Prospective Two-Center Comparison of Three Chromogenic Agars for Methicillin-Resistant Staphylococcus aureus Screening in Hospitalized Patients

Three chromogenic media, chromIDMRSA SMART (SMART), chromIDMRSA first generation (chromID), and Brilliance MRSA (OX2), were evaluated for methicillin-resistant Staphylococcus aureus (MRSA) screening using 1,220 samples. The sensi-tivity at 24 h was significantly better with the SMART agar (66.4%) than that with chromID agar (50.5%). Enrichment and incu-bation until 48 h are still needed for an optimal yield. Methicillin-resistant Staphylococcus aureus (MRSA) is a majorcause of nosocomial infections (1, 2). Asymptomatic carri-ers in the nose, throat, or on the skin represent the major reser-voirs for MRSA transmission in hospitals (3, 4). Rapid identifica-tion of MRSA colonization is of utmost importance to identify carriers in order to implement infection control procedures and reduce patient-to-patient transmission (5–7). Several chromo-genic agars have been specifically developed for MRSA screening. Thesemedia show superior sensitivity and specificity compared to those of conventional selective plates (8–10). The purpose of this study was to compare the performance of the new bioMérieux chromID MRSA SMART (SMART) agar with bioMérieux chro-mID MRSA first generation (chromID) and Oxoid Brilliance MRSA version 2 agar (OX2) with and without enrichment brot