Role of Staphylococcus aureus two component system SA1158-SA1159 in membrane fluidity perception

DIAZ, ALEJANDRA R; MANSILLA, C. .; DE MENDOZA, D

Potrero de los Funes, San Luis

Congreso; ?. XLVII Reunion Annual de la Sociedad Argentina de Investigacion en Bioquimica y Biologia Molecular; 2011

Staphylococcus aureus, a G+ bacterium, is a frequent component of human microbial flora that can turn into a dangerous pathogen. S. aureus methicilin-resistant (MRSA) strains are prevalent in hospitals, but recently, the emergence of community associated MRSA infections acquired by healthy people has led to a major concern of Public Health. The pathogenicity of S. aureus is caused by expression of a myriad of virulence factors. A sudden change in temperature may be a signal for the pathogen of being inside the host, inducing the expression of virulence-related genes. As two component systems (TCSs) allow bacteria to sense environmental temperature, in this work we analyzed two genes located in S. aureus N315 chromosome, SA1158-SA1159, as they showed homology with B. subtilis DesKR TCS, which regulates transcription of its sole desaturase in response to changes in membrane fluidity. By complementation tests we found that expression of SA1158 restores the ability of B. subtilis desK strains to activate transcription of des gene after cold shock induction. In addition, a mutant strain lacking DesK and DesR is also able to promote des transcription at low temperature when SA1158 and SA1159 are expressed under a conditional promoter. This suggest that the kinase of S. aureus, SA1158 is responding to the same signal sensed by DesK, and support a general role of these TCSs in G+ bacteria.