear ribosomal DNA ITS region sequences, and chemotaxonomic studies indicated that this strain represents a new species with a close phylogenetic relationship to Candida ruelliae and Candida haemulonii in the Metschnikowiaceae clade. This strain grew well at 40 degrees C, but showed slow and weak growth at 42 degrees C. The taxonomic description of Candida auris sp. nov. is proposed (type strain JCM15448(T)= CBS10913(T)= DSM21092(T)). PMID: 19161556 [PubMed - as supplied by publisher] (Source: Microbiolo...

Simple broad-spectrum protocol using labiase for bacterial cell lysis to prepare genomic DNA for pulsed-field gel electrophoresis analysis.

Microbiology and Immunology — Thu, 01 Jan 2009 05:00:00 +0100

Authors: Oana K, Kawakami Y, Hayashi T, Ohnishi M We have developed a simple broad-spectrum protocol using labiase for bacterial cell lysis in pulsed-field gel electrophoresis analysis. The protocol reported here is widely applicable to the preparations of genomic DNA from Gram-negative and -positive pathogens, including enterococcal strains resistant to any conventional lysis protocols. PMID: 19161557 [PubMed - as supplied by publisher] (Source: Microbiology and Immunology)

Self-assembly of sapovirus recombinant virus-like particles from polyprotein in mammalian cells.

Microbiology and Immunology — Thu, 01 Jan 2009 05:00:00 +0100

Authors: Oka T, Yamamoto M, Miyashita K, Ogawa S, Katayama K, Wakita T, Takeda N The SaV genome is a positive-sense, non-segmented single-strand RNA molecule of approximately 7.5 kb that is polyadenylated at its 3' terminus. The major capsid (VP1) of SaV is thought to be produced as the ORF1 polyprotein followed by cleavage, or translation from subgenomic RNA (3'-coterminal with the virus genome), or both. We have recently reported the formation of SaV VLP from subgenomic-like RNA in mammalian cells. In the present study, we demonstrated that the VP1 cleaved from a part of ORF1 polyprotein self-assembled into VLP in mammalian cells when a transient expression system using a recombinant vaccinia virus encoding T7 RNA polymerase was used. PMID: 19161558 [PubMed - as supplied by publi...

Non-human primate surrogate model of hepatitis C virus infection.

Microbiology and Immunology — Thu, 01 Jan 2009 05:00:00 +0100

Authors: Akari H, Iwasaki Y, Yoshida T, Iijima S More than 170 million people worldwide are chronically infected by HCV, which is the causative agent of chronic hepatitis C, cirrhosis, and finally liver cancer. Although animal models of viral hepatitis are a prerequisite for the evaluation of antiviral and vaccine efficacy, the restricted host range of HCV has hampered the development of a suitable small animal model of HCV infection. Use of the chimpanzee, the only animal known to be susceptible to HCV infection, is limited by ethical and financial restrictions. In this regard GBV-B, being closely related to HCV, appears to be a promising non-human surrogate model for the study of HCV infection. This review describes the characteristic of GBV-B infection of New World monkeys, and disc...

Errata.

Microbiology and Immunology — Thu, 01 Jan 2009 05:00:00 +0100

Authors: PMID: 19161560 [PubMed - as supplied by publisher] (Source: Microbiology and Immunology)

A WT1 protein-derived, naturally processed 16-mer peptide, WT1(332), is a promiscuous helper peptide for induction of WT1-specific Th1-type CD4(+) T cells.

Microbiology and Immunology — Mon, 01 Dec 2008 05:00:00 +0100

Authors: Fujiki F, Oka Y, Kawakatsu M, Tsuboi A, Nakajima H, Elisseeva OA, Harada Y, Li Z, Tatsumi N, Kamino E, Shirakata T, Nishida S, Taniguchi Y, Kawase I, Oji Y, Sugiyama H The Wilms' tumor gene WT1 is overexpressed in various tumors, and the WT1 protein has been demonstrated to be an attractive target antigen for cancer immunotherapy. A WT1 protein-derived 16-mer peptide, WT1(332) (KRYFKLSHLQMHSRKH), which was naturally generated through processing in cells and could elicit Th1-type CD4(+) helper T cell responses with an HLA-DRB1*0405-restriction has previously been identified by us. In the present study, it has been demonstrated that WT1(332) can induce WT1(332)-specific CD4(+) T cell responses with the restriction of not only HLA-DRB1*0405 but also HLA-DRB1*1501, -DRB1*1502, or ...

Experimental autoimmune uveoretinitis initiated by non-phagocytic destruction of inner segments of photoreceptor cells by Mac-1(+) mononuclear cells.

