Phylogrouping and characterization of Escherichia coli isolated from colonic biopsies and fecal samples of patients with flare of inflammatory bowel disease in Iran

Abstract

BackgroundAlthough the etiopathogenesis of inflammatory bowel disease (IBD) is still poorly understood, Escherichia coli has been described as a potential causative microorganism in IBD pathogenesis and also disease progression, offering a potential therapeutic target for disease management. Therefore, we conducted this study to investigate the pathotypes, phylogenetic groups, and antimicrobial resistance of E. coli isolates from patients with IBD in Iran.MethodsFecal and biopsy colonic samples were collected from IBD patients experiencing flare-up episodes referred to Taleghani hospital in Tehran, Iran, between August 2020 and January 2021. Identification of E. coli strains was performed based on biochemical and molecular methods. Antibiotic susceptibility testing was performed as recommended by the Clinical and Laboratory Standards Institute. Phylogrouping and pathotyping of each isolate were carried out using polymerase chain reaction (PCR) and multilocus sequence typing (MLST) assays.ResultsA total of 132 non-duplicate E. coli strains were isolated from 113 IBD patients, including 96 ulcerative colitis (UC), and 17 Crohn’s disease (CD) patients. In our study, 55% of CD-related E. coli and 70.5% of UC-related isolates were non-susceptible to at least three or more unique antimicrobial classes, and were considered as multidrug-resistant (MDR) strains. E. coli strains exhibited a high level of resistance to cefazolin, ampicillin, tetracycline, ceftazidime, ciprofloxacin, and cefotaxime. Enterotoxigenic E. coli (ETEC) and diffusely adherent E. coli (DAEC) were the most prevalent pathotypes, and groups B2 and D were the predominant phylogroups.ConclusionIn the present study, we found that E. coli strains that colonize the gut of Iranian patients with IBD most frequently belonged to phylogenetic groups B2 and D. We also conclude that E. coli isolates from IBD patients have been revealed to be resistant to commonly used antibiotics, in which most of them harbored strains that would be categorized as MDR.

Diffusely adherent and cyclomodulin- positive Escherichia coli are associated with colon diseases

“…DAEC isolates harbor important mbrial (Dr) and a mbrial (Afa) adhesions through which can adhere to enterocytes strongly and induce cell damage and even cell transition from epithelial to mesenchymal (1,26). Although it is controversial, the association of DAEC with IBD and CRC has been suggested in some studies (5,26) which is in agreement with our ndings. So that afa-1 + DAEC were signi cantly more frequent in patients in comparison to the healthy people, as well as higher prevalence of them in CRC patients than IBD and control group.…”

“…About bio lm formation, most of the isolates (75%) were not bio lm producers and there was not any differences between two groups for ability of bio lm formation (Table 3) Table 3 Discussion This study showed that the most frequent E. coli from patients with colon diseases, belonged to phylogroup B2 which is in agreement with some other studies (1,5,21). Phylogenetic groups of E.coli, have been developed according to the acquisition of virulence factors (2).…”

“…E.coli strains from phylogroups B2 and D, carry on the heme iron acquisition gene (chuA), which plays an important role in bacterial survival within macrophages. More importantly, by stimulation of TNF-a release, the chuA ,may promote intestinal dysbiosis involved in colon diseases (5). Similar to our results, phylogroups B2 and A were abundantly distributed among isolates from CRC and IBD patients in Zarei et al study (21).…”

“…IBD is a chronic relapse-remitting disease characterized by intestinal in ammation, and CRC is known as the fourth common cause of cancer-related death in the world. Current reliable method for diagnosis of colon diseases, is colonoscopy which is invasive, uncomfortable, time consuming and costly (4,5,6).…”

Medicinal Plants, Phytochemicals and Regulation of the NLRP3 Inflammasome in Inflammatory Bowel Diseases: A Comprehensive Review

“…Reduced mucous production also helps this tolerance break insofar as it has been shown that variants of the Muc2 mucous-reduction genes are correlated with CD in many mouse models of the disease. People with altered interactions with the intestinal lumen commensal bacteria also have an increased risk of developing CD, such as in the case of the Galactoside alpha-(1,2)-fucosyltransferase 2 (FUT2) genetic variances, in which the patients encode a fucosyltransferase enzyme incapable of secreting antigens such as ABO [ 75 , 79 , 80 ].…”