Molecular Typing of the Methicillin-Resistant Determinant (mec) and Coagulase Typing as Epidemiologic Markers for Study of Nosocomial Infections Caused by Methicillin-Resistant Staphylococcus aureus / 대한임상병리학회지

ABSTRACT

BACKGROUND: Methicillin-resistant Staphylococcus aureus(MRSA) is an increasingly common cause of nosocomial infections worldwide. Epidemiologic investigation of MRSA outbreaks and identification of pathways of nosocomial MRSA spread require the ability to distinguish individual MRSA strains. We applied molecular tap ing of the methicillin-resistant determinant (mec) and coagulase typing in the investigation of a nosocomial MRSA infections. METHODS: We randomly selected 79 strains of mecA positive MRSA isolated from patients who visited Dong-A university Hospital from Dec. 1995 to Oct. 1996. Molecular typing of MRSA was performed by comparing the size of the mac-associated hypervariable region amplified by the polymerase chain reaction (PCR). Coagulase typing with type I-VIII antisera was also used for classification of MRSA based on its phenotype. Each isolates were classified by the combination of molecular analyses and coagulase type. RESULTS: The 79 MRSA isolates were grouped Into sin hypervariable legion (HVR) genotypes on the basis of the size of the PGR products. In coagulase typing, the most predominant type was II(46.8%) and type V was not found. Nine strains were not typable. The combination of HVR genotypes and coagulase types showed 23 different types in 79 MRSA Isolates. The strains which were repeatedly isolated from the same patients showed the same HYR genotypes and coagulate types. CONCLUSION: The combination of HVR genotypes and coagulase types is thought to be useful in epidemiolgical Investigation of nosocomial infections caused by MRSA ,because of its simplicity and reproducibility.