MedWorm: Group A Streptococcus

Group A Streptococcus Causing Descending Necrotizing Mediastinitis: Report of a Case and Literature Review

Surgical Infections — Thu, 09 Feb 2012 04:04:10 +0100

Surgical Infections , Vol. 0, No. 0. (Source: Surgical Infections)

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Superantigen profiles of emm and emm-like typeable and nontypeable pharyngeal streptococcal isolates of South India

Annals of Clinical Microbiology and Antimicrobials — Thu, 02 Feb 2012 05:00:00 +0100

Conclusions: Multiplex PCR analysis revealed the presence of superantigens in all the typeable strains irrespective of their emm types. However, the presence of superantigen genes in emm and emmL nontypeable strains has not been previously reported. In this study, presence of at least one or a combination of superantigen coding genes was identified in all the emm and emmL nontypeable strains. Thus, the superantigens may inevitably play an important role in the pathogenesis of these nontypeable strains in the absence of the primary virulence factor, M protein. (Source: Annals of Clinical Microbiology and Antimicrobials)

SpyA is a membrane‐bound ADP‐ribosyltransferase of Streptococcus pyogenes which modifies a streptococcal peptide, SpyB

Molecular Microbiology — Mon, 30 Jan 2012 05:00:00 +0100

In this study we demonstrate that SpyA is a surface‐exposed membrane protein which is anchored to the streptococcal membrane by an N‐terminal transmembrane sequence. We identified a small gene upstream of spyA, designated spyB, which encodes a peptide of 35 amino acids, and is co‐transcribed with spyA. Expression of spyBA is strongly influenced by translational coupling: mutational inactivation of spyB translation completely abolishes translation of spyA. spyB expression increases with increasing cell density and reaches its maximum at late exponential growth phase. The SpyB N‐terminus is predicted to fold into an amphipathic α‐helix, a structural motif that targets a protein to the cytoplasmic membrane. Consistent with the prediction, we found that a SpyB fusion with peptide af...

Multi High-Throughput Approach for Highly Selective Identification of Vaccine Candidates: the Group A Streptococcus Case.

Molecular and Cellular Proteomics : MCP — Fri, 27 Jan 2012 05:00:00 +0100

Authors: Bensi G, Mora M, Tuscano G, Biagini M, Chiarot E, Bombaci M, Capo S, Falugi F, Manetti AG, Donato P, Swennen E, Gallotta M, Garibaldi M, Pinto V, Chiappini N, Musser JM, Janulczyk R, Mariani M, Scarselli M, Telford JL, Grifantini R, Norais N, Margarit I, Grandi G Abstract We propose an experimental strategy for highly accurate selection of bacterial vaccines without using in vitro and/or in vivo protection assays. Starting from the observation that efficacious vaccines are constituted by conserved, surface-associated and/or secreted components, the strategy contemplates the parallel application of three high throughput technologies, i.e., mass spectrometry-based proteomics, protein array and flow-cytometry analysis, to identify this category of proteins, and is based on th...

Differentiating PANDAS and non-PANDAS disorders

The Journal of Pediatrics — Sat, 14 Jan 2012 17:25:08 +0100

Not unlike autism spectrum disorder (ASD), more cases of obsessive-compulsive disorder (OCD) and/or tic disorders are being diagnosed in prepubertal children. Also, not unlike ASD, the cause of most cases is unclear. Frustrated families seeking answers frequently think we don't care. We care. We just do not have the answers. Much debate has focused on the purported role of group A streptococcus (GAS) in causing or precipitating the so-called Pediatric Autoimmume Neuropsychiatric Disorders Associated with Streptococcal infections (PANDAS). Using objective criteria to define at least the most typical clinical constellation could benefit future investigations of etiology, natural history, and management. (Source: The Journal of Pediatrics)

The structural characterization of a prophage-encoded extracellular DNase from Streptococcus pyogenes

Nucleic Acids Research — Fri, 13 Jan 2012 05:00:00 +0100

We present here the X-ray structure of this DNase in the wild-type and Asn145Ala mutant form. Through structural and sequence alignments as well as mutagenesis studies, we have identified the key residues His121, Asn145 and Glu164, which are crucial for Spd1 nucleolytic activity and shown the active site constellation. Our wild-type structure alludes to the possibility of a catalytically blocked dimeric form of the protein. We have investigated the multimeric nature of Spd1 using size-exclusion chromatography with multi-angle light scattering (SEC-MALLS) in the presence and absence of the divalent metal ion Mg2+, which suggests that Spd1 exists in a monomeric form in solution. (Source: Nucleic Acids Research)

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Evaluation of SclB gene variation in Streptococcus pyogenes (Lancefield group A Streptococcus, GAS) and potential for subtyping.

Journal of Medical Microbiology — Fri, 13 Jan 2012 05:00:00 +0100

Authors: Coelho JM, Platt S, Efstratiou A Abstract The variation of SclB nucleotide sequences in group A streptococci (GAS) and the potential usefulness for subtyping the most common serotypes encountered in the UK was evaluated. We sequenced a total of 124 strains - randomly selected iGAS and outbreak-related strains. Variability was highest amongst M/emm 89 strains, whereas very little variation was observed amongst M/emm 1 and M/emm 28 GAS strains. Repeat patterns were identified in the collagen-structure motif (CSM) of the M/emm 89 GAS strains. The sporadic strains were very diverse and encompassed most of the CSM patterns, whereas the outbreak-related strains were mainly clustered into two CSM groups. SclB nucleotide cluster analysis distinguished outbreaks strains from two di...

Lucina

Archives of Disease in Childhood — Wed, 11 Jan 2012 05:00:00 +0100

Atopic dermatitis (AD) is the most common skin disease of children and is increasing in prevalence worldwide. Skin infection with Staphylococcus aureus is common especially during exacerbations of AD. Infection with group A streptococcus (GAS) is less frequent but also well documented. Workers in San Francisco (Pediatr Dermatol 2011;28:230–4) have compared the clinical features of the two infections. A retrospective study for the period 1999–2001 revealed 245 skin culture results for children with AD, 187 (76%) positive for S aureus or GAS. Among these 187, 143 (76%) grew S aureus alone, 10 (5%) streptococci alone, of which 9 were GAS, and 34 (14%) both S aureus and streptococci, of which 29 were S aureus and GAS). Patients infected with GAS were more likely to have fever, to h...

Detection of group A Streptococcus in tonsils from pediatric patients reveals high rate of asymptomatic streptococcal carriage.

BMC Pediatrics - Latest articles — Mon, 09 Jan 2012 05:00:00 +0100

Conclusion: Our study revealed the presence of GAS within the tonsillar reticulated crypts of approximately one-third of children who underwent tonsillectomy for either adenotonsillar hypertrophy or recurrent GAS tonsillopharyngitis at the Wake Forest School of Medicine.Trial Registration. The tissue collected was normally discarded tissue and no patient identifiers were collected. Thus, no subjects were formally enrolled. (Source: BMC Pediatrics - Latest articles)

Characterization of the Group A Streptococcus Mga Virulence Regulator Reveals a Role for the C‐terminal Region in Oligomerization and Transcriptional Activation

Molecular Microbiology — Sun, 01 Jan 2012 05:00:00 +0100

In this study, high‐level purification of soluble Mga was achieved, enabling the first detailed characterization of the protein. Fluorescence titrations coupled with filter‐binding assays indicate that Mga binds cognate DNA with nanomolar affinity. Gel filtration analyses, analytical ultracentrifugation, and co‐immunoprecipitation experiments demonstrate that Mga forms oligomers in solution. Moreover, the ability of the protein to oligomerize in solution was found to correlate with transcriptional activation; DNA binding appears to be necessary but insufficient for full activity. Truncation analyses reveal that the uncharacterized C‐terminal region of Mga, possessing similarity to phosphotransferase system EIIB proteins, plays a critical role in oligomerization and in vivo activity...

Rheumatic fever - Identification, management and secondary prevention.

Australian Family Physician — Sun, 01 Jan 2012 05:00:00 +0100

Discussion Recurrent episodes of acute rheumatic fever may lead to rheumatic heart disease. Early detection of acute rheumatic fever and provision of secondary prophylaxis with antibiotics is paramount to the prevention of rheumatic heart disease. Primary healthcare providers can play an important role in identifying acute rheumatic fever and ensuring adherence to treatment within the context of a complex interplay of cultural and socioeconomic factors. The recent establishment of RHD Australia will support the development of appropriate educational resources and their dissemination among health professionals and vulnerable communities. PMID: 22276281 [PubMed - in process] (Source: Australian Family Physician)

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Knowing is Half the Battle: Targeting Virulence Factors of Group A Streptococcus for Vaccine and Therapeutics.

Current Drug Targets — Thu, 29 Dec 2011 05:00:00 +0100

Authors: Thomas C, Lee SW Abstract Group A Streptococcus (GAS) is a leading human pathogen that causes a multitude of diseases from pharyngitis, and impetigo, to more severe outcomes such as rheumatoid arthritis and necrotizing fasciitis. GAS remains a global burden as currently no vaccine exists that is completely effective. In this review we highlight recent studies on the virulence of GAS and present several approaches that have extended those findings into aims at combating GAS disease. These and other studies such as recent genome-wide efforts into host-pathogen relationships of GAS disease will likely reveal new targets of intervention. Given the recent rise in GAS strains that have acquired resistance to several types of antibiotics, it is crucial that we continue to increas...

Invasive Group A Streptococcus in a Skilled Nursing Facility--Pennsylvania, 2009-2010 [From the Centers for Disease Control and Prevention]

JAMA — Tue, 27 Dec 2011 05:00:00 +0100

(Source: JAMA)

The streptococcal collagen-like protein-1 (Scl1) is a significant determinant for biofilm formation by group A Streptococcus

BMC Microbiology - Latest articles — Wed, 14 Dec 2011 05:00:00 +0100

Conclusions: Overall, this work (i) identifies variations in biofilm formation capacity among pathogenically different GAS strains, (ii) identifies GAS surface properties that may aid in biofilm stability and, (iii) establishes that the Scl1 surface protein is an important determinant of GAS biofilm, which is sufficient to enable biofilm formation in the heterologous host Lactococcus. In summary, the GAS surface adhesin Scl1 may have an important role in biofilm-associated pathogenicity. (Source: BMC Microbiology - Latest articles)

Invasive Group A Streptococcus in a Nursing FacilityInvasive Group A Streptococcus in a Nursing Facility

Medscape Today Headlines — Mon, 05 Dec 2011 04:00:00 +0100

How important are infection control practices in nursing homes? This new report explores the issue. Morbidity & Mortality Weekly Report (Source: Medscape Today Headlines)

Structure of a Phytophthora Transglutaminase [Protein Structure and Folding]

Journal of Biological Chemistry — Fri, 02 Dec 2011 05:00:00 +0100

Transglutaminases (TGases) are ubiquitous enzymes that catalyze selective cross-linking between protein-bound glutamine and lysine residues; the resulting isopeptide bond confers high resistance to proteolysis. Phytophthora sojae, a pathogen of soybean, secretes a Ca2+-dependent TGase (GP42) that is activating defense responses in both host and non-host plants. A GP42 fragment of 13 amino acids, termed Pep-13, was shown to be absolutely indispensable for both TGase and elicitor activity. GP42 does not share significant primary sequence similarity with known TGases from mammals or bacteria. This suggests that GP42 has evolved novel structural and catalytic features to support enzymatic activity. We have solved the crystal structure of the catalytically inactive point mutant GP42 (C290S) at ...

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Acquisition of Complement Factor H Is Important for Pathogenesis of Streptococcus pyogenes Infections: Evidence from Bacterial In Vitro Survival and Human Genetic Association.

Journal of Immunology — Fri, 02 Dec 2011 05:00:00 +0100

In this study, we found that activation of human complement by different GAS strains (n = 38) correlated negatively with binding of CFH via its domains 5-7. The importance of acquisition of host CFH for survival of GAS in vitro was studied next by blocking the binding with recombinant CFH5-7 lacking the regulatory domains 1-4. Using this fragment in full human blood resulted in death or radically reduced multiplication of all of the studied CFH-binding GAS strains. To study the importance of CFH binding in vivo (i.e., for pathogenesis of streptococcal infections), we used our recent finding that GAS binding to CFH is diminished in vitro by polymorphism 402H, which is also associated with age-related macular degeneration. We showed that allele 402H is suggested to be associated with protect...

Rapid PCR Detection of Group A StreptococcusRapid PCR Detection of Group A Streptococcus

Medscape Today Headlines — Mon, 28 Nov 2011 11:50:23 +0100

The authors describe a rapid and relatively inexpensive PCR assay for diagnosing group A streptococcus from throat swab specimens. Annals of Clinical Microbiology and Antimicrobials (Source: Medscape Today Headlines)

SP-STP-regulated S. pyogenes Virulence [Molecular Bases of Disease]

Journal of Biological Chemistry — Fri, 25 Nov 2011 05:00:00 +0100

Reversible phosphorylation is the key mechanism regulating several cellular events in prokaryotes and eukaryotes. In prokaryotes, signal transduction is perceived to occur primarily via the two-component signaling system involving histidine kinases and cognate response regulators. Although an alternative regulatory pathway controlled by the eukaryote-type serine/threonine kinase (Streptococcus pyogenes serine/threonine kinase; SP-STK) has been shown to modulate bacterial growth, division, adherence, invasion, and virulence in group A Streptococcus (GAS; S. pyogenes), the precise role of the co-transcribing serine/threonine phosphatase (SP-STP) has remained enigmatic. In this context, this is the first report describing the construction and characterization of non-polar SP-STP mutants in tw...

