Diagnostic Microbiology and Infectious Disease via MedWorm.com

Erratum to “Resolution of persistent Pediococcus bacteremia with daptomycin treatment: case report and review of the literature” [Diagn Microbiol Infect Dis 66 (2010) 111–115]

Diagnostic Microbiology and Infectious Disease — Fri, 12 Mar 2010 16:32:53 +0100

The acknowledgement section was inadvertently omitted from the article. The author and Mary-Ellen Marx, Senior Manager, Medical Education at PharmaWrite and her colleagues sincerely regret the error. Acknowledgements should have read as follows: (Source: Diagnostic Microbiology and Infectious Disease)

The epidemiology of recurrent Gram-negative bacteremia in a tertiary-care hospital

Diagnostic Microbiology and Infectious Disease — Fri, 12 Mar 2010 16:32:53 +0100

We examined recurrent Gram-negative bacteremia in a prospective cohort from a tertiary hospital. Seventeen (7.1%) of 241 bacteremic patients developed recurrence (median time to recurrence = 44 days; range, 9–217 days). Recurrent and nonrecurrent bacteremic patients did not differ in clinical characteristics and mortality. (Source: Diagnostic Microbiology and Infectious Disease)

Vibrio parahaemolyticus-associated gastroenteritis in Italy: persistent occurrence of O3:K6 pandemic clone and emergence of O1:KUT serotype

Diagnostic Microbiology and Infectious Disease — Fri, 12 Mar 2010 16:32:53 +0100

We report 2 cases of O3:K6 and O1:KUT Vibrio parahaemolyticus gastroenteritis associated with consumption of local mussels in Italy in 2008. Serotypic, antibiogram, toxigenic, and pulsed-field gel electrophoresis patterns of these strains were compared to those of other isolates collected from local clinical and seafood samples in 2007 to 2008. We underline the recurrent presence of O3:K6 pandemic clone and the emergence of trh-positive O1:KUT serotype in Italy. (Source: Diagnostic Microbiology and Infectious Disease)

Demonstration and utility of clustered pseudohyphae on Gram-stained smears from Candida albicans-positive blood cultures

Diagnostic Microbiology and Infectious Disease — Fri, 12 Mar 2010 16:32:53 +0100

Abstract: The presence of clustered and branched pseudohyphae was investigated on Gram-stained smears of 78 consecutive yeast-positive blood cultures. The accuracy of the method was 96.1%, with a positive predictive value of 96.6% for Candida albicans. These findings demonstrate that the presence of clustered and branched pseudohyphae on Gram stain may be used for the rapid and presumptive identification of C. albicans from yeast-positive blood culture bottles. (Source: Diagnostic Microbiology and Infectious Disease)

Mechanisms of carbapenem resistance among a collection of Enterobacteriaceae clinical isolates in a Texas city

Diagnostic Microbiology and Infectious Disease — Fri, 12 Mar 2010 16:32:53 +0100

Abstract: Fourteen Enterobacteriaceae isolates with ertapenem MIC >2 mg/mL were analyzed to identify mechanisms of resistance. All isolates produced extended-spectrum β-lactamase or AmpC β-lactamase with variable, but decreased, expression of outer membrane proteins. One Enterobacter cloacae produced derepressed AmpC β-lactamase, 1 Escherichia coli expressed plasmid-mediated AmpC β-lactamase, and 1 E. cloacae produced a carbapenemase. (Source: Diagnostic Microbiology and Infectious Disease)

Efficacy of vancomycin and daptomycin against Staphylococcus aureus isolates collected over 29 years

Diagnostic Microbiology and Infectious Disease — Fri, 12 Mar 2010 16:32:52 +0100

Abstract: We investigated vancomycin and daptomycin efficacy for Staphylococcus aureus isolates at our institution by testing 221 methicillin-sensitive and 299 methicillin-resistant isolates recovered from serious infections between 1979 and 2007 using a microdilution method. The MIC90's for vancomycin remained constant at 2 μg/mL for methicillin-resistant S. aureus (MRSA) and methicillin-sensitive S. aureus (MSSA). For MSSA, the geometric mean vancomycin MICs remained at 1.1 μg/mL but varied from 1.1 to 1.7 for MRSA. Tolerance to vancomycin was seen in 6.5% of MRSA and 10.5% of MSSA. Daptomycin MIC90's remained at ≤1 μg/mL, and the daptomycin concentration at which 90% of the strains were killed (MBC90) remained at 2 μg/ml. Over 29 years, no trend was detected in vancomycin or dapto...

An enhanced method for the identification of Leishmania spp. using real-time polymerase chain reaction and sequence analysis of the 7SL RNA gene region

Diagnostic Microbiology and Infectious Disease — Fri, 12 Mar 2010 16:32:52 +0100

Abstract: The accurate identification of Leishmania spp. is important for the treatment of infected patients. Molecular methods offer an alternative to time-consuming traditional laboratory techniques for species determination. We redesigned a 7SL RNA gene-based polymerase chain reaction and sequence assay for increased species identification. DNA extracted from 17 reference strains and 10 cultured clinical isolates was examined. Sequence comparison was used successfully to identify organisms to the complex level with intercomplex similarity ranging from 77.5% to 98.4%. Many species within each complex were discriminated accurately by this method including Leishmania major, Leishmania tropica, Leishmania aethiopica, Leishmania guyanensis, and the previously indistinguishable Leishmania bra...

Plasmid-mediated quinolone resistance determinants qnr and aac(6′)-Ib-cr in Escherichia coli and Klebsiella spp. from Norway and Sweden

Diagnostic Microbiology and Infectious Disease — Fri, 12 Mar 2010 16:32:52 +0100

Abstract: The prevalence of the plasmid-mediated quinolone resistance genes qnr and aac(6′)-Ib-cr was investigated among clinical isolates of Escherichia coli and Klebsiella spp. selected from 2 collections of consecutive isolates collected in 2004 to 2005 in Norway (n = 2479) and Sweden (n = 2980) and 1 group of extended-spectrum β-lactamase (ESBL)-producing isolates collected in 2003 in Norway (n = 71). A total of 414 isolates was selected for screening based on resistance to nalidixic acid and/or reduced susceptibility/resistance to ciprofloxacin. The prevalence of both qnr and aac(6′)-Ib-cr was higher among the ESBL producers (9.1% and 52.3%, respectively) than in the consecutive isolates (1.1% and 3.2%, respectively). qnrS1 was detected in 6 isolates, whereas qnrB1 and qnrB7 were...

Molecular characterization of moxifloxacin resistance from Canadian Clostridium difficile clinical isolates

Diagnostic Microbiology and Infectious Disease — Fri, 12 Mar 2010 16:32:52 +0100

Abstract: Fluoroquinolone resistance in Clostridium difficile has been implicated in recent outbreaks of C. difficile infection. The purpose of this report was to characterize the molecular mechanism conferring resistance to moxifloxacin among C. difficile clinical isolates. Eighty-four C. difficile clinical isolates (collected as part of the Canadian Nosocomial Infection Surveillance Program) were evaluated in the current study. Pulsed-field gel electrophoresis was used to type the isolates. Susceptibility testing was performed using Clinical and Laboratory Standards Institute agar dilution methods. The quinolone resistance-determining region of both gyrA and gyrB was amplified using polymerase chain reaction and sequenced for each isolate. The proportion of isolates studied by the North ...

In vitro activity of tigecycline against patient isolates collected during phase 3 clinical trials for diabetic foot infections

Diagnostic Microbiology and Infectious Disease — Fri, 12 Mar 2010 16:32:52 +0100

Abstract: The in vitro activity of tigecycline and comparative antimicrobial agents was evaluated against 1828 primary baseline pathogens isolated from 844 patients enrolled in the phase 3 clinical trials investigating the efficacy of tigecycline in diabetic foot infection (DFI). The trials were global, enrolling patients in 30 countries. Tigecycline was active against the most prevalent pathogens in DFI, including Gram-positive and Gram-negative isolates of both aerobic and anaerobic bacteria with 95% of MICs ≤2 μg/mL for the entire collection. The spectrum of activity of tigecycline included important pathogens for DFI, such as Staphylococcus aureus, Enterococcus faecalis, Streptococcus agalactiae, Escherichia coli, Enterobacter cloacae, Klebsiella pneumoniae, and Bacteroides fragilis...

Identification of CTX-M β-lactamases in Escherichia coli from hospitalized patients and residents of long-term care facilities

Diagnostic Microbiology and Infectious Disease — Fri, 12 Mar 2010 16:32:52 +0100

Abstract: Bacteria harboring CTX-M extended-spectrum β-lactamases (ESBLs) have been identified worldwide, with most reports coming from regions outside North America. We have identified CTX-M enzymes in 31% of ESBL-positive Escherichia coli isolates from our hospital and more than half (53%) of the isolates from associated long-term care facilities. Approximately 3/4 of all CTX-M–bearing isolates were from urine specimens, with a predominance of CTX-M-15. A large proportion of such isolates were nonsusceptible to levofloxacin, trimethoprim/sulfamethoxazole, and all β-lactam antimicrobials with the exception of the carbapenems, requiring carbapenem therapy for acute urinary tract infection or urinary tract-related sepsis. CTX-M β-lactamases have emerged within our location, and detecti...

