Role of Staphylococcus aureus Global Regulators sae and σ B in Virulence Gene Expression during Device-Related Infection

Abstract

ABSTRACT The ability of Staphylococcus aureus to adapt to different environments is due to a regulatory network comprising several loci. Here we present a detailed study of the interaction between the two global regulators sae and σ B of S. aureus and their influence on virulence gene expression in vitro, as well as during device-related infection. The expression of sae , asp23 , hla , clfA , coa , and fnbA was determined in strain Newman and its isogenic saeS/R and sigB mutants by Northern analysis and LightCycler reverse transcription-PCR. There was no indication of direct cross talk between the two regulators. sae had a dominant effect on target gene expression during device-related infection. σ B seemed to be less active throughout the infection than under induced conditions in vitro.