To determine the prevalence and resistance profile of bacterial pathogens present in the middle ear of children with otitis media with effusion, and to report beta-lactamase-negative, ampicillin-resistant bacteria for the first time in Lebanese children.

We included 62 patients younger than 12 year (107 ears), who underwent myringotomy with tympanostomy tube placement for persistent otitis media with effusion. Bacteria were identified by Gram staining and biochemical tests, and antibiotic sensitivities tested by the disc diffusion method and via minimum inhibitory concentration (E-test).

The commonest pathogen was Haemophilus influenzae (62 per cent), followed by Streptococcus pneumoniae (26 per cent). The H influenzae resistance profile was highest for amoxicillin (81.0 per cent) and lowest for cefotaxime (19.0 per cent). There was a high risk of developing H influenzae antibiotic resistance among children with a history of smoking exposure (p = 0.001), recurrent upper respiratory tract infection (p = 0.001) or previous antibiotic treatment (p = 0.005). Fifty-two per cent of H influenzae colonies were found to be beta-lactamase-negative and ampicillin-resistant.

In these children with persistent otitis media with effusion, H influenzae was the most prevalent bacteria. It showed a high incidence of resistance to the antibiotics most commonly prescribed to treat acute otitis media.