Relationship Between Class 1 Integron And Resistance In Clinical ESBLs-producing Escherichia Coli Strains

Antibiotic resistance gene have frequently been found to be encoded by determinants carried on mobile genetic elements, such as plasmids, transposons, and integrons, which are then responsible for the horizontal transfer of antibiotic resistance genes. Integrons are elements that participate in a powerful site-specific recombination system and play a major role in spreading antibiotic resistance genes in a clinical setting. Four class of integrons have been identified according to their respective integrons found in clinical isolates and are strongly associated with multiple-antibiotic resistance. Many antibiotic resistance genes found in gram-negative bacteria are part of a gene cassette inserted into an integron. To date, more than 50 different class 1 integrons and 60 different gene cassettes have been described, including gene cassettes conferring resistance to aminoglocosides,penicillins,cephalosporins,carbapenes, rifampin, trimethoprim, chloramphenicol, erythromycin and quaternary ammonium compounds. The fact that Extended spectrumβ-lactamases ( ESBLs ) genes could be acquired by strains harboring particular integrons may enlarge the possibilities of selection of these isolates by a variety of different antimicrobials. Moreover, ESBL genes can be located on integrons, which may...