Non-specific intravenous immunoglobulins in severe infections caused by Staphylococcus and group A Streptococcus.

Farmacia Hospitalaria — Tue, 22 Nov 2011 05:00:00 +0100

Authors: Garrido-Sánchez L, Pastó-Cardona L, Jodar-Masanes R PMID: 22115857 [PubMed - as supplied by publisher] (Source: Farmacia Hospitalaria)

Association of Pharyngitis With Oral Antibiotic Use for the Treatment of Acne: A Cross-sectional and Prospective Cohort Study [Study]

Archives of Dermatology — Mon, 21 Nov 2011 05:00:00 +0100

Conclusions Our studies show that that the odds of reporting pharyngitis is more than 3 times baseline in patients receiving oral antibiotics for acne vs those who are not receiving oral antibiotics. The true clinical importance of these findings needs to be evaluated further by prospective studies, but this finding is not associated with group A streptococcus. (Source: Archives of Dermatology)

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Cysteine proteinase SpeB from Streptococcus pyogenes – a potent modifier of immunologically important host and bacterial proteins

Biological Chemistry — Fri, 04 Nov 2011 16:47:06 +0100

Biological Chemistry 392 (12): 1077-1088 Abstract Group A streptococcus (Streptococcus pyogenes) is an exclusively human pathogen that causes a wide spectrum of diseases ranging from pharyngitis, to impetigo, to toxic shock, to necrotizing fasciitis. The diversity of these disease states necessitates that S. pyogenes possess the ability to modulate both the innate and adaptive immune responses. SpeB, a cysteine proteinase, is the predominant secreted protein from S. pyogenes. Because of its relatively indiscriminant specificity, this enzyme has been shown to degrade the extracellular matrix, cytokines, chemokines, complement components, immunoglobulins, and serum protease inhibitors, to name but a few of the known substrates. Additionally, SpeB regulates other streptococcal proteins by deg...

[Clustered cases of intrafamily invasive Streptococcus pyogenes infection (or group A streptococcus).]

Archives de Pediatrie — Thu, 03 Nov 2011 04:00:00 +0100

We report the cases of two brothers, one a boy of 8.5 years with toxic shock syndrome with no bacteria identified and the second, 1 week later, his 14.5-year-old brother in hospital for sepsis due to GAS. The occurrence of a confirmed case of invasive GAS and a probable case within such a short period met the definition of clustered cases. Both brothers showed no risk factors for invasive disease and no gateway including skin was found. Antibiotic therapy was initiated in the family as recommended by the French Higher Council of Public Hygiene. PMID: 22056211 [PubMed - as supplied by publisher] (Source: Archives de Pediatrie)

Group A Streptococcus emm Gene Types in Pharyngeal Isolates, Ontario, Canada, 2002-2010.

Emerging Infectious Diseases — Tue, 01 Nov 2011 04:00:00 +0100

Authors: Shea PR, Ewbank AL, Gonzalez-Lugo JH, Martagon-Rosado AJ, Martinez-Gutierrez JC, Rehman HA, Serrano-Gonzalez M, Fittipaldi N, Beres SB, Flores AR, Low DE, Willey BM, Musser JM Abstract Group A Streptococcus (GAS) is a human-adapted pathogen that causes a variety of diseases, including pharyngitis and invasive infections. GAS strains are categorized by variation in the nucleotide sequence of the gene (emm) that encodes the M protein. To identify the emm types of GAS strains causing pharyngitis in Ontario, Canada, we sequenced the hypervariable region of the emm gene in 4,635 pharyngeal GAS isolates collected during 2002-2010. The most prevalent emm types varied little from year to year. In contrast, fine-scale geographic analysis identified inter-site variability in the mos...

An N‐Terminal Signal Peptide Of Vfr Protein Negatively Influences RopB‐Dependent SpeB Expression and Attenuates Virulence in Streptococcus pyogenes

Molecular Microbiology — Mon, 31 Oct 2011 04:00:00 +0100

SUMMARYStreptococcal pyrogenic exotoxin B (SpeB) is an extracellular cysteine protease that is a critical virulence factor made by the major human pathogen group A Streptococcus (GAS). speB expression is dependent on the regulator of proteinase B (RopB) and is upregulated with increasing cell density and during infection. Because computer modeling suggested significant structural similarity between RopB and peptide‐sensing regulatory proteins made by other Gram‐positive bacteria, we hypothesized that speB expression is influenced by RopB‐peptide interactions. Inactivation of the gene (vfr) encoding the virulence factor related (Vfr) protein resulted in increased speB transcript level during the exponential growth phase, whereas provision of only the amino‐terminal region of Vfr com...

An amino‐terminal signal peptide of Vfr protein negatively influences RopB‐dependent SpeB expression and attenuates virulence in Streptococcus pyogenes

Molecular Microbiology — Mon, 31 Oct 2011 04:00:00 +0100

SummaryStreptococcal pyrogenic exotoxin B (SpeB) is an extracellular cysteine protease that is a critical virulence factor made by the major human pathogen group A Streptococcus (GAS). speB expression is dependent on the regulator of proteinase B (RopB) and is upregulated with increasing cell density and during infection. Because computer modelling suggested significant structural similarity between RopB and peptide‐sensing regulatory proteins made by other Gram‐positive bacteria, we hypothesized that speB expression is influenced by RopB–peptide interactions. Inactivation of the gene (vfr) encoding the virulence factor related (Vfr) protein resulted in increased speB transcript level during the exponential growth phase, whereas provision of only the amino‐terminal region of Vfr co...

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[Streptococcal toxic shock syndrome or Kawasaki disease? Two case studies of children with group A streptococcal pneumonia empyema.]

Archives de Pediatrie — Sat, 29 Oct 2011 04:00:00 +0100

We report 2 cases of children with group A streptococcus pyogenes pleuropneumonia, in one child associated with Kawasaki disease and in the other with streptococcal toxic shock syndrome. These 2 features, with theoretically well-defined clinical and biological criteria, are difficult to differentiate in clinical practice, however, likely due to their pathophysiological links. In case of clinical doubt, an echocardiography needs to be performed to search for coronary involvement and treatment including intravenous immunoglobulins, and an antibiotic with an anti-toxin effect such as clindamycin has to be started early. PMID: 22041597 [PubMed - as supplied by publisher] (Source: Archives de Pediatrie)

Invasive Group A Streptococcus in a Skilled Nursing Facility --- Pennsylvania, 2009--2010

CDC Morbidity and Mortality Weekly Report — Fri, 28 Oct 2011 21:14:57 +0100

(Source: CDC Morbidity and Mortality Weekly Report)

Invasive group a streptococcus in a skilled nursing facility --- pennsylvania, 2009--2010.

MMWR Morb Mortal Wkl... — Fri, 28 Oct 2011 04:00:00 +0100

Authors: Abstract In September 2010, the Pennsylvania Department of Health was notified of a cluster of invasive group A Streptococcus (GAS) infections among residents of a skilled nursing facility specializing in neurologic and pulmonary care. The Montgomery County Health Department, the Pennsylvania Department of Health, and CDC conducted an investigation to identify additional cases and GAS carriers, assess risk factors and infection prevention practices, implement control measures, and prevent further infections. The investigators determined that, during October 12, 2009--September 22, 2010, 10 residents at the facility had noninvasive GAS infection, and 13 had invasive GAS infection; two residents with invasive infection died. An additional seven culture-confirmed GAS infect...

Streptococcus spread in nursing home

Health News - UPI.com — Fri, 28 Oct 2011 03:22:26 +0100

ATLANTA, Oct. 27 (UPI) -- Long-term care facilities should investigate cases of invasive group A Streptococcus to ensure infection prevention measures are taken, U.S. officials say. (Source: Health News - UPI.com)

Postpartum Group A Streptococcus Sepsis and Maternal Immunology

American Journal of Reproductive Immunology — Mon, 24 Oct 2011 04:00:00 +0100

Citation Mason KL, Aronoff DM. Postpartum group A Streptococcus sepsis and maternal immunology. Am J Reprod Immunol 2011Group A Streptococcus (GAS) is an historically important agent of puerperal infections and sepsis. The inception of hand‐washing and improved hospital hygiene drastically reduced the incidence of puerperal sepsis, but recently the incidence and severity of postpartum GAS infections has been rising for uncertain reasons. Several epidemiological, host, and microbial factors contribute to the risk for GAS infection and mortality in postpartum women. These include the mode of delivery (vaginal versus cesarean section), the location where labor and delivery occurred, exposure to GAS carriers, the altered immune status associated with pregnancy, the genetic background of the ...

Group A streptococcus outbreak – A clinical governance issue

International Journal of Surgery — Thu, 06 Oct 2011 22:52:32 +0100

Introduction: An outbreak of deep-seated Group A Streptococcal (GAS) infections occurred in reduction mammaplasty patients in our unit following which a peri-operative antimicrobial prophylaxis protocol was introduced. (Source: International Journal of Surgery)

Molecular insight into invasive group A streptococcal disease

Nature Reviews Microbiology — Fri, 16 Sep 2011 04:00:00 +0100

Authors: Jason N. Cole, Timothy C. Barnett, Victor Nizet & Mark J. Walker Streptococcus pyogenes is also known as group A Streptococcus (GAS) and is an important human pathogen that causes considerable morbidity and mortality worldwide. The GAS serotype M1T1 clone is the most frequently isolated serotype from life-threatening invasive (at a sterile site) infections, such (Source: Nature Reviews Microbiology)

The relationship between group A streptococcal infections and Tourette syndrome: a study on a large service‐based cohort

Developmental Medicine and Child Neurology — Wed, 14 Sep 2011 19:16:41 +0100

Aim To evaluate the relationship between diagnosis and clinical course of Tourette syndrome and group A Streptococcus (GAS).Method GAS infections, anti‐streptococcal, and anti‐basal ganglia antibodies (ABGA) were compared between 168 patients (136 males, 32 females) with Tourette syndrome; (median [range] age [25th–75th centile] 10y [8–11y]); median Tourette syndrome duration (25th–75th centile), 3y (1y 3mo–5y 9mo) and a comparison group of 177 patients (117 males, 60 females) with epileptic or sleep disorders median age [25th–75th centile], 10y [8y–1y 6mo]). One hundred and forty‐four patients with Tourette syndrome were followed up at 3‐month intervals; exacerbations of tics, obsessive–compulsive symptoms, and other psychiatric comorbidities were defined by a ...

[Consensus document on the diagnosis and treatment of acute tonsillopharyngitis.]

Anales de Pediatria — Tue, 13 Sep 2011 04:00:00 +0100

The objectives of treatment are: the reduction of symptoms, reduce the contagious period, and prevent local suppurative and systemic complications. Ideally, only confirmed cases should receive antibiotics. If there is no possibility to perform a rapid antigen-detection test, or in some cases if the result is negative, it is recommended to perform a culture and, if there is high suspicious index, to prescribe antibiotics. Penicillin is the treatment of choice, although amoxicillin is also accepted as the first option. Amoxicillin/clavulanate is not indicated in any case as empirical treatment. Macrolides are not a first choice antibiotic, and should be reserved for those patients with immediate penicillin allergy reaction or for the treatment of streptococcal carriers. It is of primordial i...

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HLA class II transgenic mice develop a safe and long lasting immune response against StreptInCor, an anti-group A streptococcus vaccine candidate.

Vaccine — Thu, 08 Sep 2011 04:00:00 +0100

In conclusion, the results presented here indicate that StreptInCor could be considered a safe vaccine against severe streptococcus-induced diseases. PMID: 21907752 [PubMed - as supplied by publisher] (Source: Vaccine)

Identification and characterization of plasmid-borne erm(T) macrolide resistance in group B and group A Streptococcus

Diagnostic Microbiology and Infectious Disease — Wed, 07 Sep 2011 04:00:00 +0100

Abstract: One hundred and seven group B Streptococcus (GBS) isolates and 344 group A Streptococcus (GAS) isolates were collected between 2005 and 2009 from 2 area hospitals and studied for resistance to erythromycin (ERY) and clindamycin (CLI) and the presence of the erm(T) macrolide resistance gene. The erm(T) gene was found in 5 (8%) of 61 erythromycin nonsusceptible GBS isolates and in 22 (55%) of 40 erythromycin nonsusceptible GAS isolates. The erm(T) gene in all 27 GBS/GAS erm(T) gene–positive isolates was located on a plasmid. Three erm(T) gene–positive plasmids were DNA sequenced. Two plasmids (1 each from GBS and GAS isolates) were both 4967 bp in size, contained the erm(T) gene, and differed by only 2 base pairs, suggesting interspecies horizontal transfer of the erm(T) gene c...

