Prevalence, Abundance, and Virulence of Adherent-Invasive Escherichia coli in Ulcerative Colitis, Colorectal Cancer, and Coeliac Disease

Abstract

Background & AimsAdherent-invasive E. coli (AIEC) has largely been implicated in the pathogenesis of Crohn’s disease (CD). E. coli strains with similar genetic backgrounds and virulence genes profiles have been associated with other intestinal disorders, such as ulcerative colitis (UC), colorectal cancer (CRC), and coeliac disease (CeD), but the role of AIEC in these diseases remains unexplored. We aimed to assess the distribution, abundance, and pathogenic features of AIEC in UC, CRC, and CeD.MethodsThe AIEC phenotype was investigated in 4,233 E. coli isolated from the ileum and colon of 14 UC and 15 CRC patients and in 38 fecal E. coli strains obtained from 17 CeD and 10 healthy (H) children. AIEC prevalence and abundance were compared with previous data from CD patients and H controls. Clonality, virulence gene carriage, and phylogenetic origin were determined for the AIEC identified.ResultsIn UC, AIEC prevalence was intermediate between CD and H subjects (UC: 35.7%, CD: 55.0%, H: 21.4%), and similar to CD patients with colonic disease (C-CD: 40.0%). In CRC, the prevalence was lower (6.7%) than these groups. In patients with AIEC, the estimated abundance was similar across all intestinal conditions. All AIEC strains isolated from UC and CRC belonged to the B1 phylogroup, except for a strain of the A phylogroup, and the majority (75% of clonally distinct AIEC) harbored the Afa/Dr operon and the cdt gene. None of the E. coli isolated from the CeD cohort were AIEC. Nonetheless, E. coli strains isolated from active CeD patients showed higher invasion indices than those isolated from H and inactive CeD pediatric patients.ConclusionWe support the hypothesis that AIEC-like strains can be involved not only in CD but also in UC. Further works are needed to study the virulence particularities of these groups of strains and to determine if there is a causative link between AIEC and UC. In contrast, we rule out the possible association of AIEC with CRC. In addition, to further study the E. coli strains in CeD for their possible pathogenic role would be of interest.

The diagnostic and prognostic potential of gut bacteria in inflammatory bowel disease

“…A recent study found that all AIEC strains isolated from UC and CRC belonged to the B1 phylogroup (except for a strain of the A phylogroup), compared to the CeD cohort which had none of the isolated E. coli being AIEC. 114 This implicates the integration of strain-specific microbial profiles in differentiating IBD from other gastrointestinal conditions. Other reports reveal that Clostridium spp., Prevotella spp ., and Actinomyces spp .…”

“… Sample source Study type/focus Study subject Analytical technology Bacteria involved Key findings Reference Biopsy Population-based case-control CD and UC RISA followed by DNA sequencing B2 + D phylogenetic E. coli More prevalent in patients with UC and CD than controls 94 Biopsy and fecal Prevalence of AIEC in selected cohorts UC, CRC, CeD Culture and identification E. coli No AIEC found in CeD. AIEC prevalence higher in CD: 55.0% than CD with colonic disease: 40.0% and UC: 35.7% 114 Fecal Characterizing isolated E. coli strains IBD and healthy controls Culture and identification E. coli strains Phylogenetic group B2 E. coli are frequent in IBD involving the left side of the colon. B2 strains with ExPEC genes are more frequent in active IBD than inactive IBD 95 Fecal Case-control analysis UC, CD, IBS UC and healthy controls Shotgun metagenomic sequencing Bacteroides uniformis and Bifidobacterium bifidum Faecalibacterium prausnitzii Escherichia/Shigella species 15 UC-specific associations, including Bacteroides uniformis and Bifidobacterium bifidum Decreased in UC compared to controls Increased in CD 11 Fecal Cross-sectional IBD and healthy controls 16S rRNA gene sequencing Proteobacteria ( Shigella/Escherichia ), Firmicutes, specifically F. prausnitzii , and Bacteroidetes ( Bacteroides and Prevotella ) Diagnostic rate ...…”

Role of adherent invasive Escherichia coli in pathogenesis of inflammatory bowel disease

“…The number of C. plasmodium in the feces of UC patients was reported to be decreased. Due to the different proportions of C. plasmodium and E. coli in ileal and colonic CD, this ratio can be considered a promising biomarker for differential diagnoses and personalized treatments[ 88 ].…”

Colonization of larval zebrafish (Danio rerio) with adherent-invasiveEscherichia coliprevents recovery of the intestinal mucosa from drug-induced colitis

“…This region of the intestine contains absorptive enterocytes, mucin secreting goblet cells, and M-like cells, all of which are also found in the mammalian small intestine (49). Accordingly, AIEC predominantly colonizes the mammalian small intestine compared to the colon of IBD patients (3, 50-52).…”