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Gursharan S Chhatwal - One of the best experts on this subject based on the ideXlab platform.
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variability in the distribution of genes encoding virulence factors and putative extracellular proteins of streptococcus pyogenes in india a region with high streptococcal disease burden and implication for development of a regional multisubunit vaccine
Clinical and Vaccine Immunology, 2012Co-Authors: Vivek Sagar, Rene Bergmann, Andreas G Nerlich, David J Mcmillan, Patric Nitsche D Schmitz, Gursharan S ChhatwalAbstract:Streptococcus pyogenes causes a wide variety of human diseases and is a significant cause of morbidity and mortality. Attempts to develop a vaccine were hampered by the genetic diversity of S. pyogenes across different regions of the world. This study sought to identify streptococcal antigens suitable for a region-specific vaccine in India. We used a two-step approach,first performing epidemiological analysis to identify the conserved antigens among Indian isolates. The second step consisted of validating the identified antigens by serological analysis. The 201 streptococcal clinical isolates from India used in this study represented 69 different emm types, with emm12 being the most prevalent. Virulence profiling of the North and South Indian S. pyogenes isolates with a custom-designed streptococcal virulence microarray identified seven conserved putative vaccine candidates. Collagen-like surface protein (SCI), putative secreted 5=-nucleotidase (PSNT), and C5a Peptidase were found in 100% of the isolates, while R28, a putative surface antigen (PSA), and a hypothetical protein (HYP) were found in 90% of the isolates. Afibronectin bindingprotein,SfbI,waspresentinonly78%oftheisolates.Inordertovalidatetheidentifiedpotentialvaccinecandidates,185serum samplesobtainedfrompatientswithdifferentclinicalmanifestationsweretestedforantibodies.Irrespectiveofclinicalmanifestations, serumsamplesshowedhighantibodytiterstoallproteinsexceptforSCIandR28.Thus,thedataindicatethatPSNT,C5aPeptidase, PSA,HYP,andSfbIarepromisingcandidatesforaregion-specificstreptococcalvaccineforthedifferentpartsofIndia.
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virulence gene pool detected in bovine group c streptococcus dysgalactiae subsp dysgalactiae isolates by use of a group a s pyogenes virulence microarray
Journal of Clinical Microbiology, 2011Co-Authors: Marcia G Rato, Rene Bergmann, A Nerlich, Ricardo Bexiga, S F Nunes, C L Vilela, Ilda Santossanches, Gursharan S ChhatwalAbstract:ABSTRACT A custom-designed microarray containing 220 virulence genes of Streptococcus pyogenes (group A Streptococcus [GAS]) was used to test group C Streptococcus dysgalactiae subsp. dysgalactiae (GCS) field strains causing bovine mastitis and group C or group G Streptococcus dysgalactiae subsp. equisimilis (GCS/GGS) isolates from human infections, with the latter being used for comparative purposes, for the presence of virulence genes. All bovine and all human isolates carried a fraction of the 220 genes (23% and 39%, respectively). The virulence genes encoding streptolysin S, glyceraldehyde-3-phosphate dehydrogenase, the plasminogen-binding M-like protein PAM, and the collagen-like protein SclB were detected in the majority of both bovine and human isolates (94 to 100%). Virulence factors, usually carried by human beta-hemolytic streptococcal pathogens, such as streptokinase, laminin-binding protein, and the C5a Peptidase precursor, were detected in all human isolates but not in bovine isolates. Additionally, GAS bacteriophage-associated virulence genes encoding superantigens, DNase, and/or streptodornase were detected in bovine isolates (72%) but not in the human isolates. Determinants located in non-bacteriophage-related mobile elements, such as the gene encoding R28, were detected in all bovine and human isolates. Several virulence genes, including genes of bacteriophage origin, were shown to be expressed by reverse transcriptase PCR (RT-PCR). Phylogenetic analysis of superantigen gene sequences revealed a high level (>98%) of identity among genes of bovine GCS, of the horse pathogen Streptococcus equi subsp. equi , and of the human pathogen GAS. Our findings indicate that alpha-hemolytic bovine GCS, an important mastitis pathogen and considered to be a nonhuman pathogen, carries important virulence factors responsible for virulence and pathogenesis in humans.
