Virulence Gene Profiles and Clonal Relationships of Escherichia coli O26:H11 Isolates from Feedlot Cattle as Determined by Whole- Genome Sequencing
Author
dc.contributor.author
González Escalona, Narjol
Author
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Toro Ibaceta, Magaly
Author
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Rump, Lydia
Author
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Cao, Guojie
Author
dc.contributor.author
Nagaraja, T. G.
Author
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Meng, Jianghong
Admission date
dc.date.accessioned
2016-11-30T15:05:27Z
Available date
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2016-11-30T15:05:27Z
Publication date
dc.date.issued
2016
Cita de ítem
dc.identifier.citation
Applied and Environmental Microbiology July 2016 Volume 82 Number 13
es_ES
Identifier
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10.1128/AEM.00498-16
Identifier
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https://repositorio.uchile.cl/handle/2250/141541
Abstract
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Escherichia coli O26 is the second most important enterohemorrhagic E. coli (EHEC) serogroup worldwide. Serogroup O26 strains are categorized mainly into two groups:enteropathogenic (EPEC) O26, carrying a locus of enterocyte effacement (LEE) and mostly causing mild diarrhea, and Shiga-toxigenic (STEC) O26, which carries the Shiga toxin (STX) gene (stx), responsible for more severe outcomes. stx-negative O26 strains can be further split into two groups. One O26 group differs significantly from O26 EHEC, while the other O26 EHEC-like group shows all the characteristics of EHEC O26 except production of STX. In order to determine the different populations of O26 E. coli present in U.S. cattle, we sequenced 42 O26:H11 strains isolated from feedlot cattle and compared them to 37 O26:H11 genomes available in GenBank. Phylogenetic analysis by whole-genome multilocus sequence typing (wgMLST) showed that O26:H11/H- strains in U.S. cattle were highly diverse. Most strains were sequence type 29 (ST29). By wgMLST, two clear lineages could be distinguished among cattle strains. Lineage 1 consisted of O26:H11 EHEC-like strains (ST29) (4 strains) and O26:H11 EHEC strains (ST21) (2 strains), and lineage 2 (36 strains) consisted of O26: H11 EPEC strains (ST29). Overall, our analysis showed U.S. cattle carried pathogenic (ST21; stx(1)(+) ehxA(+) toxB(+)) and also potentially pathogenic (ST29; ehxA(+) toxB(+)) O26:H11 E. coli strains. Furthermore, in silico analysis showed that 70% of the cattle strains carried at least one antimicrobial resistance gene. Our results showed that whole-genome sequence analysis is a robust and valid approach to identify and genetically characterize E. coli O26:H11, which is of importance for food safety and public health
es_ES
Patrocinador
dc.description.sponsorship
FDA Food Science and Research Intramural Program
Agriculture and Food Research Initiative from the USDA National Institute of Food and Agriculture 2012-68003-30155