title: Prevalence of macrolide resistance among group A streptococci isolated from pharyngotonsillitis.
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.
authors.affiliation: 1 Department of Microbiology, School of Pharmacy, Tokyo University of Pharmacy and Life Sciences , Tokyo, Japan .
authors.forename: Takeaki
authors.initials: T
authors.lastname: Wajima
authors.forename: Naoko
authors.initials: N
authors.lastname: Chiba
authors.forename: Miyuki
authors.initials: M
authors.lastname: Morozumi
authors.forename: Michi
authors.initials: M
authors.lastname: Shouji
authors.forename: Katsuhiko
authors.initials: K
authors.lastname: Sunaoshi
authors.forename: Kayoko
authors.initials: K
authors.lastname: Sugita
authors.forename: Takeshi
authors.initials: T
authors.lastname: Tajima
authors.forename: Kimiko
authors.initials: K
authors.lastname: Ubukata
mesh_terms: D000208:Acute Disease; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001425:Bacterial Outer Membrane Proteins / Q000235:genetics* / Q000378:metabolism; D002648:Child; D002675:Child, Preschool; D024881:Drug Resistance, Bacterial / Q000235:genetics*; D005260:Female; D015964:Gene Expression Regulation, Bacterial; D005838:Genotype; D006801:Humans; D007223:Infant; D018942:Macrolides / Q000494:pharmacology*; D008297:Male; D008826:Microbial Sensitivity Tests; D058885:Multilocus Sequence Typing; D010612:Pharyngitis / Q000188:drug therapy / Q000382:microbiology; D010641:Phenotype; D013290:Streptococcal Infections / Q000188:drug therapy / Q000382:microbiology; D013297:Streptococcus pyogenes / Q000187:drug effects / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism
chemical_list: D000900:Anti-Bacterial Agents; D001425:Bacterial Outer Membrane Proteins; D018942:Macrolides