Abstract
Background: Any alteration in gut microbiota may result in colonization of some pathobionts and consequently development of colon diseases. Some strains of Escherichia coli are of the pathobionts that can participate in initiation or development of colon diseases through induction of pro-inflammatory pathways or production of genotoxins.
Objectives: The present study was performed to investigate association between some E. coli pathobionts (cyclomodulin positive and afa-C+ diffusely adherent E.coli) and their characteristics, with colon diseases. Methods: Stool specimens were taken from patients referred to colonoscopy centers of two university affiliated hospitals (Yazd and Kerman, Iran). Totally, 67 patients voluntarily joined the study as the target group (21 cases of colorectal cancer and 46 cases of inflammatory bowel disease) as well as 67 healthy individuals. Stool samples were screened for E. coli isolates by culture technique. Cyclomodulin encoding genes (clbN, cnf, cdt and cif) as well as afa-C, were tracked by PCR assay. Phylogrouping, virulence gene screening, antibiotic susceptibility evaluation and biofilm formation assessment were also performed.
Results: In comparison with control group, afa-C+ DAEC was significantly associated with CRC (n=8, 38.1%, p=0.001) and IBD (n=8, 17.4%, p=0.026). The presence of clbN (n= 4, 19%) and cnf (n= 4, 19%, p= 0.053) was relatively associated with CRC. Most of the isolates from patients group (n=16, 23.9%) belonged to phylogroup B2. Iron uptake related genes were also significantly associated with isolates from patients. No significant association was found between antibiotic resistance and biofilm formation with any studied groups.
Conclusions: This study provides primarily data about the involvement of some important E. coli pathobionts in colon diseases. As afa-C+ DAEC was associated with studied colon diseases, it appears that it may be proposed as a putative marker for screening procedures. However, definitive conclusion requires more comprehensive investigations.
Keywords
Gut Microbiota Escherichia coli Cyclomodulin afa-C+ DAEC Inflammatory bowel disease Colorectal Cancer
Copyright
© 2024, Author(s). This open-access article is available under the Creative Commons Attribution 4.0 (CC BY 4.0) International License (https://creativecommons.org/licenses/by/4.0/), which allows for unrestricted use, distribution, and reproduction in any medium, provided that the original work is properly cited.