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virulence gene pool detected in bovine group c streptococcus dysgalactiae subsp dysgalactiae using a group a streptococcus pyogenes virulence microarray
Journal of Clinical Microbiology, 2011Co-Authors: Marcia G Rato, Rene Bergmann, Andreas G Nerlich, Ricardo Bexiga, S F Nunes, C L Vilela, Ilda Santossanches, Gursharan S ChhatwalAbstract:A custom designed microarray containing 220 virulence genes of S. pyogenes (GAS) was used to test group C Streptococcus dysgalactiae subsp. dysgalactiae (GCS) field strains causative of bovine mastitis and group C or group G Streptococcus dysgalactiae subsp. equisimilis (GCS/GGS) isolates from human infections - the latter used for comparative purposes - for the presence of virulence genes. All bovine and all human isolates carried a fraction of the 220 genes (23% and 39%, respectively). The virulence genes encoding streptolysin-S, glyceraldehyde-3-phosphate dehydrogenase, plasminogen-binding M-Like protein PAM and the collagen-like protein SclB were detected in the majority of both bovine and human isolates (94-100%). Virulence factors, usually carried by human beta-hemolytic streptococcal pathogens, such as streptokinase, laminin-binding protein and C5a Peptidase precursor were detected in all human isolates, but not in bovine isolates. Additionally, GAS bacteriophage-associated virulence genes encoding superantigens, DNase and/or streptodornase were detected in bovine isolates (72%), but not in the human isolates. Determinants located in non-bacteriophage-related mobile elements, such as the gene coding R28 were detected in all the bovine and human isolates. Several virulence genes, including genes of bacteriophage origin, were shown to be expressed by RT-PCR. Phylogenetic analysis of superantigen gene sequences revealed a high (>98%) identity among genes of bovine GCS, of the horse pathogen S. equi subsp. equi and of the human pathogen GAS. Our findings indicate that alpha-hemolytic bovine GCS, an important mastitis pathogen and considered to be a non-human pathogen, carries important virulence factors responsible for virulence and pathogenesis in humans.
Rene Bergmann - One of the best experts on this subject based on the ideXlab platform.
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variability in the distribution of genes encoding virulence factors and putative extracellular proteins of streptococcus pyogenes in india a region with high streptococcal disease burden and implication for development of a regional multisubunit vaccine
Clinical and Vaccine Immunology, 2012Co-Authors: Vivek Sagar, Rene Bergmann, Andreas G Nerlich, David J Mcmillan, Patric Nitsche D Schmitz, Gursharan S ChhatwalAbstract:Streptococcus pyogenes causes a wide variety of human diseases and is a significant cause of morbidity and mortality. Attempts to develop a vaccine were hampered by the genetic diversity of S. pyogenes across different regions of the world. This study sought to identify streptococcal antigens suitable for a region-specific vaccine in India. We used a two-step approach,first performing epidemiological analysis to identify the conserved antigens among Indian isolates. The second step consisted of validating the identified antigens by serological analysis. The 201 streptococcal clinical isolates from India used in this study represented 69 different emm types, with emm12 being the most prevalent. Virulence profiling of the North and South Indian S. pyogenes isolates with a custom-designed streptococcal virulence microarray identified seven conserved putative vaccine candidates. Collagen-like surface protein (SCI), putative secreted 5=-nucleotidase (PSNT), and C5a Peptidase were found in 100% of the isolates, while R28, a putative surface antigen (PSA), and a hypothetical protein (HYP) were found in 90% of the isolates. Afibronectin bindingprotein,SfbI,waspresentinonly78%oftheisolates.Inordertovalidatetheidentifiedpotentialvaccinecandidates,185serum samplesobtainedfrompatientswithdifferentclinicalmanifestationsweretestedforantibodies.Irrespectiveofclinicalmanifestations, serumsamplesshowedhighantibodytiterstoallproteinsexceptforSCIandR28.Thus,thedataindicatethatPSNT,C5aPeptidase, PSA,HYP,andSfbIarepromisingcandidatesforaregion-specificstreptococcalvaccineforthedifferentpartsofIndia.
