The Two-Component Regulatory System of Serratia marcescens in Multicellular Behaviors and Pathogenesis

Serratia marcescens is an opportunistic human pathogen and causes many nosocomial infections. In our previous works, by using the transposon mutagenesis, a two component system RssAB was identified and characterized to involve in the regulation of swarming behavior and biofilm formation. Through the regulation of flhDC, the virulence factor, hemolysin, is also impacted by RssAB and thus RssAB-FlhDC-ShlBA serves as a critical role in pathogenesis of S. marcescens. Subsequent investigation has identified at least 7 genes that are regulated by RssAB. These gene products are homologous to some interesting proteins of other pathogens such as QseBC and CcdAB. Thus in this proposal, we investigate the regulatory mechanisms of multicelluar behaviors in S. marcescens including swarming, biofilm formation, and quorum sensing system. We study how two sets of two-component regulator regulate the swarming process and biofilm formation and to evaluate the role of QseBC interplay in pathogenesis. In addition, we investigate the toxin-antitoxin system, CcdAB and persister cells formation and thereby assess their roles in antibiotics resistance. Furthermore, the proinflammatory effect of S. marcescens virulence factors, autoinducers, biofilm matrix in host would be addressed. We are wondering whether the RssAB and QseBC networks involve in the interaction with macrophages. Hence, the inflammasomes activation by the S. marcescens infection will be determined. This study will benefit us to develop well strategies to prevent and control the S. marcescens infection.

Project ID:PC10108-0894
External Project ID:NSC101-2320-B182-023-MY3