Prevalence of macrolide resistance among group a streptococci isolated from pharyngotonsillitis

Takeaki Wajima, Naoko Chiba, Miyuki Morozumi, Michi Shouji, Katsuhiko Sunaoshi, Kayoko Sugita, Takeshi Tajima, Kimiko Ubukata

Research output: Contribution to journalArticlepeer-review

15 Citations (Scopus)


A GAS Surveillance Study Group was organized to analyze group A streptococci (GAS) isolated from patients with acute pharyngotonsillitis, with participating pediatricians submitting swab samples between April and October 2012. Molecular analysis of emm typing and multilocus sequence typing (MLST), as well as antimicrobial susceptibility testing, were carried out for 363 GAS isolates. Strains belonging to emm1 were most prevalent (25.6%), followed in turn by emm12 (23.7%), emm28 (16.3%), and emm89 (15.3%). In emm1, 87.2% of strains, typed as ST28 or ST661, showed macrolide (ML) resistance mediated by the mef(A) gene. In emm12 (ST36 and ST465), 64.3% of strains were resistant to MLs because of mef(A) or erm(B), as was also true for 81.7% of emm28 (ST52). In emm89 (ST101 and ST646), however, such resistance was not seen. Due to the high levels of ML resistance observed, GAS isolates from individuals with penicillin allergies need to be isolated and their antimicrobial susceptibility tested, rather than automatically giving the patient a ML.

Original languageEnglish
Pages (from-to)431-435
Number of pages5
JournalMicrobial Drug Resistance
Issue number5
Publication statusPublished - 2014 Oct 1
Externally publishedYes

ASJC Scopus subject areas

  • Microbiology
  • Immunology
  • Pharmacology
  • Microbiology (medical)


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