Avian pathogenic Escherichia coli (APEC) and uropathogenic Escherichia coli (UPEC): characterization and comparison

Daniela Tonini Da Rocha,Carlos Tadeu Pippi Salle,Karen Apellanis Borges,Thales Quedi Furian,Vladimir Pinheiro Do Nascimento,Hamilton Luiz De Souza Moraes,Felipe De Oliveira Salle

doi:10.3855/jidc.14217

Abstract

Avian pathogenic E. coli (APEC) and uropathogenic E. coli (UPEC) are responsible for avian colibacillosis and human urinary tract infections, respectively. There are genetic similarities between the APEC and UPEC pathotypes, suggesting the APEC strains could be a potential reservoir of virulence and antimicrobial-resistance genes for the UPEC strains. This study aimed to characterize and compare APEC and UPEC strains regarding the phylogroup classification, pathogenicity and antimicrobial susceptibility. A total of 238 APEC and 184 UPEC strains were selected and characterized. The strains were assayed for antimicrobial susceptibility and classified into phylogenetic groups using a multiplex-PCR protocol. In addition, the APEC strains had previously been classified according to their in vivo pathogenicity. The results showed that both pathotypes had variation in their susceptibility to most of the antimicrobial agents evaluated, with few strains classified as multidrug resistant. The highest resistance rate for both pathotypes was to amoxicillin. Classifying the APEC and UPEC strains into phylogenetic groups determined that the most frequently frequencies were for groups D and B2, respectively. These results reflect the pathogenic potential of these strains, as all the UPEC strains were isolated from unhealthy patients, and most of the APEC strains were previously classified as pathogenic. The results indicate that distribution into phylogenetic groups provided, in part, similar classification to those of in vivo pathogenicity index, as it was possible to adequately differentiate most of the pathogenic and commensal or low-pathogenicity bacteria. However, no relationship could be found between the specific antimicrobial agents and pathogenicity or phylogenetic group for either pathotype.

Highlights

Avian pathogenic E. coli (APEC) and uropathogenic E. coli (UPEC) are responsible for avian colibacillosis and human urinary tract infections, respectively
Comparing the APEC and UPEC strains, the statistical analysis indicated higher resistance rates among UPEC strains for ampicillin, cefuroxime, and norfloxacin (p < 0.05); among APEC strains, resistance was higher for gentamicin (p < 0.05)
The antimicrobial susceptibility data in this study show that the resistance rates were higher for ampicillin and cefuroxime among UPEC, while resistance for gentamicin was higher among APEC strains

Summary

Introduction

Avian pathogenic E. coli (APEC) and uropathogenic E. coli (UPEC) are responsible for avian colibacillosis and human urinary tract infections, respectively. This study aimed to characterize and compare APEC and UPEC strains regarding the phylogroup classification, pathogenicity and antimicrobial susceptibility. Classifying the APEC and UPEC strains into phylogenetic groups determined that the most frequently frequencies were for groups D and B2, respectively. These results reflect the pathogenic potential of these strains, as all the UPEC strains were isolated from unhealthy patients, and most of the APEC strains were previously classified as pathogenic. No relationship could be found between the specific antimicrobial agents and pathogenicity or phylogenetic group for either pathotype. Manges et al [4] analyzed 217 studies carried out between 1995 and 2018 that performed multilocus sequence typing (MLST) or whole-genome sequencing (WGS) to characterize ExPEC strains and observed that 20 major sequence types accounted for more than 85% of E. coli isolates

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