title: Serotype 19A is the most common Streptococcus pneumoniae isolate in children with chronic sinusitis.
abstract: BACKGROUND
  The introduction of the heptavalent pneumococcal conjugate vaccine has altered the epidemiology of acute otitis media and invasive pneumococcal disease in children. However, sparse data regarding pediatric sinusitis are available since the licensure of pneumococcal conjugate vaccine. In this study, sinus cultures which grew Streptococcus pneumoniae at Texas Children's Hospital were evaluated with regard to pneumococcal serotype, antimicrobial susceptibility, and frequency of coinfecting organisms.
  
  
  METHODS
  S. pneumoniae isolates from sinus cultures were identified from January 1, 2007 to July 31, 2008. A retrospective chart review was performed and information including age, ethnicity, gender, and comorbidities was collected. Isolates were serotyped and their susceptibility to oral penicillin, cefotaxime, erythromycin, clindamycin, and trimethoprim-sulfamethoxazole was determined.
  
  
  RESULTS
  During the study period, 24 pneumococcal isolates were recovered from endoscopic sinus surgery cultures; 23 isolates were nonvaccine serotypes. Serotype 19A accounted for 50% of isolates. Eleven of the 12 serotype 19A isolates were nonsusceptible to oral penicillin as compared with 6 isolates of the other serotypes. Five of 12 serotype 19A isolates were nonsusceptible to cefotaxime; in comparison, all of the other serotypes were susceptible to cefotaxime. One third of the 19A isolates were nonsusceptible to all 5 antimicrobials tested. Other organisms were coisolated in 87% of cases.
  
  
  CONCLUSIONS
  Serotype 19A has become the most common pneumococcal serotype isolated from chronic or recurrent pneumococcal sinusitis in children at Texas Children's Hospital. Serotype 19A isolates have high rates of antimicrobial resistance and are frequently isolated along with multiple other organisms.
authors.affiliation: From the *Department of Pediatrics, Section of Pediatric Infectious Diseases, Baylor College of Medicine, Houston, Texas; and daggerTexas Children's Hospital, Houston, Texas.
authors.forename: J Chase
authors.initials: JC
authors.lastname: McNeil
authors.forename: Kristina G
authors.initials: KG
authors.lastname: Hulten
authors.forename: Edward O
authors.initials: EO
authors.lastname: Mason
authors.forename: Sheldon L
authors.initials: SL
authors.lastname: Kaplan
mesh_terms: D000293:Adolescent; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D015373:Bacterial Typing Techniques; D002648:Child; D002675:Child, Preschool; D015897:Comorbidity; D024881:Drug Resistance, Bacterial; D005260:Female; D006761:Hospitals; D006801:Humans; D007223:Infant; D008297:Male; D008826:Microbial Sensitivity Tests; D011008:Pneumococcal Infections / Q000453:epidemiology* / Q000382:microbiology*; D015995:Prevalence; D012703:Serotyping; D012852:Sinusitis / Q000453:epidemiology* / Q000382:microbiology*; D013296:Streptococcus pneumoniae / Q000145:classification* / Q000187:drug effects / Q000302:isolation & purification*; D013781:Texas / Q000453:epidemiology
chemical_list: D000900:Anti-Bacterial Agents