title: Microbiology of bacteria causing recurrent acute otitis media (AOM) and AOM treatment failure in young children in Spain: shifting pathogens in the post-pneumococcal conjugate vaccination era.
abstract: OBJECTIVE
  To prospectively identify the bacterial aetiology and antimicrobial susceptibility of problematic (recurrent and treatment failure) acute otitis media in Spanish children several years after the introduction of 7-valent pneumococcal conjugate vaccine.
  
  
  METHODS
  Tympanocentesis or careful sampling of spontaneous otorrhoea was performed on children aged 3 to <36 months with recurrent acute otitis media, acute otitis media treatment failure or unresolved acute otitis media.
  
  
  RESULTS
  105 acute otitis media episodes (77 sampled by tympanocentesis, 28 otorrhoea samples) were evaluated: 46 recurrent, 35 treatment failures, 24 unresolved acute otitis media. 74 episodes (70.4%) had at least one bacterium identified on culture: Streptococcus pneumoniae was identified in 21 episodes, Haemophilus influenzae (all non-typeable) in 44, Streptococcus pyogenes in 2, Moraxella catarrhalis in 2. No statistically significant difference in bacterial aetiology by episode type was detected. Non-typeable H. influenzae was the most commonly isolated pathogen in all acute otitis media types and in all age sub-groups. Forty percent of S. pneumoniae isolates were multi-drug resistant. Pneumococcal serotype 19A was the most frequently identified serotype (7/21 episodes). Multi-drug resistance was found in 56% of 19A isolates. Of non-typeable H. influenzae isolates, 15% were ampicillin resistant and 13% were amoxicillin/clavulanate resistant. S. pneumoniae and non-typeable H. influenzae DNA were each detected in 57% of samples culture negative for these pathogens, including 12 co-infections.
  
  
  CONCLUSIONS
  Combining culture and polymerase chain reaction results, H. influenzae and S. pneumoniae may be implicated in 70% and 43% of clinically problematic bacterial acute otitis media episodes, respectively. The impact of new vaccines to prevent both S. pneumoniae and non-typeable H. influenzae acute otitis media may be substantial in this population and is worth investigating.
authors.affiliation: Hospital Infantil Universitario Vall d'Hebrón, Barcelona, Spain. felix.pumarola@gmail.com
authors.forename: Felix
authors.initials: F
authors.lastname: Pumarola
authors.forename: Josep
authors.initials: J
authors.lastname: Marès
authors.forename: Isabel
authors.initials: I
authors.lastname: Losada
authors.forename: Isabel
authors.initials: I
authors.lastname: Minguella
authors.forename: Fernando
authors.initials: F
authors.lastname: Moraga
authors.forename: David
authors.initials: D
authors.lastname: Tarragó
authors.forename: Ulla
authors.initials: U
authors.lastname: Aguilera
authors.forename: Josep M
authors.initials: JM
authors.lastname: Casanovas
authors.forename: Gloria
authors.initials: G
authors.lastname: Gadea
authors.forename: Elisenda
authors.initials: E
authors.lastname: Trías
authors.forename: Santiago
authors.initials: S
authors.lastname: Cenoz
authors.forename: Alessandra
authors.initials: A
authors.lastname: Sistiaga
authors.forename: Pilar
authors.initials: P
authors.lastname: García-Corbeira
authors.forename: Jean-Yves
authors.initials: JY
authors.lastname: Pirçon
authors.forename: Cinzia
authors.initials: C
authors.lastname: Marano
authors.forename: William P
authors.initials: WP
authors.lastname: Hausdorff
mesh_terms: D000208:Acute Disease; D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D002675:Child, Preschool; D004352:Drug Resistance, Microbial; D005260:Female; D006193:Haemophilus influenzae / Q000302:isolation & purification*; D000069443:Heptavalent Pneumococcal Conjugate Vaccine; D006801:Humans; D007223:Infant; D008297:Male; D008826:Microbial Sensitivity Tests; D001936:Moraxella catarrhalis / Q000302:isolation & purification*; D010033:Otitis Media / Q000382:microbiology* / Q000628:therapy; D022242:Pneumococcal Vaccines; D011446:Prospective Studies; D012008:Recurrence; D013030:Spain; D013296:Streptococcus pneumoniae / Q000302:isolation & purification*; D013297:Streptococcus pyogenes / Q000302:isolation & purification*; D017211:Treatment Failure
chemical_list: D000900:Anti-Bacterial Agents; D000069443:Heptavalent Pneumococcal Conjugate Vaccine; D022242:Pneumococcal Vaccines
keywords: Antibiotic resistance; Haemophilus influenzae; Otitis media; Streptococcus pneumoniae; Tympanocentesis