TYPING OF METHICILLIN RESISTANT STAPHYLOCOCCUS AUREUS STRAINS BY ANTIBIOTIC SUSCEPTIBILITIES AND PULSED FIELD GEL ELECTROPHORESIS METHOD

Objective: This study was carried out for typing of Methicillin Resistant Staphylococcus aureus (MRSA) strains, isolated from patients hospitalized at Hacettepe University Adult and Oncology Hospitals between October 2003-March 2004, by using the phenotypic method of antibiotic susceptibility testing and the genotypic method of Pulsed Field Gel Electrophoresis (PFGE). Matherial and Method: Antibiotic susceptibilities of isolates used in the study were determined by MIC method. The bacteria were characterized by PFGE after their genomes were fragmented by using SmaI restriction endonuclease. Result and Discussion: Nine antibiotypes were identified, two of which were common (Ant1 and Ant2). A dominant type (Type A) was identified as the result of the PFGE analysis. Three other types (Type B, C, D) were presented with fewer examples than this predominant type. Type A has 8, type B has 2, and type C has 5 subtypes. It has been determined that no MRSA epidemic has occurred in the particular study period. The results obtained indicate that the PFGE technique in typing studies is more sensitive than the phenotypic typing method of comparing antibiotic susceptibility patterns