High prevalence of CTX-M-15 and first report of CTX-M-3, CTX-M-22, CTX-M-28 and plasmid-mediated AmpC beta-lactamase producing Enterobacteriaceae causing urinary tract infections in Bosnia and Herzegovina in hospital and community settings.

To investigate molecular epidemiology of extended-spectrum β-lactamase/ESBL and plasmid-mediated AmpC β-lactamase/pAmpC producing Gram-negative bacteria causing urinary tract infections (UTIs) in Zenica-Doboj Canton, Bosnia and Herzegovina, in the period Decembar 2009-May 2010.Antibiotic susceptibility was determined by disc diffusion and broth microdilution according to CLSI guidelines. Double-disk synergy test was performed in order to screen for ESBLs/pAmpC beta-lactamases. PCR was used to detect blaESBL/blaampC/blacarb genes. Genetic relatedness of the strains was determined by pulsed-field-gel-electrophoresis (PFGE).Among 85 patients with UTIs caused by ESBL producing isolates, 44 (51.8%) were from in-patients and 41 (48.2%) from outpatients. Klebsiella spp. was the most frequently isolated from in-patients, in 28 (63.6%) cases. Among outpatients, Klebsiella spp./Escherichia coli were the most frequently isolated, in 19 (46.3%)/16 (39.0%) cases. Twenty-one (75.0%) from hospital and nine (47.4%) from outpatient Klebsiella spp. isolates were positive for blaTEM, whereas 27 (96.4%) from in-patients and 6 (31.6%) from outpatient were blaCTX-M positive (18 hospital and five outpatient isolates were encoding blaCTX-M-15). One Klebsiella oxytoca and one Enterobacter cloacae inpatient isolates were positive for blaCTX-M-28. One Klebsiella pneumoniae outpatient isolate were positive for blaCTX-M-22 and one E. coli for blaCTX-M-3. One hospital Proteus mirabilis strain was positive for blaCMY-2 and two Klebsiella spp. strains for blaDHA-1, whereas two E. coli, one K. oxytoca and one Proteus vulgaris outpatient strains were positive for blaCMY-2.Identification of blaCTX-M-3, blaCTX-M-22 and blaCTX-M-28 among Enterobacteriaceae is uncommon. In this study we report the emergency of CMY-2 and DHA-1 plasmid-mediated beta-lactamases.