Molecular and genetic potential of the virulent effects of Escherichia coli isolates taken from ulcer colitis patients

Introduction. The human microbiota is part of the «human-microbiome» system and is actively involved in developing various pathological responses and conditions in the body. It is currently essential to study the pathogenesis of ulcerative colitis (UC), a polyetiologic disease, by assessing the contribution of representatives of the indigenous microbiota to this pathology’s development. A particular role is assigned to the major representatives of the microflora - strains of E. coli, abundantly inhabiting the large intestine, the plasticity of the genome that allows the transition from a commensal state to a pathogenic one. The aim of the study. To study the genomic potential of virulence and resistance of strains of E. coli isolated from UC patients. Methods. As part of the study, PCR indication of a collection of 87 (n=87) E. coli strains isolated from patients with ulcerative colitis was carried out. Results. The subgroup At - 48.28% of strains (n=42) was the main phylogenetic group inhabiting UC patients’ large intestine. 75.86 and 36.78% of strains, respectively, possess invasive and adhesive properties. The primary representatives of the spectrum of genes encoding pathogenicity factors are pap, aer, cnf. The prevalence of genes encoding extended-spectrum beta-lactamases in clade ABt is due to the occurrence of blaTEM, blaSHV, and blaOXA in 35.71%, 33.33%, 9.52% of strains (p=0.01). The presence of more evolutionarily late beta-lactamases of the CTX-M class, which have a worldwide tendency to spread, is noted in phylogroups B1 - 81.82% and D2 - 52.38% (p=0.01). Conclusion. The study of genetic predictors encoding proteins responsible for virulent interaction with the human body made it possible to assess the pathogenic potential of Escherichia coli strains isolated from UC patients residing in the Samara region. Determination of the phenotypic properties of fermentation of antibacterial drugs proposed in the National Clinical Guidelines made it possible to describe the level of resistance of E. coli isolates in the microecological niche of the large intestine in inflammatory disease. The proposed approach makes it possible to use the experience to characterize isolated strains of the microbiome and in other inflammatory bowel diseases, in order to study the possibilities of metabolic conjugation of a microorganism and humans.

Escherichia coli, genes of virulence factors, beta-lactamase, Escherichia coli, ulcerative colitis