Staphylococcus aureus ABC transporter is regulated by SAOUHSC01313-01314 TCS upon temperature change

DÍAZ, A. R. ; DE MENDOZA, D; MANSILLA, C. .

Congreso; SAIB; 2012

Staphylococcus aureus, a G+ bacterium, is an opportunistic pathogen capable of causing severe diseases. S. aureus methicilin-resistant (MRSA) strains are a major cause of nosocomial and community-acquired infections worldwide. A sudden change in temperature may be a signal for the pathogen of being inside the host, inducing the expression of virulence-related genes. Since two component systems (TCSs) allow bacteria to sense environmental parameters, we studied two contiguous genes located in S. aureus chromosome NCTC 8325, SAOUHSC01313-01314 coding for a putative histidine kinase (HKsa) and response regulator (RRsa), respectively. These proteins showed homology with B. subtilis DesKR TCS that regulates des transcription at low temperature. Linked upstream of this TCS are located two genes, SAOUHSC01311-01312, encoding a putative ABC transporter that carries in its promoter a regulatory box identical to that of des. In this work, we investigated whether signal sensed by HKsa mediates activation of ABC transporter. We performed -gal assays of B. subtilis desKR mutants carrying a transcriptional fusion of SAOUHSC01311 promoter to lacZ. We found that Psa01311-lacZ is activated when HKsa-RRsa are expressed under a conditional promoter, indicating that S. aureus TCS, without additional factors, regulates ABC transporter expression.