title: Differences in nasopharyngeal bacterial flora in children with nonsevere recurrent acute otitis media and chronic otitis media with effusion: implications for management.
abstract: BACKGROUND
  The interactions between nasopharyngeal flora and the individual entities covered by the broad term otitis media have not been completely elucidated. We investigated in infants and children ages 6 months to 7 years with nonsevere recurrent acute otitis media (rAOM) or with chronic otitis media with effusion (cOME): (1) the nasopharyngeal carriage rate and bacterial density of respiratory pathogens and alpha-hemolytic streptococci in comparison with healthy children; (2) the resistance pattern of respiratory pathogens; and (3) the relationship between the type of nasopharyngeal colonization and long term outcome.
  
  
  METHODS
  Nasopharyngeal cultures were obtained from 85 children with rAOM,113 children with cOME and 55 controls. A semiquantitative analysis was used in the reading of cultures. A 12-week follow-up without treatment was planned.
  
  
  RESULTS
  The carrier rate of respiratory pathogens was significantly greater in cOME (70%) than in rAOM (45%) (P = 0.0006) or controls (31%) (P < 0.0001). Similarly colonization density was significantly greater in cOME than in rAOM. The carriage rate and the colonization density of alpha-hemolytic streptococci were significantly lower in rAOM than in cOME or controls. The incidence of resistant (R) strains was greater in rAOM (Streptococcus pneumoniae penicillin-R, 24%; macrolide-R, 64%; Haemophilus influenzae amoxicillin-R, 24%) compared with cOME (S. pneumoniae penicillin-R,18%; macrolide-R, 44%; H. influenzae amoxicillin-R, 5%) or controls (S. pneumoniae penicillin-R, 8%; macrolide-R, 23%; H. influenzae amoxicillin-R, 10%). During the follow-up period persistence of OME and occurrence of AOM were greater among carriers of respiratory pathogens at baseline.
  
  
  CONCLUSIONS
  There are substantial differences in nasopharyngeal flora between children with nonsevere rAOM and children with cOME. The results of nasopharyngeal cultures should be taken into account to avoid treatment with drugs that are ineffective and likely to select resistant organisms.
authors.affiliation: Department of Pediatrics, University of Milan, Italy.
authors.forename: Paola
authors.initials: P
authors.lastname: Marchisio
authors.forename: Laura
authors.initials: L
authors.lastname: Claut
authors.forename: Alessandro
authors.initials: A
authors.lastname: Rognoni
authors.forename: Susanna
authors.initials: S
authors.lastname: Esposito
authors.forename: Desiderio
authors.initials: D
authors.lastname: Passali
authors.forename: Luisa
authors.initials: L
authors.lastname: Bellussi
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Drago
authors.forename: Gianni
authors.initials: G
authors.lastname: Pozzi
authors.forename: Stefania
authors.initials: S
authors.lastname: Mannelli
authors.forename: Giancarlo
authors.initials: G
authors.lastname: Schito
authors.forename: Nicola
authors.initials: N
authors.lastname: Principi
mesh_terms: D000208:Acute Disease; D000900:Anti-Bacterial Agents / Q000008:administration & dosage / Q000494:pharmacology; D002353:Carrier State; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D002908:Chronic Disease; D015331:Cohort Studies; D015169:Colony Count, Microbial; D016001:Confidence Intervals; D004352:Drug Resistance, Microbial; D005260:Female; D005500:Follow-Up Studies; D006193:Haemophilus influenzae / Q000187:drug effects / Q000254:growth & development; D006801:Humans; D007223:Infant; D008297:Male; D008826:Microbial Sensitivity Tests; D001936:Moraxella catarrhalis / Q000187:drug effects / Q000254:growth & development; D009305:Nasopharynx / Q000382:microbiology*; D016017:Odds Ratio; D010033:Otitis Media / Q000188:drug therapy / Q000453:epidemiology* / Q000382:microbiology*; D010034:Otitis Media with Effusion / Q000188:drug therapy / Q000453:epidemiology / Q000382:microbiology; D015995:Prevalence; D011336:Probability; D012008:Recurrence; D012016:Reference Values; D018570:Risk Assessment; D012720:Severity of Illness Index; D013296:Streptococcus pneumoniae / Q000187:drug effects / Q000254:growth & development
chemical_list: D000900:Anti-Bacterial Agents