HA-MRSA in Japan in the early 1980s

This study aimed to determine the characteristics of Japanese healthcare-associated methicillin-resistant Staphylococcus aureus (HA-MRSA) strains in the early 1980s and their linkage with current MRSA strains. Twenty mecA-positive MRSA, 8 mecA-negative MRSA and 3 mecA-positive methicillin-susceptible S. aureus (MSSA) were identified in the present study. For 31 S. aureus strains, we determined methicillin resistance genotypically and performed multilocus sequence typing (MLST), staphylococcal cassette chromosome mec (SCCmec) typing, and whole-genome sequencing.