Chlamydia pneumoniae IgG and IgA antibody titers and prognosis in patients with coronary heart disease: results from the CLARICOR trial

Diagnostic Microbiology and Infectious Disease — Fri, 12 Mar 2010 16:32:52 +0100

Abstract: The association observed between coronary heart disease (CHD) and Chlamydia (Chlamydophila) pneumoniae antibodies prompted, during the 1990s, several primary and secondary prevention trials with various antibiotics. In our CLARICOR trial, a randomized placebo-controlled trial in 4372 patients with stable CHD, a brief clarithromycin regimen was followed, unexpectedly, by increased long-term mortality. We now compare C. pneumoniae antibody levels at entry with population levels, with the patients' individual histories, and with their subsequent outcomes. IgG antibody levels were somewhat raised, but elevated IgA and IgG titers were unrelated to entry data (including prior acute myocardial infarction), except for an association with smoking and with not using statins. Hazards of mor...

Screening for amino acid substitutions in the Candida albicans Erg11 protein of azole-susceptible and azole-resistant clinical isolates: new substitutions and a review of the literature

Diagnostic Microbiology and Infectious Disease — Fri, 12 Mar 2010 16:32:51 +0100

In this study, we investigated the antifungal susceptibility to fluconazole, itraconazole, and voriconazole of 73 clinical isolates of Candida albicans. Screening for amino acid substitutions in Erg11 was performed on each of the 73 isolates. Twenty isolates displayed a marked decrease in azole susceptibility. Amino acid substitutions were detected in more than two-thirds of the strains. In all, 23 distinct substitutions were identified. Four have not been described previously, among which N136Y and Y447H are suspected to be involved in azole resistance. We suggest that the high genetic polymorphism of ERG11 must be considered in the rationale design of new azole compounds targeting lanosterol 14α-demethylase. A review of all Erg11 amino acid polymorphisms described to date is given. (Sou...

kDNA minicircle signatures of Leishmania (Viannia) braziliensis in oral and nasal mucosa from mucosal leishmaniasis patients

Diagnostic Microbiology and Infectious Disease — Fri, 12 Mar 2010 16:32:51 +0100

Abstract: Polymerase chain reaction (PCR) and low-stringency single-specific primer PCR (LSSP-PCR) analyses were used to detect Leishmania (Viannia) braziliensis DNA and investigate kDNA signatures of parasite populations present in oral and nasal mucosa lesions from mucosal leishmaniasis patients. A total of 25 samples from 22 patients were processed by specific PCR/hybridization assays. Parasite DNA was detected in all samples analyzed. The intraspecific polymorphism of the variable region of L. (V.) braziliensis kDNA minicircles was also investigated by LSSP-PCR. Similar kDNA signatures were observed in parasites recovered from nasal and oral mucosa lesions of the same patient. In contrast, genetically divergent profiles were detected in lesions from patients biopsied at different times...

Acute HIV infection among pregnant women in Malawi

Diagnostic Microbiology and Infectious Disease — Fri, 12 Mar 2010 16:32:51 +0100

Abstract: There are limited data on acute HIV infection (AHI) prevalence during pregnancy. Malawian pregnant women admitted in the third trimester and meeting eligibility criteria underwent dual HIV rapid antibody testing. AHI prevalence was retrospectively detected through HIV RNA pooling of seronegative plasma. Among 3,825 pregnant women screened, dual HIV rapid testing indicated that 30.2% were HIV positive, 69.7% were HIV negative, and 0.1% were indeterminate. Sensitivity and specificity of dual rapid testing was 99.0% and 98.7%, respectively. Of 2,666 seronegative specimens, 2,327 had samples available for HIV RNA pooling; 5 women (0.21%) (95% confidence interval, 0.03–0.40%) had AHI with a median peripartum viral load of 1,324,766 copies/mL. Pregnant women are at risk for AHI, warr...

Triplex real-time polymerase chain reaction assay for simultaneous detection of Staphylococcus aureus and coagulase-negative staphylococci and determination of methicillin resistance directly from positive blood culture bottles

Diagnostic Microbiology and Infectious Disease — Fri, 12 Mar 2010 16:32:51 +0100

We describe here a 1-step, triplex real-time polymerase chain reaction (PCR) assay for the detection and identification of staphylococci directly from signal-positive blood culture bottles containing Gram-positive cocci in clusters (GPCC). The triplex assay targeted and detected tuf, nuc, and mecA genes in a single tube and had a detection limit of 105 CFU/mL for each gene target. A total of 341 GPCC-positive blood culture bottles were collected between November 12, 2008, and August 11, 2009. Among them, 230 methicillin-resistant coagulase-negative staphylococci (CoNS), 54 methicillin-susceptible CoNS, 22 methicillin-resistant Staphylococcus aureus, 22 methicillin-susceptible S. aureus, and 13 nonstaphylococci species were identified by conventional methods. The results obtained by triplex...

New cfiA variant and novel insertion sequence elements in carbapenem-resistant Bacteroides fragilis isolates from Korea

Diagnostic Microbiology and Infectious Disease — Fri, 12 Mar 2010 16:32:51 +0100

This study reconfirmed the correlation between ISs and carbapenem resistance in B. fragilis. (Source: Diagnostic Microbiology and Infectious Disease)

Erratum to “Selection of colistin-resistant Acinetobacter baumannii isolates in postneurosurgical meningitis in an intensive care unit with high presence of heteroresistance to colistin” [Diagn Microbiol Infect Dis 65 (2009) 188–191]

Diagnostic Microbiology and Infectious Disease — Tue, 16 Feb 2010 16:29:57 +0100

After publication of the abovementioned article, it was discovered that surnames and given names of authors were reversed. Names should be as follows: Carlos Hernan Rodriguez, Karina Bombicino, Gabriela Granados, Marcela Nastro, Carlos Vay, and Angela Famiglietti. (Source: Diagnostic Microbiology and Infectious Disease)

Epidemiology of pediatric community-acquired bloodstream infections in a children hospital in Paris, France, 2001 to 2008

Diagnostic Microbiology and Infectious Disease — Tue, 16 Feb 2010 16:29:57 +0100

Abstract: In 2001 to 2008, we documented 483 cases of pediatric community-acquired bacteremia mostly because of Streptococcus agalactiae (5 years). Pneumococcal conjugate vaccination affected the serotype distribution of pneumococcal bacteremia but not its frequency. Serotype 19A represented 12% and 22% of pneumococci in the prevaccine and vaccine periods, respectively. (Source: Diagnostic Microbiology and Infectious Disease)

Antimicrobial activity of daptomycin tested against Staphylococcus aureus with vancomycin MIC of 2 μg/mL isolated in the United States and European hospitals (2006–2008)

Diagnostic Microbiology and Infectious Disease — Tue, 16 Feb 2010 16:29:56 +0100

In conclusion, S. aureus strains with vancomycin MIC of 2 μg/mL showed high rates of hVISA and vancomycin tolerance. Daptomycin retained potent bactericidal activity against S. aureus with decreased susceptibility to vancomycin. (Source: Diagnostic Microbiology and Infectious Disease)

Spectrum of activity, mutation rates, synergistic interactions, and the effects of pH and serum proteins for fusidic acid (CEM-102)

Diagnostic Microbiology and Infectious Disease — Tue, 16 Feb 2010 16:29:55 +0100

In conclusion, these in vitro results for fusidic acid tested against contemporary strains confirm a persisting antimicrobial spectrum, especially against staphylococci and some other Gram-positive species. (Source: Diagnostic Microbiology and Infectious Disease)

Lichtheimia hongkongensis sp. nov., a novel Lichtheimia spp. associated with rhinocerebral, gastrointestinal, and cutaneous mucormycosis

Diagnostic Microbiology and Infectious Disease — Tue, 16 Feb 2010 16:29:55 +0100

Abstract: Three thermotolerant “Absidia-like” isolates with unique morphologic characteristics, recovered from nasopharyngeal swab of a liver transplant recipient, gastric biopsy of a renal transplant recipient, and skin biopsy of a man with burn, respectively, were characterized. Microscopic examination showed nonseptate hyphae with highly branched sporangiophores. Uniquely, most side branches were circinate, and abundant pleomorphic giant cells with fingerlike projections were observed, characteristics absent from other Absidia/Lichtheimia spp. ITS1-5.8S–ITS2 rRNA gene cluster, partial EF1α gene, and partial β-actin gene sequencing showed that the 3 strains formed a distinct cluster, most closely related to, but distinct from, Lichtheimia corymbifera, Lichtheimia blakesleeana, an...

Detection of Histoplasma capsulatum DNA in human samples by real-time polymerase chain reaction

Diagnostic Microbiology and Infectious Disease — Tue, 16 Feb 2010 16:29:55 +0100

Abstract: The main aim of our study was to determine the added value of real-time polymerase chain reaction (PCR) for the diagnosis of Histoplasma capsulatum in routine biologic practice. No amplification signal was observed with the 18 non-H. capsulatum strains used to test the specificity of the protocol. The sensitivity threshold of the real-time PCR assay was about 10 fg of H. capsulatum DNA per microliter, tested with a 10-fold serial dilution of the positive control. We analyzed 348 human samples submitted for the routine diagnosis of systemic mycosis. Real-time PCR using the TaqMan system was evaluated against direct microscopic examination and culture. Among the 341 samples without PCR inhibition (n = 7), 66 tested positive by culture, whereas 74 tested positive by real-time PCR. S...

Sequential changes of Legionella antigens and bacterial load in the lungs and urines of a mouse model of pneumonia

Diagnostic Microbiology and Infectious Disease — Tue, 16 Feb 2010 16:29:54 +0100

Abstract: Legionella pneumophila is an important cause of community- and hospital-acquired pneumonia. In spite of the introduction of the urinary antigen detection method, Legionella pneumonia may be still underdiagnosed. We performed kinetic and quantitative analysis of diagnostic markers, such as bacterial loads, DNA assays, and antigen titers, in a 28-day time course murine model of L. pneumophila pneumonia. L. pneumophila replicated approximately 100-fold in the lungs of A/J mice in the first 48 h, and then became undetectable on day 14. Unexpectedly, pathogens other than L. pneumophila were consistently recovered from the lungs and livers at the acute phases, although those numbers were far below Legionella loads in the lungs. The peaks of specific antigen titer were observed on 48 h...

