The antibiotic susceptibilities and beta-lactamase production of clinical isolated Branhamella catarrhalis from acute otitis media in children.

Branhamella catarrhalis has been misconsidered as a normal resident in human respiratory tract for a long time. However, many authors recently have reported its pathogenecity and isolated it from the otolaryngological region. In our study, this organism can be isolated from the ear and nasal discharge in the child with acute otitis media by the rate of 7.5% and 21.4% respectively. Out of this 107 isolated strains, 97 strains (90.7%) were found to be beta-lactamase producing organisms. The MIC measurement of penicillins and cephems (except CEX) for inhibition of all these strains in our study is 6.25 micrograms/ml or less and because of the unreliability of the ABPC's susceptibility test by disk method, it is necessary to check the beta-lactamase production in each strain. Becoming of the high emergence rate of beta-lactamase producing strains, B. catarrhalis should be considered to be as important pathogen as Streptococcus pneumoniae and Haemophilus influenzae in upper respiratory tract infections in children.