Project description:Identification of Genes and Genomic Islands Correlated with High Pathogenicity through Tilling Microarray-Based Comparative Genomics in S. suis. Streptococcus suis is an important zoonotic pathogen that can cause meningitis and sepsis in both pigs and humans. S. suis isolates have been categorized into groups of different levels of pathogenicity, with sequence type (ST) ST1 clonal complex strains having a higher degree of virulence than other STs. However, the genetic basis of the differences in pathogenicity is still poorly understood. In this study, a comprehensive genomic comparison of 31 S. suis strains from different clinical sources with the genome sequence of the high pathogenicity (HP) strain GZ1 was conducted using NimbleGen’s tilling microarray platform.
Project description:Identification of Genes and Genomic Islands Correlated with High Pathogenicity through Tilling Microarray-Based Comparative Genomics in S. suis. Streptococcus suis is an important zoonotic pathogen that can cause meningitis and sepsis in both pigs and humans. S. suis isolates have been categorized into groups of different levels of pathogenicity, with sequence type (ST) ST1 clonal complex strains having a higher degree of virulence than other STs. However, the genetic basis of the differences in pathogenicity is still poorly understood. In this study, a comprehensive genomic comparison of 31 S. suis strains from different clinical sources with the genome sequence of the high pathogenicity (HP) strain GZ1 was conducted using NimbleGenM-bM-^@M-^Ys tilling microarray platform. Comparative genomic analysis on the 31 S. suis strains of different serotypes and ST types through tilling arrays.
Project description:Streptococcus suis is an emerging zoonotic agent causing meningitis and septicemia. Outbreaks in humans in China with atypical cases of streptococcal toxic shock-like syndrome have been described to be caused by a clonal epidemic S. suis strain characterized as sequence type (ST) 7 by multilocus sequence typing, different from the classical ST1 usually isolated in Europe. Previous in vitro studies showed that Toll-like receptor (TLR) 2 plays a major role in S. suis ST1 interactions with host cells. In the present study, the in vivo role of TLR2 in systemic infections caused by S. suis ST1 or ST7 strains using TLR2 deficient (TLR2-/-) mice was evaluated. TLR2-mediated recognition significantly contributes to the acute disease caused by the highly virulent S. suis ST1 strain, since the TLR2-/- mice remained unaffected when compared to wild type (WT) mice. The lack of mortality could not be associated with a lower bacterial burden; however, a significant decrease in the induction of pro-inflammatory mediators, as evaluated by microarray, real-time PCR and protein assays, was observed. On the other hand, TLR2-/- mice infected with the epidemic ST7 strain presented no significant differences regarding survival and expression of pro-inflammatory mediators when compared to the WT mice. Together, these results show a TLR2-independent host innate immune response to S. suis that depends on the strain.
Project description:Streptococcus suis is an important zoonotic pathogen that can cause meningitis and sepsis in both pigs and humans. In this study,we evaluated the genetic difference of 40 Streptococcus suis strains belonging to various sequence types by comparative genomic hybridization to identify genes associated with the variation in pathogenicity using NimbleGen’s tilling microarray platform. Application of Comparative Phylogenomics to Identify Genetic Differences Relating to Pathogenicity of Streptococcus suis
Project description:Streptococcus suis is an emerging zoonotic agent causing meningitis and septicemia. Outbreaks in humans in China with atypical cases of streptococcal toxic shock-like syndrome have been described to be caused by a clonal epidemic S. suis strain characterized as sequence type (ST) 7 by multilocus sequence typing, different from the classical ST1 usually isolated in Europe. Previous in vitro studies showed that Toll-like receptor (TLR) 2 plays a major role in S. suis ST1 interactions with host cells. In the present study, the in vivo role of TLR2 in systemic infections caused by S. suis ST1 or ST7 strains using TLR2 deficient (TLR2-/-) mice was evaluated. TLR2-mediated recognition significantly contributes to the acute disease caused by the highly virulent S. suis ST1 strain, since the TLR2-/- mice remained unaffected when compared to wild type (WT) mice. The lack of mortality could not be associated with a lower bacterial burden; however, a significant decrease in the induction of pro-inflammatory mediators, as evaluated by microarray, real-time PCR and protein assays, was observed. On the other hand, TLR2-/- mice infected with the epidemic ST7 strain presented no significant differences regarding survival and expression of pro-inflammatory mediators when compared to the WT mice. Together, these results show a TLR2-independent host innate immune response to S. suis that depends on the strain.
Project description:Streptococcus suis is an emerging zoonotic agent causing meningitis and septicemia. Outbreaks in humans in China with atypical cases of streptococcal toxic shock-like syndrome have been described to be caused by a clonal epidemic S. suis strain characterized as sequence type (ST) 7 by multilocus sequence typing, different from the classical ST1 usually isolated in Europe. Previous in vitro studies showed that Toll-like receptor (TLR) 2 plays a major role in S. suis ST1 interactions with host cells. In the present study, the in vivo role of TLR2 in systemic infections caused by S. suis ST1 or ST7 strains using TLR2 deficient (TLR2-/-) mice was evaluated. TLR2-mediated recognition significantly contributes to the acute disease caused by the highly virulent S. suis ST1 strain, since the TLR2-/- mice remained unaffected when compared to wild type (WT) mice. The lack of mortality could not be associated with a lower bacterial burden; however, a significant decrease in the induction of pro-inflammatory mediators, as evaluated by microarray, real-time PCR and protein assays, was observed. On the other hand, TLR2-/- mice infected with the epidemic ST7 strain presented no significant differences regarding survival and expression of pro-inflammatory mediators when compared to the WT mice. Together, these results show a TLR2-independent host innate immune response to S. suis that depends on the strain. Total RNA obtained from spleen of C57BL/6 mice or C57BL/6 TLR2-KO mice infected with Streptococcus suis strain SC84. Four replicates in both groups.
Project description:Streptococcus suis is an emerging zoonotic agent causing meningitis and septicemia. Outbreaks in humans in China with atypical cases of streptococcal toxic shock-like syndrome have been described to be caused by a clonal epidemic S. suis strain characterized as sequence type (ST) 7 by multilocus sequence typing, different from the classical ST1 usually isolated in Europe. Previous in vitro studies showed that Toll-like receptor (TLR) 2 plays a major role in S. suis ST1 interactions with host cells. In the present study, the in vivo role of TLR2 in systemic infections caused by S. suis ST1 or ST7 strains using TLR2 deficient (TLR2-/-) mice was evaluated. TLR2-mediated recognition significantly contributes to the acute disease caused by the highly virulent S. suis ST1 strain, since the TLR2-/- mice remained unaffected when compared to wild type (WT) mice. The lack of mortality could not be associated with a lower bacterial burden; however, a significant decrease in the induction of pro-inflammatory mediators, as evaluated by microarray, real-time PCR and protein assays, was observed. On the other hand, TLR2-/- mice infected with the epidemic ST7 strain presented no significant differences regarding survival and expression of pro-inflammatory mediators when compared to the WT mice. Together, these results show a TLR2-independent host innate immune response to S. suis that depends on the strain. Total RNA obtained from spleen of C57BL/6 mice or C57BL/6 TLR2-KO mice infected with Streptococcus suis strain P1/7. Four replicates in both groups.