Microbiology and Immunology — Mon, 01 Dec 2008 05:00:00 +0100

Authors: Miura-Takeda S, Tashiro-Yamaji J, Oku H, Takahashi T, Shimizu T, Sugiyama T, Ikeda T, Kubota T, Yoshida R EAU in mice is a model of human posterior uveitis. EAU is a Th1-dependent disease that has been assumed to target the neural retina and related tissues; however, in situ effector cells and the target have not yet been clearly demonstrated. In the present study, we induced EAU in B10R mice by immunizing them with human interphotoreceptor retinoid-binding protein peptide 161-180. Histological examinations revealed that EAU occurred approximately 11 days after the immunization and reached a peak on day 14. Retinae from normal or EAU mice were treated with proteases to obtain mono-dispersed cells. The mono-dispersed cells thus obtained were separated into three to four fractio...

Regulation of marA, soxS, rob, acrAB and micF in Salmonella enterica serovar Typhimurium.

Microbiology and Immunology — Mon, 01 Dec 2008 05:00:00 +0100

Authors: Hartog E, Ben-Shalom L, Shachar D, Matthews KR, Yaron S Importance of the overexpression of AcrAB efflux pumps in the low-level resistance of pathogens to antimicrobials requires a better understanding of the AcrAB regulation. The goal of the present research was to study the transcription of acrAB, as well as the genes that play a role in its regulation in Salmonella enterica serovar Typhimurium. We monitored the transcription of these genes during growth at 30 degrees C and 37 degrees C, and thoroughly studied the effect of salicylate, paraquat and decanoate. The strengths of the promoters' activities were ordered from strong to weak as micF > rob > acrAB > soxS, marRAB. At both temperatures, marRAB was mainly upregulated by salicylate and decanoate, soxS by paraqua...

Herpes simplex virus type 1 dysregulates anti-fungal defenses preventing monocyte activation and downregulating toll-like receptor-2.

Microbiology and Immunology — Mon, 01 Dec 2008 05:00:00 +0100

Authors: Cermelli C, Orsi CF, Ardizzoni A, Lugli E, Cenacchi V, Cossarizza A, Blasi E We investigated the interplay occurring between pathogens in the course of dual infections, using an in vitro model in which the THP-1 monocytic cell line is first infected with HSV-1 and then exposed to Ca or Cn. These three pathogens share some pathogenic features: they cause opportunistic infections, target macrophages and are neurotropic. Here, we show that HSV-1-infected THP-1 cells exhibited augmented phagocytosis against the two opportunistic fungi but reduced capability to counteract fungal infection: the better ingestion by monocytes was followed by facilitated fungal survival and replication. Reduced IL-12 production was also observed. Cytofluorimetric analysis showed that HSV-1-infected mon...

Receptor activator of nuclear factor-kappa B ligand induces osteoclast formation in RAW 264.7 macrophage cells via augmented production of macrophage-colony-stimulating factor.

Microbiology and Immunology — Mon, 01 Dec 2008 05:00:00 +0100

Authors: Islam S, Hassan F, Tumurkhuu G, Dagvadorj J, Koide N, Naiki Y, Yoshida T, Yokochi T RAW 264.7 macrophage cells differentiate into osteoclast-like cells in the presence of RANKL. Participation of M-CSF in RANKL-induced osteoclast formation of RAW 264.7 cells was examined. TRAP-positive osteoclast-like cells appeared in RAW 264.7 cells cultured in the presence of RANKL. RANKL-induced osteoclast formation was markedly inhibited by anti-M-CSF antibody. RANKL augmented M-CSF mRNA expression and M-CSF production in RAW 264.7 cells. Further, anti-M-CSF antibody inhibited the expression of RANK, c-fms, c-fos and TRAP mRNA in RANKL-stimulated RAW 264.7 cells. However, anti-M-CSF antibody did not affect the expression of DC-STAMP in the stimulated cells. Therefore, RANKL was suggested t...

A WT1 protein-derived, naturally processed 16-mer peptide, WT1, is a promiscuous helper peptide for induction of WT1-specific Th1-type CD4 T cells.

Microbiology and Immunology — Mon, 01 Dec 2008 05:00:00 +0100

Experimental autoimmune uveoretinitis initiated by non-phagocytic destruction of inner segments of photoreceptor cells by Mac-1 mononuclear cells.

Microbiology and Immunology — Mon, 01 Dec 2008 05:00:00 +0100

Variable gene family usage of protective and non-protective anti-Vibrio cholerae O1 LPS antibody heavy chains.

