A one-year longitudinal study of enterohemorrhagic Escherichia coli O157 fecal shedding in a beef cattle herd
| Autor: | F.J. Babinec, L.C. Rhades, Natalia Amigo, P.J. Delicia, M.C. Fort, L. Urquiza, A. Bentancor, Ángel Adrián Cataldi, Mariano Larzabal, V.N. Baldone, J. Sabio y García |
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| Rok vydání: | 2019 |
| Předmět: |
Male
Veterinary medicine Genotype 040301 veterinary sciences Argentina Cattle Diseases Beef cattle Biology Escherichia coli O157 medicine.disease_cause Shiga Toxin 0403 veterinary science Feces 03 medical and health sciences fluids and secretions STX2 Grazing medicine Animals Longitudinal Studies Adhesins Bacterial Escherichia coli Escherichia coli Infections 030304 developmental biology Bacterial Shedding 0303 health sciences Virulence General Veterinary Escherichia coli Proteins Incidence (epidemiology) 04 agricultural and veterinary sciences Herd Cattle |
| Zdroj: | Research in Veterinary Science. 127:27-32 |
| ISSN: | 0034-5288 |
| Popis: | Bovines are the primary reservoir of enterohemorrhagic Escherichia coli (EHEC) O157:H7 and the main source of its transmission to humans. Here, we present a one-year longitudinal study of fecal shedding of E. coli O157. E. coli O157 obtained from recto-anal mucosal samples were characterized by multiplex PCR. The E. coli O157 prevalence ranged from 0.84% in July to 15.25% in November. The confinement within pens resulted in prevalence of 11%. Most animals (61.86%; 75/118) shed E. coli O157 at least in one sampling occasion. Of the positive animals, 82.19%, 16.44%, and 1.37% were stx positive on one, two and three sampling occasions, respectively. All the E. coli O157 isolated strains carried the genes eae and rfbO157, whereas 11%, 33% and 56% contained stx1, stx2 and stx1/stx2, respectively. The stx1/stx2 and stx2 types were significantly higher during the grazing and finishing periods, respectively, in comparison with the rearing and grazing periods. The presence of stx2a subtype was evident in four isolates, whereas stx2c was present in at least seven. However, both subtypes were present simultaneously in two isolates. The stx1/stx2c, stx1/stx2d and stx1/stx2NT genotypes occurred in 24, 2 and 15 isolates, respectively. The simultaneous occurrence of stx1 and stx2c significantly increased during grazing. Some cases of within-pen and between-pen transmission occurred throughout the study. Contagion levels during in-field grazing were higher than during permanent confinement in the pens. Thus, the individual patterns of shedding varied depending on the proportion of animals shedding the bacteria within pens and the time of shedding. |
| Databáze: | OpenAIRE |
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