Distribution of emm genotypes in group A streptococcus isolates of Korean children from 2012 to 2019

Abstract

Abstract Objectives: Changes in the epidemiology of group A streptococcus (GAS) infection is related to emm genotype. We studied the distribution of emm genotypes and their antibiotic susceptibility among Korean children. Methods: Isolates from children with GAS infection between 2012 and 2019 were collected. emm typing and cluster analysis was performed according to the Centers for Disease Control emm cluster classification. Antimicrobial susceptibility was tested using the E-test and resistance genes were analyzed for macrolide resistant phenotypes. Results: Among 169 GAS isolates, 115 were from children with scarlet fever. Among invasive isolates, emm1 (6/22, 27.3%), emm12 (4/22, 18.2%), and emm4 (4/22, 18.2%) were most common. In scarlet fever, although emm4 (38/115, 33.0%) was the most prevalent throughout the study period, emm4 was replaced by emm3 (28/90, 31.1%) during an outbreak in 2017e2018. Among all isolates, only 2 (1.2%) exhibited erythromycin resistance and harbored both ermA and ermB genes. Conclusions: In this analysis of GAS isolated from Korean children, emm1 was the most prevalent in invasive infection. In scarlet fever, emm4 was prevalent throughout the study period,with an increase in emm3 during 2017e2018. GAS isolates during 2012e2019 demonstrated low erythromycin resistance