Microbiology and Immunology — Mon, 01 Dec 2008 05:00:00 +0100

Authors: Wade TK, Wade WF Vibrio cholerae causes cholera, an enteric disease of humans that is a worldwide problem. The O1 serogroup of Vibrio cholerae contains two predominant serotypes (Inaba and Ogawa) of LPS, a proven protective antigen for humans and experimental animals. We generated B-cell hybridomas from mice immunized with either: (i) two doses of purified Inaba LPS; (ii) two doses of an Inaba hexasaccharide conjugate (terminal six perosamine bound to a protein carrier), (iii) four doses of purified Inaba LPS; or (iv) a low dose of purified Inaba LPS followed by a booster with the Inaba conjugate. We showed previously that the first and third immunization protocols induce vibriocidal antibodies, as does the fourth; the second protocol induces antibodies that bind Inaba and Oga...

Antimicrobial susceptibilities of Propionibacterium acnes isolated from patients with acne vulgaris.

Microbiology and Immunology — Mon, 01 Dec 2008 05:00:00 +0100

Authors: Ishida N, Nakaminami H, Noguchi N, Kurokawa I, Nishijima S, Sasatsu M Antibiotic susceptibilities of Propionibacterium acnes in Japan were determined. Erythromycin-resistance was found in 10.4% (5/48) of the strains, and four of these were cross-resistance to clindamycin. Although the erythromycin ribosome methylase gene erm(X) was looked for, no strain carrying erm(X) was found. Sequencing analysis revealed that all of the erythromycin-resistant strains had a mutation in the peptidyl transferase region of the 23S rRNA gene: G2057A, A2058G, or A2059G. Consequently, our results show that P. acnes resistance to macrolides is caused by a mutation in the 23S rRNA gene, and has been increasing in Japan. PMID: 19120976 [PubMed - in process] (Source: Microbiology and Immunology)

Analysis of severe acute respiratory syndrome coronavirus structural proteins in virus-like particle assembly.

Microbiology and Immunology — Mon, 01 Dec 2008 05:00:00 +0100

Authors: Nakauchi M, Kariwa H, Kon Y, Yoshii K, Maeda A, Takashima I SARS-CoV has four major structural proteins: the N, S, M, and E proteins. To investigate the mechanism of SARS-CoV assembly, we cloned the genes encoding these four proteins into the eukaryotic expression vector pCAGGS and transfected them into 293T cells. When all four expression vectors were co-transfected VLP formed, as confirmed using electron microscopy. Using a rabbit polyclonal antibody specific to the N protein, N-protein-containing particles similar in size to the VLP were also observed by immunoelectron microscopy, indicating that the VLP contained the N protein. Co-immunoprecipitation analyses demonstrated an interaction between the N and M proteins, suggesting that N protein binds directly to M protein to ...

Identification of a WT1 protein-derived peptide, WT1, as a HLA-A 0206-restricted, WT1-specific CTL epitope.

Microbiology and Immunology — Sat, 01 Nov 2008 04:00:00 +0100

Authors: Li Z, Oka Y, Tsuboi A, Fujiki F, Harada Y, Nakajima H, Masuda T, Fukuda Y, Kawakatsu M, Morimoto S, Katagiri T, Tatsumi N, Hosen N, Shirakata T, Nishida S, Kawakami Y, Udaka K, Kawase I, Oji Y, Sugiyama H The Wilms' tumor gene WT1 is overexpressed in various kinds of hematopoietic malignancies as well as solid cancers, and this protein has been demonstrated to be an attractive target antigen for cancer immunotherapy. WT1-specific CTL epitopes with a restriction of HLA-A 2402 or HLA-A 0201 have been already identified. In the present study it has been demonstrated that a 9-mer WT1-derived WT1(187) peptide, which had already been shown to elicit a WT1-specific CTL response with a restriction of HLA-A 0201, can also elicit a CTL response with a restriction of HLA-A 0206. In all t...

Diagnosis of toxic shock syndrome by two different systems; clinical criteria and monitoring of TSST-1-reactive T cells.

Microbiology and Immunology — Sat, 01 Nov 2008 04:00:00 +0100

Authors: Matsuda Y, Kato H, Ono E, Kikuchi K, Muraoka M, Takagi K, Imanishi K, Itoh S, Itoh T, Ogawa T, Nitta K, Inokuchi S, Hibi T, Ohta H, Uchiyama T Two methods of TSS diagnosis were evaluated: comparison of symptoms with clinical criteria and monitoring for evidence of selective activation of Vbeta2(+) T cells by the causative toxin, TSS toxin-1 (TSST-1). Ten patients with acute and systemic febrile infections caused by Staphylococcus aureus were monitored for increase in TSST-1-reactive Vbeta2(+) T cells during their clinical courses. Nine of the ten patients were diagnosed with TSS based on evidence of selective activation of Vbeta2(+) T cells by TSST-1; however, clinical symptoms met the clinical criteria for TSS in only six of these nine patients. In the remaining patient, clin...

