High incidence of Alloiococcus otitis in otitis media with effusion

Background. The etiology of otitis media with effusion (OME) is unclear. Al though the majority of effusions show inflammation, culture methods yield p ositive results for bacteria in only 20 to 30% of cases. Methods. The polymerase chain reaction was used for detection of three uppe r respiratory tract pathogens, Haemophilus influenzae, Moraxella catarrhali s and Streptococcus pneumoniae, and a fairly recently described bacterium, Alloiococcus otitis (A otitidis), that is solely found in OME, The study in cluded 67 middle ear effusions that were collected from 48 pediatric OME pa tients during ventilation tube placement, Results. PCR tested positive for 57 (85.1%) of the middle ear effusions, Th irty-one (46.3%) A otitis-, 12 (17.9%) H; influenzae-, 25 (37.3%) M. catarr halis- and 14 (20.9%) S. pneumoniae-positive effusions were obtained. All f our study organisms showed similar distribution in effusions of various dur ation (P = 0.72) and in different effusion types (P = 0.59). Only the propo rtion of M; catarrhalis-positive effusions was lowered by recent antimicrob ial therapy (P < 0.05). Although the study organisms had equal distribution s among singly and multiply positive specimens (P = 0.90), A. otitis was de tected 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 < 0.0 01), 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.