Direct detection of Streptococcus pneumoniae in positive blood cultures by real-time polymerase chain reaction

Diagnostic Microbiology and Infectious Disease — Thu, 14 Jan 2010 16:33:18 +0100

Abstract: We developed a real-time polymerase chain reaction specific for Streptococcus pneumoniae to be applied directly from blood culture bottles without previous DNA extraction step. For the 128 blood culture bottles tested, the assay had 94% and 98.4% sensitivity and specificity, respectively. This assay provides rapid and accurate identification of this pathogen. (Source: Diagnostic Microbiology and Infectious Disease)

Reevaluation of the Premier Clostridium difficile toxin A and B immunoassay with comparison to glutamate dehydrogenase common antigen testing evaluating Bartels cytotoxin and Prodesse ProGastro™ Cd polymerase chain reaction as confirmatory procedures

Diagnostic Microbiology and Infectious Disease — Thu, 14 Jan 2010 16:33:16 +0100

Abstract: Enzyme immunoassays are currently the most common tests used in the clinical laboratory for the detection of Clostridium difficile toxins; however, significant problems with their performance have recently been described. We prospectively reevaluated the Meridian Premier C. difficile toxin A/B assay with direct comparison to a 2-step algorithm that screened for C. difficile common antigen and compared cytotoxin and real-time polymerase chain reaction (PCR) as confirmatory procedures. The Premier assay lacked sufficient sensitivity, missing 25% of true-positive samples. PCR was the most sensitive method and the only procedure that allowed same day testing and reporting. (Source: Diagnostic Microbiology and Infectious Disease)

Comparison of the clinical and microbiologic characteristics of patients with Enterobacter cloacae and Enterobacter aerogenes bacteremia: a prospective observation study

Diagnostic Microbiology and Infectious Disease — Wed, 13 Jan 2010 00:00:00 +0100

Abstract: We compared the characteristics and outcomes of 172 Enterobacter cloacae bacteremia and 67 Enterobacter aerogenes bacteremia (EAB) cases. Antimicrobial resistance rates to E. cloacae were higher than those to E. aerogenes. However, EAB more frequently presented as septic shock and was associated with poorer outcomes. (Source: Diagnostic Microbiology and Infectious Disease)

QuantiFERON®-TB Gold In-Tube as help for the diagnosis of tuberculosis in a French pediatric hospital

Diagnostic Microbiology and Infectious Disease — Wed, 13 Jan 2010 00:00:00 +0100

In conclusion, despite its objectivity and its higher specificity (especially in Bacille Calmette–Guérin vaccinated children), the real place of QFT-G IT in TB diagnosis in children remains difficult to define. (Source: Diagnostic Microbiology and Infectious Disease)

Fibrin ring granulomas in Rickettsia typhi infection

Diagnostic Microbiology and Infectious Disease — Wed, 13 Jan 2010 00:00:00 +0100

We describe a 71-year-old man hospitalized for fever and productive cough. Laboratory investigation showed anemia, thrombocytopenia, elevated transaminases, hyponatremia, and hypoalbuminemia. Computerized tomography of the abdomen, thorax, and sinuses, echocardiography, and a gallium scan did not reveal the source of the fever. The patient remained febrile despite courses of piperacillin–tazobactam/azithromycin and ceftriaxone/vancomycin. A bone marrow biopsy showed fibrin ring granulomas, and 2 rickettsial serologic panels were positive for Rickettsia typhi infection and negative for Q fever. The patient was given doxycycline, and the fever resolved within 48 h. We propose that fibrin ring granulomas also occur in murine typhus. (Source: Diagnostic Microbiology and Infectious Disease)

CEM-101, a novel fluoroketolide: antimicrobial activity against a diverse collection of Gram-positive and Gram-negative bacteria

Diagnostic Microbiology and Infectious Disease — Fri, 18 Dec 2009 00:00:00 +0100

In this study, CEM-101 and comparator antimicrobials were tested against a collection of very low prevalence aerobic and anaerobic bacteria collected via the SENTRY Antimicrobial Surveillance Program platform. CEM-101 was highly active against all Gram-positive organisms (MIC50, 0.015 μg/mL) as compared with telithromycin (MIC50, 0.06 μg/mL), clarithromycin (MIC50, 0.12 μg/mL), and erythromycin (MIC50, 0.25 μg/mL). Among Gram-negative pathogens, CEM-101 also displayed a high potency against most strains (MIC50, 4 μg/mL) but was found to be equivalent or less active when compared with other antimicrobials tested with MIC50 values ranging from ≤0.12 μg/mL for levofloxacin to 8 μg/mL for telithromycin. Among the strict anaerobic species, CEM-101 activity mirrored that of the aerobic ...

Susceptibility to tigecycline of isolates from samples collected in hospitalized patients with secondary peritonitis undergoing surgery

Diagnostic Microbiology and Infectious Disease — Fri, 18 Dec 2009 00:00:00 +0100

Abstract: Activity of tigecycline against nosocomial secondary peritonitis isolates collected along 18 months in 29 Spanish hospitals was tested by Etest in a central laboratory, considering Food and Drug Administration (FDA)/British Society for Antimicrobial Chemotherapy (BSAC)/European Committee on Antimicrobial Susceptibility Testing (EUCAST) breakpoints. A total of 600 facultative/aerobic isolates (392 Gram negative, 208 Gram positive) and 100 anaerobes were tested. None of the 220 Escherichia coli isolates was resistant to tigecycline (MIC50/MIC90 = 0.25/0.5 μg/mL), with 0.5% (FDA breakpoint) and 3.6% (BSAC/EUCAST breakpoint) intermediate strains. All Extended-spectrum beta-lactamase (ESBL)-producing E. coli isolates (15 strains), all Klebsiella pneumoniae, and Klebsiella oxytoca iso...

Infections after the use of alemtuzumab in solid organ transplant recipients: a comparative study

Diagnostic Microbiology and Infectious Disease — Mon, 07 Dec 2009 16:10:48 +0100

Abstract: We undertook a retrospective cohort study comparing infection in solid organ transplant recipients receiving alemtuzumab (n = 726) versus basiliximab (n = 215) or antithymocyte globulin (ATG) (n = 85). Eighty-one percent of patients had kidney transplants. Overall, 33% of patients in the alemtuzumab group (240/724) developed infection compared with 40% (87/215) in the basiliximab group (odds ratio [OR], 0.72; 95% confidence interval [CI], 0.53–0.99; P = .04). The frequency of infection was similar in the alemtuzumab and ATG groups (33% versus 36%, respectively, P = .53). The frequency of fungal infections, most caused by Candida spp., was similar in the alemtuzumab and basiliximab groups (10% versus 9%); disseminated fungal infection occurred in 68% of the patients with fungal ...

Extent of Interlaboratory discrepancies for polyclonal Histoplasma antigen Enzyme imunoassay (EIA) cannot be determined without a large split-sample study (reply)

Diagnostic Microbiology and Infectious Disease — Fri, 27 Nov 2009 00:00:00 +0100

We appreciate the clarification by regarding their Associated Regional and University Pathologists (ARUP) Histoplasma antigen assay that utilizes reagents provided by Immuno-Mycologics, Inc., Norman, OK. However, we differ with a number of opinions expressed in their letter. (Source: Diagnostic Microbiology and Infectious Disease)

Antimicrobial susceptibility of multidrug-resistant Streptococcus pneumoniae strains with penicillin MICs of 8 to 32 mg/L

Diagnostic Microbiology and Infectious Disease — Fri, 27 Nov 2009 00:00:00 +0100

Abstract: The in vitro activity of 22 antibiotics (including novobiocin) and β-lactam/gentamicin combinations was assessed against 11 multidrug-resistant pneumococcal strains. Among orally administered drugs, only telithromycin, levofloxacin, and linezolid were active against all isolates, but their use is not indicated in pediatrics. Novobiocin could be a potential therapeutic alternative. (Source: Diagnostic Microbiology and Infectious Disease)

Determination of capsulation status in Haemophilus influenzae by multiplex polymerase chain reaction

Diagnostic Microbiology and Infectious Disease — Mon, 23 Nov 2009 00:00:00 +0100

Abstract: Since the introduction of Haemophilus influenzae type b conjugate vaccines, there have been concerns regarding the emergence of invasive non–type b strains. Serotyping of H. influenzae with commercially available reagents is subjective. Definitive characterization of the capsulation status can be performed by polymerase chain reaction (PCR) amplification of capsular genes. However, PCR amplification of the conserved export locus in the 2 known phylogenic lines of type b strains and detection of serotype conferring genes in each of the 6 serotypes require multiple assays. To rapidly screen multiple isolates, we devised a multiplex method using 15 primers, which produced a serotype-specific, distinct pattern of amplicons with reference-encapsulated H. influenzae. We applied this ...