Antimicrobial and anti-inflammatory activity of five Taxandria fragrans oils in vitro.

Microbiology and Immunology — Sat, 01 Nov 2008 04:00:00 +0100

In conclusion, T. fragrans oil showed both antimicrobial and anti-inflammatory activity in vitro, however, the clinical relevance of this remains to be determined. PMID: 19090831 [PubMed - in process] (Source: Microbiology and Immunology)

Analysis of peripheral blood lymphocyte phenotypes and Th1/Th2 cytokines profile in the systemic immune responses of Helicobacter pylori infected individuals.

Microbiology and Immunology — Sat, 01 Nov 2008 04:00:00 +0100

In this study, peripheral blood T lymphocyte phenotypes and serum Th1/Th2 based cytokines of 32 H. pylori positive patients were analyzed and compared to those of healthy controls. While alphabeta TCR(+) lymphocytes and their phenotype analysis were not significantly different to those of healthy controls, the percentage of pan gammadelta TCR(+) lymphocytes was up to 2.4 times greater in the H. pylori positive group then in healthy controls. Furthermore, significant increases in IL-10 concentrations in serum samples of H. pylori patients indicated that their immune systems had switched toward a Th2 type immune response. The correlation between phenotype and type of T cell response in the peripheral blood during H. pylori infection is discussed. PMID: 19090832 [PubMed - in process] (Sou...

Interaction between cFLIP and Itch, a ubiquitin ligase, is obstructed in Trypanosoma cruzi-infected human cells.

Microbiology and Immunology — Sat, 01 Nov 2008 04:00:00 +0100

Authors: Murata E, Hashimoto M, Aoki T Death receptor-mediated host cell apoptosis, a defense strategy for elimination by the immune system of parasite-infected cells, is inhibited by Trypanosoma cruzi, the causative agent of Chagas' disease. It has previously been reported by us that, in infected cells, T. cruzi upregulates and exploits cFLIP(L), a mammalian inhibitor of death receptor signaling. Here it is shown that ubiquitination of cFLIP(L,) leading to proteasomal degradation, is inhibited in parasite-infected cells. The extent of expression of Itch, a protein thought to be an ubiquitin ligase for cFLIP(L), was found to be equivalent in T. cruzi-infected and in uninfected cells. However, co-immunoprecipitation analysis showed that the interaction between cFLIP(L) and Itch is stron...

Immunoreactivity of five antigens of Mycobacterium tuberculosis in patients attending a public health care facility in an area with high endemicity for TB.

Microbiology and Immunology — Sat, 01 Nov 2008 04:00:00 +0100

The objective of this study was to evaluate people attending a primary health clinic in Rio de Janeiro, Brazil for immunoreactivity to five Mycobacterium tuberculosis antigens, as these antigens are markers of immune response and factors associated with active TB. The serum antibody titers of different categories of patients (defined by microbiological and radiological characteristics and by response to therapy on follow-up) to 38 kDa, 16 kDa, MPT64, ESAT-6 and MT10.3 antigens were determined blind with ELISA. Positive tests to each antigen were defined with ROC analysis. OR were calculated for factors associated with humoral response in patients with active TB. A total of 201 patients underwent serological testing. Patients with confirmed active TB responded more frequently to MPT64 (44%)...

Identification of a WT1 protein-derived peptide, WT1, as a HLA-A*0206-restricted, WT1-specific CTL epitope.

Microbiology and Immunology — Sat, 01 Nov 2008 04:00:00 +0100

Authors: Li Z, Oka Y, Tsuboi A, Fujiki F, Harada Y, Nakajima H, Masuda T, Fukuda Y, Kawakatsu M, Morimoto S, Katagiri T, Tatsumi N, Hosen N, Shirakata T, Nishida S, Kawakami Y, Udaka K, Kawase I, Oji Y, Sugiyama H The Wilms' tumor gene WT1 is overexpressed in various kinds of hematopoietic malignancies as well as solid cancers, and this protein has been demonstrated to be an attractive target antigen for cancer immunotherapy. WT1-specific CTL epitopes with a restriction of HLA-A*2402 or HLA-A*0201 have been already identified. In the present study it has been demonstrated that a 9-mer WT1-derived WT1(187) peptide, which had already been shown to elicit a WT1-specific CTL response with a restriction of HLA-A*0201, can also elicit a CTL response with a restriction of HLA-A*0206. In all t...

