Rapid molecular typing of methicillin resistant Staphylococcus aureus by PCR-RFLP

OBJECTIVE: To establish a new, rapid, and reliable genotypic fingerprinting technique for methicillin-resistant Staphylococcus aureus (MRSA) typing in routine epidemiological surveillance. DESIGN: The method is based on polymerase chain reaction (PCR) restriction fragment-length polymorphism (RFLP) following HaeII digestion of simultaneo usly amplified parts of the protein A gene, the coagulase gene, and the hyp ervariable region adjacent to mecA. A total of 46 MRSA initial isolates wer e analyzed, including 14 isolates from five countries; the six German epide mic strains; 16 isolates from the Frankfurt metropolitan area, which were k nown to be heterogeneous by pulsed-field gel electrophoresis (PFGE); and 10 isolates obtained during three epidemics, all of which displayed an identi cal genotype. RESULTS: Restriction analysis by PCR-RFLP permitted discrimination of 10 of 14 international isolates, all six German epidemic strains, and 15 of 16 n ational isolates. It also confirmed the homogeneous character of the 10 out break isolates. CONCLUSIONS: This new and rapid PCR-RFLP typing method is an attractive too l in routine epidemiological surveillance. Its impressive characteristics a re ease of performance and interpretation, while at the same time guarantee ing good discriminatory power, reproducibility, and typeability (Infect Con trol Hosp Epidemiol 2001;22:294-298).