Comparison of the Usefulness of Pulsed-Field Gel Electrophoresis and Ribotyping in Epidemiological Study of Methicillin-Resistant Staphylococcus aureus / 대한임상병리학회지

ABSTRACT

BACKGROUND: Methicillin-resistant Staphylococcus aureus (MRSA) is one of the most frequent agents of hospital infections. The aim of this study was to evaluate the polymorphism of MRSA strains from our hospital by pulsed-field gel electrophoresis (PFGE) and ribotyping, and to compare effectiveness of two methods for epidemiologic investigation. METHODS: A total of 40 MRSA isolates were studied. All strains were isolated from patients from October 1990 to May 1995 13 isolates from NS ward, 9 from GS and OS ward, 11 from medical ward, and 7 from other medical centers. All strains were analyzed and classified by ribotyping and PFGE patterns. RESULTS: Eight different ribotypes (H1-H8) and ten ribotypes (E1-E10) were seen by HindIII and EcoRI digestion. The problem was that some isolates showed discordance between classifications by HindIII and EcoRI digestion and three isolates from other medical centers had same ribotypes with that of our hospital strains. PFGE analysis revealed 19 different types (A to S). The PFGE analysis showed ward specificity, 54% of isolates from NS ward and 54% of isolates from medical ward were PFGE types D and J respectively, and 33% of isolates from GS and OS ward was H type and 33% was G type. CONCLUSIONS: PFGE was a more effective epidemiological tool for the typing of MRSA strains but a combination with ribotyping could provide more detailed strain differentiation.