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ARS Home » Northeast Area » Wyndmoor, Pennsylvania » Eastern Regional Research Center » Characterization and Interventions for Foodborne Pathogens » Research » Publications at this Location » Publication #422170
Research Project: Molecular Analysis of Foodborne Pathogen Responses to Stressors

Location: Characterization and Interventions for Foodborne Pathogens

Title: Foodborne potential of extraintestinal pathogenic E. coli: comparative characterization of human clinical and food isolates

Author
item Guragain, Manita
item BOSILEVAC, JOSEPH - US Department Of Agriculture (USDA)
item Paoli, George
item Liu, Yanhong

Submitted to: International Association for Food Protection
Publication Type: Abstract Only
Publication Acceptance Date: 3/25/2025
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: Introduction: Extraintestinal pathogenic Escherichia coli (ExPEC) are suggested to be food borne, however, characteristics of food isolated ExPEC is poorly understood. Purpose: Comparative characterization of ExPEC from human clinical and food samples to understand risk of poultry ExPEC as foodborne pathogens. Methods: Forty human clinical and 44 poultry (chicken or turkey meat) ExPEC isolates were characterized for genomes and phenotypes. Biofilm mass was quantified using crystal violet assay. Antimicrobial resistance (AMR) and sanitizer tolerance were evaluated using Kirby-Bauer disc diffusion and 6X6 drop plate methods respectively. Difference in frequency of AMR phenotypes were compared using Fisher Exact test. Difference in biofilm mass was compared using one-way ANOVA. Genomes were sequenced using long read and short read technologies and assembled using Fly9 2.9.2 and/or GEA pipeline. Core genomes were aligned using Parsnp 1.2 and maximum likelihood phylogenetic tree was estimated using PhyML 3.3.20180214. Results: Most ExPEC strains (79/84) formed little to no biofilm. A small number of ExPECs (Human, 4/44; poultry, 1/40) showed increased tolerance towards 300 ppm of quaternary ammonium compound (QAC). AMR frequency was lower in human isolates (45%, n=40) compared to poultry isolates (68%, n=30), however, most of this resistance resulted from isolates from one geographical region. Among 18 antibiotics tested, highest frequency of resistance was noted against ampicillin, doxycycline, and streptomycin, while none against ertapenem and cefepime. Among 6 poultry ExPECs phylogenetically grouped with human clinical isolates, 3 showed AMR phenotype, 2 formed moderate biofilm mass, and four belonged to phylogroup B2 know for better persistence and high virulence in human host. Significance: Presence of AMR and biofilm phenotypes in poultry ExPEC isolates with close phylogeny to human clinical isolates suggest the potential of poultry as a source of high risk ExPEC.