A Decade of Pediatric CA-MRSA Surveillance in Northern Taiwan: Retrospective Resistance Analysis and Recent Genotypic Characterization.

Methicillin-resistant (MRSA) is a major cause of pediatric infections and has shown evolving molecular characteristics over time. This study aimed to investigate the phenotypic and genotypic features of MRSA isolates collected from pediatric patients at a tertiary medical center in northern Taiwan between 2011 and 2020. A total of 182 MRSA strains were analyzed for SCCmec types, PVL gene presence, antimicrobial susceptibility, multilocus sequence typing (MLST), and clonal relatedness using pulsed-field gel electrophoresis (PFGE). ST59/SCCmec Vt was the most prevalent genotype, followed by ST59/SCCmec IV and ST8/SCCmec IV. Most ST59/SCCmec Vt and ST8/SCCmec IV isolates clustered genetically. Clindamycin and erythromycin resistance remained high, whereas co-trimoxazole susceptibility ranged from 76% to 100%. These findings confirm ST59 as the dominant clone and highlight the emergence of ST8 and ST45 in community-associated MRSA (CA-MRSA) infections. Oral co-trimoxazole remains the most effective empirical option, while clindamycin and erythromycin should be avoided. Continuous molecular surveillance is warranted to monitor trends and guide treatment strategies in pediatric MRSA infections.