Identification of probiotic lactobacilli used for animal feeds on the basis of 16S ribosomal RNA gene sequence.

Microbiology and Immunology — Sat, 01 Nov 2008 04:00:00 +0100

In this study the 16S rRNA gene sequence of L. acidophilus in two commercial agents which have been used in animal feeds, LAB-MOS and Ghenisson 22, was determined. Phylogenetic tree analysis revealed that the two agents, strain MNFLM01 in LAB-MOS and strain GAL-2 in Ghenisson 22, belonged to L. rhamnosus (a member of the L. casei group) and L. johnsonii (a member of the L. acidophilus group), respectively. Biochemical tests assigned the two as L. rhamnosus and ambiguously as L. acidophilus. The data suggest that 16S rRNA gene sequence analysis provides more accurate identification of Lactobacillus species than biochemical tests and would allow quality assurance of relevant commercial products. The 16S rRNA gene sequences of strains MNFLM01 and GAL-2 determined in this study have been submi...

A taxonomic study on erysipelothrix by DNA-DNA hybridization experiments with numerous strains isolated from extensive origins.

Microbiology and Immunology — Tue, 30 Sep 2008 17:21:17 +0100

In conclusion, it was confirmed that members of the E. rhusiopathiae and E. tonsillarum groups resemble each other in regard to many phenotypic characteristics, but differ in their ability to produce acid from saccharose and in their pathogenicity for swine. The genus Erysipelothrix certainly contains two main species: E. rhusiopathiae and E. tonsillarum. PMID: 18822080 [PubMed - in process] (Source: Microbiology and Immunology)

Identification of the repeated number of C and D regions of tyrosine phosphorylation motifs in Helicobacter pylori cagA using multiplex PCR.

Microbiology and Immunology — Tue, 30 Sep 2008 17:21:13 +0100

Authors: An B, Lee G, Lim K, Moon BS, Kim JB Various tyrosine phosphorylation motif regions of H. pylori cagA exist. The number of these regions was found to have some influence on cell signaling, which was found to be more pronounced when in D (ESS) region than in C (WSS) region. A molecular biological method with multiplex PCR was developed to distinguish C and D regions, and to identify the repetition number of tyrosine phosphorylation of the cagA gene. Multiplex PCR using novel primer sets was performed on 73 strains of H. pylori isolated from Korean patients with upper gastrointestinal diseases. The Western cagA was identified in only 3 strains (4.1%) whereas East Asia cagA was identified in 69 strains (94.5%). These results were reconfirmed through a sequencing analysis. The meth...

Production and characterization of rabbit polyclonal sera against Shiga toxins Stx1 and Stx2 for detection of Shiga toxin-producing Escherichia coli.

Microbiology and Immunology — Tue, 30 Sep 2008 17:21:10 +0100

In this study, rabbit polyclonal Stx1 and Stx2 antisera were raised and employed in the standardization of immunoassays for STEC detection. Using their respective antisera, the limit of detection of the toxin was 35.0 pg for Stx1 and 5.4 pg for Stx2. By immunoblotting, these antisera recognized both toxin subunits. Cross-reactivity was observed in the A subunit, but only Stx2 antiserum was able to neutralize the cytotoxicity of both toxins in the Vero cell assay. Six stx-harboring E. coli isolates were analyzed for their virulence traits. They belonged to different serotypes, including the O48:H7, described for the first time in Brazil. Only three strains harbored eae, and the e-hly gene and hemolytic activity was detected in five strains. Three isolates showed new stx2 variants (stx(2v-ha...

Diversity of laccase among Cryptococcus neoformans serotypes.

Microbiology and Immunology — Tue, 30 Sep 2008 17:21:04 +0100

Authors: Ito-Kuwa S, Nakamura K, Valderrama B, Aoki S, Vidotto V, Osafune T The pathogenic yeast C. neoformans is classified into three varieties with five serotypes; var. grubii (serotype A), var. neoformans (serotype D), var. gattii (serotypes B and C), and serotype AD. Melanin is a virulence factor in the species, and its biosynthesis is catalyzed by laccase, encoded by the LAC1 gene. In order to estimate the natural variability of the LAC1 gene among Cryptococcus serotypes, the laccase protein sequence from 55 strains was determined and the phylogenetic relationships between cryptococcal and related fungal laccases revealed. The deduced laccase proteins consisted of 624 amino acid residues in serotypes A, D and AD, and 613 to 615 residues in serotypes B and C. Intra-serotype amino ...

Decreased interferon-alpha production and impaired regulatory function of plasmacytoid dendritic cells induced by the hepatitis C virus NS 5 protein.