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virulence gene pool detected in bovine group c streptococcus dysgalactiae subsp dysgalactiae isolates by use of a group a s pyogenes virulence microarray
Journal of Clinical Microbiology, 2011Co-Authors: Marcia G Rato, Rene Bergmann, A Nerlich, Ricardo Bexiga, S F Nunes, C L Vilela, Ilda Santossanches, Gursharan S ChhatwalAbstract:ABSTRACT A custom-designed microarray containing 220 virulence genes of Streptococcus pyogenes (group A Streptococcus [GAS]) was used to test group C Streptococcus dysgalactiae subsp. dysgalactiae (GCS) field strains causing bovine mastitis and group C or group G Streptococcus dysgalactiae subsp. equisimilis (GCS/GGS) isolates from human infections, with the latter being used for comparative purposes, for the presence of virulence genes. All bovine and all human isolates carried a fraction of the 220 genes (23% and 39%, respectively). The virulence genes encoding streptolysin S, glyceraldehyde-3-phosphate dehydrogenase, the plasminogen-binding M-like protein PAM, and the collagen-like protein SclB were detected in the majority of both bovine and human isolates (94 to 100%). Virulence factors, usually carried by human beta-hemolytic streptococcal pathogens, such as streptokinase, laminin-binding protein, and the C5a Peptidase precursor, were detected in all human isolates but not in bovine isolates. Additionally, GAS bacteriophage-associated virulence genes encoding superantigens, DNase, and/or streptodornase were detected in bovine isolates (72%) but not in the human isolates. Determinants located in non-bacteriophage-related mobile elements, such as the gene encoding R28, were detected in all bovine and human isolates. Several virulence genes, including genes of bacteriophage origin, were shown to be expressed by reverse transcriptase PCR (RT-PCR). Phylogenetic analysis of superantigen gene sequences revealed a high level (>98%) of identity among genes of bovine GCS, of the horse pathogen Streptococcus equi subsp. equi , and of the human pathogen GAS. Our findings indicate that alpha-hemolytic bovine GCS, an important mastitis pathogen and considered to be a nonhuman pathogen, carries important virulence factors responsible for virulence and pathogenesis in humans.
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virulence gene pool detected in bovine group c streptococcus dysgalactiae subsp dysgalactiae using a group a streptococcus pyogenes virulence microarray
Journal of Clinical Microbiology, 2011Co-Authors: Marcia G Rato, Rene Bergmann, Andreas G Nerlich, Ricardo Bexiga, S F Nunes, C L Vilela, Ilda Santossanches, Gursharan S ChhatwalAbstract:A custom designed microarray containing 220 virulence genes of S. pyogenes (GAS) was used to test group C Streptococcus dysgalactiae subsp. dysgalactiae (GCS) field strains causative of bovine mastitis and group C or group G Streptococcus dysgalactiae subsp. equisimilis (GCS/GGS) isolates from human infections - the latter used for comparative purposes - for the presence of virulence genes. All bovine and all human isolates carried a fraction of the 220 genes (23% and 39%, respectively). The virulence genes encoding streptolysin-S, glyceraldehyde-3-phosphate dehydrogenase, plasminogen-binding M-Like protein PAM and the collagen-like protein SclB were detected in the majority of both bovine and human isolates (94-100%). Virulence factors, usually carried by human beta-hemolytic streptococcal pathogens, such as streptokinase, laminin-binding protein and C5a Peptidase precursor were detected in all human isolates, but not in bovine isolates. Additionally, GAS bacteriophage-associated virulence genes encoding superantigens, DNase and/or streptodornase were detected in bovine isolates (72%), but not in the human isolates. Determinants located in non-bacteriophage-related mobile elements, such as the gene coding R28 were detected in all the bovine and human isolates. Several virulence genes, including genes of bacteriophage origin, were shown to be expressed by RT-PCR. Phylogenetic analysis of superantigen gene sequences revealed a high (>98%) identity among genes of bovine GCS, of the horse pathogen S. equi subsp. equi and of the human pathogen GAS. Our findings indicate that alpha-hemolytic bovine GCS, an important mastitis pathogen and considered to be a non-human pathogen, carries important virulence factors responsible for virulence and pathogenesis in humans.
