The distribution of the emm types and antimicrobial susceptibility to group A streptococcus in children of Beijing, 2014

Abstract

Objective To investigate the distribution of the emm types and antimicrobial susceptibility to group A streptococcus(GAS) in Beijing. Methods A total of 371 strains of GAS were isolated from the oropharyngeal swabs which were collected from 36 hospitals in Beijing from May to July in 2014.The emm types were performed by PCR and sequencing.The minimum inhibitory concentrations(MIC) in 10 kinds of antibiotics(Penicillin, Ampicillin, Erythromycin, Clinamycin, Tetracycline, Levofloxacin, Tigecycline, Vancomycin, Linezolid and Streptogramin ) were detected by VITEK-2 compact with GPS-67 test kit.Antimicrobial susceptibility was evaluated based on M100-S22 criteria and susceptible rate, intermediary rate, and drug resistance rate was analyzed. Results Five emm types and 15 subtypes were identified, and emm1 type was 54.7%(203/371 strains), emm 12 type was 44.2%(164/371 strains) and other emm types were 1.1%(4/37 strains). And 207 strains of GAS were selected for antimicrobial susceptibility test.All of 207 isolates were sensitive to Penicillin, Ampicillin, Levofloxacin, Tigecycline, Vancomycin, Linezolid and Streptogramin.The percentages of the strains that were of resistance to Clindamycin, Erythromycin and Tetracycline were 98.5%(204/207 strains), 98.1%(203/207 strains) and 92.8%(192/207 strains), respectively.There were no statistically significant difference in the rates of the strains that were resistant to Erythromycin, Lindamycin and Tetracycline among different districts, ages and clinical diagnosis(P>0.05). Conclusions The emm types of all strains were distributed intensively in Beijing in 2014, and emm1, emm12 constituted the main types.The strains of GAS are sensitive to β-lactams and quinolones antibiotics and highly resistant to the macrolide antibiotics and resistant higher to Clindamycin and Erythromycin, which suggests a reasonably use of antibiotics in hospitals nowadays. Key words: Group A streptococcus; emm gene; Antimicrobial susceptibility; Child