Spread of community-acquired methicillin-resistant Staphylococcus aureus (MRSA) in hospitals in Taipei, Taiwan in 2005, and comparison of its drug resistance with previous hospital-acquired MRSA

Panton-Valentine leucocidin (PVL)-positive methicillin-resistant Staphylococcus aureus (PVL' MRSA) is an emerging pathogen in the community worldwide. The incidence of PVL+ MRSA in Taipei, Taiwan was 23.3% for hospital MRSA. PVL' MRSA was isolated from both outpatients and inpatients. Some PVL+ (mecA(+)) strains (36.8%) showed low MIC values (<= 2 mu g/ml) to oxacillin. A major PVL' MRSA resistance pattern was oxacillin and clindamycin resistance (81 %). There was no multidrug resistance over three drugs, in contrast to patient PVL- MRSA with resistance to five drugs as a major resistance pattern. The majority of PVL+ MRSA belonged to multilocus sequence (ST) type 59, while PVLMRSA belonged to ST239, ST59 and ST5. The data suggests that although PVL+ CA-MRSA is isolated at a high incidence from hospitals in Taipei, the drug resistance is mostly selected in the community and less prominent compared with previous PVL- hospital-acquired MRSA.