Phylogenetic Backgrounds and Virulence-Associated Traits of Escherichia coli Isolates from Surface Waters and Diverse Animals in Minnesota and Wisconsin

Abstract

Possible external reservoirs for extraintestinal pathogenic (ExPEC) strains that cause infections in humans are poorly defined. Because of the tremendous human health importance of ExPEC infections, we assessed surface waters and domesticated and wild animals in Minnesota and Wisconsin as potential reservoirs of ExPEC of human health relevance. We characterized 595 isolates (obtained from 1999 to 2002; 280 from seven surface water sites, 315 from feces of 13 wild and domesticated animal species) for phylogroup and virulence genotype, including inferred ExPEC status, by using multiplex PCR-based methods. We also compared the pulsed-field gel electrophoresis (PFGE) profiles of the isolates with a large private PFGE profile library. We found a predominance of non-ExPEC strains (95% and 93% among water and animal isolates, respectively), which were mainly from phylogroups A and B1, plus a minority of ExPEC strains (5% and 7% among water isolates and animal isolates, respectively), predominantly from phylogroup B2. The ExPEC strains, although significantly associated with cats, dogs, and turkeys, occurred in several additional animal species (goat, horse, chicken, pig) and were distributed broadly across all surface water sites. Virulence gene content among the animal source ExPEC isolates segregated significantly in relation to host species, following established patterns. PFGE analysis indicated that 11 study isolates closely matched (94% to 100% profile similarity) reference human clinical and fecal isolates. These findings imply what probably is a low but non-zero risk to humans from environmental and animal source isolates, especially those from specific human-associated animal species. Our detection of potentially pathogenic strains that may pose a health threat to humans among isolates from surface waters and wild and domesticated animals suggests a need for heightened attention to these reservoirs as possible sources for human acquisition of disease-causing Although cats, dogs, and turkeys were especially high-prevalence sources, the presence of such strains in other animal species and at all sampled water sites suggests that this potential risk may be widespread.

Molecular characterization and antimicrobial resistance of potentially human‐pathogenic Escherichia coli strains isolated from riding horses

“…In the current study, phylogenetic assessment of the equine isolates showed no relationship among virulence, resistance and phylogenetic background; resistant/non-resistant and virulent/non-virulent E. coli strains frequently belonged to B1 phylo-group. In agreement with our results, many studies around the world have reported B1 as the predominant phylo-type in equine E. coli isolates [ 34 , 39 , 40 ]. Conversely, Sukmawinata et al (2019), reported B2 as the most common phylogenetic group among extended-spectrum β-lactamase-producing E. coli isolates from healthy thoroughbred race horses in Japan [ 41 ].…”

Antimicrobial Resistance in Escherichia coli and Enterococcal Isolates From Irrigation Return Flows in a High-Desert Watershed

“…In contrast, Escobar-Paramo et al (2004a) found that E. coli responsible for acute and severe diarrhea were not found in groups B2 and D, while those causing chronic and mild diarrhea were distributed among all phylogroups. In surface water samples and animal feces collected in the Upper Midwest of the United States, 57 and 51% of E. coli isolates were found to belong to group B1, respectively, with substantially fewer isolates belonging to all other phylogroups ( Johnson et al, 2017 ). However, they reported that about 95% of the strains among water and fecal isolates were non-extraintestinal, with those determined to be extraintestinal to be predominantly from group B2.…”

The Avian Pathogenic Escherichia coli (APEC) pathotype is comprised of multiple distinct, independent genotypes

“…Consequently, there is an extensive genetic substructure within the species E. coli (Clermont et al, 2013;Beghain et al, 2018;Clermont et al, 2019;Denamur et al, 2020), composed of at least eight phylogenetic groups segregated into three clusters: phylogroups B2, G, and F, phylogroups A, B1, C and E, and phylogroup D, with phylogroup D most closely related to E. coli origin (Gonzalez-Alba et al, 2019) (Figure 1). Each phylogenetic group is broadly linked to an ecological niche, with strains belonging to phylogroups B2 and D commonly associated with virulent extra-intestinal infection (Pires-Dos-Santos et al, 2013;Beghain et al, 2018), strains from phylogroup A often associated with commensalism (Mosquito et al, 2015), and phylogroup B1 associated with environmental reservoirs (Johnson et al, 2017).…”