Sequence Type Changes Associated with Decreasing Macrolide-Resistant Mycoplasma pneumoniae , Japan

M ycoplasma pneumoniae is a major cause of com- munity-acquired pneumonia, and macrolideresistant M. pneumoniae is a serious concern in Asia (1-3). Throughout Japan, an outbreak of macrolideresistant M. pneumoniae infection occurred during 2011-2012 (2). After this outbreak, the number of drug-resistant strains decreased for every year from 2013 through 2019. In contrast, China and South Korea still showed a high rate of macrolide resistance in M. pneumoniae during 2014-2018 (1,3). We determined antimicrobial drug susceptibility and performed analysis by using multilocus sequence typing (MLST), clonal complexes (CCs), and P1 gene typing for M. pneumoniae isolated from children to identify trends concerning this bacterium in Japan.