Environmental pH changes, but not the LuxS signaling pathway, regulates SpeB expression in M1 group A streptococci.

Journal of Medical Microbiology — Fri, 02 Sep 2011 04:00:00 +0100

Authors: Chiang-Ni C, Zheng PX, Tsai PJ, Chuang WJ, Lin YS, Liu CC, Wu JJ Abstract The autoinducer-2/LuxS signaling pathway participates in quorum-sensing in diverse bacterial species. In group A streptococcus, LuxS has been shown to be involved in regulating expression of several important virulence factors. Streptococcal pyrogenic exotoxin B (SpeB), a cysteine protease that has important roles in group A streptococcus pathogenesis, is positively regulated by LuxS in M3 and M5 strains. In the present study, we found that the supernatant harvested from an overnight culture stimulated M1 strains to express speB. However, mutation of the luxS gene in M1 strains or treating M1 strains with luxS mutant culture supernatant did not affect speB expression, indicating that the LuxS pathway...

Rapid PCR detection of group A streptococcus from flocked throat swabs: a retrospective clinical study

Annals of Clinical Microbiology and Antimicrobials — Thu, 01 Sep 2011 23:00:00 +0100

Conclusions: In this retrospective study, the GAS PCR assay appeared to perform as well as conventional throat swab culture, the current standard of practice. Since the GAS PCR assay, including DNA extraction, can be performed in approximately 1 hour, prospective studies of this assay are warranted to evaluate the clinical impact of the assay on management of patients with pharyngitis. (Source: Annals of Clinical Microbiology and Antimicrobials)

Group A Streptococcus Gene Expression in Humans with Pharyngitis using a Microarray.

Journal of Medical Microbiology — Wed, 27 Jul 2011 23:00:00 +0100

In this study, a novel electrochemical detection based microarray was used to identify gene expression patterns among humans with culture confirmed GAS pharyngitis. Using 14 samples (11 GAS positive and 3 GAS negative) obtained from subjects seen at the Brooke Army Medical Center pediatric clinic, this study demonstrated two different clusters of gene expression patterns. One cluster expressed a larger number of genes related to phages, immune system evasion and survival among competing oral flora signifying a potentially more virulent pattern of gene expression. The other cluster showed a greater number of genes related to nutrient acquisition and protein expression. This in vivo genome wide analysis of GAS gene expression in humans with pharyngitis evaluates global gene expression in ter...

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Significant decline in the erythromycin resistance of group A streptococcus isolates at a German paediatric tertiary care centre

European Journal of Clinical Microbiology and Infectious Diseases — Wed, 27 Jul 2011 15:51:35 +0100

Abstract Group A streptococcus (GAS) is considered to be a major pathogen of bacterial tonsillopharyngitis in children. Although GAS is generally susceptible to penicillin, macrolides are often used as the second-line treatment. Over the last several decades, the rising macrolide resistance of GAS has been detected in several countries. With the current study, we aimed to determine the development of macrolide resistance at our paediatric centre. From March 2006 to May 2009, 350 GAS isolates were tested for susceptibility to erythromycin, azithromycin, clindamycin, penicillin and cefotaxime. Macrolide-resistant isolates were screened for the presence of genes related to macrolide resistance (mefA, ermB, ermTR, prtF1). In comparison to a prior study at our hospital, the eryt...

Septic polyarthritis caused by group A streptococcus in an immunocompetent adult: rare case

Rheumatology International — Tue, 26 Jul 2011 15:47:42 +0100

We report a rare case of multifocal septic arthritis associated to spondylodiscitis and endocarditis caused by group A beta-hemolytic streptococcus (GABHS) in an immunocompetent adult, and we discuss diagnosis and therapeutic difficulties, while insisting into the rational use of corticosteroids that seems to be the only risk factor in our patient. Content Type Journal ArticlePages 1-4DOI 10.1007/s00296-011-2029-1Authors Assia Laatiris, University Hospital of Rabat-Sale, Sale, MoroccoBouchra Amine, University Hospital of Rabat-Sale, Sale, MoroccoYousra Ibn Yacoub, University Hospital of Rabat-Sale, Sale, MoroccoNajia Hajjaj-Hassouni, University Hospital of Rabat-Sale, Sale, Morocco Journal Rheumatology InternationalOnline ISSN 1437-160XPrint ISSN 0172-8172 (Source: Rheumato...

BET 1: Can inflammatory markers distinguish streptococcal from viral tonsillitis?

Emergency Medicine Journal — Sun, 24 Jul 2011 23:00:00 +0100

A short-cut review was performed to evaluate whether inflammatory markers such as C reactive protein (CRP), erythrocyte sedimentation rate (ESR), white cell count (WCC) and procalcitonin (PCT) are able to discriminate between streptococcal and viral tonsillitis, enabling a reduction in the overuse of antibiotics. Eight studies with a total of 1031 participants were found. The author, date and country of publication, patient group studied, study type, relevant outcomes, results and study weaknesses of these papers are tabulated. The clinical bottom line is that WCC, CRP and PCT levels are higher in patients with streptococcal tonsillitis compared to patients with tonsillitis or pharyngitis without group A streptococcus isolated from a throat swab. Which of these markers has the best test pe...

Study of T Serotypes and Emm Genotypes of Streptococcus pyogenes in Children with Pharyngitis and Tonsillitis.

Journal of Nippon Medical School — Sun, 17 Jul 2011 18:15:03 +0100

Authors: Okabe T, Takeda S, Hida M, Narisada T Streptococcus pyogenes, or group A Streptococcus (GAS), causes superficial infections of the upper respiratory tract that manifest as diseases such as pharyngitis and tonsillitis. T serotypes, emm genotypes, and the antimicrobial susceptibility of GAS isolated from the pharynges of patients with pharyngitis and tonsillitis were studied. The two most common T serotypes were T12 (10/25: 40%) and T1 (7/25: 28%), and the two most common emm genotypes were emm12 (12/27: 44%) and emm1 (7/27: 26%). Good correlation was observed between these T serotypes and emm genotypes. PMID: 21720091 [PubMed - in process] (Source: Journal of Nippon Medical School)

Time course of virulence factors produced by group A streptococcus during a food-borne epidemic

Journal of Infection and Chemotherapy — Wed, 13 Jul 2011 06:18:37 +0100

Abstract We studied the protein amount and activity of the major virulence factors hemolysin, cysteine protease streptococcal pyrogenic exotoxin B (SpeB), and NAD glycohydrolase (NADase), which are produced by Streptococcus pyogenes type T-25, with a food poisoning outbreak. The three virulence factors were analyzed by activity and amount of protein using supernatants at 2–30 h of culture. All these virulence factors were confirmed by their activity. Streptolysin O (SLO), SpeB, and NADase were immunochemically confirmed at protein level by Western blot analysis. Two hemolytic forms (70 and 60 kDa) of SLO were identified. SpeB was detected as a 44-kDa precursor form and a 30-kDa mature form. NADase was 50 kDa. SLO protein peaked at 8 h of culture, which...

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From transcription to activation: how group A streptococcus, the flesh‐eating pathogen, regulates SpeB cysteine protease production

Molecular Microbiology — Thu, 23 Jun 2011 23:00:00 +0100

SummaryStreptococcal pyrogenic exotoxin B (SpeB) is a protease secreted by group A streptococci and known to degrade a wide range of host and GAS proteins in vitro. Although the role of SpeB in GAS infection is debated, recent evidence has conclusively demonstrated that SpeB is critical for the pathogenesis of severe invasive disease caused by GAS. Genetic inactivation of the speB gene results in significantly decreased virulence in a necrotizing fasciitis model of infection. Production of fully active SpeB by GAS is extremely complex. Following transcription and translation the SpeB protein is secreted as an inactive zymogen, which is autocatalytically processed through a series of intermediates to form an active protease. Each step from transcription to protease activation is tightly con...

[Treatment of streptococcal tonsillitis with once-a-day amoxicillin: a meta-analysis.]

Anales de Pediatria — Tue, 21 Jun 2011 23:00:00 +0100

CONCLUSIONS: Amoxicillin, administered once daily is not inferior to other dosages of the same antibiotic or penicillin V. These results are important because they may facilitate compliance. PMID: 21703951 [PubMed - as supplied by publisher] (Source: Anales de Pediatria)

Unique Infective Complication after Routine Vasectomy: A Case Report

The Journal of Sexual Medicine — Tue, 14 Jun 2011 23:00:00 +0100

Conclusion. To our knowledge, this is the first reported case of oropharyngeal transmission of GAS that led to rapidly progressive infection of the scrotum following vasectomy. Care should be taken to minimize exposure during postoperative healing. Ramaswamy K and Kaminetsky J. Unique infective complication after routine vasectomy: A case report. J Sex Med **;**:**–**. (Source: The Journal of Sexual Medicine)

Cervicofacial Necrotizing Fasciitis and Steroids: Case Report and Literature Review

Journal of Oral and Maxillofacial Surgery — Mon, 13 Jun 2011 04:00:00 +0100

Necrotizing fasciitis (NF) is a devastating disease that typically affects immunocompromised patients but can also affect healthy patients. The disease can be caused by a monomicrobial or polymicrobial infection and spreads rapidly. Monomicrobial infections are usually due to group A streptococcus and are uncommon. (Source: Journal of Oral and Maxillofacial Surgery)

Niche‐specific contribution to streptococcal virulence of a MalR‐regulated carbohydrate binding protein

Molecular Microbiology — Sat, 04 Jun 2011 23:00:00 +0100

SummaryLow G+C Gram‐positive bacteria typically contain multiple LacI/GalR regulator family members, which often have highly similar amino‐terminal DNA binding domains, suggesting significant overlap in target DNA sequences. The LacI/GalR family regulator catabolite control protein A (CcpA) is a global regulator of the Group A Streptococcus (GAS) transcriptome and contributes to GAS virulence in diverse infection sites. Herein, we studied the role of the maltose repressor (MalR), another LacI/GalR family member, in GAS global gene expression and virulence. MalR inactivation reduced GAS colonization of the mouse oropharynx but did not detrimentally affect invasive infection. The MalR transcriptome was limited to only 25 genes, and a highly conserved MalR DNA‐binding sequence was ident...

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A microbial platform for rapid and low-cost virus-like particle and capsomere vaccines.

Vaccine — Fri, 03 Jun 2011 23:00:00 +0100

Authors: Middelberg AP, Rivera-Hernandez T, Wibowo N, Lua LH, Fan YY, Magor G, Chang C, Chuan YP, Good M, Batzloff M Studies on a platform technology able to deliver low-cost viral capsomeres and virus-like particles are described. The technology involves expression of the VP1 structural protein from murine polyomavirus (MuPyV) in Escherichia coli, followed by purification using scaleable units and optional cell-free VLP assembly. Two insertion sites on the surface of MuPyV VP1 are exploited for the presentation of the M2e antigen from influenza and the J8 peptide from Group A Streptococcus (GAS). Results from testing on mice following subcutaneous administration demonstrate that VLPs are self adjuvating, that adding adjuvant to VLPs provides no significant benefit in terms of antibody...

Virulence potential of Group A streptococci isolated from throat cultures of children from north India.

Indian J Med Res — Tue, 31 May 2011 23:00:00 +0100

Authors: Dhanda V, Vohra H, Kumar R Background & objectives: Rheumatic fever (RF)/rheumatic heart disease (RHD) caused by Group A streptococcus (GAS) are more prevalent in north India as compared to the western world, where invasive diseases are common. This could be due to variation in the virulence of GAS in different geographic locations. Hence, we studied the virulence potential of GAS isolated from the throat of children from north India. Methods: Fifty GAS isolated consecutively, from children with mild pharyngitis (20), severe pharyngitis (24) and asymptomatic pharyngeal carriers (6), were characterized by emm typing and opacity factor (OF). Adherence and internalization of GAS in HEp-2 cells and opsonophagocytosis in convalescent serum samples were studied. Results:Twenty e...

An Outbreak of Invasive Group A Streptococcus in Post-Partum Patients: Investigation, Intervention and Efforts to Change Behavior in a Obstetrics Unit

American Journal of Infection Control — Mon, 30 May 2011 17:34:59 +0100

Two post-partum vaginal delivery patients from the same obstetrics unit presented within 24 hours of each other with invasive group A streptococcus (GAS) infection. An outbreak investigation was performed. A retrospective analysis identified all GAS infections in the hospital within the previous 6 months. Healthcare workers (HCWs) caring for patients infected with GAS were cultured and not allowed to work until all cultures were negative or 24 hours after receiving treatment. Infants and other family members of the patients and partners of GAS positive HCWs were also cultured. Individuals who were GAS culture positive were treated and retested in 14 days. Positive isolates were sent for pulse field gel electrophoresis (PFGE). A survey of 10 institutions to assess mask use during vaginal d...

