Antimicrobial resistance and production of beta-lactamases in Bulgarian clinical isolates Moraxella catarrhalis

Abstract

One hundred and fifteen strains of Moraxella catarrhalis from inpatients and healthy children were collected from 2000 to 2005. MICs to 17 antimicrobial agents from different groups were determined. High resistance rate to penicillin G, aminopenicillins and first generation cephalosporins (98.26%) was found. Susceptibility to cefuroxime, cefotaxime and ceftriaxone was from 86.08 to 97.40%. All M. catarrhalis strains were susceptible to aminopenicillin/inhibitor combinations, ceftazidime, ceftibuten, ciprofloxacin and gentamicin. The susceptibility rates to azithromycin, clarithromycin, tetracycline and trimethoprim/sulfamethoxazole were reduced in range of 6-9%. Presence of bro1 or bro2 genes was revealed in 113 M. catarrhalis strains by PCR. The overall prevalence of the BRO-1 and BRO-2 enzymes was 92.92 and 7.08% respectively. MICs of Penicillin were significantly higher in bro1 positive isolates.