[Multidrug resistant bacteria in a psychiatric milieu].

Isolation rates of multiple-drug resistant (MDR) bacteria were evaluated retrospectively in a psychiatric care facility. Over the six-year study period, 66 MDR bacterial strains were found. Methicillin-resistant Staphylococcus aureus contributed half of all MDR strains and 31% of all S. aureus strains. Among Pseudomonas aeruginosa strains, 22% were resistant to ticarcillin or imipenem, and among Enterobacteriaceae, 4.1% were MDR strains (production of a derepressed cephalosporinase or of an extended-spectrum beta-lactamase). Although most MDR strains were probably acquired during hospitalizations in short-term care facilities outside our institution, patient-to-patient transmission, either direct or via other individuals, cannot be ruled out. These data indicate that psychiatric care facilities should adopt the MDR strain monitoring strategies already used in other hospitals.