Screening for Staphylococcus aureus with a reduced susceptibility to vancomycin in: a Belgian hospital

The aim of the present study was to investigate the prevalence of vancomycin resistance in clinical methicillin resistant Staphylococcus aureus (MRSA) isolates in our hospital by screening on Mueller-Hinton agar with 5 mg/l teicoplanin (MH-Teico), as recommended by the Comite de l'Antibiogramme of the Societe Francaise de Microbiologie (CA-SFM). Seventeen of 1002 clinical MRSA isolated from 404 patients showed in 2003 growth of at least four colonies on this medium, but only one was confirmed as homogeneous vancomycin-resistant S. aureus (VISA) and five as heterogeneous VISA (hVISA) by population analysis. None of the patients presented with severe infection but awareness is needed and screening on MH-Teico as recommended by CA-SFM is a convenient method. Surveillance should be focused on patients with risk factors for selection of such strains: patients with a prolonged course of glycopeptide therapy and persistence of MRSA infection or colonization.