Staphylococcus aureus: Current perspectives on molecular pathogenesis and virulence

Abstract

Staphylococcus aureus has developed a sophisticated regulatory system to manage its virulence. Sensing different environmental signals and responding by changing the synthesis of virulence components required for survival in the host, including cell surface adhesins, extracellular enzymes, and toxins, is one of the primary roles of this interconnected network. The accessory gene regulator (agr), a quorum-sensing system that detects the local concentration of a cyclic peptide signaling molecule, is one of the well-studied of these S. aureus regulatory mechanisms. Through the use of this system, S. aureus is able to detect its own population density and translate this information into a particular pattern of gene expression. In addition to agr, this pathogen senses certain stimuli via different two-component systems and synchronizes responses with alternate sigma factors and cytoplasmic regulators of the SarA protein family. These disparate regulatory mechanisms combine host-derived and environmental information to form a network that guarantees the best possible pathogen response to shifting circumstances. An overview of the most significant and thoroughly researched S. aureus regulatory systems is provided in this article, along with a synopsis of their roles during host interactions.