Typing of methicillin-resistant Staphylococcus aureus (MRSA) strains from an intensive care unit by random amplified polymorphic DNA (RAPD)

The identification and control of methicillin-resistant Staphylococcus aure us (MRSA) is of primary concern in intensive care units (ICUs) worldwide. T he introduction and circulation of particular strains is best studied by ge nomic procedures and random amplified polymorphic DNA (RAPD) is well suited for this task. In this study 14 isolates of MRSA, obtained over an 8 month period from the blood cultures of 12 patients in an ICU at our hospital, were typed by RAP D method using seven primers. Three separate groups were distinguished and clustering of certain types in time and space was noted. These results sugg est that although different strains of MRSA were involved in this outbreak, cross-infection with individual types occurred. RAPD fingerprinting is a r elatively simple method that allows epidemiologic investigation of MRSA out breaks in hospital infection.