Erratum to “Phenotypic and genotypic characterization of drug-resistant Mycobacterium tuberculosis strains” [Diagn Microbiol Infect Dis 62 (2008) 199–204]

Diagnostic Microbiology and Infectious Disease — Fri, 13 Nov 2009 16:17:00 +0100

After publication of the above mentioned article, a revised was provided and is included below. Furthermore, on page 203 under Section 4.3 Pyrazinamide, the sentence reading “Our study observed that around 60% of PZA-resistant strains had pncA gene mutations from positions 136 to 188, and although pncA is a small gene, mutations in various positions of its structure have been found (Zhang and Mitchinson, 2003).”, should read, “Our study observed that around 60% of PZA-resistant strains had pncA gene mutations from positions 99 to 175, and although pncA is a small gene, mutations in various positions of its structure have been found (Zhang and Mitchinson, 2003).” (Source: Diagnostic Microbiology and Infectious Disease)

Zyvox® Annual Appraisal of Potency and Spectrum program: linezolid surveillance program results for 2008

Diagnostic Microbiology and Infectious Disease — Fri, 13 Nov 2009 16:16:59 +0100

In conclusion, the activity of linezolid remained uniform and stable across the sampled geographic regions studied when compared to the 2006 to 2007 results. Documented LZD-R remains rare (only 0.13% overall but highest for CoNS [0.41%] and enterococci [0.69%]) among the 24 countries sampled for the 6 different pathogen groups. Rates of clindamycin resistance and the frequency of MRSA varied by geographic region and between nations; therefore, like oxazolidinones, it requires continued surveillance for changing resistance patterns. (Source: Diagnostic Microbiology and Infectious Disease)

Linezolid surveillance program results for 2008 (LEADER Program for 2008)

Diagnostic Microbiology and Infectious Disease — Fri, 13 Nov 2009 16:16:59 +0100

In conclusion, linezolid activity sampled by the 5th year of this LEADER Program showed sustained potency and spectrum (99.64% susceptibility levels). The nonsusceptible strain isolation rates remained stable and the plasmid-mediated ribosomal-based resistance mechanism that emerged in Staphylococcus aureus and Staphylococcus epidermidis strains in 2007 showed no evidence of dissemination or increased prevalence. However, there was evidence of cfr persistence with the S. epidermidis strain. The LEADER Program continues to be an effective and sensitive surveillance tool to detect and monitor novel oxazolidinone resistance phenotypes and genotypes. (Source: Diagnostic Microbiology and Infectious Disease)

Plasmid-mediated carbapenem-hydrolyzing enzyme KPC-2 and ArmA 16S rRNA methylase conferring high-level aminoglycoside resistance in carbapenem-resistant Enterobacter cloacae in China

Diagnostic Microbiology and Infectious Disease — Wed, 11 Nov 2009 00:00:00 +0100

Abstract: The emergence and spread of carbapenem-resistant Enterobacteriaceae in the world are a major concern. We investigated 5 isolates of Enterobacter cloacae that were resistant to all clinically available antimicrobial agents, except polymyxin B. The MICs of imipenem and aminoglycosides were >32 and >256 mg/L, respectively. All of the isolates produced 5 extended-spectrum beta-lactamase (ESBLs) with pIs of 5.4 (TEM-1), 6.7 (KPC-2), 8.2 (SHV-12), 8.4 (CTX-M-14), and ArmA 16S rRNA methylase. blaKPC-2 was located on a large nonconjugative plasmid, whereas armA was located on another conjugative plasmid. Although carbapenem-resistant Enterobacteriaceae remains rare, the emergence of this group of organism merits monitoring. (Source: Diagnostic Microbiology and Infectious Disease)

Trends in antibiotic susceptibility of bloodstream pathogens in hospitalized patients in France, 1996 to 2007

Diagnostic Microbiology and Infectious Disease — Wed, 11 Nov 2009 00:00:00 +0100

We report the results of a French national prospective survey based on the College of Bacteriology–Virology and Hygiene study group network performed each October during the 1996 to 2007 period, with focus on Enterobacteriaceae (7708 isolates) and Staphylococcus aureus (2271 isolates). The most relevant antimicrobial susceptibilities trends were i) a decrease in fluoroquinolones susceptibility among Enterobacteriaceae (96–90%, P < 0.0001) and Escherichia coli isolates (98–89%, P < 0.0001), respectively, ii) the slight but significant decrease in cefotaxime susceptibility among E. coli (P = 0.016), and iii) the significant increase in gentamicin susceptibility among S. aureus strains (P = 0.016). This survey reports antibiotic susceptibility of bloodstream pathogens in France. The emp...

Surface gene mutations of hepatitis B virus among high-risk patients with occult hepatitis B virus infection

Diagnostic Microbiology and Infectious Disease — Wed, 11 Nov 2009 00:00:00 +0100

Abstract: Surface gene mutants of hepatitis B virus (HBV) have been reported in a variety of patient groups. Because of limited data regarding these mutations in patients with occult HBV infections; we aimed to determine these mutations among high-risk patients with occult HBV infection. The presence of HBV-DNA was determined in patients with isolated anti-HBc by real-time polymerase chain reaction (PCR). Then, surface gene region was amplified by nested PCR and mutations were analyzed after sequencing. The mutations that resulted in nonfunctional hepatitis B surface antigen (HBsAg) were insertion of single nucleotide in 2 cases, which causes frameshift and single-nucleotide replacement, and premature stop codons at Leu15 and Gly10 in the other 2 cases. Amino acid substitution at amino aci...

Evaluation of a real-time polymerase chain reaction assay for the laboratory diagnosis of giardiasis

Diagnostic Microbiology and Infectious Disease — Wed, 11 Nov 2009 00:00:00 +0100

Abstract: A real-time polymerase chain reaction (PCR) assay was evaluated in comparison with the combination of conventional methods (microscopic examination and antigen detection assay) during the period 2006 to 2008 on 771 fecal samples belonging to 386 patients to assess its usefulness for an accurate laboratory diagnosis of giardiasis. The real-time PCR assay detected Giardia intestinalis DNA in 195 samples (106 patients), including 26 samples (21 patients) negative by the conventional assays. Among the 21 patients, in 8 cases, giardiasis was previously diagnosed also by conventional methods in additional samples of the same patients, whereas in 13, it would have been undiagnosed if real-time PCR assay was not used. The real-time PCR assay demonstrated a detection limit of 2 cysts per ...

Rapid detection and differentiation of the exfoliative toxin A-producing Staphylococcus aureus strains based on ϕETA prophage polymorphisms

Diagnostic Microbiology and Infectious Disease — Wed, 11 Nov 2009 00:00:00 +0100

Abstract: The exfoliative toxin A (ETA) is encoded by the gene located on Staphylococcus aureus prophages. We have developed a single-reaction multiplex polymerase chain reaction (PCR) assay for rapid and specific detection of various ϕETA prophages of serogroup B responsible for dissemination of eta gene and ETA production in clinical strains. This PCR strategy enabled to classify the ETA-positive strains into 6 groups designated ETA-B1, ETA-B2, ETA-B3, ETA-B4, ETA-B5, and ETA-B6. The method was tested on a diverse set of 101 ETA and/or ETB-positive S. aureus strains isolated in 22 Czech maternity hospitals and 1 Slovak maternity hospital between 1998 and 2009. This novel PCR strategy is reliable in the rapid identification of yet undescribed ETA-converting B prophages and differentiatio...

The epidemiology of travelers' diarrhea in Incirlik, Turkey: a region with a predominance of heat-stabile toxin producing enterotoxigenic Escherichia coli

Diagnostic Microbiology and Infectious Disease — Wed, 11 Nov 2009 00:00:00 +0100

This study evaluated travelers' diarrhea among US military personnel on short-term deployment to Incirlik Air Base, Turkey, from June through September 2002. Upon reporting for care for travelers' diarrhea, subjects were enrolled into the study and completed a series of questionnaires and provided stool specimens for pathogen identification and antimicrobial susceptibility testing. Fifty-three percent of the 202 participating subjects had a pathogen isolated from their stool. Enterotoxigenic Escherichia coli (ETEC) was the predominant pathogen (41%), followed by Campylobacter spp. (12%). The most common ETEC phenotype recovered was stable toxin (ST) CS6 (47% of all ETEC). Most (91.1%) of the cases presented with water diarrhea regardless of isolated pathogen. However, there were some diffe...

Rapid identification of tuberculosis epididymo-orchitis by INNO-LiPA Rif TB and QuantiFERON-TB Gold In Tube tests: case report

Diagnostic Microbiology and Infectious Disease — Mon, 09 Nov 2009 00:00:00 +0100

Abstract: Diagnosis of extrapulmonary tuberculosis (TB) is often missed or delayed because of nonspecific clinical and laboratory findings. Novel detection methods, such as polymerase chain reaction and QuantiFERON®-TB Gold In Tube, can aid in the diagnosis of active extrapulmonary TB. Here, we demonstrate a case of epididymo-orchitis as the sole presentation of TB in a 32-year-old man. (Source: Diagnostic Microbiology and Infectious Disease)

Extent of interlaboratory discrepancies for polyclonal Histoplasma antigen enzyme immunoassay cannot be determined without a large split-sample study

Diagnostic Microbiology and Infectious Disease — Mon, 09 Nov 2009 00:00:00 +0100

We read with interest the article by and we would like the opportunity to comment. It is necessary to clarify that Immuno-Mycologics, Inc. (IMMY, Norman, OK) does not perform laboratory testing, as implied in the article. IMMY produces standardized reagents for purchase by clinical laboratories that perform testing. ARUP Laboratories, Salt Lake City, UT, purchases reagents from IMMY and, after validating the performance of the reagents in the ARUP reagent laboratory, performs Histoplasma antigen testing at ARUP Laboratories. The key reagent in both the ARUP assay and the test developed by MiraVista Diagnostics (Indianapolis, IN) is a polyclonal antibody generated from rabbits immunized with Histoplasma antigens (). Polyclonal antibodies have the limitation of not detecting a specific antig...

