Acta clinica Croatica, Vol. 43 No. 4, 2004.
Original scientific paper
Antibiotic Susceptibilities and ß-Lactamase Production of Moraxella Catarrhalis Isolates from Zagreb, Croatia
Branka Bedenić
Jasmina Vraneš
Abstract
Moraxella catarrhalis, a commensal of the nasopharynx, has been recognized with increasing frequency as a potential pathogen in respiratory tract infections. The ß-lactamase production in Moraxella catarrhalis, first described in 1977, has been ever more frequently reported in many countries of the world. However, there have no such reports from Croatia so far. The aim of this study was to investigate antibiotic susceptibilities and ß-lactamase production in Moraxella catarrhalis isolates from Croatia. Fifty Moraxella catarrhalis strains were collected from various clinical specimens at Zagreb University Children's Hospital during the 1990-1992 period. Antibiotic susceptibilities to a wide range of antibiotics were determined by the broth microdilution method according to NCCLS. In all strains, ß-lactamases were detected by the disk chromogenic substrate (nitrocefin) test. The prevalence of ß-lactamase positive strains in the study period was 100%. No resistance to amoxicillin/clavulanate, cephalexin, ceftibuten, tetracycline, erythromycin, azithromycin and chloramphenicol was observed. In all strains, the activity of amoxicillin was strongly enhanced in the presence of clavulanic acid. Older cephalosporins were equally active, however, the thirdgeneration cephalosporin ceftibuten showed significantly lower minimal inhibitory concentrations compared with older compounds. Among non ß-lactam antibiotics, tetracycline and erithromycin showed similar activity. Azithromycin had a markedly stronger inhibitory activity in comparison with erythromycin and tetracycline. According to our results, amoxicillin combined with clavulanic acid should be the antibiotic of choice for the treatment of infections caused by ß-lactamase positive isolates of Moraxella catarrhalis. Oral cephalosporins, tetracycline, macrolides or azithromycin could be an option too.
Keywords
Moraxella-Branhamella catarrhalis - drug effects; Anti-infective agents - pharmacology; Respiratory tract
Hrčak ID:
14556
URI
Publication date:
1.12.2004.
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