Marcia G Rato - One of the best experts on this subject based on the ideXlab platform.
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virulence gene pool detected in bovine group c streptococcus dysgalactiae subsp dysgalactiae isolates by use of a group a s pyogenes virulence microarray
Journal of Clinical Microbiology, 2011Co-Authors: Marcia G Rato, Rene Bergmann, A Nerlich, Ricardo Bexiga, S F Nunes, C L Vilela, Ilda Santossanches, Gursharan S ChhatwalAbstract:ABSTRACT A custom-designed microarray containing 220 virulence genes of Streptococcus pyogenes (group A Streptococcus [GAS]) was used to test group C Streptococcus dysgalactiae subsp. dysgalactiae (GCS) field strains causing bovine mastitis and group C or group G Streptococcus dysgalactiae subsp. equisimilis (GCS/GGS) isolates from human infections, with the latter being used for comparative purposes, for the presence of virulence genes. All bovine and all human isolates carried a fraction of the 220 genes (23% and 39%, respectively). The virulence genes encoding streptolysin S, glyceraldehyde-3-phosphate dehydrogenase, the plasminogen-binding M-like protein PAM, and the collagen-like protein SclB were detected in the majority of both bovine and human isolates (94 to 100%). Virulence factors, usually carried by human beta-hemolytic streptococcal pathogens, such as streptokinase, laminin-binding protein, and the C5a Peptidase precursor, were detected in all human isolates but not in bovine isolates. Additionally, GAS bacteriophage-associated virulence genes encoding superantigens, DNase, and/or streptodornase were detected in bovine isolates (72%) but not in the human isolates. Determinants located in non-bacteriophage-related mobile elements, such as the gene encoding R28, were detected in all bovine and human isolates. Several virulence genes, including genes of bacteriophage origin, were shown to be expressed by reverse transcriptase PCR (RT-PCR). Phylogenetic analysis of superantigen gene sequences revealed a high level (>98%) of identity among genes of bovine GCS, of the horse pathogen Streptococcus equi subsp. equi , and of the human pathogen GAS. Our findings indicate that alpha-hemolytic bovine GCS, an important mastitis pathogen and considered to be a nonhuman pathogen, carries important virulence factors responsible for virulence and pathogenesis in humans.