Molecular identification of phaeohyphomycosis due to Alternaria infectoria in a patient with acute myeloid leukemia—a case report

Diagnostic Microbiology and Infectious Disease — Fri, 06 Nov 2009 00:00:00 +0100

We report the case of a 15-year old with acute myeloid leukemia who developed breakthrough invasive fungal rhinitis. The fungus was identified as Alternaria infectoria by polymerase chain reaction (PCR) and successfully treated by surgical excision and combination antifungal therapy, emphasizing the utility of fungal PCR in timely diagnosis of invasive fungal infections. (Source: Diagnostic Microbiology and Infectious Disease)

Development of a microarray for identification of pathogenic Clostridium spp.

Diagnostic Microbiology and Infectious Disease — Mon, 02 Nov 2009 00:00:00 +0100

In this study, we developed an oligonucleotide diagnostic microarray for pathogenic Clostridium spp. The microarray specificity was tested against 65 Clostridium isolates. The applicability of this microarray in a clinical setting was assessed with the use of mock stool samples. The microarray was successful in discriminating at least 4 species with the limit of detection as low as 104 CFU/mL. In addition, the pattern of virulence and antibiotic resistance genes of tested strains were determined through the microarrays. This approach demonstrates the high-throughput detection and identification of Clostridium spp. and provides advantages over traditional methods. Microarray-based techniques are promising applications for clinical diagnosis and epidemiologic investigations. (Source: Diagnos...

Evaluation of rapid diagnostic tests for malaria case management in Gabon

Diagnostic Microbiology and Infectious Disease — Wed, 21 Oct 2009 00:00:00 +0100

Abstract: A laboratory-confirmed diagnosis is the basis of malaria case management. Rapid diagnostic tests (RDTs) create new opportunities for improved care in endemic areas. Diagnostic performance of OptiMAL-IT® and Acon® was assessed in comparison with microscopy at 2 sites in Gabon. Between February 2008 and January 2009, 2125 febrile children under 11 years old were diagnosed using microscopy and RDTs. Plasmodial infection was detected more frequently using Acon® (27%) and OptiMAL-IT® (27%) compared to microscopy (20%) (P < 0.01). Among the samples diagnosed positive by OptiMAL-IT®, 78% were infected by Plasmodium falciparum, whereas 99% of positive blood smears were P. falciparum infections, 0.5% Plasmodium malariae, and 0.5% Plasmodium ovale. Both RDTs had similar sensitivity (S...

Evaluation of direct method of drug susceptibility testing of Mycobacterium tuberculosis to rifampicin and isoniazid by nitrate reductase assay in a national reference laboratory

Diagnostic Microbiology and Infectious Disease — Mon, 19 Oct 2009 00:00:00 +0100

Abstract: The aim of this study was to evaluate a simple, rapid, and inexpensive colorimetric nitrate reductase assay (NRA) for direct drug susceptibility testing (DST) of Mycobacterium tuberculosis against rifampicin (RIF) and isoniazid (INH). A total of 118 smear-positive specimens were processed from patients on antituberculosis treatment. A comparison was made between the direct NRA of DST with the direct proportion method and with the internationally accepted indirect 1% proportion method as the “gold standard”. The sensitivity and specificity of the direct NRA and indirect proportion method were 94% and 98%, and 100% and 98% for RIF and INH, respectively. Excellent agreement was found between the 2 tests with κ values of 0.92 and 0.98, and P value was less than 0.001 for RIF and...

A novel OXA-10–like β-lactamase is present in different Enterobacteriaceae

Diagnostic Microbiology and Infectious Disease — Fri, 16 Oct 2009 00:00:00 +0100

Abstract: OXA 101, a novel OXA-10 like enzyme, was found forming part of a class 1 integron located in a conjugative plasmid in three different species of Enterobacteriaceae. This β-lactamase is related to OXA-35 and OXA-56 and displays a narrow substrate hydrolysis profile. (Source: Diagnostic Microbiology and Infectious Disease)

Lack of galactomannan reactivity in dematiaceous molds recovered from cancer patients with phaeohyphomycosis

Diagnostic Microbiology and Infectious Disease — Fri, 16 Oct 2009 00:00:00 +0100

Abstract: We determined the in vitro galactomannan reactivity of isolates recovered from 17 patients with invasive phaeohyphomycosis, 4 of whom had positive galactomannan antigenemia. All isolates were nonreactive using the galactomannan immunoassay. Galactomannan antigenemia in patients with phaeohyphomycosis should raise the possibility of concomitant invasive aspergillosis. (Source: Diagnostic Microbiology and Infectious Disease)

Distribution of blaOXA-carrying imipenem-resistant Acinetobacter spp. in 3 hospitals in Taiwan

Diagnostic Microbiology and Infectious Disease — Fri, 16 Oct 2009 00:00:00 +0100

Abstract: We investigated the molecular epidemiology and OXA-type carbapenemase genes of 83 imipenem-resistant Acinetobacter spp. collected from 2 university hospitals (hospitals A and B) and a regional hospital (hospital C) during 2007 in Taiwan. Genotyping by pulsed-field gel electrophoresis identified 51 pulsotypes. None of the pulsotypes established predominance throughout the 3 hospitals. Multiplex polymerase chain reaction of blaOXA genes showed that 100% (18/18), 91%(31/34), and 100% (31/31) of the Acinetobacter spp. collected from hospital A, B, and C, respectively, possessed blaOXA-51–like genes. None of the strains carrying blaOXA-23–like and blaOXA-24–like genes were found in hospital A. The coexistences of blaOXA-51–like/blaOXA-23–like and blaOXA-51–like/blaOXA-24�...

In vitro activity of tigecycline against 2423 clinical isolates and comparison of the available interpretation breakpoints

Diagnostic Microbiology and Infectious Disease — Fri, 16 Oct 2009 00:00:00 +0100

In conclusion, tigecycline exhibited potent activity against pathogens recently isolated in a region that experiences high antimicrobial resistance rates. Indications that the available criteria might categorize differently tigecycline susceptibility status in K. pneumoniae and Enterobacter spp. isolates were also detected. (Source: Diagnostic Microbiology and Infectious Disease)

Utility of a combination of RD1 and RD2 antigens as a diagnostic marker for tuberculosis

Diagnostic Microbiology and Infectious Disease — Fri, 16 Oct 2009 00:00:00 +0100

Abstract: We evaluated the diagnostic potential of a cocktail of 4 antigens encoded by regions of difference (RD) 1 and 2 of Mycobacterium tuberculosis, that is, early secretory antigenic target-6, culture filtrate protein-10 (CFP-10), CFP-21, and mycobacterial protein from species tuberculosis-64 (MPT-64) on the basis of antigen and antibody detection by enzyme-linked immunosorbent assay. Parallel detection of antigens and antibodies in the serum samples of pulmonary tuberculosis (PTB) patients resulted in higher sensitivity as compared to either of the single tests in both smear-positive (90%) and smear-negative (60%) PTB patients. In addition, combined detection of antigens and antibodies in the fluids of extrapulmonary tuberculosis (EPTB) patients could detect >90% of the patients with...

Summary trends for the Meropenem Yearly Susceptibility Test Information Collection Program: a 10-year experience in the United States (1999–2008)

Diagnostic Microbiology and Infectious Disease — Fri, 16 Oct 2009 00:00:00 +0100

Abstract: The Meropenem Yearly Susceptibility Test Information Collection (MYSTIC) Program was a global, longitudinal antimicrobial resistance surveillance network of more than 100 medical centers worldwide monitoring the susceptibility of meropenem and selected other broad-spectrum comparator agents. In 1999, and from 2000 through 2008, a total of 10 or 15 United States (USA) medical centers each forwarded 200 nonduplicate clinical isolates from serious infections to a central processing laboratory. Over the 10-year period of this surveillance program, the activity of meropenem and an average of 11 other antimicrobial agents were assessed against a total of 27 289 bacterial isolates using Clinical and Laboratory Standards Institute reference methods. Meropenem consistently demonstrated ...

Genotypes, superantigen gene profiles, and presence of exfoliative toxin genes in clinical methicillin-susceptible Staphylococcus aureus isolates

Diagnostic Microbiology and Infectious Disease — Thu, 15 Oct 2009 00:00:00 +0100

Abstract: We compared genotype and virulence gene profiles for strains from carriers with autologous invasive infection (n = 56), nasal isolates from matched carriers (n = 108), and invasive strains from noncarriers (n = 34). Superantigen gene profiles and presence of exfoliative toxin genes A and D were associated with clonal complex rather than with invasive disease. (Source: Diagnostic Microbiology and Infectious Disease)

Occurrence and genotyping using automated repetitive-sequence–based PCR of methicillin-resistant Staphylococcus aureus ST398 in Southeast Austria

Diagnostic Microbiology and Infectious Disease — Thu, 15 Oct 2009 00:00:00 +0100

In conclusion, MRSA ST398 was continuously detected in Southeast Austria; first in 2004 with up to 5 MRSA ST398 isolates in 2008. Automated rep-PCR proved as a reliable technique in determining genetic relatedness of NT-MRSA ST398 and demonstrates clonal spread of MRSA ST398 in the investigated region. (Source: Diagnostic Microbiology and Infectious Disease)

Effect of oxygen limitation on the in vitro activity of levofloxacin and other antibiotics administered by the aerosol route against Pseudomonas aeruginosa from cystic fibrosis patients

Diagnostic Microbiology and Infectious Disease — Thu, 15 Oct 2009 00:00:00 +0100

Abstract: Studies have demonstrated that thickened mucous layers in the lungs of cystic fibrosis (CF) patients contain areas of low oxygen tension. These microaerophilic environments may reduce the activity of aerosol antibiotics used in the management of chronic infection in CF. The aim of this study was to compare the MICs of levofloxacin, tobramycin, amikacin, and aztreonam against Pseudomonas aeruginosa under reference and anaerobic conditions and evaluate the in vitro pharmacodynamics of levofloxacin under aerobic and hypoxic testing conditions. The MICs for 114 isolates of P. aeruginosa from CF patients were determined in cation-adjusted Mueller Hinton broth alone or supplemented with 1% potassium nitrate for anaerobic testing. Levofloxacin time–kill curves were performed under aer...

