Molecular characterization of Escherichia coli isolates from patients with urinary tract infections in Palestine.

Antibiotic resistance of Escherichia coli isolated from urinary tract infections (UTIs) is increasing worldwide. A total of 41 E. coli isolates were obtained from urine samples from hospitalized patients with a UTI in three hospitals in the northern districts of the West Bank, Palestine during March and June 2011. Resistance rates were: erythromycin (95 %), trimethoprim-sulfamethoxazole (59 %), ciprofloxacin (56 %), gentamicin (27 %), imipenem (22 %), amoxicillin (93 %), amoxicillin-clavulanic acid (32 %), ceftazidime (66 %) and cefotaxime (71 %). No meropenem-resistant isolates were identified in this study. Among the isolates, phylogenetic group B2 was observed in 13 isolates, D in 12 isolates, A in 11 isolates and B1 in five isolates. Thirty-five of the isolates were positive for an extended-spectrum β-lactamase phenotype. Among these isolates, the blaCTX-M gene was detected in 25, and eight harboured the blaTEM gene. None of the isolates contained the blaSHV gene. Transformation experiments indicated that some of the β-lactamase genes (i.e. blaCTX-M and blaTEM) with co-resistance to erythromycin and gentamicin were plasmid encoded and transmissible. Apart from this, enterobacterial repetitive intergenic consensus-PCR (ERIC-PCR) revealed that the 41 isolates were genetically diverse and comprised a heterogeneous population with 11 ERIC-PCR profiles at a 60 % similarity level.