Several pieces of evidence support that ciprofloxacin and quinolones can be used as an adjunct to immunosuppressant therapy in cases of inflammatory bowel disease (IBD). Quinolone resistance is frequently reported in clinical isolates of Enterobacterales, additionally, it has previously been confirmed that more severe IBD activity is associated with the Enterobacterales blooming in the gut. Therefore, this study aimed to investigate fluoroquinolone resistance and associated genes among E.coli isolates from colonic biopsies of Iranian patients with IBD

In this cross-sectional study, E. coli were isolated from inflamed ileum and/or colon tissue of patients with IBD, including Ulcerative colitis (UC) and Crohn’s disease (CD), during colonoscopy. Demographic data and clinical characteristics were recorded. Phenotypic and molecular detection of quinolone resistant-E. coli were carried out

A total of 107 individual E. coli strains were isolated from colonic/ileal biopsies of 121 IBD patients, including 99 (81.8%) UC and 22 (18.2%) CD patients. Antimicrobial susceptibility testing revealed that 57% of investigated isolates exhibited a phenotypical non-susceptibility to at least one quinolone. Plasmid-mediated quinolone resistance (PMQR) genes qnrS, oqxA, and oqxB were detected in both UC and CD-associated E. coli. A significant positive correlation was found between the intestinal carriage of ciprofloxacin quinolones-resistant E. coli and prior long-term antibiotic therapy with ciprofloxacin.

The results of our study indicate that a significant proportion of both UC and CD patients were intestinally colonized with quinolone-resistant E. coli strains alarming a potential risk factor associated with the disease course and its complications