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Updated: May 2, 2026

A Murine Model of Group B Streptococcus Vaginal Colonization
Published on: November 16, 2016
Prevalence of macrolide resistance among group A streptococci isolated from pharyngotonsillitis
Takeaki Wajima1, Naoko Chiba, Miyuki Morozumi
11 Department of Microbiology, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences , Tokyo, Japan .
Abstract:
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.
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Tonsillitis I: Introduction
Etiology
Three primary contributing factors have been identified.
Atypical Pneumonia
Acute Pharyngitis
Acute pharyngitis is the inflammation of the back of the throat (pharynx), commonly resulting in a sore throat. It is a frequently encountered condition that prompts individuals to seek medical advice.
Classification
Acute pharyngitis can be categorized based on its underlying cause:
Development of Antibiotic Resistance