Isolation and Identification of Moraxella catarrhalis in Children with Otitis Media in Khartoum State

Abstract

The main aim of this study was to detect M.catarrhalis in children with otitis media in Khartoum State, during the period from January to March 2011. A total of 110 specimens of middle ear discharge were collected by sterile swabs from Khartoum Center of Ear, Nose and Throat (ENT), Head and Neck Surgery, the specimens were then cultured on chocolate agar, sheep blood agar and MacConkey agar, in which 90 gave growth (82%) while 20 gave no growth (18%). There were 3 M.catarrhalis (3.3%) isolated from middle ear discharge of infected children. The colonial morphology, Gram stain, biochemical tests and susceptibility tests of the isolated M.catarrhalis were compared with the reference strains (ATCC 23246, ATCC 25240 and ATCC 25238). The isolated M.catarrhalis colonies on chocolate agar and sheep blood agar could be pushed along the surface of the agar like a hockey puck. Also it was positive for oxidase, catalase, DNase, tributyrin tests and reduced nitrate to nitrite. ‫%4.2 ‪The percentage of M.catarrhalis among males was 4.2% and‬‬ ‫.‪among female patients‬‬ ‫‪When susceptibility test was done, all isolated M.catarrhalis were‬‬ ‫,‪found to be sensitive to Amoxyclav, azithromycin, ceftazidime‬‬ ‫,‪chloramphenicol‬‬ ‫,‪cephotaxime‬‬ ‫,‪cephalexin‬‬ ‫,‪ceftriaxon‬‬ ‫‪ciprofloxacin, co- trimoxazole and erythromycin. Whereas all of‬‬ ‫‪them were resistant to ampicillin. Moreover M.catarrhalis isolates‬‬ ‫.‪(100%) produced β-lactamase enzyme‬‬