title: High incidence of Alloiococcus otitis in otitis media with effusion.
abstract: BACKGROUND
  The etiology of otitis media with effusion (OME) is unclear. Although the majority of effusions show inflammation, culture methods yield positive results for bacteria in only 20 to 30% of cases.
  
  
  METHODS
  The polymerase chain reaction was used for detection of three upper respiratory tract pathogens, Haemophilus influenzae, Moraxella catarrhalis and Streptococcus pneumoniae, and a fairly recently described bacterium, Alloiococcus otitis (A. otitidis), that is solely found in OME. The study included 67 middle ear effusions that were collected from 48 pediatric OME patients during ventilation tube placement.
  
  
  RESULTS
  PCR tested positive for 57 (85.1%) of the middle ear effusions. Thirty-one (46.3%) A. otitis-, 12 (17.9%) H. influenzae-, 25 (37.3%) M. catarrhalis- and 14 (20.9%) S. pneumoniae-positive effusions were obtained. All four study organisms showed similar distribution in effusions of various duration (P = 0.72) and in different effusion types (P = 0.59). Only the proportion of M. catarrhalis-positive effusions was lowered by recent antimicrobial therapy (P < 0.05). Although the study organisms had equal distributions among singly and multiply positive specimens (P = 0.90), A. otitis was detected significantly more often with one of the three other species (15 of 19, 78.9%) than the other species with each other (4 of 19, 21.1%, P < 0.001).
  
  
  CONCLUSIONS
  The findings suggest a bacterial etiology for OME. Association of A. otitis with the three other species implies that this organism might have the capability of augmenting bacterial colonization in the middle ear.
authors.affiliation: Institute of Biotechnology, University of Helsinki, Finland. Panu.Hendolin@Helsinki.fi
authors.forename: P H
authors.initials: PH
authors.lastname: Hendolin
authors.forename: U
authors.initials: U
authors.lastname: Kärkkäinen
authors.forename: T
authors.initials: T
authors.lastname: Himi
authors.forename: A
authors.initials: A
authors.lastname: Markkanen
authors.forename: J
authors.initials: J
authors.lastname: Ylikoski
mesh_terms: D002648:Child; D002675:Child, Preschool; D005260:Female; D016908:Gram-Positive Bacterial Infections / Q000175:diagnosis* / Q000453:epidemiology; D006192:Haemophilus Infections / Q000175:diagnosis / Q000453:epidemiology; D006193:Haemophilus influenzae / Q000302:isolation & purification; D006801:Humans; D007223:Infant; D007777:Lactobacillaceae / Q000302:isolation & purification*; D008297:Male; D001936:Moraxella catarrhalis / Q000302:isolation & purification; D016870:Neisseriaceae Infections / Q000175:diagnosis / Q000453:epidemiology; D010034:Otitis Media with Effusion / Q000382:microbiology*; D011008:Pneumococcal Infections / Q000175:diagnosis / Q000453:epidemiology; D016133:Polymerase Chain Reaction; D012680:Sensitivity and Specificity; D013296:Streptococcus pneumoniae / Q000302:isolation & purification