title: Quorum sensing-mediated regulation of staphylococcal virulence and antibiotic resistance.
abstract: Accessory gene regulator (agr)-mediated quorum sensing plays a central role in staphylococcal pathogenesis. It primarily upregulates secreted virulence factors and downregulates cell surface proteins, thereby governing invasiveness of staphylococci and cell dispersal from biofilms. Except for α- and β-PSMs, which are directly controlled by AgrA, the effector functions of agr are primarily mediated by RNAIII, a regulatory RNA encoded by this operon. agr phenotype and expression considerably influence the chronicity of an infection. It has also been linked with altered susceptibility of Staphylococcus aureus against antibiotics. Four classes of S. aureus and Staphylococcus epidermidis AIPs exist based on sequence variation, and lead to inter-strain and species cross-inhibition. Certain agr classes have been associated with specific clonal complexes, disease syndromes and intermediate-susceptibility to glycopeptides. It is also being investigated as a prophylactic and therapeutic target. This article describes the presently available literature regarding the role of agr in S. aureus and S. epidermidis infections.
authors: Department of Medical Microbiology, Postgraduate Institute of Medical Education and Research (PGIMER), Chandigarh, 160012, India.
authors: Rachna
authors: R
authors: Singh
authors: Pallab
authors: P
authors: Ray
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics*; D044822:Biodiversity; D018441:Biofilms / Q000254:growth & development; D024901:Drug Resistance, Multiple, Bacterial / Q000235:genetics*; D015964:Gene Expression Regulation, Bacterial; D014644:Genetic Variation; D006460:Hemolysin Proteins / Q000096:biosynthesis; D053038:Quorum Sensing / Q000235:genetics*; D013203:Staphylococcal Infections / Q000235:genetics / Q000473:pathology; D013211:Staphylococcus aureus / Q000187:drug effects / Q000235:genetics / Q000472:pathogenicity*; D013212:Staphylococcus epidermidis / Q000187:drug effects / Q000235:genetics / Q000472:pathogenicity*; D015534:Trans-Activators / Q000235:genetics*; D037521:Virulence Factors / Q000235:genetics
chemical_list: C095698:Agr protein, Staphylococcus aureus; D001426:Bacterial Proteins; D006460:Hemolysin Proteins; D015534:Trans-Activators; D037521:Virulence Factors
keywords: RNAIII; Staphylococcus; agr; antibiotic resistance; biofilm; quorum sensing; virulence