Study of the IgG endoglycosidase EndoS in group A streptococcal phagocyte resistance and virulence

BMC Microbiology - Latest articles — Thu, 26 May 2011 23:00:00 +0100

Conclusions: We conclude that in a highly virulent M1T1 background, EndoS has no significant impact on GAS phagocyte resistance and pathogenicity. However, local accumulation or high levels of expression of EndoS in certain GAS strains may contribute to virulence. (Source: BMC Microbiology - Latest articles)

Acute purulent pericarditis in childhood: don’t forget β-haemolytic group-A Streptococcus

Intensive Care Medicine — Thu, 26 May 2011 16:11:32 +0100

Content Type Journal ArticlePages 1-2DOI 10.1007/s00134-011-2259-4Authors François Angoulvant, AP-HP, Hôpital Robert-Debré, Service des Urgences Pédiatriques, Pôle de Pédiatrie Aiguë et Médecine Interne, Université Paris Diderot-Paris VII, Paris, FranceHélène Bellanger, AP-HP, Hôpital Robert-Debré, Service des Urgences Pédiatriques, Pôle de Pédiatrie Aiguë et Médecine Interne, Université Paris Diderot-Paris VII, Paris, FranceSuzel Magnier, AP-HP, Hôpital Robert-Debré, Service de Cardiologie Pédiatrique, Pôle de Pédiatrie Spécialisée, Université Paris Diderot-Paris VII, Paris, FrancePhilippe Bidet, AP-HP, Hôpital Robert-Debré, Service de Microbiologie, Pôle de Biologie, Université Paris Diderot-Paris VII, Paris, FranceCarole Saizou, AP-HP, Hôpital Robert-...

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How Common Is Rheumatic Heart Disease?

PediatricEducation.org — Mon, 23 May 2011 00:38:38 +0100

Discussion Acute rheumatic fever (ARF) is a nonsupprative, auto-inflammatory response after group A streptococcus (GAS) that affects multiple organs, including the heart. Chronic heart effects, particularly of the mitral and other heart valves, is termed rheumatic heart disease (RHD). ARF is thought to be caused by an autoimmune phenomenon where antibodies to the GAS cross react with normal host antigens. About 60% of ARF patients develop RHD and this is correlated to the initial carditis’s severity. ARF symptoms can present 2-5 weeks after the GAS pharyngitis. Diagnosis of ARF includes 2 major, or 1 major and 2 minor Jones’ criteria in the clinical setting of a preceding GAS infection. The updated Jones’ criteria include: Major criteria Carditis – 30-45% of pati...

Cutting Edge Issues in Rheumatic Fever

Clinical Reviews in Allergy and Immunology — Thu, 19 May 2011 16:33:35 +0100

Abstract Although the incidence of acute rheumatic fever and rheumatic heart disease has decreased significantly in regions of the world where antibiotics are easily accessible, there remains a high incidence in developing nations as well as in certain regions where there is a high incidence of genetic susceptibility. These diseases are a function of poverty, low socioeconomic status, and barriers to healthcare access, and it is in the developing world that a comprehensive prevention program is most critically needed. Development of group A streptococcal vaccines has been under investigation since the 1960s and 50 years later, we still have no vaccine. Factors that contribute to this lack of success include a potential risk for developing vaccine-induced rheumatic hea...

A rapid, high-resolution melting (HRM) multiplex PCR assay to detect macrolide resistance determinants in group A streptococcus

International Journal of Antimicrobial Agents — Wed, 18 May 2011 23:00:00 +0100

Detection and differentiation of macrolide resistance genes in group A streptococcus (GAS) (Streptococcus pyogenes) is clinically and epidemiologically relevant. We have developed a rapid, high-resolution melting (HRM) multiplex polymerase chain reaction (PCR) assay for this purpose. (Source: International Journal of Antimicrobial Agents)

A Retrospective Review of Streptococcal Infections in Pediatric Atopic Dermatitis

Pediatric Dermatology — Sat, 30 Apr 2011 23:00:00 +0100

Abstract: In order to assess the clinical characteristics and impact of group A streptococcal infection in children with atopic dermatitis, a retrospective review was performed in children diagnosed with atopic dermatitis who had a skin culture. Culture results and clinical characteristics of those with group A streptococcus were compared with those with Staphlococcus aureus. Infection with group A streptococcus was present in 16%; infection with Staphlococcus aureus was present in 72%, and 14% had mixed cultures. Patients infected with group A streptococcus were more likely to be febrile, to have facial and periorbital involvement, and to be hospitalized compared with those infected with Staphlococcus aureus alone (p ≤ 0.01 for all comparisons). Bacteremia and cellulitis were sig...

The histone-like protein Hlp is essential for growth of Streptococcus pyogenes: comparison of genetic approaches to study essential genes.

Applied and Environmental Microbiology — Thu, 28 Apr 2011 23:00:00 +0100

Authors: Bugrysheva JV, Froehlich BJ, Freiberg JA, Scott JR Selection of possible targets for vaccine and drug development requires an understanding of the physiology of bacterial pathogens, for which the ability to manipulate expression of essential genes is critical. For Streptococcus pyogenes (the group A streptococcus or GAS), an important human pathogen, the lack of genetic tools for such studies has seriously hampered research. To address this problem, we characterized variants of the inducible P(tet) cassette, in both the sense and antisense context, as tools to regulate transcription from GAS genes. We found that although the three operator P(tet) construct (P(tet)(O)(3)) had low uninduced expression, its induction level was low, while the two operator construct (P(tet)(O)(2)) ...

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Streptococcal M1 protein constructs a pathological host fibrinogen network

Nature — Tue, 05 Apr 2011 23:00:00 +0100

Authors: Pauline Macheboeuf, Cosmo Buffalo, Chi-yu Fu, Annelies S. Zinkernagel, Jason N. Cole, John E. Johnson, Victor Nizet & Partho Ghosh M1 protein, a major virulence factor of the leading invasive strain of group A Streptococcus, is sufficient to induce toxic-shock-like vascular leakage and tissue injury. These events are triggered by the formation of a complex between M1 and fibrinogen that, unlike M1 or fibrinogen (Source: Nature)

Lateral gene transfer of streptococcal ICE element RD2 (region of difference 2) encoding secreted proteins

BMC Microbiology - Latest articles — Thu, 31 Mar 2011 23:00:00 +0100

Conclusions: Taken together, the data indicate that the RD2 element has disseminated by lateral gene transfer to genetically diverse strains of human-pathogenic streptococci. (Source: BMC Microbiology - Latest articles)

Comparison of the Inverness Medical Acceava Strep A Test With the Genzyme OSOM and Quidel QuickVue Strep A Tests

Clinical Pediatrics — Wed, 23 Mar 2011 00:00:00 +0100

Previous studies of the accuracy of rapid in-office tests for group A Streptococcus had disparate results, ranging from a sensitivity of 70% to more than 90%. The sensitivity and specificity of 3 commercially available Strep A tests were determined in 2 private pediatric office settings. Acceava Strep A, Genzyme OSOM Strep A, and the Quidel QuickVue Strep A tests were the representative rapid tests for detection of Streptococcus pyogenes. Overnight culture on standard 5% sheep blood agar was the reference standard for this study. All 3 Clinical Laboratory Improvement Amendments—waived tests had sensitivities and specificities that exceeded 95%. (Source: Clinical Pediatrics)

Distinct signatures of diversifying selection revealed by genome analysis of respiratory tract and invasive bacterial populations [Microbiology]

Proceedings of the National Academy of Sciences — Tue, 22 Mar 2011 00:00:00 +0100

Many pathogens colonize different anatomical sites, but the selective pressures contributing to survival in the diverse niches are poorly understood. Group A Streptococcus (GAS) is a human-adapted bacterium that causes a range of infections. Much effort has been expended to dissect the molecular basis of invasive (sterile-site) infections, but little is known about the genomes of strains causing pharyngitis (streptococcal “sore throat”). Additionally, there is essentially nothing known about the genetic relationships between populations of invasive and pharyngitis strains. In particular, it is unclear if invasive strains represent a distinct genetic subpopulation of strains that cause pharyngitis. We compared the genomes of 86 serotype M3 GAS pharyngitis strains with those of 215 invas...

Group A Streptococcus Antibiotic Resistance in Southern Brazil: A 17-Year Surveillance Study

Microbial Drug Resistance — Sat, 19 Mar 2011 19:12:57 +0100

Microbial Drug Resistance , Vol. 0, No. 0. (Source: Microbial Drug Resistance)

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An outbreak of scarlet fever in a primary school

Archives of Disease in Childhood — Fri, 11 Mar 2011 00:00:00 +0100

Scarlet fever, due to infection with an erythrogenic toxin-producing Group A streptococcus, is an uncommon and generally mild illness, although serious sequelae do occur. In March 2009, 57 of the 126 (45%) pupils in a primary school in Lancashire, UK developed scarlet fever over a 4-week period. Infection was transmitted via direct contact between pupils, particularly among the youngest pupils. A significant degree of transmission also occurred between siblings. The median number of days absent from school was 3 (range 1–10 days). No children were hospitalised. Control measures, including hygiene advice to the school and exclusion of pupils for 24h while initiating penicillin treatment, were ineffective. The outbreak occurred against a background of an unusually high incidence of inv...

[Necrotizing fasciitis : 2011 update.]

Der Unfallchirurg — Sat, 05 Mar 2011 00:00:00 +0100

Authors: Herr M, Grabein B, Palm HG, Efinger K, Riesner HJ, Friemert B, Willy C Necrotizing fasciitis belongs to a group of complicated soft tissue infections that can be even life threatening. Despite growing knowledge about its etiology, predictors, and the clinical progression, the mortality remains at a high level with 20%. A relevant reduction can be achieved only by an early diagnosis followed by consistent therapy. The clinical findings in about 75% of the cases are pain out of proportion, edema and tenderness, blisters, and erythema. It is elementary to differentiate a necrotizing or a non-necrotizing soft tissue infection early. In uncertain cases it can be necessary to perform a surgical exploration to confirm the diagnosis. The histopathologic characteristics are the fascial...

Do cardiomyocytes mount an immune response to Group A Streptococcus?

Cytokine — Thu, 03 Mar 2011 00:00:00 +0100

Authors: Li Z, Bryant AE, Hamilton SM, Bayer CR, Ma Y, Stevens DL Some patients with Group A Streptococcal toxic shock syndrome (StrepTSS) develop a unique form of cardiomyopathy characterized by global hypokinesia and reduced cardiac index. Here we investigated the immune responses of cardiomyocytes to Group A Streptococcus both in vivo and in vitro. Our data demonstrate that cardiomyocyte-derived cytokines are produced following both direct GAS stimulation and after exposure to GAS-activated inflammatory cells. These locally produced, cardiomyocyte-derived cytokines may mediate cardiac contractile dysfunction observed in patients with StrepTSS-associated cardiomyopathy and may hold the key to our ability to attenuate this severe complication. PMID: 21377378 [PubMed - as supplied ...

SLS-mediated Group A Streptococcal Translocation [Microbiology]

Journal of Biological Chemistry — Fri, 21 Jan 2011 00:00:00 +0100

Group A Streptococcus pyogenes (GAS) is a human pathogen that causes local suppurative infections and severe invasive diseases. Systemic dissemination of GAS is initiated by bacterial penetration of the epithelial barrier of the pharynx or damaged skin. To gain insight into the mechanism by which GAS penetrates the epithelial barrier, we sought to identify both bacterial and host factors involved in the process. Screening of a transposon mutant library of a clinical GAS isolate recovered from an invasive episode allowed identification of streptolysin S (SLS) as a novel factor that facilitates the translocation of GAS. Of note, the wild type strain efficiently translocated across the epithelial monolayer, accompanied by a decrease in transepithelial electrical resistance and cleavage of tra...

A novel monoclonal antibody against FbaA that can inhibit the binding of the complement regulatory protein Factor H to Group A Streptococcus.

Clinical and Vaccine Immunology — Wed, 12 Jan 2011 00:00:00 +0100

In this study, we prepared monoclonal antibodies against FbaA, assayed them for specificity, and located their binding domains in FbaA. We found a monoclonal antibody called FbaAmab2, which demonstrated the highest affinity to GAS among all the monoclonal antibodies. Based on the binding with component peptides, the detected epitope, which was specific for FbaAmab2, was the amino acid residues 95∼118 of FbaA; on the other hand, it did not bind with the truncated protein of the internally deleted residues of the 95∼118 segment of FbaA. Furthermore, the predominant amino acids specific for FbaAmab2 screened by phage display epitope library were I, T, P, D and L, corresponding to the amino acid residues 101, 103, 105, 106 and 110 of FbaA, respectively. The binding location of FbaA with FH...

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CAS communication: Influenza, meningococcal infection and other bacterial co-infection including pneumococcal and invasive group A streptococcal infection (iGAS)

NeLM - News — Tue, 11 Jan 2011 00:00:00 +0100

Source: CAS Area: News This CAS communication contains a letter from the interim CMO about the increase in a number of significant bacterial infections such as those caused by Neisseria meningitidis (meningococcal disease) and others that may occur as co-infections with flu. Organisms such as Streptococcus pyogenes (Group A Streptococcus), Streptococcus pneumoniae, Staphylococcus aureus and Haemophilus influenzae, which can cause co-infection with flu, may affect people who typically are not considered to be at risk of severe illness from flu, such as those not currently in a risk group for seasonal influenza vaccination. Some of these bacterial co-infections can progress to severe illness rapidly and may carry a high mortality. Clinicians are advised of the following: ...