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virulence gene pool detected in bovine group c streptococcus dysgalactiae subsp dysgalactiae using a group a streptococcus pyogenes virulence microarray
Journal of Clinical Microbiology, 2011Co-Authors: Marcia G Rato, Rene Bergmann, Andreas G Nerlich, Ricardo Bexiga, S F Nunes, C L Vilela, Ilda Santossanches, Gursharan S ChhatwalAbstract:A custom designed microarray containing 220 virulence genes of S. pyogenes (GAS) was used to test group C Streptococcus dysgalactiae subsp. dysgalactiae (GCS) field strains causative of bovine mastitis and group C or group G Streptococcus dysgalactiae subsp. equisimilis (GCS/GGS) isolates from human infections - the latter used for comparative purposes - for the presence of virulence genes. All bovine and all human isolates carried a fraction of the 220 genes (23% and 39%, respectively). The virulence genes encoding streptolysin-S, glyceraldehyde-3-phosphate dehydrogenase, plasminogen-binding M-Like protein PAM and the collagen-like protein SclB were detected in the majority of both bovine and human isolates (94-100%). Virulence factors, usually carried by human beta-hemolytic streptococcal pathogens, such as streptokinase, laminin-binding protein and C5a Peptidase precursor were detected in all human isolates, but not in bovine isolates. Additionally, GAS bacteriophage-associated virulence genes encoding superantigens, DNase and/or streptodornase were detected in bovine isolates (72%), but not in the human isolates. Determinants located in non-bacteriophage-related mobile elements, such as the gene coding R28 were detected in all the bovine and human isolates. Several virulence genes, including genes of bacteriophage origin, were shown to be expressed by RT-PCR. Phylogenetic analysis of superantigen gene sequences revealed a high (>98%) identity among genes of bovine GCS, of the horse pathogen S. equi subsp. equi and of the human pathogen GAS. Our findings indicate that alpha-hemolytic bovine GCS, an important mastitis pathogen and considered to be a non-human pathogen, carries important virulence factors responsible for virulence and pathogenesis in humans.
Victor Nizet - One of the best experts on this subject based on the ideXlab platform.
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An Experimental Group A Streptococcus Vaccine That Reduces Pharyngitis and Tonsillitis in a Nonhuman Primate Model
American Society for Microbiology, 2019Co-Authors: Tania Rivera-hernandez, Diane G. Carnathan, Scott Jones, Amanda J. Cork, Mark R. Davies, Peter M. Moyle, Istvan Toth, Michael R. Batzloff, James Mccarthy, Victor NizetAbstract:GAS-related diseases disproportionally affect disadvantaged populations (e.g., indigenous populations), and development of a vaccine has been neglected. A recent strong advocacy campaign driven by the World Health Organization and the International Vaccine Institute has highlighted the urgent need for a GAS vaccine. One significant obstacle in GAS vaccine development is the lack of a widely used animal model to assess vaccine efficacy. Researchers in the field use a wide range of murine models of infection and in vitro assays, sometimes yielding conflicting results. Here we present the nonhuman primate pharyngeal infection model as a tool to assess vaccine-induced protection against colonization and clinical symptoms of pharyngitis and tonsillitis. We have tested the efficacy of an experimental vaccine candidate with promising results. We believe that the utilization of this valuable tool by the GAS vaccine research community could significantly accelerate the realization of a safe and effective GAS vaccine for humans.Group A Streptococcus (GAS) infections account for an estimated 500,000 deaths every year. This bacterial pathogen is responsible for a variety of mild and life-threatening infections and the triggering of chronic autoimmune sequelae. Pharyngitis caused by group A Streptococcus (GAS), but not asymptomatic GAS carriage, is a prerequisite for acute rheumatic fever (ARF). Repeated bouts of ARF may trigger rheumatic heart disease (RHD), a major cause of heart failure and stroke accounting for 275,000 deaths annually. A vaccine that prevents pharyngitis would markedly reduce morbidity and mortality from ARF and RHD. Nonhuman primates (NHPs) have been utilized to model GAS diseases, and experimentally infected rhesus macaques develop pharyngitis. Here we use an NHP model of GAS pharyngitis to evaluate the efficacy of an experimental vaccine, Combo5 (arginine deiminase [ADI], C5a Peptidase [SCPA], streptolysin O [SLO], interleukin-8 [IL-8] protease [SpyCEP], and trigger factor [TF]), specifically designed to exclude GAS components potentially linked to autoimmune complications. Antibody responses against all Combo5 antigens were detected in NHP serum, and immunized NHPs showed a reduction in pharyngitis and tonsillitis compared to controls. Our work establishes the NHP model as a gold standard for the assessment of GAS vaccines