Erratum to “A simple and rapid nested polymerase chain reaction-restriction fragment length polymorphism technique for differentiation of pathogenic and nonpathogenic Leptospira spp.” [Diagn Microbiol Infect Dis 63 (2009) 251–256]

Diagnostic Microbiology and Infectious Disease — Mon, 12 Oct 2009 15:00:16 +0100

Following publication of the above mentioned article, a revised image was provided by the author. The revised figure is included below. (Source: Diagnostic Microbiology and Infectious Disease)

Antipseudomonal activity of piperacillin/tazobactam: more than a decade of experience from the SENTRY Antimicrobial Surveillance Program (1997–2007)

Diagnostic Microbiology and Infectious Disease — Mon, 12 Oct 2009 15:00:15 +0100

In conclusion, piperacillin/tazobactam remained a very active β-lactam when tested in vitro against clinical isolates of P. aeruginosa found in the SENTRY Program (1997–2007). Trends toward slightly decreased susceptibility were noted in all regions over the last decade (except LA); only polymyxins had susceptibility rates at >90%. Resistance surveillance programs should be sustained to document emerging resistance patterns of old and newer agents for difficult-to-treat pathogens such as P. aeruginosa. (Source: Diagnostic Microbiology and Infectious Disease)

Development and evaluation of a multiplex polymerase chain reaction assay to identify Salmonella serogroups and serotypes

Diagnostic Microbiology and Infectious Disease — Mon, 12 Oct 2009 15:00:15 +0100

Abstract: To improve limitations of Salmonella serotyping, 2 multiplex polymerase chain reaction (M-PCR) were developed using a strategy that identifies first the genes encoding serogroups (rfbJ, wzx). According to the serogroup determined, a second M-PCR identifies serotype (fliC, fljB, wcdB, and sdf-I sequence). Standardization and evaluation of both M-PCRs were carried out. (Source: Diagnostic Microbiology and Infectious Disease)

Expanded studies of piperacillin/tazobactam formulations: variations among branded product lots and assessment of 46 generic lots

Diagnostic Microbiology and Infectious Disease — Mon, 12 Oct 2009 15:00:15 +0100

Abstract: The experience with analyzing the potency of piperacillin/tazobactam generic formulations by a precise multiorganism in vitro assay was expanded to 46 lots (29 manufacturers, 17 countries). Across all generic lots, the range of activity compared with a reference branded lot (RLOT; Zosyn®; Wyeth Pharmaceuticals, Philadelphia, PA) was +10% to −42% (average, −16%). Eight lots of Zosyn® were also tested with a range of +7 to −19 (average, only −6%), and the reproducibility (13 replicates) of the RLOT assay was confirmed (±3%). This ongoing quality assurance project demonstrated wide activity variations in piperacillin/tazobactam generic lots with a consistent trend toward subpotent performance (−16%) compared with the branded product. Generic substitutions within hospita...

Comparative evaluation of the ARCHITECT Toxo IgG, IgM, and IgG Avidity assays for anti-Toxoplasma antibodies detection in pregnant women sera

Diagnostic Microbiology and Infectious Disease — Mon, 12 Oct 2009 15:00:14 +0100

Abstract: We assessed the performance of the ARCHITECT Toxo IgG, IgM, and IgG Avidity assays against corresponding assays on AxSYM and Vidas using 730 sera from pregnant women. The ARCHITECT Toxo IgG and IgM assays showed a relative sensitivity of 97.5% and 89.9% and a relative specificity of 99.1% and 99.8%, respectively. If IgM sensitivity is calculated only for sera drawn less than 4 months after infection, the relative sensitivity rises to 98.1%. Correlation between the ARCHITECT and Vidas Avidity assays was 0.87 (n = 103). Testing 86 IgG-positive specimens from recent infection (4 months) exhibited high avidity results in 72.5% (137/189) of cases. The method can be used reliably to exclude recent infections in sera with concurrently positive results for IgM and IgG (IgG, >3 IU/mL). (S...

Quantitative evaluation of T-cell response after specific antigen stimulation in active and latent tuberculosis infection in adults and children

Diagnostic Microbiology and Infectious Disease — Mon, 12 Oct 2009 15:00:13 +0100

Abstract: We have evaluated the quantitative T-cell response after specific Mycobacterium tuberculosis antigen stimulation in active tuberculosis (TB) and latent TB infection (LTBI) patients. In adults, the median number of T cells after RD1 antigen stimulation was significantly higher in active TB patients than in LTBI patients. In children, the number of responder T cells against the specific antigens was higher in active TB than in LTBI patients, although the differences were not significant. In summary, in patients with suspected clinical TB, although there is overlapping in the number of responder T cells between both groups, a T-cell count above the described threshold could suggest active TB, especially in patients with a high probability of having active TB and low probability of h...

Rapid identification of Propionibacterium acnes from blood cultures by fluorescence in situ hybridization

Diagnostic Microbiology and Infectious Disease — Thu, 08 Oct 2009 00:00:00 +0100

Abstract: A newly designed probe for rapid identification of Propionibacterium acnes by fluorescence in situ hybridization was evaluated using 111 isolates from subculture and showed 100% sensitivity and specificity. A sensitivity of 95% and a specificity of 100% were achieved with direct application on 55 blood cultures containing Gram-positive rods. (Source: Diagnostic Microbiology and Infectious Disease)

A rapid, simple, and sensitive loop-mediated isothermal amplification method to detect toxigenic Vibrio cholerae in rectal swab samples

Diagnostic Microbiology and Infectious Disease — Thu, 08 Oct 2009 00:00:00 +0100

Abstract: Loop-mediated isothermal amplification (LAMP) method was designed for clinical diagnosis of Vibrio cholerae carrying the ctxA gene. The detection limits of the method were 5 fg of purified genomic DNA/reaction and 0.54 CFU/reaction. The method was applied to rectal swab samples from cholera patients and healthy volunteers (19 subjects each) and yielded the same results as the “gold standard” culture method, while the polymerase chain reaction-based method failed to detect V. cholerae in 8 of the positive samples. Direct application of this LAMP method without precultivation enabled the rapid detection of 5 asymptomatic carriers from rectal swabs of 21 household contacts of cholera patients. This LAMP method could be a sensitive, specific, inexpensive, and rapid detection tool...

Molecular epidemiology of a Streptococcus pneumoniae serotype 1 outbreak in a Tunisian jail

Diagnostic Microbiology and Infectious Disease — Mon, 05 Oct 2009 00:00:00 +0100

Abstract: The microbiologic investigations of an outbreak implicating 17 inmates demonstrated the spread of a pneumococcal serotype 1 clone not only in this jail but also in the area of Tunis. This clone, which is fully susceptible to antibiotics but not included in the heptavalent conjugate vaccine, should be closely monitored. (Source: Diagnostic Microbiology and Infectious Disease)

CTX-M and ampC β-lactamases contributing to increased prevalence of ceftriaxone-resistant Escherichia coli in Changi General Hospital, Singapore

Diagnostic Microbiology and Infectious Disease — Mon, 05 Oct 2009 00:00:00 +0100

Abstract: Data from an 800-bed hospital showed an increase in the incidence density of ceftriaxone-resistant Escherichia coli, from 13.1 to 21.7 per 100 000 inpatient days over a 4-year period. Detailed testing performed on 54 E. coli isolates showed blaCTX-M extended-spectrum β-lactamase (ESBL) genes (n = 37) and blaCMY-like ampC genes (n = 15). Typing data showed only limited clonal transmission in isolates with ESBL. (Source: Diagnostic Microbiology and Infectious Disease)

Emergence of multidrug-resistant Salmonella enterica serovar Typhi with reduced susceptibility to fluoroquinolones in Cambodia

Diagnostic Microbiology and Infectious Disease — Mon, 05 Oct 2009 00:00:00 +0100

Abstract: From December 2006 to April 2009, we conducted an etiology study among Cambodian patients presenting with acute fever of unknown origin. Salmonella enterica serovar Typhi was detected in 0.9% (41/4985) blood cultures. Antimicrobial susceptibility testing showed decreased susceptibility to ampicillin (56% resistant; MIC90, >256 μg/mL), chloramphenicol (56% resistant; MIC90, >256 μg/mL), trimethoprim/sulfamethoxazole (56% resistant; MIC90, >256 μg/mL), nalidixic acid (81% resistant; MIC90, not defined), ciprofloxacin (0% resistant; MIC90, 0.5 μg/mL), and ceftriaxone (0% resistant; MIC90, 0.094 μg/mL). Multidrug resistance, defined as antimicrobial resistance to ampicillin, chloramphenicol, and trimethoprim/sulfamethoxazole, was found in 56% of the isolates, and 80% had reduced...