Dextromethorphan Efficiently Increases Bactericidal Activity, Attenuates Inflammatory Responses and Prevents Group A Streptococcal Sepsis.

Antimicrobial Agents and Chemotherapy — Mon, 03 Jan 2011 00:00:00 +0100

In this study, we investigated the potential protective effect of DM in GAS infection using an air pouch infection mouse model. Our results showed that DM treatment increased the survival rate of GAS-infected mice. Bacterial numbers in the air pouch were lower in mice treated with DM compared to those infected with GAS alone. The bacterial elimination efficacy was associated with increased cell viability and bactericidal activity of air-pouch infiltrating cells. Moreover, DM treatment prevented bacterial dissemination in the blood and reduced serum levels of proinflammatory cytokines IL-6, TNF-α, and IL-1β and chemokines MCP-1, MIP-2, and RANTES. In addition, GAS-induced mouse liver injury was reduced by DM treatment. Taken together, DM can increase bacterial killing and reduce inflammat...

An aggressive group a streptococcal cellulitis of the hand and forearm requiring surgical debridement.

Orthopedics — Sat, 01 Jan 2011 00:00:00 +0100

This article presents a case of an 85-year-old woman with a rapidly progressing, erythematous, painful, swollen hand associated with fever, hypotension, and mental status change. Due to a high clinical suspicion for necrotizing fasciitis, the patient was rapidly resuscitated and underwent immediate surgical irrigation and debridement. All intraoperative fascial pathology specimens were negative for necrotizing fasciitis, leading to a final diagnosis of Group A streptococcal cellulitis. Although surgical intervention is not commonly considered in patients with cellulitis, our patient benefited from irrigation and debridement with soft tissue decompression. In cases of necrotizing fasciitis as well as rapidly progressive cellulitis, prompt diagnosis and aggressive treatment may help patients...

Experts Differ on Treatment for Group A Strep

Pediatric News — Sat, 01 Jan 2011 00:00:00 +0100

LAS VEGAS — What's the treatment of choice for group A streptococcal tonsillopharyngitis? In 2009, attendees at this pediatric update sponsored by the American Academy of Pediatrics California District 9 were advised that cephalexin was the best first-line treatment. But those who returned this year heard a conflicting recommendation – for amoxicillin taken in one dose per day. Both recommendations differ from the AAP Red Book. (Source: Pediatric News)

Group A Streptococcus virulence factors genes in north India & their association with emm type in pharyngitis.

Indian J Med Res — Sat, 01 Jan 2011 00:00:00 +0100

This study also supports concept of isolate-associated virulence rather than type relatedness. PMID: 21321428 [PubMed - in process] (Source: Indian J Med Res)

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Properties of metabolic substances produced by group A streptococcus from a food-borne epidemic

Journal of Infection and Chemotherapy — Tue, 28 Dec 2010 15:04:56 +0100

Abstract Here we report a large food poisoning outbreak by Streptococcus pyogenes that occurred in Kanagawa, Japan, in July 2005. To compare cases of type T-B3264 (Chiba) and type T-28 (Tokyo) reported to date, we studied the properties and activity of the major virulence factors produced by Streptococcus pyogenes type T-25 (Kanagawa): hemolysin, cysteine protease streptococcal pyrogenic exotoxin B (SpeB), and NAD glycohydrolase (NADase). These virulence factors were also analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The titer of hemolysin was 9 50% hemolytic dose (HD50) per milliliter (HD50/ml) for T-25, 173 HD50/ml for T-28, and 147 HD50/ml for T-B3264. The hemolytic titer of T-25 was very low compared with those of T-28 an...

emm type distribution pattern of group A streptococcus in North India: Need for a new preventive approach.

Indian J Med Res — Wed, 01 Dec 2010 00:00:00 +0100

Authors: Dhanda V, Kumar R, Thakur JS, Chakraborti A PMID: 21245627 [PubMed - in process] (Source: Indian J Med Res)

Ongoing purifying selection on intergenic spacers in group A streptococcus.

Infection, Genetics and Evolution — Fri, 26 Nov 2010 00:00:00 +0100

Authors: Luo H, Tang J, Friedman R, Hughes AL Bacterial intergenic spacers are non-coding genomic regions enriched with cis-regulatory elements for gene expression. A population genetics approach was used to investigate the evolutionary force shaping the genetic diversity of intergenic spacers among 13 genomes of group A streptococcus (GAS). Analysis of 590 genes and their linked 5' intergenic spacers showed reduced nucleotide diversity in spacers compared to synonymous nucleotide diversity in protein-coding regions, suggestive of past purifying selection on spacers. Certain spacers showed elevated nucleotide diversity indicative of past homologous recombination with divergent genotypes. In addition, analysis of the difference between mean nucleotide difference and number of segregatin...

Necrotizing group A streptococcal periorbital infection following adalimumab therapy for rheumatoid arthritis.

Cutaneous and Ocular Toxicology — Mon, 15 Nov 2010 00:00:00 +0100

Conclusions: Anti-TNF-α agents are powerful immune-modulating drugs with potentially serious side effects. This case is the first to link adalimumab to necrotizing periorbital infection. Resolved infection does not preclude reintroduction of anti-TNF therapy however, careful assessment of the risks versus benefits of therapy is required at the individual patient level. PMID: 21077727 [PubMed - as supplied by publisher] (Source: Cutaneous and Ocular Toxicology)

Factors associated with Group A Streptococcus emm type diversification in a large urban setting in Brazil: a cross-sectional study

BMC Infectious Diseases — Thu, 11 Nov 2010 00:00:00 +0100

Background: Group A Streptococcus (GAS) strain diversity varies across different regions of the world, according to low versus high-income countries. These differences may be related to geographic, environmental, socioeconomic, or host-related factors. However, local factors may also affect strain diversity. We compared the emm types of GAS isolates from children with and without sore throat in one large urban setting in Brazil. Methods: Children 3-15 years of age were consecutively recruited from slum and non-slum pediatric outpatient clinics between April-October, 2008. Throat cultures were performed and data intake forms were completed. GAS isolates were typed by emm sequencing. Results: From 2194 children, 254 (12%) GAS isolates were obtained. Of 238 GAS isolates that were emm-typed, 6...

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Fatal group A Streptococcus purpura fulminans in a child receiving TNF-α blocker

European Journal of Pediatrics — Tue, 09 Nov 2010 12:51:06 +0100

We describe a fatal case of purpura fulminans caused by group A Streptococcus in an 8-year-old child with systemic juvenile idiopathic arthritis treated with etanercept. This case highlights the clinical association of severe bacterial infection and TNF-α inhibition in children. Pediatricians should educate their patients who are treated with TNF-α blockers regarding early warning symptoms and should also have a lower threshold for initiating antibiotic therapy in case of fever. Content Type Journal ArticleDOI 10.1007/s00431-010-1341-1Authors Christian Renaud, Division of Infectious Diseases, Department of Pediatrics, CHU Sainte-Justine, University of Montreal, 3175 côte Sainte-Catherine (Québec), Montreal, Québec Canada H3T 1C5Philippe Ovetchkine, Division of Infectious Dis...

Allelic replacement of the streptococcal cysteine protease SpeB in a deltasrv mutant background restores biofilm formation

BMC Research Notes — Thu, 04 Nov 2010 00:00:00 +0100

Conclusions: The constitutive production of SpeB by the srv mutant strain is responsible for the significant reduction of biofilm formation previously observed. The double mutant supports a model by which Srv contributes to biofilm formation and/or dispersal through regulation of speB/SpeB. (Source: BMC Research Notes)

Epidemic of Group A Streptococcus M/emm59 Causing Invasive Disease in Canada

Clinical Infectious Diseases Latest Issue — Fri, 29 Oct 2010 14:28:15 +0100

Conclusions. Western Canada has witnessed the rapid emergence of a rare GAS strain causing invasive disease predominately in a select population of disadvantaged persons. (Source: Clinical Infectious Diseases Latest Issue)

Self-adjuvanting polyacrylic nanoparticulate delivery system for group A streptococcus (GAS) vaccine

Nanomedicine : Nanotechnology, Biology, and Medicine — Wed, 27 Oct 2010 23:00:00 +0100

Abstract: Infection with Streptococcus pyogenes, commonly known as group A Streptococcus (GAS), is responsible for acute and postinfectious complications, including rheumatic fever and rheumatic heart disease (RHD). RHD is a global health burden, and Australia's indigenous population has one of the highest incidences of RHD worldwide. A potential peptide (J14) vaccine candidate has been previously identified from the C-terminal region of the M protein. However, such peptide-based vaccine development is hampered by a lack of carriers and adjuvants suitable for humans use. We have developed a fully synthetic peptide subunit vaccine candidate based on polyacrylate dendritic polymer. Intranasal administration of this nanoparticulate construct without additional adjuvant induced J14-specific Ig...

Clinical characteristics of children with group A streptococcal toxic shock syndrome admitted to pediatric intensive care units

European Journal of Pediatrics — Wed, 27 Oct 2010 16:01:43 +0100

Conclusions: STSS is a very severe condition secondary to invasive GAS infection. It can occur at any age, but especially in young children. Due to the lack of specific symptoms and signs and its very rapid progression to shock and organ dysfunction, pediatricians and emergency physicians must be aware of this possibility and immediately initiate aggressive treatment when suspected. Content Type Journal ArticleDOI 10.1007/s00431-010-1337-xAuthors Antonio Rodríguez-Nuñez, Pediatric Emergency and Critical Care Division, Hospital Clínico Universitario de Santiago de Compostela, Santiago de Compostela, SpainSilvia Dosil-Gallardo, Pediatric Emergency and Critical Care Division, Hospital Clínico Universitario de Santiago de Compostela, Santiago de Compostela, SpainIolanda Jordan, Pe...

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Augmented adherence and internalization of group A Streptococcus pyogenes to influenza A virus infected MDCK cells

Journal of Basic Microbiology — Wed, 20 Oct 2010 23:00:00 +0100

Abstract (Source: Journal of Basic Microbiology)

Comparison of the Inverness Medical Acceava Strep A Test With the Genzyme OSOM and Quidel QuickVue Strep A Tests

Clinical Pediatrics — Tue, 12 Oct 2010 20:50:43 +0100

Previous studies of the accuracy of rapid in-office tests for group A Streptococcus had disparate results, ranging from sensitivity of 70% to more than 90%. The sensitivity and specificity of 3 commercially available Strep A tests were determined in 2 private pediatric office settings. Acceava Strep A, Genzyme OSOM Strep A, and the Quidel QuickVue Strep A tests were the representative rapid tests for detection of Streptococcus pyogenes. Overnight culture on standard 5% sheep blood agar was the reference standard for this study. All 3 CLIA (Clinical Laboratory Improvement Amendments)-waived tests had sensitivities and specificities that exceeded 95%. (Source: Clinical Pediatrics)

Necrotizing soft tissue infections for the orthopaedic surgeon

Orthopaedics and Trauma — Fri, 01 Oct 2010 00:00:00 +0100

Abstract: Necrotizing soft tissue infections (NSTI) which include necrotizing fasciitis (NF) are potentially deadly. They more commonly affect men, the elderly and diabetics and are associated with both group A. streptococcus and S. aureus – community acquired MRSA has been responsible for a number of recent cases. Treatment of infections of the extremities often falls to orthopaedic surgeons. Diagnosis remains primarily clinical but such adjuncts as the LRINEC (Laboratory Risk Indicator score for NECrotizing fasciitis) and MRI scanning may be useful. Early definitive debridement within 24 h of admission reduces mortality. (Source: Orthopaedics and Trauma)

Decline in Erythromycin Resistance in Group A Streptococci from Acute Pharyngitis due to Changes in the emm Genotypes Rather Than Restriction of Antibiotic Use.

The Korean Journal of Laboratory Medicine — Thu, 30 Sep 2010 23:00:00 +0100

CONCLUSIONS: The erythromycin resistance rate of GAS isolated from children with acute pharyngitis was significantly lower in 2009 (4.6%) than in 2002 (44.8%). We observed a remarkable change in the distribution of emm genotypes during the 7-yr period. The significant decline in erythromycin resistance in 2009 might be associated with a prominent decrease in the resistant genotype emm12 (3.4% in 2009 vs. 28.0% in 2002) rather than restriction of macrolide use. PMID: 20890080 [PubMed - in process] (Source: The Korean Journal of Laboratory Medicine)

The group A Streptococcus small regulatory RNA FasX enhances streptokinase activity by increasing the stability of the ska mRNA transcript

Molecular Microbiology — Thu, 30 Sep 2010 23:00:00 +0100

Summary (Source: Molecular Microbiology)

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Treatment of Group A streptococcal infections

Paediatrics and Child Health — Thu, 30 Sep 2010 17:47:29 +0100

Abstract: Group A Streptococcus is a major cause of global death and morbidity. There has been much focus on the resurgence of severe and invasive forms in industrialized countries but most morbidity results from the non-suppurative sequelae of childhood infection in resource poor settings. Penicillin remains the main stay of treatment and prevention. In this article, we review the treatment of the varied manifestations of Group A streptococcal infection in childhood. (Source: Paediatrics and Child Health)

Dermal mast cells reduce progressive necrosis caused by subcutaneous infection with Streptococcus pyogenes in mice.

