Methicillin-resistant Staphylococcus aureus (MRSA) with reduced susceptibility to glycopeptides (GISA) in 63 French general hospitals.

Clinical isolates of methicillin-resistant Staphylococcus aureus (n = 1070) collected from 63 French general hospitals during June 2000 (n = 1070) were screened initially for reduced susceptibility to glycopeptides (GISA) on brain-heart infusion agar containing teicoplanin 6 mg/L. Glycopeptide MICs were determined for the 145 isolates that grew on the screening plates. Of the 1070 isolates, 1.4% were GISA on Mueller-Hinton agar, and 2.9% by Etest with a high inoculum, while 0.7% and 2.9% were GISA by vancomycin and teicoplanin population analysis profiles, respectively. Most isolates were resistant to gentamicin and rifampicin or fosfomycin or fusidic acid, as determined by disk diffusion. Pulsed-field gel electrophoresis of the 31 GISA isolates identified four clones, with dissemination of one predominant clone. In these French hospitals there was a low incidence of GISA and hetero-GISA.