Study On The Typing Of Methicillin-resistant Staphylococcus Haemolyticus By RAPD

Staphylococcus hemolyticus accounts for the second majority in clinical Coagulase-negative staphylococci (CoNS) isolates, just following Staphylococcus epidermidis. The multi-resistance of methicillin-resistant staphylococcus haemolyticus (MRSH) is most significant in CoNS. It is important to supervise the epidemic of MRSH infection in earlier period and control it. To establish a rapid and sensitive coarse screening tool for supervising the epidemic of MRSH infection in hospitals, the typing of 81 MRSH isolates were studied by Random Amplified Polymorphic DNA (RAPD) technique.In this study, 81 MRSH isolates collected during April 2002 to April 2003 from the first affiliated hospital, college of medicine, Zhejiang University were typed by RAPD technique. Five group primers were designed for RAPD. Repeat attempts were done to select the optimized reaction condition and reaction system. The results were analyzed by SPSS software, and the dendrogram was used for cluster analysis.The results showed that the MRSH isolates can be typed by all the primers except one group (H12 and M13) reproducibly under the optimized reaction condition and reaction system. Among these 81 MRSH isolates, thirteen types were grouped byPrimer ERIC2, and five of 13 types have one isolate each with distinct difference. While, only eight types v/ere grouped by Primer ERICIR, and 70.3% of these isolates were grouped as the same type. The primer ERIC2 has higher discrimination compared with primer ERICIR.MRSH typing by RAPD assay with primer ERIC2 is rapid, sensitive and stable. RAPD with suitable primer could be a coarse screening tool to supervise the epidemic of MRSH infection in hospitals.