Characterization of Escherichia coli Isolates from Hospital Inpatients or Outpatients with Urinary Tract Infection

Abstract

e Uropathogenic Escherichia coli (UPEC) is the most common cause of community-and hospital-acquired urinary tract infections (UTIs). Isolates from uncomplicated community-acquired UTIs express a variety of virulence traits that promote the efficient colonization of the urinary tract. In contrast, nosocomial UTIs can be caused by E. coli strains that differ in their virulence traits from the community-acquired UTI isolates. UPEC virulence markers are used to distinguish these facultative extraintestinal pathogens, which belong to the intestinal flora of many healthy individuals, from intestinal pathogenic E. coli (IPEC). IPEC is a diarrheagenic pathogen with a characteristic virulence gene set that is absent in UPEC. Here, we characterized 265 isolates from patients with UTIs during inpatient or outpatient treatment at a hospital regarding their phylogenies and IPEC or UPEC virulence traits. Interestingly, 28 of these isolates (10.6%) carried typical IPEC virulence genes that are characteristic of enteroaggregative E. coli (EAEC), Shiga toxin-producing E. coli (STEC), and atypical enteropathogenic E. coli (aEPEC), although IPEC is not considered a uropathogen. Twenty-three isolates harbored the astA gene coding for the EAEC heat-stable enterotoxin 1 (EAST1), and most of them carried virulence genes that are characteristic of UPEC and/or EAEC. Our results indicate that UPEC isolates from hospital patients differ from archetypal community-acquired isolates from uncomplicated UTIs by their spectrum of virulence traits. They represent a diverse group, including EAEC, as well as other IPEC pathotypes, which in addition contain typical UPEC virulence genes. The combination of typical extraintestinal pathogenic E. coli (ExPEC) and IPEC virulence determinants in some isolates demonstrates the marked genome plasticity of E. coli and calls for a reevaluation of the strict pathotype classification of EAEC.

Comparison of the Common Adhesin Coding Operons Distribution in Uropathogenic and Phylogenetic Group B2 and A Escherichia coli Isolates

“…This species is also a common cause of extraintestinal infections, such as urinary-tract infection and septicemia (1,3). Phylogenetic studies have shown that UPEC has four main phylogenetic groups, designated as A, B1, B2, and D (4).…”

“…Escherichia coli is one of the most extensively studied Gram-negative bacteria in microbiology (1,2). This species is also a common cause of extraintestinal infections, such as urinary-tract infection and septicemia (1,3).…”

Presence of virulence genes and pathogenicity islands in extraintestinal pathogenic Escherichia coli isolates from Brazil

“…ExPEC are often classified in different groups according to the anatomical site of infection, with uropathogenic E. coli (UPEC) being associated with urinary tract infections (UTIs) [1]. UTIs are one of the most common infections in the general population globally [2], and E. coli are the most commonly isolated etiological agent of UTIs, accounting for approximately 70%-85% of urinary infections.…”

Genes of Virulence and Phylogenetic Group in Isolates of Avian Pathogenic Escherichia coli

“…Previously, it has been reported that the isolates that cause extraintestinal infections (ExPEC), including urinary infections and sepsis, are derived mainly from the B2 group and in a smaller proportion from the D group, while commensal and intestinal pathogenic E. coli (IPEC) are derived of groups A and B [12,13].…”