The Relation between Class I Integrons and Multidrug-Resistance in Extended-Spectrum Beta Lactamase Producing Escherichia coli Isolates.

Document Type : Original Article


1 department of medical microbiology and immunology, faculty of medicine, suez canal university, Ismailia, Egypt

2 department of Medical Microbiology and Immunology, Faculty of Medicine, Suez Canal University, Ismailia, Egypt.


Background: The emergence and development of multidrug resistant (MDR) strains is due to inappropriate use of antibiotics and horizontal gene transfer between bacteria. The MDR strains of E. coli are highly associated with the presence of integrons; also, extended-spectrum beta lactamase producing isolates are usually resistant to various antibiotics. This study aimed to determine the incidence of class 1 integrons and its association with drug resistance in ESBL producing E. coli isolated from patients who were suffering from UTI.
Methods: this study was conducted on 232 hospitalized patients with UTI, from which 160 E. coli strains were isolated. Antibiotic susceptibility testing and screening for ESBL production were performed by Kirby-Bauer disk diffusion method on Mueller- Hinton agar. Confirmation for ESBL production was performed by combined disc diffusion test. All MDR ESBL producing E. coli isolates were examined by conventional PCR for the presence of intI1 gene and related gene cassettes.
Results: One hundred sixty E. coli strains (69 %) were isolated from 232 hospitalized patients. The highest percentage of resistance was to azetronam (92%) followed by ceftazidime and cefotaxime (90%) then ciprofloxacin (79 %). seventy two E. coli isolates (45%) were found to be ESBL producers and out of them, 61 isolates (84.7 %) were MDR. Out of the 61 MDR ESBL-producing isolates, class I integron was identified in 56 isolates (91.8%).
Conclusion: our findings indicate high prevalence of class 1 integrons and gene cassettes suggests possible risk for the dissemination of resistance genes and the spread of MDR bacteria


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