Frequency and Molecular Characterization of β-lactamases Producing Escherichia coli Isolated from North of Palestine

Aims: The aim of this study was to determine the prevalence and molecular characterization of AmpC β-lactamases and extended-spectrum β-lactamases (ESβLs) among E. coli isolates.

Place and Duration of Study: Department of Biology and Biotechnology, An-Najah National University, Palestine, during February-April 2015.

Methodology: A total 52 isolates of E. coli were recovered from different hospitals and private labs in Jennin district-Palestine. These isolates were used to detect ESβLs and AmpC β-lactamases using phenotypic tests and molecular techniques.

Results: The prevalence of ESβLs and AmpC β-lactamases using conventional methods was 32.7% and 26.9%, respectively. Whereas, the prevalence using PCR technique was 67.3% and 5.8% for ESβLs and AmpC β-lactamases, respectively. TEM gene was the dominant (82.9%) among E. coli that carried ESβL genes. Other genes were (0.0%), (2.9%) and (15.4%) for CTX-M, SHV and OXA genes, respectively. Whereas, AmpC β-lactamases only DHA gene was detected and the prevalence was (5.8%). Molecular analysis by construction phylogenetic tree showed that all sequenced TEM, SHV, OXA and DHA genes were belonged to TEM-1, SHV-1, OXA-1 and DHA-1, respectively. ERIC results showed that these strains were diverse and unrelated clones.

Conclusions: Our results showed high frequency of ESβLs and AmpC β-lactamases among E. coli isolates in Palestine. According to these results we recommend the continuous monitoring and surveillance of the prevalence, proper control and prevention practices and effective antibiotic use will limit the further spread of Amp-C β-lactamases and ESβLs producing isolates within hospitals in Palestine.