[Diversification of agr locus among Staphylococcus aureus isolated from carriers and from hospital patients with infection syndromes]

Abstract

In Staphylococcus aureus, the accessory gen regulator (agr) system globally controls the production of virulence factors. Strains of S. aureus can be divided into four major agr groups (I-IV) on the basis of agrD and agrC polymorphisms. The aim of this study was to estimate the prevalence of the four agr specificity groups among S. aureus strains isolated from health carriers and from hospital patients. Fifty S. aureus strains from nose swabs obtained from medical students and fifty strains from hospital patients, mainly from dermatology, were identified by multiplex PCR. Most of S. aureus strains from carriers belonged to I (38%) and III (30%) group agr, in contrast to S. aureus strains from infections, which belonged mainly to IV (50%) and II (24%) group (p < 0.05). A relationship between agr group and type of disease was observed: agr group IV strains were associated with skin infection and agr groups I-III strains with other type of infections (p < 0.05).