Molecular identification of rapidly growing mycobacteria isolates from pulmonary specimens of patients in the State of Pará, Amazon region, Brazil

Diagnostic Microbiology and Infectious Disease — Mon, 05 Oct 2009 00:00:00 +0100

In this study, we show that the description of new RGM species requires the establishment of standardized procedures for RGM identification and the alert of the clinician about their involvement in pulmonary disease and the necessity of treatment for control and cure. (Source: Diagnostic Microbiology and Infectious Disease)

Imported malaria in children: incidence and risk factors for severity

Diagnostic Microbiology and Infectious Disease — Wed, 30 Sep 2009 00:00:00 +0100

Abstract: To assess the incidence of imported malaria in children and to determine the frequency of delayed diagnosis and risk factors for severe malaria, we performed a retrospective multicenter cohort study in the northern region of France and included all children with a positive test for malaria from 2000 to 2006. The incidence of imported malaria in children (Source: Diagnostic Microbiology and Infectious Disease)

Leishmania spp. identification by polymerase chain reaction–restriction fragment length polymorphism analysis and its applications in French Guiana

Diagnostic Microbiology and Infectious Disease — Sun, 27 Sep 2009 00:00:00 +0100

We describe a new restriction fragment length polymorphism–polymerase chain reaction technique using a 615-bp fragment of the RNA polymerase II gene and 2 restriction enzymes, TspRI and HgaI. Seven reference strains (Leishmania (Leishmania) amazonensis, Leishmania (Viannia) lainsoni, Leishmania (Viannia) braziliensis, L. (V.) guyanensis, Leishmania (Viannia) naiffi, Leishmania (Leishmania) major, Leishmania (Leishmania) infantum) and 112 clinical samples from positive lesions were used for the development of the technique. The rates of positive species identification were 85.7% for punch skin biopsy specimens, 93.1% for positive Giemsa-stained smears, and 100% for positive culture supernatants. In the framework of cutaneous leishmaniasis species surveillance for the 2006 to 2008 period, ...

Treatment approaches to prosthetic joint infections: results of an Emerging Infections Network survey

Diagnostic Microbiology and Infectious Disease — Sun, 27 Sep 2009 00:00:00 +0100

We report the results of an Emerging Infections Network survey of 994 infectious disease consultants (IDCs) regarding their participation in the medical management of prosthetic joint infections and observations of adverse effects associated with antibiotic-impregnated materials (response rate, 54.8%). There was general agreement about when a prosthesis can be retained, but substantial variability in the duration of suppressive antibiotics was recommended, with 36% supporting life-long suppression. For 2-stage procedures, 95% recommended a minimum of 4 weeks of systemic antibiotics after the first stage. However, there was little agreement regarding the duration of an antibiotic-free period before reimplantation. Eleven percent of IDCs reported adverse events related to antibiotic-impregna...

A rapid, 2-well, multiplex real-time polymerase chain reaction assay for the detection of SCCmec types I to V in methicillin-resistant Staphylococcus aureus

Diagnostic Microbiology and Infectious Disease — Fri, 25 Sep 2009 00:00:00 +0100

Abstract: For us to assess the spread of methicillin-resistant Staphylococcus aureus (MRSA), typing of the staphylococcal cassette chromosome mec (SCCmec) is a valuable addition to existing typing methods, such as multilocus sequence typing (MLST). Traditional SCCmec typing assays, that is, that of Oliveira et al. and Ito et al., are polymerase chain reaction (PCR) based, requiring electrophoresis. We introduce a rapid, 2-well, multiplex real-time PCR assay that can be used directly on bacterial suspensions and is able to characterize SCCmec type I to V based on the detection of the ccr genes and the mec complex. The assay was evaluated on 212 clinical MRSA isolates from various countries, associated with MLST clonal complexes (CC) 1, 5, 8, 22, 30, and 45, as well as pig-associated CC398. ...

High prevalence of tcdC deletion-carrying Clostridium difficile and lack of association with disease severity

Diagnostic Microbiology and Infectious Disease — Thu, 24 Sep 2009 00:00:00 +0100

Abstract: We assessed the prevalence of tcdC deletion-carrying Clostridium difficile using a stool polymerase chain reaction (PCR) assay that detects previously described 18- and 39-bp deletions (J. Clin. Microbiol. 2008;46:1996). We divided inpatients into 2 groups, those for whom the assay detected a deletion in tcdC and those for whom no deletion was detected. We compared risk factors (antibiotic use, hospitalization, nursing home stay, immunocompromise, age >65 years), complications (pseudomembranous colitis, toxic megacolon, colonic perforation, colectomy, and intensive care unit admission), duration of antibiotic treatment, and 30-day mortality between the groups. Forty-two of 141 patients had deletion-positive C. difficile. Prior nursing home stay and age >65 years were significantl...

Imipenem-resistant Pseudomonas aeruginosa gastrointestinal carriage among hospitalized patients: risk factors and resistance mechanisms

Diagnostic Microbiology and Infectious Disease — Thu, 24 Sep 2009 00:00:00 +0100

Abstract: Risk factors for imipenem (IMP)-resistant Pseudomonas aeruginosa (IRPA) digestive carriage were analyzed, and genetic events contributing to select resistant isolates in patients exposed to IMP were investigated. Among the 150 patients with hospital-acquired P. aeruginosa digestive carriage, 38 isolates were IRPA. DNA pulsotypes revealed 16 distinct clones. In 4 patients, a second P. aeruginosa isolate showed resistance to IMP compared with the initial susceptible isolate. By comparing the different oprD sequences between IMP-susceptible P. aeruginosa and IRPA strains, a genetic event was systematically found for each resistant isolate, leading to either the absence of OprD or a truncated porin. The multivariate analysis demonstrated that prior IMP exposure was associated with IR...

Characterization of plasmids encoding CMY-2 AmpC β-lactamases from Escherichia coli in Canadian intensive care units

Diagnostic Microbiology and Infectious Disease — Thu, 24 Sep 2009 00:00:00 +0100

Abstract: The dissemination of CMY-2 AmpC β-lactamases among Escherichia coli in Canadian intensive care units occurs through a combination of clonal spread of virulent strains and the horizontal transfer of genetically similar IncI1, IncA/C, and IncK/B plasmids. (Source: Diagnostic Microbiology and Infectious Disease)

Lactobacillus rhamnosus hepatic abscess associated with Mirizzi syndrome: a case report and review of the literature

Diagnostic Microbiology and Infectious Disease — Tue, 22 Sep 2009 00:00:00 +0100

We report the first case of life-threatening bacteremic liver abscess due to Lactobacillus rhamnosus associated with Mirizzi syndrome in a 74-year-old Chinese man. Literature on sporadic reports of Lactobacillus liver abscess is reviewed. (Source: Diagnostic Microbiology and Infectious Disease)

Clinical and molecular epidemiology of methicillin-resistant Staphylococcus aureus carrying SCCmecIV in a university hospital in Porto Alegre, Brazil

Diagnostic Microbiology and Infectious Disease — Tue, 22 Sep 2009 00:00:00 +0100

This study show that OSPC isolates are not only causing community-associated infections but are also involved in HCAI in our country. (Source: Diagnostic Microbiology and Infectious Disease)

The Helicobacter pylori Mfd protein is important for antibiotic resistance and DNA repair

Diagnostic Microbiology and Infectious Disease — Tue, 22 Sep 2009 00:00:00 +0100

Abstract: A Helicobacter pylori mutant defective in a putative mfd gene was constructed and characterized. The mfd gene is required for DNA repair and is involved in DNA recombination processes. The mfd mutant strain displayed a greatly increased susceptibility to antibiotics, indicating that this gene plays a significant role in the antibiotic resistance of H. pylori strain J99. (Source: Diagnostic Microbiology and Infectious Disease)

Usefulness and influence of age of a novel Rapid HpStAR™ stool antigen for the diagnosis of Helicobacter pylori infection in children

Diagnostic Microbiology and Infectious Disease — Tue, 22 Sep 2009 00:00:00 +0100

Abstract: A novel rapid monoclonal enzyme immunoassay stool antigen for Helicobacter pylori detection (Rapid HpStAR™) was evaluated in 16 infected and 92 noninfected children. The overall sensitivity, specificity, and positive and negative predictive values were 87.5%, 97.8%, 87.5%, and 97.8%, respectively, with an accuracy of 96.2%. The negative predictive value was good in all age groups, reaching 100% in younger children. (Source: Diagnostic Microbiology and Infectious Disease)

In vivo selection of carbapenem-resistant Klebsiella pneumoniae by OmpK36 loss during meropenem treatment

Diagnostic Microbiology and Infectious Disease — Tue, 22 Sep 2009 00:00:00 +0100

Abstract: We recovered a carbapenem-resistant Klebsiella pneumoniae isolate H224 under in vivo meropenem selection pressure. Insertional inactivation of a major porin gene, ompK36, by IS5 element might play a role in acquiring carbapenem resistance in this strain harboring plasmid-borne DHA-1 AmpC β-lactamase. (Source: Diagnostic Microbiology and Infectious Disease)

Diversity of the blaSHV genes

Diagnostic Microbiology and Infectious Disease — Tue, 22 Sep 2009 00:00:00 +0100

Abstract: We investigated the diversity of nucleotide sequences of 297 SHV-encoding genes, based on nucleotide synonymous mutations and the presence or absence of the nonsynonymous mutation T92A. The analysis of this diversity allowed us to develop and propose a classification to differentiate the nucleotide sequence variants of the blaSHV genes. (Source: Diagnostic Microbiology and Infectious Disease)

Comparison of nucleic acid extraction methods for the detection of Mycoplasma pneumoniae

Diagnostic Microbiology and Infectious Disease — Tue, 22 Sep 2009 00:00:00 +0100

Abstract: Four nucleic acid extraction procedures (2 automated and 2 manual) were compared for their efficiency at isolating Mycoplasma pneumoniae DNA. Oropharyngeal swabs from healthy volunteers were spiked with varying amounts of M. pneumoniae, extracted, and tested using real-time polymerase chain reaction. Our data indicate that both automated extraction methods consistently outperform the manual procedures. (Source: Diagnostic Microbiology and Infectious Disease)

Panton–Valentine leukocidin (PVL)-positive methicillin-susceptible and resistant Staphylococcus aureus in Taiwan: identification of oxacillin-susceptible mecA-positive methicillin-resistant S. aureus

Diagnostic Microbiology and Infectious Disease — Tue, 22 Sep 2009 00:00:00 +0100

Abstract: Methicillin-resistant Staphylococcus aureus (MRSA) arises when methicillin-susceptible S. aureus (MSSA) acquires the staphylococcal cassette chromosome mec (SCCmec). Most pvl-positive MRSA in Taiwan belong to ST59 lineage and carry SCCmec V. The genetic profiles of 51 MSSA were compared with those of 80 MRSA from the same hospitals. Nine pvl-positive MSSA (oxacillin MIC ≤2 μg/mL) shared >80% similarity in pulsed field gel electrophoresis pattern with 17 pvl-positive SCCmec V MRSA. Further investigation found that 5 of these 9 isolates were MRSA by cefoxitin and carried SCCmec V. All 26 pvl-positive isolates had very similar genetic profile (ST59, protein A clonal complex [spa-CC] c2:441/437, and agr group I). The success of the ST59:SCCmec V MRSA may be due in part to its hete...

