Extended-Spectrum -Lactamases among Enterobacteriaceae Isolated from Urinary Tract Infections in Gaza Strip, Palestine.

Background: Extended-spectrum -lactamase-producing organisms causing urinary tract infections are increasing in incidence and pose a major impendence to health-care facility, having limited therapeutic options. This study aimed to assess the prevalence of ESBLs in Enterobacteriaceae isolates causing urinary tract infections in Gaza strip, Palestine, and to characterize -lactamase types and associated resistance genes.

Methods: Eighty-five Enterobacteriaceae isolates were recovered from urinary tract infections within three months in Gaza Strip hospitals. The characterization of -lactamase genes and the genetic environments of CTX-M, the identification of associated resistance genes, and the presence and characterization of integrons were tested by PCR and sequencing.

Results: The occurrence rate of ESBL among tested isolates was 30 (35.3%), and among ESBL-positive isolates, was the highest followed by . ESBL-CTX-M-1 group was confirmed in 93.3%, and the remaining carried CTX-M-9 group. CTX-M-15, CTX-M-3, CTX-M-1, CTX-M-14, CTX-M-27, and CTX-M-37 enzymes were demonstrated among the isolates with the majority (73%) being CTX-M-15. IS was demonstrated in 27 (90%, high incidence) of ESBL isolates. Class 1 integrons have been detected in higher rates (53.3%) in ESBL-positive isolates in comparison with non-ESBL isolates (6, 33.3%). Cassettes of integron-1 contain (, , , , , , and ) genes. The gene was demonstrated in 36.7% of ESBL-positive isolates.

Conclusions: This study indicates that was the most prevalent -lactamase in this region. Our study demonstrates for the first time in Palestine the identification of in and , also in The coexpression of multiple -lactamase genes with and in the presence of IS and integrons in individual strains will increase the dissemination of highly resistant strains. ESBL producers were more resistant than non-ESBLs producers for almost all tested antibiotics.