Journal of Medical Microbiology — Wed, 29 Sep 2010 23:00:00 +0100

Authors: Matsui H, Sekiya Y, Takahashi T, Nakamura M, Imanishi K, Yoshida H, Murayama SY, Takahashi T, Tsuchimoto K, Uchiyama T, Ubukata K A single subcutaneous (s.c.) infection with 1x10(7) CFU of GAS472, a group A streptococcus (GAS) serotype M1 strain isolated from the blood of a patient suffering from streptococcal toxic shock syndrome, led to severe damage of striated muscle layers in the feet of mast cell (MC)-deficient WBB6F1-Kit(W)/Kit(W-v) (W/W(v)) mice 72 h after infection. In contrast, no damages were recognized in striated muscle layers in the feet of the control WBB6F1-Kit(+/+) (+/+) mice 72 h after infection. In addition, adoptively transferred MCs reduced progressive tissue necrosis of the feet of W/W(v) mice after infection. However, there was no significant difference ...

Shr of group A streptococcus is a new type of composite NEAT protein involved in sequestering haem from methaemoglobin

Molecular Microbiology — Fri, 24 Sep 2010 20:50:31 +0100

Summary (Source: Molecular Microbiology)

033 Month of birth of people attending a Tourette syndrome clinic

Journal of Neurology, Neurosurgery and Psychiatry — Fri, 24 Sep 2010 15:41:34 +0100

Conclusions No significant variation from the fluctuations seen in national birth data was observed for the month of birth of patients with Tourette syndrome. This suggests that seasonal environmental factors during foetal development or early life are unlikely to contribute to an increased risk of Tourette syndrome. (Source: Journal of Neurology, Neurosurgery and Psychiatry)

CdhA, a GAS Chain-forming Virulence Factor [Molecular Bases Of Disease]

Journal of Biological Chemistry — Fri, 24 Sep 2010 13:38:47 +0100

In this study, we demonstrated that SP-STK-controlled cell division is mediated under the positive regulation of secretory protein that possesses a cysteine and histidine-dependent aminohydrolases/peptidases (CHAP) domain with functionally active cell wall hydrolase activity (henceforth named as CdhA (CHAP-domain-containing and chain-forming cell wall hydrolase). Deletion of the CdhA-encoding gene resulted in severe cell division and growth defects in GAS mutants. The mutant expressing the truncated CdhA (devoid of the CHAP domain), although displayed no such defects, it became attenuated for virulence in mice and highly susceptible to cell wall-acting antibiotics, as observed for the mutant lacking CdhA. When CdhA was overexpressed in the wild-type GAS as well as in heterologous strains, ...

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Evaluation of a Group A Streptococcus synthetic oligosaccharide as vaccine candidate.

Vaccine — Wed, 22 Sep 2010 23:00:00 +0100

Authors: Kabanova A, Margarit I, Berti F, Romano MR, Grandi G, Bensi G, Chiarot E, Proietti D, Swennen E, Cappelletti E, Fontani P, Casini D, Adamo R, Pinto V, Skibinski D, Capo S, Buffi G, Gallotta M, Seeberger PH, Christ WJ, Stewart Campbell A, Pena J, Rappuoli R, Costantino P Bacterial infections caused by Group A Streptococcus (GAS) are a serious health care concern that currently cannot be prevented by vaccination. The GAS cell-wall polysaccharide (GAS-PS) is an attractive vaccine candidate due to its constant expression pattern on different bacterial strains and protective properties of anti-GAS-PS antibodies. Here we report for the first time the immunoprotective efficacy of glycoconjugates with synthetic GAS oligosaccharides as compared to those containing the native GAS-PS. A ...

Prevalence of Streptococcal Pharyngitis and Streptococcal Carriage in Children: A Meta-analysis

PEDIATRICS — Wed, 01 Sep 2010 15:03:38 +0100

CONCLUSIONS: Prevalence rates of GAS disease and carriage varied by age; children who were younger than 5 years had lower rates of throat cultures that were positive for GAS. (Source: PEDIATRICS)

Pragmatic Scoring System for Pharyngitis in Low-Resource Settings

PEDIATRICS — Wed, 01 Sep 2010 15:03:38 +0100

CONCLUSIONS: This clinical decision rule could reduce unnecessary antibiotic treatment significantly in low-resource settings. (Source: PEDIATRICS)

Streptococcal Inhibitor of Complement Promotes Innate Immune Resistance Phenotypes of Invasive M1T1 Group A Streptococcus

Karger Publishers — Tue, 31 Aug 2010 23:00:00 +0100

J Innate Immun (DOI:10.1159/000317672) (Source: Karger Publishers)

Clostridiolysin S, a Post-translationally Modified Biotoxin from Clostridium botulinum [Microbiology]

Journal of Biological Chemistry — Fri, 27 Aug 2010 13:40:49 +0100

Through elaboration of its botulinum toxins, Clostridium botulinum produces clinical syndromes of infant botulism, wound botulism, and other invasive infections. Using comparative genomic analysis, an orphan nine-gene cluster was identified in C. botulinum and the related foodborne pathogen Clostridium sporogenes that resembled the biosynthetic machinery for streptolysin S, a key virulence factor from group A Streptococcus responsible for its hallmark β-hemolytic phenotype. Genetic complementation, in vitro reconstitution, mass spectral analysis, and plasmid intergrational mutagenesis demonstrate that the streptolysin S-like gene cluster from Clostridium sp. is responsible for the biogenesis of a novel post-translationally modified hemolytic toxin, clostridiolysin S. (Source: Journal ...

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Clostridiolysin S, a Post-translationally Modified Biotoxin [Microbiology]

Journal of Biological Chemistry — Fri, 27 Aug 2010 13:40:49 +0100

Pragmatic Scoring System for Pharyngitis May Be Helpful in Low-Resource Settings

Medscape Medical News Headlines — Thu, 12 Aug 2010 18:05:03 +0100

A clinical decision rule for group A streptococcus could significantly reduce unnecessary antibiotic treatment of pharyngitis in low-resource settings. Medscape Medical News (Source: Medscape Medical News Headlines)

Strep Accounts for 37 Percent of Pharyngitis in Children

Modern Medicine — Sun, 08 Aug 2010 23:00:00 +0100

Group A Streptococcus accounts for 37 percent of pediatric pharyngitis cases, though prevalence varies by age, and clinical scoring systems could reduce unnecessary antibiotic prescribing for non-group A Streptococcus pharyngitis in low-resource settings, according to research published online Aug. 9 in Pediatrics. (Source: Modern Medicine)

BRIEF REPORT: Neonatal Cellulitis and Sepsis Caused by Group A Streptococcus

Pediatric Dermatology — Sat, 31 Jul 2010 23:00:00 +0100

(Source: Pediatric Dermatology)

Shr of Group A Streptococcus is a new type of composite NEAT protein involved in sequestering heme from methemoglobin

Molecular Microbiology — Sat, 31 Jul 2010 23:00:00 +0100

(Source: Molecular Microbiology)

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Specific Behavior of Intracellular Streptococcus pyogenes That Has Undergone Autophagic Degradation Is Associated with Bacterial Streptolysin O and Host Small G Proteins Rab5 and Rab7 [Microbiology]

Journal of Biological Chemistry — Fri, 09 Jul 2010 15:11:05 +0100

In this study, we found that two host small G proteins, Rab5 and Rab7, were associated with the pathway of autophagosome formation and the fate of intracellular GAS. Rab5 was involved in bacterial invasion and endosome fusion. Rab7 was clearly multifunctional, with roles in bacterial invasion, endosome maturation, and autophagosome formation. In addition, this study showed that the bacterial cytolysin SLO supported the escape of GAS into the cytoplasm from endosomes, and surprisingly, a SLO-deficient mutant of GAS was viable longer than the wild-type strain although it failed to escape the endosomes. This intracellular behavior of GAS is unique and distinct from that of other types of bacterial invaders. Our results provide a new picture of GAS infection and host-cell responses in epitheli...

Asymptomatic colonization of upper respiratory tract by potential bacterial pathogens

Indian Journal of Pediatrics — Tue, 29 Jun 2010 16:34:35 +0100

Conclusions S. pneumoniae carriage rate was comparatively higher in the Community and its antimicrobial resistance is an issue to address. Content Type Journal ArticleDOI 10.1007/s12098-010-0118-xAuthors Rupak Dhakal, JIPMER Department of Microbiology Puducherry IndiaS. Sujatha, JIPMER Department of Microbiology Puducherry IndiaS. C. Parija, JIPMER Department of Microbiology Puducherry IndiaB. V. Bhat, JIPMER Department of Pediatrics Puducherry India Journal Indian Journal of PediatricsOnline ISSN 0973-7693Print ISSN 0019-5456 (Source: Indian Journal of Pediatrics)

Role for antibodies in altering behavior and movement

Autism Research — Mon, 28 Jun 2010 23:00:00 +0100

This article summarizes this discussion. In immune-mediated diseases, antibodies can contribute to the pathogenesis of the disease and are sometimes the force that drives the disease process. This concept has not been established for autism. In autoimmune diseases, such as systemic lupus erythematosus (SLE), antibodies are found to react with double-stranded DNA. These antibodies also cross-react with N-methyl-D aspartate receptors. Many SLE patients suffer neurologic syndromes of the central nervous system (CNS). Similarly individuals infected with Group A streptococcus (GAS) have antibodies against the GAS carbohydrate, which cross-react with tubulin and lysoganglioside GM1 on neurons. During the acute stage of infection, GAS-infected patients develop Syndenham chorea where the disease p...

Expand the Pharyngitis Paradigm for Adolescents and Young Adults: Centor RM. Ann Intern Med 2009;151:812–5

The Journal of Emergency Medicine — Tue, 22 Jun 2010 05:33:41 +0100

This review article highlights Fusobacterium necrophorum as an important and under-recognized etiology of infectious pharyngitis in adolescents and young adults. Previous studies and standard-of-care guidelines have focused primarily on treating streptococcal pharyngitis, with a goal of reducing post-streptococcal complications such as rheumatic fever. Many algorithms recommend that non-streptococcal pharyngitis should not be treated with antibiotics. The author suggests that pharyngitis caused by F. necrophorum should also be strongly considered for treatment with antibiotics. Three studies are cited suggesting that the overall prevalence of these bacteria in patients with clinical pharyngitis and tonsillitis is approximately 10%, very similar to the prevalence of Group A streptococcus in...

[Right-sided Lower Abdominal Pain and Diarrhea of a Young Diabetic Woman.]

Praxis — Tue, 08 Jun 2010 23:00:00 +0100

We report the case of a 24-years old diabetic women hospitalised because of right-sided lower abdominal pain and diarrhea. She fulminantly developed shock before appendectomy could be performed and was transferred to intensive care unit. Hypotension remained and laparoscopy revealed primary peritonitis and toxic shock syndrome by Group A Streptococcus which was cultivated in blood and ascites. Therapy with penicilline and clindamycine resolved symptoms. During hospitalisation Clostridium difficile colitis occurred. This complication leaded to prolonged hospitalisation. PMID: 20533233 [PubMed - as supplied by publisher] (Source: Praxis)

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Invasive group A streptococcal infection: AN UPDATE ON THE EPIDEMIOLOGY AND ORTHOPAEDIC MANAGEMENT.

The Journal of Bone and Joint Surgery. British volume — Mon, 31 May 2010 23:00:00 +0100

Authors: Brown CN, Pollard TC, Iyer S, Andrade AJ Invasive group A streptococcus (iGAS) is the most common cause of monomicrobial necrotising fasciitis. Necrotising infections of the extremities may present directly to orthopaedic surgeons or by reference from another admitting specialty. Recent epidemiological data from the Health Protection Agency suggest an increasing incidence of iGAS infection in England. Almost 40% of those affected had no predisposing illnesses or risk factors, and the proportion of children presenting with infections has risen. These observations have prompted the Chief Medical Officer for the Central Alerting System in England to write to general practitioners and hospitals, highlighting the need for clinical vigilance, early diagnosis and rapid initiation of ...