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streptococcus iniae m like protein contributes to virulence in fish and is a target for live attenuated vaccine development
PLOS ONE, 2008Co-Authors: Jeffrey B Locke, Victor Nizet, Ramy K Aziz, Mike R Vicknair, John T BuchananAbstract:Background Streptococcus iniae is a significant pathogen in finfish aquaculture, though knowledge of virulence determinants is lacking. Through pyrosequencing of the S. iniae genome we have identified two gene homologues to classical surface-anchored streptococcal virulence factors: M-like protein (simA) and C5a Peptidase (scpI). Methodology/Principal Findings S. iniae possesses a Mga-like locus containing simA and a divergently transcribed putative mga-like regulatory gene, mgx. In contrast to the Mga locus of group A Streptococcus (GAS, S. pyogenes), scpI is located distally in the chromosome. Comparative sequence analysis of the Mgx locus revealed only one significant variant, a strain with an insertion frameshift mutation in simA and a deletion mutation in a region downstream of mgx, generating an ORF which may encode a second putative mga-like gene, mgx2. Allelic exchange mutagenesis of simA and scpI was employed to investigate the potential role of these genes in S. iniae virulence. Our hybrid striped bass (HSB) and zebrafish models of infection revealed that M-like protein contributes significantly to S. iniae pathogenesis whereas C5a Peptidase-like protein does not. Further, in vitro cell-based analyses indicate that SiMA, like other M family proteins, contributes to cellular adherence and invasion and provides resistance to phagocytic killing. Attenuation in our virulence models was also observed in the S. iniae isolate possessing a natural simA mutation. Vaccination of HSB with the ΔsimA mutant provided 100% protection against subsequent challenge with a lethal dose of wild-type (WT) S. iniae after 1,400 degree days, and shows promise as a target for live attenuated vaccine development. Conclusions/Significance Analysis of M-like protein and C5a Peptidase through allelic replacement revealed that M-like protein plays a significant role in S. iniae virulence, and the Mga-like locus, which may regulate expression of this gene, has an unusual arrangement. The M-like protein mutant created in this research holds promise as live-attenuated vaccine.
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a streptococcal protease that degrades cxc chemokines and impairs bacterial clearance from infected tissues
The EMBO Journal, 2006Co-Authors: Carlos Hidalgograss, Victor Nizet, Inbal Mishalian, Mary Dangoor, Ilia Belotserkovsky, Yoni Eran, Amnon Peled, Emanuel HanskiAbstract:Group A Streptococcus (GAS) causes the life-threatening infection in humans known as necrotizing fasciitis (NF). Infected subcutaneous tissues from an NF patient and mice challenged with the same GAS strain possessed high bacterial loads but a striking paucity of infiltrating polymorphonuclear leukocytes (PMNs). Impaired PMN recruitment was attributed to degradation of the chemokine IL-8 by a GAS serine Peptidase. Here, we use bioinformatics approach coupled with target mutagenesis to identify this Peptidase as ScpC. We show that SilCR pheromone downregulates scpC transcription via the two-component system—SilA/B. In addition, we demonstrate that in vitro, ScpC degrades the CXC chemokines: IL-8 (human), KC, and MIP-2 (both murine). Furthermore, using a murine model of human NF, we demonstrate that ScpC, but not the C5a Peptidase ScpA, is an essential virulence factor. An ScpC-deficient mutant is innocuous for untreated mice but lethal for PMN-depleted mice. ScpC degrades KC and MIP-2 locally in the infected skin tissues, inhibiting PMN recruitment. In conclusion, ScpC represents a novel GAS virulence factor functioning to directly inactivate a key element of the host innate immune response.
Andreas G Nerlich - One of the best experts on this subject based on the ideXlab platform.