Microbiology and Immunology — Tue, 30 Sep 2008 17:20:55 +0100

This study concentrated on the interaction of human peripheral blood derived pDC with HCV NS3, NS4, and NS5 proteins, and their maturation, cytokine secretion and functional properties. It was shown that HCV NS5 interferes with CD40L induced maturation of pDC as indicated by decreased expression of CD83 and CD86 markers. CpG ODN stimulated HCV NS3 and NS5 treated pDC showed decreased production of IFN-alpha. In the case of NS3, IFN-alpha production was reduced to 126 pg/ml as compared to 245 pg/ml in controls (P < 0.01), and with NS5, IFN-alpha production was reduced to 92 pg/ml as compared to 238 pg/ml in controls (P < 0.05). In the presence of HCV NS5, the T cell stimulatory capacity of pDC was impaired, as indicated by decreased proliferation of T cells, and decreased production b...

Isolation of tetracycline-resistant clinical Helicobacter pylori without mutations in 16S rRNA gene in Bangladesh.

Microbiology and Immunology — Tue, 30 Sep 2008 17:20:52 +0100

Authors: Khan R, Nahar S, Mukhopadhyay AK, Berg DE, Ahmad MM, Okamoto K, Nair GB, Rahman M The occurrence of 16S rRNA gene mutations associated with resistance to tetracycline in H. pylori isolated in Bangladesh was investigated. Tetracycline susceptibility was determined by the agar dilution method. The 16S rRNA genes of these isolates were sequenced and analyzed. A tetracycline accumulation assay was performed. DNA sequence and transformation tests of nine tetracycline-resistant (MIC = 2 mug/ml) Bangladeshi H. pylori clinical isolates showed that in no case was the resistance due to mutations in the 16S rRNA gene, the only known cause of tetracycline resistance in this pathogen. Tetracycline accumulation assays implicated altered uptake or efflux. PMID: 18822085 [PubMed - in proc...

Protective effects of farnesol against oral candidiasis in mice.

Microbiology and Immunology — Fri, 01 Aug 2008 16:31:50 +0100

Authors: Hisajima T, Maruyama N, Tanabe Y, Ishibashi H, Yamada T, Makimura K, Nishiyama Y, Funakoshi K, Oshima H, Abe S Farnesol is known as a quorum-sensing molecule for Candida albicans and is recognized to play pathogenic roles in Candida infection. To assess the possible role of farnesol in mucosal C. albicans infection, the effects of farnesol treatment against experimental oral candidiasis in mice were examined. Prednisolone-pretreated ICR mice were orally infected with C. albicans and 3, 24 and 30 hr later the animals were orally given farnesol. Forty-eight hr later they were killed for observation. Farnesol treatment in a dose ranging between 1.125 and 9 mumol/mouse showed a protective effect against oral candidiasis in a dose-dependent manner, at least as estimated by symptom ...

Diversity of staphylocoagulase and identification of novel variants of staphylocoagulase gene in Staphylococcus aureus.

Microbiology and Immunology — Fri, 01 Aug 2008 16:31:50 +0100

Authors: Kinoshita M, Kobayashi N, Nagashima S, Ishino M, Otokozawa S, Mise K, Sumi A, Tsutsumi H, Uehara N, Watanabe N, Endo M Staphylocoagulase (SC) is a major phenotypic determinant of Staphylococcus aureus. Serotype of SC (coagulase type) is used as an epidemiological marker and 10 types (I-X) have been discriminated so far. To clarify genetic diversity of SC within a single and among different serotype(s), we determined approximately 1500 bp-nucleotide sequences of SC gene encoding D1, D2, and central regions (N-terminal half and central regions of SC; SC(NC)) for a total of 33 S. aureus strains comprising two to three strains from individual coagulase types (I-VIII, X) and 10 strains which were not determined as previously known SC serotypes (ND-strains). Amino acid sequence iden...

Two types of allograft-induced cytotoxic macrophage, one against allografts and the other against syngeneic or allogeneic tumor cells.

Microbiology and Immunology — Fri, 01 Aug 2008 16:31:50 +0100

Authors: Yoneda Y, Tashiro-Yamaji J, Kubota T, Yoshida R In the 1990s, based on the results of studies using beta(2)M, CD4 or CD8 knockout mice, several groups reported that the main effector cells responsible for skin or organ allograft rejection were non-T, non-NK cells. Similarly, we demonstrated that in an animal model of transplantation of BALB/c (H-2(d)) skin onto or Meth A (H-2(d)) tumor cells into C57BL/6 (H-2(b)) mice, AIM, which expressed iNOS, IL-12, and IL-18, were the main effector cells and also that they were cytotoxic against syngeneic tumor cells. Here, we examined whether the same population of macrophages could react with two distinct types of target cell. When BALB/c skin or Meth A tumor cells were transplanted into C57BL/6 mice, cytotoxic activity against the allog...