Genetic Switch to Hypervirulence Reduces Colonization Phenotypes of the Globally Disseminated Group A Streptococcus M1T1 Clone

The Journal of Infectious Diseases Latest Issue — Thu, 27 May 2010 17:22:34 +0100

Conclusion. Reduced colonization capacity provides a potential explanation for why the covS mutation, which confers hypervirulence, has not become fixed in the globally disseminated M1T1 group A Streptococcus clone, but rather may arise anew under innate immune selection in individual patients. (Source: The Journal of Infectious Diseases Latest Issue)

The Scl1 of M41-type group A Streptococcus binds the high-density lipoprotein

FEMS Microbiology Letters — Thu, 13 May 2010 23:00:00 +0100

Streptococcal collagen-like protein 1 (Scl1) is a virulence factor on the surface of group A Streptococcus (GAS). We have reported previously that several Scl1 proteins derived from various M-type GAS strains, including M41, can bind to low-density lipoprotein, but the Scl1 protein derived from the M6-type GAS strain cannot. Here, we demonstrated that recombinant protein, designated C176, derived from Scl1.41 of the GAS M41-type strain also binds both plasma and purified high-density lipoprotein (HDL). Next, we determined that the intact noncollagenous region of C176 was necessary and sufficient for HDL binding. C176[ndash]HDL interaction could be eliminated by the presence of low concentrations of the nonionic detergent, Tween 20, indicating the hydrophobic nature of this interaction. We ...

How Bacterial Community Evolves To Survive

Health News from Medical News Today — Thu, 13 May 2010 10:00:00 +0100

An international team led by a University of Cincinnati (UC) researcher has shown how a bacterial community evolves to survive hostile host defenses in the body. The team, led by Malak Kotb, PhD, chair of UC's of molecular genetics, biochemistry and microbiology department, analyzed the evolution over time of the community structure of Group A streptococcus (also known as GAS or Strep A), a bacterium often found in the throat or on the skin. It can cause many human diseases, ranging from strep throat to debilitating and often deadly diseases of the heart, skin, kidney and brain... (Source: Health News from Medical News Today)

Superantigen Genes are More Important than the emm Type for the Invasiveness of Group A Streptococcus Infection

The Journal of Infectious Diseases Latest Issue — Tue, 11 May 2010 15:28:28 +0100

Conclusions. These results indicate that the presence of superantigen genes is more important for the invasiveness of group A Streptococcus infection than emm type and may be the connection between the high‐risk HLA type of the host and the pathogen. Furthermore, we found a very clear correlation between the presence of the genes spea1–spea3 and the presence of the gene emm1, which indicates that the relationship between emm1 and invasiveness is based on the superantigen gene profile. Our data suggest that the superantigen gene profile is of high importance for the clinical outcome of group A Streptococcus infections. (Source: The Journal of Infectious Diseases Latest Issue)

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Molecular mimicry between streptococcal pyrogenic exotoxin B and endothelial cells

Laboratory Investigation AOP — Sun, 09 May 2010 23:00:00 +0100

Authors: Yueh-Hsia Luo, Woei-Jer Chuang, Jiunn-Jong Wu, Ming T Lin, Ching-Chuan Liu, Pao-Yen Lin, Jun-Neng Roan, Tak-Wah Wong, Yuh-Ling Chen & Yee-Shin Lin (Source: Laboratory Investigation AOP)

NPC iblog: Antibiotic strategy for preventing complications of sore throat in young people

NeLM - News — Sun, 09 May 2010 23:00:00 +0100

Source: National Prescribing Centre (NPC) Area: News The NPC have published an iblog discussing a "Perspective" article published in the Annals of Internal Medicine which considered the causative organisms, and antibiotic treatments to avoid potential complications in adolescents and young adults who present with sore throats. The article states that although most antimicrobial therapy for bacterial pharyngitis has focussed on a group A beta-haemolytic streptococcus (GABHS) as the causative agent, Fusobacterium necrophorum (FN), a gram-negative anaerobe, occurs at a similar frequency to that of group-A streptococcus (GAS) in young adults and adolescents with acute pharaygitis (about 10%). The authors of the article state that in the absence of clinical data, and no simple means...

Parainfectious optic neuropathy in a young patient with group A Streptococcus pyogenes orbital cellulitis.

Canadian Journal of Ophthalmology — Tue, 04 May 2010 11:02:22 +0100

Authors: Kassiri K, Nathoo N, El-Hakim H, Sabri K PMID: 20436531 [PubMed - as supplied by publisher] (Source: Canadian Journal of Ophthalmology)

Invasive group A streptococcal infection in pregnancy

Journal of Infection — Thu, 22 Apr 2010 23:00:00 +0100

Summary: We conducted a literature review of 55 pregnancies with symptomatic Group A streptococcus (Streptococcus pyogenes) infection reported in English (20 cases), French (2 cases) and Japanese (33 cases) to seek ways of improving prognosis. Multiparous women (83% [39/47]) in the third trimester (90% [47/52]) were prone to infection from winter to spring (75% [21/28]). Onset was heralded by flu-like symptoms, such as high fever (94% [46/49]), with upper respiratory (40% [22/55]) and/or gastrointestinal symptoms (49% [27/55]). Characteristic findings were early onset of shock (91% [50/55]) and infection-induced strong uterine contraction (73% [40/55]) suggestive of placental abruption. The clinical course was too acute and severe to rescue the mother (58% [32/55] died) and/or infant (66% ...

MtsR is a dual regulator that controls virulence genes and metabolic functions in addition to metal homeostasis in the group A streptococcus

Molecular Microbiology — Mon, 19 Apr 2010 23:00:00 +0100

In conclusion, we report here that MtsR is a global regulator in GAS that shapes the expression of vital virulence factors and genes involved in metabolic functions and metal transport, and we discuss the implications for the GAS disease process. (Source: Molecular Microbiology)

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Induction of TGF-{beta}1 and TGF-{beta}1-dependent predominant Th17 differentiation by group A streptococcal infection [Immunology]

Proceedings of the National Academy of Sciences — Tue, 30 Mar 2010 17:53:34 +0100

Recurrent group A Streptococcus (GAS) tonsillitis and associated autoimmune diseases indicate that the immune response to this organism can be... (Source: Proceedings of the National Academy of Sciences)

Beneficial use of immunoglobulins in the treatment of Sydenham chorea

European Journal of Pediatrics — Mon, 29 Mar 2010 05:39:46 +0100

Abstract This double case report indicates that treatment with intravenous immunoglobulins (IVIG) is effective in patients with Sydenham chorea (SC). SC is a rare but impressive clinical manifestation following streptococcal infection. This movement disorder characterised by chorea, emotional lability and muscle weakness, is one of the major criteria of acute rheumatic fever. Treatment of SC is typically limited to supportive care and palliative medications. Curative treatment is still in the experimental stage. Recent research on patients with SC proved that antibodies against the group A streptococcus cross-react with epitopes of neurons in the basal ganglia, namely, intracellular tubulin and extracellular lysoganglioside. Therefore, immune modulating therapy by means of...

The streptococcal M protein: a highly versatile molecule.

Trends in Microbiology — Fri, 26 Mar 2010 00:00:00 +0100

Authors: Smeesters PR, McMillan DJ, Sriprakash KS Interaction of the M-protein of group A Streptococcus (GAS) with it numerous host binding partners might assist the bacteria in evading host immune responses. Although the extensive diversity of this protein has been highlighted by different GAS typing schemes, most of the structural and functional information has been obtained from a limited number of types. Increasing numbers of epidemiological, clinical and biological reports suggest that the structure and function of the M protein is less conserved than previously thought. This review focuses on the known interactions between M proteins and host ligand proteins, emphasizing that our understanding of this well-studied molecule is fragmented. PMID: 20347595 [PubMed - as supplied b...

Lemierre syndrome associated with group A streptococcal infection

The American Journal of Emergency Medicine — Fri, 26 Mar 2010 00:00:00 +0100

We report a case of Lemierre syndrome caused by group A Streptococcus (GAS) in a 4-year-old girl. She was initially diagnosed with GAS pharyngitis but failed treatment with azithromycin and subsequently developed right-sided neck swelling concerning for a deep neck abscess. A neck computed tomography scan revealed right internal jugular vein thrombosis but no abscess. Blood culture grew GAS, sensitive to penicillin and ceftriaxone but resistant to clindamycin and azithromycin. The patient was treated with ceftriaxone and anticoagulation resulting in complete recovery. Although very unusual, physicians must be aware that GAS can cause Lemierre syndrome. Penicillin should remain the drug of choice for GAS pharyngitis. Early diagnosis and treatment of Lemierre syndrome is crucial to decrease ...

[Case Report] Nosocomial transmission of necrotising fasciitis

LANCET — Fri, 19 Mar 2010 00:00:00 +0100

In June, 2008, a previously healthy 8-month-old girl presented with chickenpox, fever (39·5°C), and a red, painful, and swollen right arm with dusky and purplish skin discoloration (). Empirical intravenous antimicrobial therapy with amoxicillin-clavulanate and clindamycin was initiated after microbiological screening (blood culture and wound smear). A diagnosis of cellulitis with suspicion of necrotising fasciitis was made and surgical debridement was undertaken within 8 h after admission (). Macroscopic and microscopic examination confirmed extensive necrosis. A few hours later, she developed hypotension, renal failure, coagulopathy, and thrombocytopenia. Probable toxic shock syndrome was diagnosed and intensive supportive care started. Multi-susceptible group A streptococcus was isola...

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Microbiological investigation of a hospital outbreak of invasive group A streptococcal disease in Krakow, Poland

Clinical Microbiology and Infection — Sat, 13 Mar 2010 00:00:00 +0100

Clin Microbiol Infect The present study reports the epidemiological investigations undertaken in one of Krakow's city hospitals regarding the source of infection and the routes of transmission of a group A streptococcus (Streptococcus pyogenes), using fluorescent in situ hybridization as a rapid method for detecting S. pyogenes carriage in the medical personnel involved. Four patients from the gynaecology department and two patients from the surgery department presented with clinical signs of infection. Characteristics of the S. pyogenes strains isolated from patients and from one medical staff member, including the emm gene and superantigens encoding genes, are described. All patients (four confirmed and two probable cases) survived; the operating theatre aid was identified as an S. pyoge...

Preferences for health outcomes associated with Group A Streptococcal disease and vaccination

Health and Quality of Life Outcomes — Fri, 12 Mar 2010 00:00:00 +0100

Conclusions: Parents strongly prefer to prevent GAS disease in children compared to vaccine adverse events. However, WTP/QALY thresholds were higher for the prevention of vaccine adverse events. Regret for errors of commission vs. omission may differ and should be considered by vaccine policymakers. (Source: Health and Quality of Life Outcomes)

Interactome analysis of longitudinal pharyngeal infection of cynomolgus macaques by group A Streptococcus [Microbiology]

Proceedings of the National Academy of Sciences — Tue, 09 Mar 2010 17:27:19 +0100

Relatively little is understood about the dynamics of global host–pathogen transcriptome changes that occur during bacterial infection of mucosal surfaces.... (Source: Proceedings of the National Academy of Sciences)

Broad Spectrum Respiratory Pathogen Analysis of Throat Swabs from Military Recruits Reveals Interference Between Rhinoviruses and Adenoviruses.

Microbial Ecology — Tue, 09 Mar 2010 00:00:00 +0100

In this study, we explore the carriage rates and disease associations of adenovirus, enterovirus, rhinovirus, Streptococcus pneumoniae, Haemophilus influenzae, and Neisseria meningitidis in military recruits using high-density resequencing microarrays. The results showed that rhinoviruses, adenoviruses, S. pneumoniae, H. influenzae, and N. meningitidis were widely distributed in recruits. Of these five agents, only adenovirus showed significant correlation with illness. Among the samples tested, only pathogens associated with FRI, such as adenovirus 4 and enterovirus 68, revealed strong temporal and spatial clustering of specific strains, indicating that they are transmitted primarily within sites. The results showed a strong negative association between adenoviral FRI and the presence of ...

Macrolide-resistant Streptococcus pyogenes in Central Greece: prevalence; mechanism and molecular identification

International Journal of Antimicrobial Agents — Mon, 08 Mar 2010 00:00:00 +0100

Streptococcus pyogenes [group A Streptococcus (GAS)] is the most common bacterial agent implicated in acute tonsillopharyngitis and can also cause a variety of skin and soft-tissue infections and severe invasive disease. Macrolides constitute an alternative choice for the treatment of streptococcal tonsillopharyngitis and other respiratory tract infections, especially valuable in patients allergic to β-lactams. (Source: International Journal of Antimicrobial Agents)

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Genome Study Shows How Strep Throat Germ Circumvents Our Immune System

Immune System / Vaccines News From Medical News Today — Tue, 23 Feb 2010 10:00:00 +0100

Investigators at The Methodist Hospital Research Institute in Houston examined for the first time the long-term response to strep throat on a genome-wide level, shedding light on how group A streptococcus interacts with the patient's immune system and attempts to circumvent it. Results were published in the Proceedings of the National Academy of Sciences (PNAS)... (Source: Immune System / Vaccines News From Medical News Today)

Modest Genetic Differences Seen in Streptococcus Strains

Modern Medicine — Tue, 16 Feb 2010 00:00:00 +0100

Group A Streptococcus strains from successive epidemics have relatively modest genetic differences but very different global gene expression, which may provide clues about their biology, according to a study published online Feb. 8 in the Proceedings of the National Academy of Sciences. (Source: Modern Medicine)

Dissection of the Molecular Basis for Hypervirulence of an In Vivo–Selected Phenotype of the Widely Disseminated M1T1 Strain of Group A Streptococcus Bacteria

The Journal of Infectious Diseases Latest Issue — Fri, 12 Feb 2010 21:58:19 +0100

The Journal of Infectious Diseases, Volume 0, Issue 0, Page 000, Latest Articles. Group A streptococci (GAS) may engage different sets of virulence strategies, depending on the site of infection and host context. We previously isolated 2 phenotypic variants of a globally disseminated M1T1 GAS clone: a virulent wild‐type (WT) strain, characterized by a SpeB+/SpeA−/Sda1low phenotype, and a hypervirulent animal‐passaged (AP) strain, better adapted to survive in vivo, with a SpeB−/SpeA+/Sda1high phenotype. This AP strain arises in vivo due to the selection of bacteria with mutations in covS, the sensor part of a key 2‐component regulatory system, CovR/S. To determine whether covS mutations explain the hypervirulence of the AP strain, we deleted covS from WT bacteria (ΔCovS) an...