Diagnostic value of enzyme-linked immunosorbent assays using hypothetical proteins CT226 and CT795 as antigens in Chlamydia trachomatis serodiagnosis

Diagnostic Microbiology and Infectious Disease — Mon, 21 Sep 2009 23:00:00 +0100

Abstract: The CT226 and the CT795 proteins were produced as purified recombinant proteins and were used as antigens in enzyme-linked immunosorbent assay (ELISA) tests for the detection of Chlamydia trachomatis IgG antibodies. The performances of the developed ELISA tests were compared with our in-house microimmunofluorescence test and the species-specific pELISA test using a panel of 342 sera. Our results indicate that the performance of the CT795 ELISA test was higher than that of the CT226 ELISA test according to the microimmunofluorescence and to the pELISA. To assess whether a combination of tests could improve the serodiagnosis of C. trachomatis infections, we associated results obtained with these tests to that using the previously developed CT694 ELISA test. Combining ELISA test res...

Visual DNA microarrays for simultaneous detection of human immunodeficiency virus type-1 and Treponema pallidum coupled with multiplex asymmetric polymerase chain reaction

Diagnostic Microbiology and Infectious Disease — Fri, 18 Sep 2009 00:00:00 +0100

Abstract: Based on gold label silver stain and coupled with multiplex asymmetric polymerase chain reaction (PCR) analysis, we developed the visual DNA microarray for simultaneous, sensitive, and specific detection of human immunodeficiency virus type-1 (HIV-1) and Treponema pallidum. The 5′-end amino-modified oligonucleotides were immobilized on glass surface, which were used as the capturing probes to bind the complement biotinylated target DNA. The gold-conjugated streptavidins were introduced to the microarray for specific binding to biotin. The black image of microarray spots, which were the result from the precipitation of silver onto nanogold particles and bound to streptavidins, was visualized and accounted as the detection of biotinylated target DNA. Multiplex asymmetric PCR prod...

Dog bite wound infection by Pasteurella dagmatis misidentified as Pasteurella pneumotropica by automated system Vitek 2

Diagnostic Microbiology and Infectious Disease — Thu, 17 Sep 2009 23:00:00 +0100

Human pasteurellosis are most often caused by dog and cat bites, resulting in cellulitis and subcutaneous abscesses. The second most common site of infection or colonization is the respiratory tract. Systemic diseases are uncommon and mostly occur in patients with underlying diseases. Pasteurella multocida is the most frequent species in human infections, but other species may be involved, such as Pasteurella canis, Pasteurella dagmatis, and Pasteurella stomatis (). Automated systems are commonly used for Pasteurella identification. However, the failure of commercial systems to satisfactorily identify microorganisms is of concern, and unusual identification should be correlated with patient's clinical pictures. We are reporting here a case of misidentification of P. dagmatis by automated s...

Disseminated Rhodococcus equi infection in a kidney transplant patient without initial pulmonary involvement

Diagnostic Microbiology and Infectious Disease — Thu, 17 Sep 2009 00:00:00 +0100

This report shows that R. equi should be considered as a cause of infection in solid organ transplant recipients even without initial clinical and radiologic signs of pulmonary involvement. Despite adequate therapy, the outcome can be fatal. (Source: Diagnostic Microbiology and Infectious Disease)

Concurrent measurement of adenosine deaminase and dipeptidyl peptidase IV activity in the diagnosis of tuberculous pleural effusion

Diagnostic Microbiology and Infectious Disease — Thu, 17 Sep 2009 00:00:00 +0100

Abstract: Measurement of pleural fluid adenosine deaminase (ADA) levels aids diagnosing tuberculous pleural effusion (TPE). Dipeptidyl peptidase IV (DPP) enzyme is closely related to ADA. Our aim was to determine the value of concurrent measurement of these T-cell–associated enzymes, ADA and DPP levels in the diagnosis of TPE. Patients with pleural effusion were grouped as TPE, parapneumonic, malignant, congestive heart failure related, and miscellaneous pleural effusions. Pleural and serum ADA and DPP levels were measured. Pleural and serum levels of ADA and pleural DPP were higher in TPE group than the rest. In 7 patients, pleural biopsy revealed granulomatous pleuritis. All of these patients had TPE and had elevated serum and pleural ADA levels. Serum and pleural ADA or DPP levels and...

Evidence for daptomycin Etest lot-related MIC elevations for Staphylococcus aureus

Diagnostic Microbiology and Infectious Disease — Wed, 16 Sep 2009 23:00:00 +0100

Abstract: MIC testing was performed simultaneously by Etest and broth microdilution (BMD) on 587 Staphylococcus aureus isolates submitted by local laboratories to a reference laboratory for confirmatory testing (May 2005 to July 2008). Testing bias was assessed for Etest to BMD MIC ratios. Categoric and essential agreement, very major (BMD nonsusceptible, Etest susceptible), and major (BMD susceptible, Etest nonsusceptible) errors were evaluated. Agar and broth calcium concentrations were consistent with current Clinical and Laboratory Standards Institute and manufacturer recommendations. There was a consistent bias for higher Etest MIC values compared with BMD. Ratios ranged from 0.25 to 4 (average 1.3), with substantial variability noted among the 8 different Etest lots tested. Overall, ...

Characterization of class 1 integrons and gene cassettes in clinical isolates of Klebsiella pneumoniae from Taiwan

Diagnostic Microbiology and Infectious Disease — Mon, 14 Sep 2009 18:02:28 +0100

Abstract: We surveyed the prevalence and contents of class 1 integrons in clinical Klebsiella pneumoniae isolates collected from Kaohsiung, Taiwan, during 2 periods (1993 and 2004). Class 1 integrons were present in 78 isolates (34.2%) from 1993 (n = 228) and 129 (32.9%) from 2004 (n = 392) and contained varied gene cassette number, type, and array. We found 2 atypical sul3-associated class 1 integrons and identified 26 different gene cassettes, including an aac(6′)-Ib-cr cassette here firstly described in K. pneumoniae from Taiwan. The continuing evolution of class 1 integrons is threatening to undermine the effectiveness of antimicrobial therapy for K. pneumoniae. (Source: Diagnostic Microbiology and Infectious Disease)

Specific IgG avidity in active and inactive human neurocysticercosis

Diagnostic Microbiology and Infectious Disease — Mon, 14 Sep 2009 18:02:28 +0100

We reported for the first time that IgG avidity assay may distinguish active from inactive NC. (Source: Diagnostic Microbiology and Infectious Disease)

Impact of human serum albumin on oritavancin in vitro activity against Staphylococcus aureus

Diagnostic Microbiology and Infectious Disease — Mon, 14 Sep 2009 18:02:28 +0100

Abstract: Human serum albumin (HSA) did not affect oritavancin MICs against non–vancomycin-intermediate Staphylococcus aureus (non-VISA) strains. In time–kill assays, oritavancin bactericidal activity in the presence of HSA was significantly more rapid than comparators against non-VISA strains. HSA increased oritavancin MICs by 4-fold for VISA strains, reflective of reduced oritavancin activity in time–kill assays with HSA. (Source: Diagnostic Microbiology and Infectious Disease)

Predominance of CTX-M–type extended-spectrum β-lactamase genes among enterobacterial isolates from outpatients in Brazil

Diagnostic Microbiology and Infectious Disease — Mon, 14 Sep 2009 18:02:28 +0100

Abstract: Two hundred fifty-seven nalidixic acid-resistant enterobacterial isolates were collected in a Brazilian community from January 2000 to May 2005 to determine the prevalence of plasmid-encoded extended-spectrum β-lactamases. The blaCTX-M genetic environment was determined by polymerase chain reaction and sequencing. Eleven isolates (4.2%) harbored a blaCTX-M-2 gene, 3 isolates blaCTX-M-9, 2 isolates blaCTX-M-8, and 6 isolates blaSHV-5. Two novel blaCTX-M-2 variants, namely, blaCTX-M-74 and blaCTX-M-75, were identified. (Source: Diagnostic Microbiology and Infectious Disease)

Change in the molecular epidemiology of methicillin-resistant Staphylococcus aureus bloodstream infections in Taiwan

Diagnostic Microbiology and Infectious Disease — Mon, 14 Sep 2009 18:02:28 +0100

Abstract: A multiresistant community-associated methicillin-resistant Staphylococcus aureus clone (sequence type 59) established itself as a significant cause of nosocomial bloodstream infections soon after emergence in the communities. Multiresistance might be one of the characteristics that could have contributed to its quick adaptation to hospital environments. (Source: Diagnostic Microbiology and Infectious Disease)

In vitro activity of daptomycin against Staphylococcus aureus and vancomycin-resistant Enterococcus faecium isolates associated with skin and soft tissue infections: first results from India