Description of extraintestinal pathogenic Escherichia coli based on phylogenetic grouping, virulence factors, and antimicrobial susceptibility

Abstract

Background and Objectives: Extraintestinal pathogenic Escherichia coli (ExPEC) is a recently recognized and highly diverse pathotype of E. coli. Its significance as a pathogen has increased due to the emergence of hypervirulent and multi- drug-resistant (MDR) strains. The aim of this study was to characterize ExPEC isolates from humans based on their phylo- genetic group, virulence factor profile, and antimicrobial susceptibility.
 Materials and Methods: The isolates were collected from patients with extraintestinal infections caused by E. coli, includ- ing urinary tract infections, bacteremia, and surgical site infections. The E. coli phylogenetic groups were determined using multiplex PCR. Additionally, the isolates were evaluated for their biofilm-forming abilities, susceptibility to antimicrobial agents, and presence of virulence genes.
 Results: In this study, the isolates were classified into four phylogenetic groups: A (48.3%), B2 (25.8%), D (19.35%), and B1 (6.45%). All isolates exhibited at least one of the ten analyzed virulence factors. However, there was no direct evidence linking a specific phylogenetic group to a particular virulence factor. Nevertheless, the presence of the fimH, fyuA, ompT, traT, and kpsMTII virulence genes was correlated with the production of strong biofilms, multidrug resistance (MDR), and the production of alpha hemolysin.
 Conclusion: This study provides a description of the phylogenetic groups in ExPEC and their potential association with virulence factor profiles and antimicrobial susceptibility.

First Insights on Resistance and Virulence Potential of Escherichia coli from Captive Birds of Prey in Portugal

“…As for phylogenetic grouping, it is described that both groups B2 and D primarily include strains with a higher pathogenic potential, while isolates from groups A and B1 are often regarded as commensals [18]. In this study, more than half (63%) of the isolates tested belonged to either group D or B2, revealing the importance of these falconry birds as vectors of E. coli strains with pathogenic potential.…”