Synthetic fibril peptide promotes clearance of scrapie prion protein by lysosomal degradation.

Microbiology and Immunology — Fri, 01 Aug 2008 16:31:50 +0100

Authors: Okemoto-Nakamura Y, Yamakawa Y, Hanada K, Tanaka K, Miura M, Tanida I, Nishijima M, Hagiwara K Transmissible spongiform encephalopathies are infectious and neurodegenerative disorders that cause neural deposition of aggregates of the disease-associated form of PrP(Sc). PrP(Sc) reproduces by recruiting and converting the cellular PrP(C), and ScN2a cells support PrP(Sc) propagation. We found that incubation of ScN2a cells with a fibril peptide named P9, which comprises an intrinsic sequence of residues 167-184 of mouse PrP(C), significantly reduced the amount of PrP(Sc) in 24 hr. P9 did not affect the rates of synthesis and degradation of PrP(C). Interestingly, immunofluorescence analysis showed that the incubation of ScN2a cells with P9 induced colocalization of the accumulatio...

Toxoplasma gondii-derived heat shock protein 70 induces lethal anaphylactic reaction through activation of cytosolic phospholipase A and platelet-activating factor via Toll-like receptor 4/myeloid differentiation factor 88.

Microbiology and Immunology — Fri, 01 Aug 2008 16:31:50 +0100

Authors: Fang H, Mun HS, Kikumura A, Sayama Y, Norose K, Yano A, Aosai F Toxoplasma gondii-derived heat shock protein 70 (T.g.HSP70) was proven to induce IFN-gamma-dependent lethal anaphylactic reaction in T. gondii-infected mice through an alternative PAF-mediated pathway, but not the classical immunoglobulin (Ig)E-dependent pathway. Although marked IFN-gamma production was observed by CD11b(+), CD11c(+), CD4(+) and CD8(+) splenocytes, CD11b(+) and CD11c(+) cells were shown to be the key effecter cells which generated pro-inflammatory lipid such as PAF and caused T.g.HSP70-induced anaphylactic reaction. In the present study, we found that the T.g.HSP70-induced anaphylactic reaction was not observed in TLR 4-deficient ((-/-)) mice, whereas it was observed in WT and TLR2(-/-) mice. The ...

Polymerase chain reaction detection of bacterial 16S rRNA gene in human blood.

Microbiology and Immunology — Fri, 01 Aug 2008 16:31:50 +0100

Authors: Moriyama K, Ando C, Tashiro K, Kuhara S, Okamura S, Nakano S, Takagi Y, Miki T, Nakashima Y, Hirakawa H Bacterial 16S ribosomal RNA genes (rDNA) were detected in blood samples from two healthy individuals by PCR under conditions involving 30 cycles that did not produce any visible products from negative control saline. Even from control samples, PCR involving 35-40 cycles yielded visible bands. Major clones detected in the blood samples, but not in control, were the Aquabacterium subgroup, Stenotrophomonas subgroup, Budvicia subgroup, Serratia subgroup, Bacillus subgroup and Flavobacteria subgroup. No clone was located within the bacteroides-clostridium-lactobacillus cluster, which is indigenous to gastrointestinal flora. PMID: 18667036 [PubMed - in process] (Source: Micro...

Use of a serum-based antifungal susceptibility assay to predict the in vivo efficacy of novel echinocandin compounds.

Microbiology and Immunology — Fri, 01 Aug 2008 16:31:50 +0100

Authors: Maki K, Matsumoto S, Watabe E, Iguchi Y, Tomishima M, Ohki H, Yamada A, Ikeda F, Tawara S, Mutoh S In vitro susceptibility assays of antifungal activity do not always accurately predict in vivo efficacy. As well as having a clear clinical importance, the ability to predict efficacy is also essential for effective screening of novel drug compounds. Initial screening of novel compounds must often be based on in vitro data. The present report describes the use of serum-MIC, an in vitro test of antifungal susceptibility, to accurately predict in vivo efficacy of echinocandin drugs in a mouse model of disseminated candidiasis. The basis of the serum-MIC method was to measure the inhibitory activity of a test compound against Candida albicans hyphal growth in the presence of pooled ...

Role of the MexXY multidrug efflux pump in moderate aminoglycoside resistance in Pseudomonas aeruginosa isolates from Pseudomonas mastitis.

