title: Macrolide resistance and emm type distribution of invasive pediatric group A streptococcal isolates: three-year prospective surveillance from a children's hospital.
abstract: OBJECTIVE
  Macrolide-resistant group A streptococci (GAS) have been suggested to have more invasive potential. An M protein-based GAS vaccine is currently in development. We sought to define the GAS emm types and macrolide resistance rates among pediatric invasive GAS isolates collected prospectively during a recent 40-month period at our children's hospital.
  
  
  METHODS
  We prospectively identified and collected GAS isolates from patients with invasive GAS disease (isolates from normally sterile sites). Susceptibility assays for erythromycin and clindamycin were performed by E-test. emm typing was performed by the Centers for Disease Control and Prevention. Clinical characteristics of patients were identified by chart review.
  
  
  RESULTS
  A total of 37 patient isolates were identified, of which 35 isolates were able to be characterized. Four patients had underlying illness. No macrolide resistance was detected among the isolates. The most common emm types causing invasive disease were emm 1.0 (43%) and emm 12.0 (11.1%).
  
  
  CONCLUSIONS
  In this group of 35 invasive GAS isolates, no cases of macrolide resistance were found. emm type 1 accounted for the highest percentage of invasive disease, followed by emm type 12. The type-specific GAS M protein-based vaccine currently in development includes the emm types of 33 of 35 (94%) of the invasive emm types in this series.
authors.affiliation: Columbus Children's Hospital, Columbus, OH, USA. jaggip@pediatrics.ohio-state.edu
authors.forename: Preeti
authors.initials: P
authors.lastname: Jaggi
authors.forename: Bernard
authors.initials: B
authors.lastname: Beall
authors.forename: Jason
authors.initials: J
authors.lastname: Rippe
authors.forename: Robert R
authors.initials: RR
authors.lastname: Tanz
authors.forename: Stanford T
authors.initials: ST
authors.lastname: Shulman
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D002648:Child; D024901:Drug Resistance, Multiple, Bacterial; D006776:Hospitals, Pediatric; D006801:Humans; D018942:Macrolides / Q000494:pharmacology*; D011159:Population Surveillance; D013290:Streptococcal Infections / Q000453:epidemiology / Q000382:microbiology*; D013297:Streptococcus pyogenes / Q000145:classification / Q000187:drug effects* / Q000378:metabolism
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D018942:Macrolides