Epidemiological markers of Streptococcus pyogenes strains in Tunisia

Clinical Microbiology and Infection — Tue, 02 Feb 2010 00:00:00 +0100

Clin Microbiol Infect To further understand the epidemiology of Streptococcus pyogenes or group A streptococcus (GAS) infections in Tunisia, phenotypic and genomic markers of GAS isolates, including antibiotic susceptibility, biotypes, T and emm types and toxin gene profiles, have been characterized. A total of 103 isolates, collected between 2000 and 2006, were investigated; 47 were recovered from invasive infections, and 56 from non-invasive infections. Rates of tesistance to tetracycline, erythromycin, clindamycin and rifampin were 70.8%, 4.8%, 4.8% and 0.9%, respectively. High levels of resistance to streptomycin and kanamycin were observed in 1.9% and 4.8% of isolates, respectively. Biotype 3 was most common. Twenty different T patterns were observed, with a predominance of T3/13/B326...

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The 4.5S RNA component of the signal recognition particle is required for group A Streptococcus virulence.

Microbiology — Thu, 28 Jan 2010 00:00:00 +0100

Authors: Treviño J, Perez N, Sumby P The signal recognition particle (SRP) is a ribonucleoprotein complex that targets proteins for secretion in a co-translational manner. While originally thought to be essential in all bacteria, recent data show that the SRP is dispensable in at least some streptococcal species. The SRP from the human pathogen group A Streptococcus (GAS, Streptococcus pyogenes) is predicted to be composed of protein Ffh and RNA 4.5S. Deletion of ffh alters the secretion of several GAS proteins, and leads to a severe reduction in virulence. Here, we report that mutation of the 4.5S RNA-encoding gene results in phenotypes both similar and distinct from that observed following ffh mutation. Similarities include a reduction in secretion of the hemolysin streptolysin ...

Combinational SNARE Proteins VAMP8 and Vti1b Mediate Fusion of Antimicrobial and Canonical Autophagosomes with Lysosomes.

Mol Biol Cell — Wed, 20 Jan 2010 00:00:00 +0100

We examined the involvement of endocytic soluble N-ethylmaleimide-sensitive factor attachment protein receptors (SNAREs) in xenophagosome/lysosome fusion. Confocal microscopic analysis showed that SNAREs, including VAMP7, VAMP8, and Vti1b, colocalized with GFP-LC3 in xenophagosomes. Knockdown of Vti1b and VAMP8 with siRNAs disturbed the colocalization of LC3 with LAMP1. The invasive efficiency of GAS into cells was not altered by knockdown of VAMP8 or Vti1b, whereas cellular bactericidal efficiency was significantly diminished, indicating that antimicrobial autophagy was functionally impaired. Knockdown of Vti1b and VAMP8 also disturbed colocalization of LC3 with LAMP1 in canonical autophagy, in which LC3-II proteins were negligibly degraded. In contrast, knockdown of Syntaxin 7 and Syntax...

The Human Immune Response to Streptococcal Extracellular Antigens: Clinical, Diagnostic, and Potential Pathogenetic Implications

Clinical Infectious Diseases Latest Issue — Tue, 12 Jan 2010 21:28:11 +0100

Conclusions. Single time‐point cultures and single antibody titers are often misleading. Sequential samples more accurately define infection, allowing correlation of titer increases with temporal confirmation of GAS acquisition. Understanding kinetics of the immune response(s) to GAS infection is necessary in formulating accurate clinical diagnostic conclusions, to appropriate design of clinical and epidemiological studies examining the association of GAS with subsequent sequelae, and to providing insight into pathogenetic mechanisms associated with this important human pathogen. (Source: Clinical Infectious Diseases Latest Issue)

Reactive oxygen species induced by Streptococcus pyogenes invasion trigger apoptotic cell death in infected epithelial cells

Cellular Microbiology — Mon, 11 Jan 2010 00:00:00 +0100

Streptococcus pyogenes (group A streptococcus, GAS), one of the most common pathogens of humans, attaches and invades into human pharyngeal or skin epithelial cells. We have previously reported that induction of apoptosis is associated with GAS invasion, which induces mitochondrial dysfunction and apoptotic cell death. We demonstrate here that GAS-induced apoptosis is mediated by reactive oxygen species (ROS) production. Both the induction of apoptosis and ROS production markedly increased upon invasion of wild-type GAS strain JRS4 into HeLa cells; however, the apoptotic response was not observed in fibronectin-binding protein F1-disrupted mutant SAM1-infected cells. In Bcl-2-overexpressing HeLa cells (HBD98-2-4), the induction of apoptosis, ROS production and mitochondrial dysfunction wer...

Complement inhibition by gram-positive pathogens: molecular mechanisms and therapeutic implications

Journal of Molecular Medicine — Fri, 08 Jan 2010 21:44:04 +0100

Abstract The plasma proteins of the complement system are essential in the innate immune response against bacteria. Complement labels bacteria with opsonins to support phagocytosis and generates chemoattractants to attract phagocytes to the site of infection. In turn, bacterial human pathogens have evolved different strategies to specifically impair the complement response. Here, we review the large arsenal of complement inhibitors produced by the gram-positive pathogens Staphylococcus aureus and Group A Streptococcus. We discuss how these bacterial molecules provide us with new tools to treat both infectious and inflammatory disease conditions in humans. Content Type Journal ArticleCategory ReviewDOI 10.1007/s00109-009-0572-yAuthors Alexander Laarman, University Medica...

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Structure-activity relationship of lipopeptide Group A streptococcus (GAS) vaccine candidates on toll-like receptor 2.

Vaccine — Wed, 30 Dec 2009 00:00:00 +0100

Authors: Zaman M, Abdel-Aal AB, Phillipps KS, Fujita Y, Good MF, Toth I Incorporation of lipoamino acids (LAAs) into peptide structures effectively imparts self-adjuvanting activity onto otherwise ineffective immunogens. Our fully synthetic lipopeptide vaccine candidates against group A streptococcus (GAS) were composed of J14 as a target GAS B-cell epitope alongside a universal helper T-cell epitope (P25) and a LAA-based lipid moiety. In the current study, we investigated the ability of our lipopeptides to activate nuclear factor-kappaB (NF-kappaB) in a toll-like receptor-2 (TLR2)-dependent manner as the possible mode of action and reported the structure-function requirements for novel TLR2 targeting lipopeptides based on LAAs. The NF-kappaB activation was dependent on the dose and th...

Bactericidal and anti-inflammatory properties of a standardized Echinacea extract (Echinaforce®): Dual actions against respiratory bacteria

Phytomedicine — Mon, 28 Dec 2009 00:00:00 +0100

Abstract: Common symptoms of upper respiratory infections, such as sore throat, cough, and inflammation, are often caused by bacteria, sometimes as a complication of virus infection. Extracts of Echinacea purpurea (Asteraceae) have been advocated traditionally for use by individuals suffering from these symptoms, although the underlying basis for the beneficial effects of Echinacea is not known. We hypothesized that Echinacea could inactivate certain respiratory bacteria and could also reverse inflammatory effects caused by these bacteria in epithelial cells. In order to test this we used a commercial standardized extract of Echinacea purpurea (Echinaforce®), and a novel cytokine array system designed to measure simultaneously the levels of 20 different cytokines secreted by bronchial epi...

The ribonucleases J1 and J2 are essential for growth and have independent roles in mRNA decay in Streptococcus pyogenes

Molecular Microbiology — Wed, 16 Dec 2009 00:00:00 +0100

We report that RNases J1 and J2 affect the rate of decay of Class I messages and the length of the first phase in decay of Class II messages. (Source: Molecular Microbiology)

M1T1 group A streptococcal pili promote epithelial colonization but diminish systemic virulence through neutrophil extracellular entrapment

Journal of Molecular Medicine — Fri, 04 Dec 2009 07:18:49 +0100

Abstract Group A Streptococcus is a leading human pathogen associated with a diverse array of mucosal and systemic infections. Cell wall anchored pili were recently described in several species of pathogenic streptococci, and in the case of GAS, these surface appendages were demonstrated to facilitate epithelial cell adherence. Here we use targeted mutagenesis to evaluate the contribution of pilus expression to virulence of the globally disseminated M1T1 GAS clone, the leading agent of both GAS pharyngitis and severe invasive infections. We confirm that pilus expression promotes GAS adherence to pharyngeal cells, keratinocytes, and skin. However, in contrast to findings reported for group B streptococcal and pneumococcal pili, we observe that pilus expression reduces GAS vi...

Clinical lesson: old diseases may affect older patientsCovering Letter

Journal of Infection — Tue, 01 Dec 2009 00:00:00 +0100

We describe a case in a 34 year-old, black-African patient with well-controlled HIV disease, in whom the findings of carditis, along with fever and elevated acute phase reactants, fulfilled the Duckett-Jones Criteria (one major and two minor criteria, respectively) and followed a recent Group A Streptococcus pharyngitis. The patient was confident that she had not had rheumatic fever as a child. The case highlights a number of important points. Firstly, the importance of scrutinising previous microbiological results that may not initially seem relevant to the patient's presenting complaint. Secondly, that ASO titres may be negative in up to 80-90% of patients with the condition, as it was in this particular case and that when this occurs, efforts should be made to look for rising titres of ...

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Expand the pharyngitis paradigm for adolescents and young adults.

Annals of Internal Medicine — Tue, 01 Dec 2009 00:00:00 +0100

Authors: Centor RM Current guidelines and review articles emphasize that clinicians should consider group A beta-hemolytic streptococcus in the diagnosis and management of patients with acute pharyngitis. Recent data suggest that in adolescents and young adults (persons aged 15 to 24 years), Fusobacterium necrophorum causes endemic pharyngitis at a rate similar to that of group A beta-hemolytic streptococcus. On the basis of published epidemiologic data, F. necrophorum is estimated to cause the Lemierre syndrome-a life-threatening suppurative complication-at a higher incidence than that at which group A streptococcus causes acute rheumatic fever. Moreover, these estimates suggest greater morbidity and mortality from the Lemierre syndrome. The diagnostic paradigm for adolescent pharyngi...

Epidemiology of group a streptococcal pharyngitis & impetigo: A cross-sectional & follow up study in a rural community of northern India.

Indian J Med Res — Tue, 01 Dec 2009 00:00:00 +0100

CONCLUSION: In north India, pharyngitis was more common than impetigo. Most prevalent emm types of GAS in this region differ from those included in M protein-based vaccines. PMID: 20090140 [PubMed - in process] (Source: Indian J Med Res)

Staphylococcal and streptococcal infections

Medicine — Mon, 30 Nov 2009 16:03:39 +0100

Abstract: Staphylococcal and streptococcal infections are common infectious diseases and can range from mild, superficial skin infections to severe, life-threatening systemic infections. Staphylococcus aureus, group A streptococcus, and Streptococcus pneumoniae are the three major pathogens. The prevalence of invasive infections caused by community-associated meticillin-resistant S. aureus and group A streptococcus appears to be increasing. The emergence of drug resistance (e.g. meticillin and glycopeptide resistance in S. aureus, macrolide resistance in group A streptococci and penicillin resistance in S. pneumoniae), is concerning and a potential threat to successful treatment. Streptococcus suis has recently emerged as an important human pathogen. (Source: Medicine)

Scl1, the multifunctional adhesin of group A Streptococcus, selectively binds cellular fibronectin and laminin, and mediates pathogen internalization by human cells

FEMS Microbiology Letters — Mon, 23 Nov 2009 00:00:00 +0100

The streptococcal collagen-like protein-1, Scl1, is widely expressed by the well-recognized human pathogen group A Streptococcus (GAS). Screening of human ligands for binding to recombinant Scl1 identified cellular fibronectin and laminin as binding partners. Both ligands interacted with the globular domain of Scl1, which is also able to bind the low-density lipoprotein. Native Scl1 mediated GAS adherence to ligand-coated glass cover slips and promoted GAS internalization into HEp-2 cells. This work identifies new ligands of the Scl1 protein that are known to be important in GAS pathogenesis and suggests a novel ligand-switching mechanism between blood and tissue environments, thereby facilitating host colonization and GAS dissemination. (Source: FEMS Microbiology Letters)