Genomic Characterization of ST1-t1784 CA-MRSA Isolates Prevalent in Kanto Region, Japan

From 2018-2019, we collected 164 MRSA isolates from 13 clinical sites in Kanto region, Japan. SCCmec typing and MLST analysis showed that SCCmec Type-IV CA-MRSA accounted for about 80% of the total and that 61 isolates belonged to clonal complex 1 (CC1) consisted of ST1 and ST1-related groups. In addition, spa typing showed that most of the CC1 isolates possessed t1784 type, whose prevalence was recently reported in Japan. In this study, we analyzed genomic characteristics of the spa-t1784 isolates.