Open AccessMolecular and Epidemiological Evidence for Spread of Multiresistant Methicillin-Susceptible Staphylococcus aureus Strains in Hospitals
Author(s) -
Pierre-Yves Donnio,
Frédéric Février,
Pablo Bifani,
Marie Dehem,
Christèle Kervégant,
Nathalie Wilhelm,
Anne-Lise Gautier-Lerestif,
Nathalie Lafforgue,
Michel Cormier,
Alain Le Coustumier
Publication year - 2007
Publication title -
antimicrobial agents and chemotherapy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.07
H-Index - 259
eISSN - 1070-6283
pISSN - 0066-4804
DOI - 10.1128/aac.01414-06
Subject(s) - sccmec , staphylococcus aureus , multilocus sequence typing , microbiology and biotechnology , biology , typing , molecular epidemiology , methicillin resistant staphylococcus aureus , staphylococcal infections , meticillin , micrococcaceae , clone (java method) , antibacterial agent , genotype , virology , genetics , antibiotics , gene , bacteria
The excision of the staphylococcal chromosomal cassettemec (SCCmec ) from methicillin-resistantStaphylococcus aureus (MRSA) strains results in methicillin-susceptibleS. aureus (MSSA) strains. In order to determine the proportion and diversity of multidrug-resistant MSSA (MR-MSSA) strains derived from MRSA strains, 247mecA -negative isolates recovered in 60 French hospitals between 2002 and 2004 were characterized. Thespa types of all strains were determined, and a subset of the strains (n = 30) was further genotyped by multilocus sequence typing. The IDI-MRSA assay was used to test the isolates for the presence of the SCCmec element, which was detected in 68% of all isolates analyzed. Molecular analysis of the samples suggested that 92% of the MR-MSSA isolates were derived from MRSA clones of diverse genetic backgrounds, of which the clone of sequence type 8 and SCCmec type IVA accounted for most of the samples. High variations in incidence data and differences in the molecular characteristics of the isolates from one hospital to another indicate that the emergence of MR-MSSA resulted from independent SCCmec excisions from epidemic MRSA isolates, as well as the diffusion of methicillin-susceptible strains after the loss of SCCmec . MR-MSSA could constitute a useful model for the study of the respective genetic and environmental factors involved in the dissemination ofS. aureus in hospitals.