Characterisation of Escherichia coli isolates from the blood of haematological adult patients with bacteraemia: translocation from gut to blood requires the cooperation of multiple virulence factors

Abstract

The aim of the study was to investigate whether there are unique pathotypes of Escherichia coli capable of transmission from the gastrointestinal tract to the vascular bed. The study included E. coli strains isolated from clinical materials collected from 115 patients suffering from haematologic malignancies diagnosed with bacteraemia. The genotyping techniques established that 89 E. coli isolates from the blood had the same genotype as the E. coli from the patient’s bowel. The presence of 21 genes encoding virulence factors typical of various E. coli pathotypes and their relationship with the phylogenetic group was established. One-dimensional analysis showed that the focG gene occurred more frequently in the control bowel group, while the ampicillin-resistant afa/dr E. coli were associated with bacteraemia. Blood isolates with the highest occurrence of virulence factors belonged to pathogenic group B2 and non-pathogenic group A. The co-occurrence of multiple genes encoding papC, sfa, usp and cnf1 virulence factors probably predisposes E. coli to translocation from the gastrointestinal tract to the vascular bed in the group of patients with haematologic malignancies. Based on clustering analysis, dominance of the most virulent strains assigned to the cluster with seven virulence factors encoded by the following genes, papC, sfaD/E, cnf1, usp, agn43, hlyA and iutA, was found. The obtained results enforce the previously proposed concept of bowel–blood translocation and further expand our hypothesis by defining the unique virulence characteristics of E. coli isolates, which predispose them to bowel colonisation or translocation and bacteraemia in this group of patients.

Intra-operative biopsy in chronic sinusitis detects pathogenic Escherichia coli that carry fimG/H, fyuA and agn43 genes coding biofilm formation

“…II, the sequence of three fragment genes, kspMTII [ 34 ] (synthesis capsule, group II), iha [ 35 ] (enterobactin Iha iron regulated gene homologue adhesion) and focG [ 34 ] (F1C fimbriae), were amplified. In multiplex PCR system III, the sequence of three fragment genes, iutA [ 36 ] (aerobactin receptor), fyuA [ 37 , 38 ] (yersiniabactin receptor) and ibeA [ 39 ] (invasion of brain endothelium A), were amplified.…”

Extra-intestinal pathogenic Escherichia coli (ExPEC): Disease, carriage and clones

“…A collection of small association studies have attempted to establish the role of particular VFs associated with intestinal translocation and have all demonstrated that a collection, as opposed to individual VFs, are likely to be related to these events (55)(56)(57). In a recent study, Krawczyk et al (57) assessed VF profiles of ExPEC bacteraemia isolates derived from bowel translocation events in patients with haematological malignancy and concluded that the cooccurrence of multiple virulence genes was associated with an increased likelihood of intestinal translocation events.…”

Bloodstream Infection with Extended-spectrum Beta-lactamase–producingEscherichia coli: the role of virulence genes

“…[1] The co-occurrence of multiple genes encoding papC , sfa , usp and cnf1 virulence factors probably predisposes Escherichia coli to translocation from the gastrointestinal tract to the vascular bed in patients with hematologic malignancies. [2] A recent study showed that differences in virulence gene prevalence between cystitis and pyelonephritis isolates could be limited to 8 genes. [3] However, the association of virulence gene and disease severity is still controversial.…”