Ghassan Tayh - Laboratoire des Microorganismes et Biomolécules Actives, Faculté des Sciences de Tunis, Université de Tunis El Manar, ۲۰۹۲ Tunis, Tunisie
Nahed Al Laham - Department of Laboratory Medicine, Faculty of Applied Medical Sciences, AlAzhar University-Gaza, Palestine
Imene Fhoula - Laboratoire des Microorganismes et Biomolécules Actives, Faculté des Sciences de Tunis, Université de Tunis El Manar, ۲۰۹۲ Tunis, Tunisie
Nahed Abedelateef - Biological Science, Al-Aqsa University –Gaza, P. O. Box ۴۰۵۱, Gaza strip, Palestine.
Mohamed El-Laham - Biological Science, Medical Technology, Israa University – Gaza, Gaza strip, Palestine.
Abed Elkader Elottol - Medical Science Department, University College of Science and Technology - Gaza, Khan Yunis, Gaza Strip, Palestine..
Karim Ben Slama - Laboratoire des Microorganismes et Biomolécules Actives, Faculté des Sciences de Tunis, Université Tunis-El Manar, ۲۰۹۲ Tunis & Tunisie. Institut Supérieur des Sciences Biologiques Appliquées de Tunis.

Introduction: Extended-Spectrum β-Lactamases (ESBLs) hydrolyze broad-spectrum cephalosporin, monobactam, and penicillin. This study investigated ESBL-producing Escherichia coli and Klebsiella pneumoniae bacteria in the Gaza strip and explored their susceptibility to various antimicrobials to provide a reference for physicians in managing the hospital infection. Methods: Ninety-six isolates, comprising ۶۹ E. coli and ۲۷ K. pneumoniae were obtained from urine, wound, blood, and ear discharge samples from April-June ۲۰۱۳ in Gaza hospitals. The ESBL-producing isolates were screened using the double-disc diffusion test. Antibiotics susceptibility test was determined by the disc diffusion method on Mueller-Hinton agar, and PCR identified β-lactamases genes. Results: Our results revealed high rates of ESBL-producing K. pneumoniae (۵۹.۳%) and E. coli (۳۹.۱%) among isolates. About ۶۵.۱% of ESBL-producing isolates were susceptible to imipenem while exhibited ۱۰۰% resistance to cefotaxime and ampicillin and ۷۴.۴% to sulfamethoxazole/trimethoprim. Except for imipenem, higher antibiotic resistance rates were observed among ESBL producers than non-ESBL producers. This study showed that the antimicrobial resistance and ESBLs were higher in K. pneumoniae isolates than E. coli isolates, and most K. pneumoniae isolates harbored simultaneously two or three β-lactamases-encoding genes. Conclusion: High ESBL-producing rates among K. pneumoniae and E. coli isolates and higher resistance rates to antibiotics among ESBL compared to non-ESBL producing isolates necessitate antimicrobial resistance surveillance and molecular characterization of ESBLs-producing bacteria to achieve a specific treatment.

Beta-lactamase genes, ESBL isolates, Antibiotics resistance, Carbapenem, E. coli, K. pneumonia