Correlation between susceptibility and BRO type enzyme of Moraxella catarrhalis strains.
Clinical isolates of Moraxella catarrhalis (76 isolates) were screened for beta-lactamase production and antibiotic susceptibility. beta-Lactamases (detected in 90.8% of isolates) were typed using isoelectric focusing to BRO-1 (87%) and BRO-2 (13%). Minor variations in electrofocusing patterns between the two types were seen. Isolates expressing BRO type enzymes showed solid resistance to penicillin, ampicillin and cephalothin, in particular BRO-1 producers. BRO-1 isolates were less susceptible to cephems and to beta-lactamase inhibitors than BRO-2 isolates. Isolates harbouring BRO-1 enzymes have more enzymatic activity than those expressed by BRO-2 isolates. Apart from resistance to tetracycline (14.5%), all isolates were consistently susceptible to erythromycin, chloramphenicol, ciprofloxacin and gentamicin. The conjugal transfer of BRO beta-lactamase gene(s) between M. catarrhalis isolates occurred with a frequency of 10(-5) to 10(-7)/donor cell. The data emphasize the importance of M. catarrhalis as an etiological agent spreading beta-lactamases that may inhibit some beta-lactams and lead to failure in treatment of mixed infections.
Kadry
Ashraf A
AA
Pharmaceutics Department, Faculty of Pharmacy, King Saud University, Riyadh, Saudi Arabia.
Fouda
Soliman I
SI
Elkhizzi
Noura A
NA
Shibl
Atef M
AM
D003227:Conjugation, Genetic; D006801:Humans; D007525:Isoelectric Focusing; D008826:Microbial Sensitivity Tests; D001936:Moraxella catarrhalis / Q000145:classification / Q000187:drug effects* / Q000201:enzymology; D014169:Transformation, Bacterial; D018440:beta-Lactam Resistance / Q000502:physiology*; D001618:beta-Lactamases / Q000096:biosynthesis* / Q000737:chemistry; D047090:beta-Lactams / Q000494:pharmacology*
D047090:beta-Lactams; D001618:beta-Lactamases