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variability in the distribution of genes encoding virulence factors and putative extracellular proteins of streptococcus pyogenes in india a region with high streptococcal disease burden and implication for development of a regional multisubunit vaccine
Clinical and Vaccine Immunology, 2012Co-Authors: Vivek Sagar, Rene Bergmann, Andreas G Nerlich, David J Mcmillan, Patric Nitsche D Schmitz, Gursharan S ChhatwalAbstract:Streptococcus pyogenes causes a wide variety of human diseases and is a significant cause of morbidity and mortality. Attempts to develop a vaccine were hampered by the genetic diversity of S. pyogenes across different regions of the world. This study sought to identify streptococcal antigens suitable for a region-specific vaccine in India. We used a two-step approach,first performing epidemiological analysis to identify the conserved antigens among Indian isolates. The second step consisted of validating the identified antigens by serological analysis. The 201 streptococcal clinical isolates from India used in this study represented 69 different emm types, with emm12 being the most prevalent. Virulence profiling of the North and South Indian S. pyogenes isolates with a custom-designed streptococcal virulence microarray identified seven conserved putative vaccine candidates. Collagen-like surface protein (SCI), putative secreted 5=-nucleotidase (PSNT), and C5a Peptidase were found in 100% of the isolates, while R28, a putative surface antigen (PSA), and a hypothetical protein (HYP) were found in 90% of the isolates. Afibronectin bindingprotein,SfbI,waspresentinonly78%oftheisolates.Inordertovalidatetheidentifiedpotentialvaccinecandidates,185serum samplesobtainedfrompatientswithdifferentclinicalmanifestationsweretestedforantibodies.Irrespectiveofclinicalmanifestations, serumsamplesshowedhighantibodytiterstoallproteinsexceptforSCIandR28.Thus,thedataindicatethatPSNT,C5aPeptidase, PSA,HYP,andSfbIarepromisingcandidatesforaregion-specificstreptococcalvaccineforthedifferentpartsofIndia.
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virulence gene pool detected in bovine group c streptococcus dysgalactiae subsp dysgalactiae using a group a streptococcus pyogenes virulence microarray
Journal of Clinical Microbiology, 2011Co-Authors: Marcia G Rato, Rene Bergmann, Andreas G Nerlich, Ricardo Bexiga, S F Nunes, C L Vilela, Ilda Santossanches, Gursharan S ChhatwalAbstract:A custom designed microarray containing 220 virulence genes of S. pyogenes (GAS) was used to test group C Streptococcus dysgalactiae subsp. dysgalactiae (GCS) field strains causative of bovine mastitis and group C or group G Streptococcus dysgalactiae subsp. equisimilis (GCS/GGS) isolates from human infections - the latter used for comparative purposes - for the presence of virulence genes. All bovine and all human isolates carried a fraction of the 220 genes (23% and 39%, respectively). The virulence genes encoding streptolysin-S, glyceraldehyde-3-phosphate dehydrogenase, plasminogen-binding M-Like protein PAM and the collagen-like protein SclB were detected in the majority of both bovine and human isolates (94-100%). Virulence factors, usually carried by human beta-hemolytic streptococcal pathogens, such as streptokinase, laminin-binding protein and C5a Peptidase precursor were detected in all human isolates, but not in bovine isolates. Additionally, GAS bacteriophage-associated virulence genes encoding superantigens, DNase and/or streptodornase were detected in bovine isolates (72%), but not in the human isolates. Determinants located in non-bacteriophage-related mobile elements, such as the gene coding R28 were detected in all the bovine and human isolates. Several virulence genes, including genes of bacteriophage origin, were shown to be expressed by RT-PCR. Phylogenetic analysis of superantigen gene sequences revealed a high (>98%) identity among genes of bovine GCS, of the horse pathogen S. equi subsp. equi and of the human pathogen GAS. Our findings indicate that alpha-hemolytic bovine GCS, an important mastitis pathogen and considered to be a non-human pathogen, carries important virulence factors responsible for virulence and pathogenesis in humans.
