Emergence of the community-acquired methicillin-resistant Staphylococcus aureus USA300 clone in Japan

We isolated methicillin-resistant Staphylococcus aureus (MRSA) from a 3-month-old Indian girl who was born in the United States, moved to Japan, and suffered from subcutaneous abscesses in 2007. The MRSA (strain NN36) belonged to multilocus sequence type (ST) 8, exhibited agr1, staphylococcal cassette chromosome mec (SCCmec) type IVa, and coagulase type III, and was positive for Panton-Valentine leukocidin (PVL) and the arginine catabolic mobile element (ACME), just like the USA300 clone, which is the predominant community-acquired MRSA (CA-MRSA) in the United States. Strain NN36 shared an identical pulsed-field gel electrophoresis (PFGE) pattern with the USA300 clone. Although the USA300 clone is of spa1, strain NN36 possessed spa985. Strain NN36 was resistant to erythromycin and kanamycin, in addition to beta-lactam agents (e.g., oxacillin). The data suggest that the USA300 clone has emerged in Japan. Because the USA300 clone has recently spread to European countries, surveillance of the USA300 clone should be actively performed in Japan.