title: Genetic commonality of macrolide-resistant group A beta hemolytic streptococcus pharyngeal strains.
abstract: BACKGROUND
  Group A beta hemolytic streptococcus (GABHS) pharyngitis is a common childhood illness. Penicillin remains the gold standard therapy, but macrolides are indicated for the penicillin allergic patient, and are often used for convenience.
  
  
  METHODS
  We conducted a surveillance study of children with pharyngitis and positive streptococcal rapid antigen testing from 10/05 to 10/06 at 2 sites (A & B). Demographics, treatment, and resistance data was collected and compared to previous data from 2002. Erythromycin (EM) resistance was determined by disk diffusion and E-test on 500 isolates. Pulse field gel electrophoresis (PFGE) was performed to measure genetic relatedness of isolates. StatXact version 8 software (Cytel Inc., Cambridge, MA) was utilized to perform Fisher's exact test and exact confidence interval (CI) analysis.
  
  
  RESULTS
  There were no differences in resistance rates or demographic features, with the exception of race, between sites A & B. EM resistance was 0 in 2002, 3.5% in 2005-06 at site A, and 4.5% in 2005-06 at site B. 3/7 and 3/9 had inducible resistance at A and B respectively. 8 isolates had relatedness > or =80%, 5 of which were 88% homologous on PFGE.
  
  
  CONCLUSIONS
  Community macrolide resistance has increased following increased macrolide use. These results may have treatment implications if use continues to be high.
authors: Children's Mercy Hospitals and Clinics, University of Missouri-Kansas City School of Medicine, KC, MO, USA. amyers@cmh.edu
authors: Angela L
authors: AL
authors: Myers
authors: Mary Anne
authors: MA
authors: Jackson
authors: Rangaraj
authors: R
authors: Selvarangan
authors: Richard V
authors: RV
authors: Goering
authors: Christopher
authors: C
authors: Harrison
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001426:Bacterial Proteins / Q000235:genetics; D002648:Child; D024901:Drug Resistance, Multiple, Bacterial; D005260:Female; D006801:Humans; D018942:Macrolides / Q000494:pharmacology*; D008297:Male; D008826:Microbial Sensitivity Tests; D010612:Pharyngitis / Q000382:microbiology*; D011446:Prospective Studies; D013290:Streptococcal Infections / Q000382:microbiology*; D013297:Streptococcus pyogenes / Q000187:drug effects / Q000235:genetics*
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D018942:Macrolides