AUTHOR=Xu Zhongmin , Chen Bo , Zhang Qiang , Liu Liang , Zhang Anding , Yang Yujie , Huang Kaisong , Yan Shuxian , Yu Junping , Sun Xiaomei , Jin Meilin 

TITLE=Streptococcus suis 2 Transcriptional Regulator TstS Stimulates Cytokine Production and Bacteremia to Promote Streptococcal Toxic Shock-Like Syndrome

JOURNAL=Frontiers in Microbiology

VOLUME=9

YEAR=2018

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2018.01309

DOI=10.3389/fmicb.2018.01309

ISSN=1664-302X

ABSTRACT=<p>Two large-scale outbreaks of streptococcal toxic shock-like syndrome (STSLS) have revealed <italic>Streptococcus suis</italic> 2 to be a severe and evolving human pathogen. We investigated the mechanism by which <italic>S. suis</italic> 2 causes STSLS. The transcript abundance of the transcriptional regulator gene <italic>tstS</italic> was found to be upregulated during experimental infection. Compared with the wild-type 05ZY strain, a <italic>tstS</italic> deletion mutant (Δ<italic>tstS</italic>) elicited reduced cytokine secretion in macrophages. In a murine infection model, <italic>tstS</italic> deletion resulted in decreased virulence and bacterial load, and affected cytokine production. Moreover, TstS expression in the P1/7 strain of <italic>S. suis</italic> led to the induction of STSLS in the infected mice. This is noteworthy because, although it is virulent, the P1/7 strain does not normally induce STSLS. Through a microarray-based comparative transcriptomics analysis, we found that TstS regulates multiple metabolism-related genes and several virulence-related genes associated with immune evasion.</p>