engleski

Prevalence, molecular characterization and antimicrobial resistance of extended-spectrum beta-lactamase-producing Gramnegative bacteria isolated from outpatient clinical and environmental samples in Zenica-Doboj Canton, Bosnia and Herzegovina

Objectives An environment have been considered as potential sources of extended-spectrum beta-lactamase (ESBL) producing Gramnegative bacteria causing infection in the community. ESBL-producing bacteria has increasingly detected in environmental samples in different countries since 2002 and have gained considerable attention worldwide. The aim of the study was to determine the prevalence, molecular characteristics and antimicrobial resistance of ESBL-producing Gramnegative bacteria collected from clinical outpatient and environmental samples (water, food, environmental surfaces) in Zenica-Doboj Canton, Bosnia and Hezegovina, during December 2009-May 2010 and Decembar 2013 – May 2014, respectively. Methods All environmental samples were analysed according to International Standardization Organization. Antibiotic susceptibility was determined using the disk-diffusion method for all isolates and additionally minimum inhibitory concentration (MIC) for clinical samples in accordance to CLSI. Production of ESBLs was determined by double-disk sinergy test. PCR was used for detection of blaESBL, blaAmpC and blaCARB genes of clinical isolates. Results Among clinical outpatient samples, 184 (out of 2857 Gram-negative bacteria, 6.5%) ESBL-producing bacteria were isolated: 38 (64.4%) from urine samples, 16 (27.1%) from surgical wounds and five (8.5%) from other clinical samples (upper respiratory tract, swab of umbillicus, cannula, eyes, swab of genital region). In outpatient samples Klebsiella spp. were isolated in 28 (47.5%), E. coli in 19 (32.2%), non-fermentors in three (5.1%), and other bacteria in nine (15.3%) samples. Among environmental samples, 52 (out of 381 Gram-negative bacteria, 13.6%) were ESBL-producing isolates: 37 (71.2%) from water, seven (13.5%) from food and eight (15.4%) from environmental surfaces). The most prevalent ESBL-producing bacteria isolated from environmental samples was E. coli 26 (50.0%), Klebsiella spp. 10 (19.2%) , non-fermentors 9 (17.3%) and other bacteria from seven (13.5%) samples. Clinical outpatient ESBL-producing isolates showed resistance to all cephalosporins, ranging from 25% (cefepim) to 100% (cefuroxime). Environmental ESBL-producing isolates showed resistance to cefuroxime, aztreonam, cefpodoxime, amoxicillin/clavulanic and cefoxitin in the rangevof 65.0%-100.0%. Thirty (50.8%) outpatient clinical isolates were blaTEM-1 positive, 20 (33.9%) were blaCTX-M (13 isolates were blaCTX-M-15), and 11 (18.6%) were blaSHV-1 ; five isolates produced CMY-2 beta-lactamase. Carbapenemases were not detected. Conclusions Water, food and environmental surfaces are important reservoirs of ESBL-producing bacteria, which might be transmitted to human through the food chain. Therefore, the proper hygiene and controlled use of cephalosporins is necessary for a prevention and spread of resistant bacteria.

extended-spectrum beta-lactamases; Gram-negative bacteria; cephalosporins

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