Microbiology and Immunology — Fri, 01 Aug 2008 16:31:50 +0100

Authors: Chuanchuen R, Wannaprasat W, Ajariyakhajorn K, Schweizer HP The contribution of the MexXY multidrug efflux system to aminoglycoside resistance was investigated in 18 clinical isolates of Pseudomonas aeruginosa obtained from dairy cows with Pseudomonas mastitis. All of the isolates expressed MexXY as determined by reverse transcription-PCR. The loss of mexXY resulted in increased susceptibility (two- to 16-fold decline in MIC) to aminoglycosides, confirming the contribution of this system in aminoglycoside resistance in these strains. As the impact of DeltamexXY varied, overexpression of MexXY alone is not sufficient for aminoglycoside resistance. Expression of mexXY also varied and did not strictly correlate with aminoglycoside insusceptibility. Transcription levels of mexY we...

Nasal administration of Lactococcus lactis improves local and systemic immune responses against Streptococcus pneumoniae.

Microbiology and Immunology — Fri, 01 Aug 2008 16:31:50 +0100

Authors: Medina M, Villena J, Salva S, Vintiñi E, Langella P, Alvarez S Lactococcus lactis NZ9000 is a non-pathogenic non-invasive bacterium extensively used for the delivery of antigens and cytokines at the mucosal level. However, there are no reports concerning the per se immunomodulatory capacity of this strain. The aim of the present study was to investigate the intrinsic immunostimulating properties of the nasal administration of L. lactis NZ9000 in a pneumococcal infection model. Mice were preventively treated with L. lactis (2, 5 or 7 days with 10(8) cells/day per mouse) and then challenged with Streptococcus pneumoniae. The local and the systemic immune responses were evaluated. Our results showed that nasal administration of L. lactis for 5 days (LLN5d) increased the clea...

Cloning and molecular characterization of outer membrane protein A (ompA) gene from Mycobacterium bovis.

Microbiology and Immunology — Fri, 01 Aug 2008 16:31:50 +0100

Authors: Singh JP, Verma R The ompA gene, 981 bp in size and identified in the Mycobacterium bovis genome, was cloned and sequenced. Predicted amino acid sequences showed a protein of molecular weight 33.5 kDa with an isoelectric point of 7.28 and an OmpA conserved domain at the carboxy terminal with signal sequence at the N-terminal. Homology search showed complete homology with the Mycobacterium tuberculosis ompA gene with varying degree of homology with omp genes of other bacteria, so it was predicted that it may act like porin. The ompA gene of M. bovis was expressed in the pProEX HTb expression vector. Recombinant protein OmpA, was purified by using a nickel affinity column. The expressed recombinant OmpA (32 kDa) was confirmed by western blot with Ni-NTA horseradish peroxidase (H...

Characterization of rat beta-glucan receptor dectin-1.

Microbiology and Immunology — Fri, 01 Aug 2008 16:31:50 +0100

In this study, DNA/amino acid sequences of rat dectin-1 were analyzed by rapid amplification of cDNA ends. The sequence of rat dectin-1 was found to be highly homologous to that of the mouse. It possesses essential motifs for the recognition of beta-glucan and signal transduction. However, the position of the start codon in the detected sequence was not conserved, and its cytoplasmic tail was shorter than that observed in other species. Similar to mouse dectin-1, two major isoforms of rat dectin-1 that were generated by alternative splicing were identified: a full-length isoform and a shorter isoform deficient in the stalk domain. It was also demonstrated that rat dectin-1 is capable of binding fungal beta-glucan and activating nuclear factor-kappa B via Syk and the CARD9/Bcl10-mediated pa...

Incorporation of beta-amyloid protein through the bovine ileal epithelium before and after weaning: Model for orally transmitted amyloidoses.

Microbiology and Immunology — Fri, 01 Aug 2008 16:31:50 +0100

Authors: Ano Y, Nakayama H, Sakai Y, Sakudo A, Endo M, Ebisu S, Li J, Uetsuka K, Manabe N, Onodera T To determine the mechanism of bovine intestinal incorporation of the pathogen, and the pathogenesis of prion protein in the early stage, cows suckling and weaning were orally given a fusion protein of Abeta-EGFP. Abeta-EGFP was incorporated through the villous columnar epithelial cells and accumulated in crypt patches in the ileum of suckling cows. The sites of the uptake and accumulation of Abeta-EGFP are very close to the peripheral nervous system; however, such uptake of Abeta-EGFP was not observed in 6-month-old post-weaning cows. The present study, therefore, suggests that the weaning period is very important for the risk of transmission. PMID: 18667042 [PubMed - in process] (S...

Studies on diarrheagenic Escherichia coli isolated from children with diarrhea in Myanmar.