Paper Title
Genotypic and Phenotypic Characterization of Extended-Spectrum-β-Lactamase-ProducingKlebsiella pneumoniae from Clinical Samples in Egypt

Abstract
ESBL producing bacteria presents a serious antibiotic management problem. ESBL producing bacteria are able to hydrolyze extended-spectrum penicillins, cephalosporins, and aztreonam. They are generally found in a significant number of Escherichia coli and Klebsiella pneumoniae strains. Materials and Methods: This study was conducted to detect ESBLs among K. pneumonia isolates by molecular and phenotypic methods. One hundred clinical Klebsiella pneumoniae isolates were collected. They were phenotypically characterized by double disk diffusion test (DDDT). Polymerase chain reaction (PCR) analysis wasfuther carried out to detectthe β-lactamase resistance genes . Objectives: To investigate ESBL-producionamong Klebsiella pneumoniaeisolates from Egyptian patients and to determine the prevalence ofthe β-lactamase resistance genes together with the prevalence of both class 1 and class 2 integrons among the collected isolates. Results: In this study phenotypic characterization indicated that 24 % of the K. pneumoniae isolates were found to be ESBL-producers. Among these 15 of the phenotypically positive isolates were genotypically positive for at least one ofthe ESBL production genes. The bla SHV gene was the most prevalant (62.5%), followed by blaCTX-Mgene(45.83%), and theblaTEM(25%). The int1 gene washighly prevalent among all isolates tested (90%), while only one isolate harbored the int2 gene (1%). Conclusion: The results of the current study indicates the highprevalance of ESBLs as well as integrons Therefore, continuos monitoring of betalactamase resistance, the adoption of rational consumption of beta-lactam antibiotics and beta-lactamase inhibitors and the establishment of a surveillance system is urgently needed to prevent further dissemination in Egypt. Keywords - Phenotypic; Molecular; Extended-Spectrum β-lactamase (ESBL); Klebsiella Pneumoniae