Virulence factor regulation and regulatory networks in Streptococcus pyogenes and their impact on pathogen-host interactions.
Streptococcus pyogenes (group A streptococcus, GAS) is a very important human pathogen with remarkable adaptation capabilities. Survival within the harsh host surroundings requires sensing potential on the bacterial side, which leads in particular to coordinately regulated virulence factor expression. GAS 'stand-alone' response regulators (RRs) and two-component signal transduction systems (TCSs) link the signals from the host environment with adaptive responses of the bacterial cell. Numerous putative regulatory systems emerged from GAS genome sequences. Only three RRs [Mga, RofA-like protein (RALP) and Rgg/RopB] and three TCSs (CsrRS/CovRS, FasBCAX and Ihk/Irr) have been studied in some detail with respect to their growth-phase-dependent activity and their influence on GAS-host cell interaction. In particular, the Mga-, RALP- and Rgg/RopB-regulated pathways display interconnected activities that appear to influence GAS colonization, persistence and spreading mechanisms, in a growth-phase-related fashion. Here, we have summarized our current knowledge about these RRs and TCSs to highlight the questions that should be addressed in future research on GAS pathogenicity.
Kreikemeyer
Bernd
B
University Hospital Rostock, Department of Medical Microbiology and Hospital Hygiene, Schillingallee 70, 18055 Rostock, Germany. Bernd.Kreikemeyer@med.uni-rostock.de
McIver
Kevin S
KS
Podbielski
Andreas
A
D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism; D015964:Gene Expression Regulation, Bacterial; D008957:Models, Genetic; D018085:Regulon / Q000235:genetics; D015398:Signal Transduction / Q000502:physiology*; D013297:Streptococcus pyogenes / Q000235:genetics* / Q000254:growth & development / Q000472:pathogenicity*; D014158:Transcription, Genetic; D014774:Virulence; D037521:Virulence Factors / Q000235:genetics* / Q000378:metabolism
D001426:Bacterial Proteins; D037521:Virulence Factors