Emergence of Panton-Valentine Leukocidin-Positive ST80 Clone of Community-Associated Methicillin-Resistant Staphylococcus aureus in Busan, Korea

Community-associated methicillin resistant Staphylococcus aureus (CA-MRSA) has become widespread in the community and healthcare settings, and a number of clonal lineages emerged on every country. Sequence type (ST) 80 clone of CA-MRSA was dominant in Europe and has increasingly been isolated from the Middle East but so far never found in Korea. In this study, 48 MRSA isolates recovered from ear infections were characterized by multilocus sequence typing (MLST), staphylococcal cassette chromosome mec (SCCmec) typing, staphylocoagulase (SC) genotyping, staphylococcal protein A gene (spa) typing, accessory gene regulator (agr) typing, and virulence gene profiling. Most MRSA strains belonged to three major clones: ST5-SCCmec II-SC type II (n=19, 39.6%), ST239-SCCmec III-SC type IV (n=15, 31.2%), and ST72-SCCmec IV-SC type Vb (n=11, 22.9%). Among the isolates, one strain was Panton-Valentine leukocidin (PVL)-positive ST80-SCCmec IV-SC type XIa - spa type t044-agr group III, and exfoliative toxin D-positive. This strain was susceptible to most antibiotics, but resistant to tetracycline and fusidic acid. This is the first report on the emergence of European ST80 CA-MRSA clone in Korea.