Community-acquired urinary tract infections by extended-spectrum beta-lactamase-producing Enterobacteriaceae in Zenica-Doboj Canton, Bosnia and Herzegovina

The aim of this study was to determine the incidence and antimicrobial resistance of ESBL-producing strains in the community-acquired urinary tract infections (CAUTIs), which is necessary for antimicrobial therapy selection. From January 2003 to September 2004, 4,112 consecutive, non-duplicate coliform isolates from CAUTIs were analyzed. Antimicrobial susceptibility testing to fifteen antimicrobials was performed by disc-diffusion method. Double-disk synergy test (DDST) with amoxicillin-clavulanat, cefotaxime, ceftazidime, ceftriaxone and aztreonam, and Etest strips with PM/PML (AB Biodisk) was performed according to CLSI recommendation in order to detect the ESBL producers. The overall incidence of ESBL producing strains was 2.6% (108/4112), it was significantly higher in males, 8.4% (79/936) than in females, 0.9% (29/3176). The highest prevalence of ESBL producers was noted in the oldest and youngest age group: 4.8% (52/106) and 2.6% (27/1045), respectively. An increase from 2.2% (52/2402) to 3.3% (56/1710), and a shift of ESBL producers toward the age group 0-6 years (1.6% and 3.8%, respectively) in this period was observed. The incidence of ESBL producing strains among isolated Klebsiella spp. were 7.8% (83/1060), E. coli 0.7% (18/2561), Citrobacter spp. 0.6% (1/156), Enterobacter spp. 7.7% (3/39) and Proteus spp. 1.0% ( 3/297). Among ESBL producing isolates Klebsiella spp. predominated, 76.9% (83/108), followed by E. coli 16.7% (18/108). ESBL producing strains showed significantly higher resistance rates to all tested antibiotics as compared to to non-ESBL-producers. The increase and shift toward the youngest age group of the ESBL producer incidences is of our concern. Further studies are required to detect ESBL types in terms of highly different geographical dissemination of these isolates