Microarray-based detection of extended virulence and antimicrobial resistance gene profiles in phylogroup B2 Escherichia coli of human, meat and animal origin

Abstract

Extra-intestinal pathogenic Escherichia coli (ExPEC) causing urinary tract infections (UTIs) most often belong to phylogenetic group B2 and stem from the patient's own faecal flora. It has been hypothesized that the external reservoir for these uropathogenic E. coli in the human intestine may be meat and food-production animals. To investigate such a connection, this study analysed an E. coli phylogroup B2 strain collection (n5161) of geographical and temporally matched isolates, published previously, from UTI patients (n552), community-dwelling humans (n536), imported (n55) and Danish (n513) broiler chicken meat, Danish broiler chickens (n517), imported (n53) and Danish (n527) pork, and healthy Danish pigs (n58). The isolates were subjected to microarray analysis for 315 virulence genes and variants and 82 antimicrobial resistance genes and variants. In total, 133 different virulence and antimicrobial resistance genes were detected in at least one UTI isolate. Between 66 and 87 of these genes were also detected in meat and animal isolates. Cluster analyses of virulence and resistance gene profiles, respectively, showed that UTI and community-dwelling human isolates most often grouped with meat and animal isolates, indicating genotypic similarity among such isolates. Furthermore, B2 isolates were detected from UTI patients and meat, with indistinguishable gene profiles. A considerable proportion of the animal and meat isolates belonged to the ExPEC pathotype. In conclusion, these findings suggest that B2 E. coli from meat and animal origin can be the source of most of the virulence and antimicrobial resistance genes detected in uropathogenic E. coli isolates and that there is a general resemblance of animal, meat and UTI E. coli based on extended gene profiling. These findings support the hypothesis of a zoonotic link between E. coli causing UTIs and E. coli from meat and animals.3Dr Brousseau passed away before the completion of the study.4Present address: Steno Diabetes Center A/S, Niels Steensens

Biological and Physicochemical Wastewater Treatment Processes Reduce the Prevalence of Virulent Escherichia coli

“…It contains 306 probes targeting different alleles and versions of 195 virulence or virulence-related genes; 96 antibiotic resistance gene probes; 4 positive-control probes, tnaA (tryptophanase), uidA (␤-glucuronidase), lacY (lactose permease), and lacZ (␤-galactosidase); and 2 negative controls derived from the green fluorescent protein of Aequoria victoria and chlorophyll synthase from Arabidopsis thaliana. A complete list of probe names can be found in Table S1 in the supplemental material, and their sequences can be found in supplemental material reported previously (22,28).…”

“…The oligonucleotide probes (70-mers) used in the DNA microarray of this study were developed and validated previously (22,28). The current microarray probe assembly is dubbed MaxVir1.0.…”

“…The phylotyping of E. coli isolates within the four main groups A, B1, B2, and D was performed by using two genes, chuA and yjaA, and a DNA fragment, namely, TSPE4.C2 (19). E. coli isolates were classified into defined pathotypes according to the set of VGs or markers which they contain (22,28). The complete list of probes, genes, and rules used to determine the various pathotypes can be found in Table S1 in the supplemental material.…”

“…Isolate libraries were analyzed by using a DNA microarray capable of detecting 195 virulence or virulencerelated genes as well as 96 antimicrobial resistance genes (22,28). Our results suggest a possible link between enhanced VG loss and the quinolone resistance peptide synthesis gene (qnrS) during wastewater treatment.…”

Zoonotic Potential of Escherichia coli Isolates from Retail Chicken Meat Products and Eggs

“…Many human and animal-source ExPEC isolates exhibit similar virulence genes and clonal backgrounds, suggesting that they may represent zoonotic pathogens (6). ExPEC virulence genes are common among E. coli isolates from food products, particularly raw meats (5) and especially poultry meat (7).…”