A longitudinal study of faecal shedding of Yersinia enterocolitica and Yersinia pseudotuberculosis by Merino lambs in south-eastern Australia.

Autor: Stanger KJ; University of Melbourne, Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, 250 Princes Highway, Werribee, VIC 3030, Australia. Electronic address: kelly.stanger@unimelb.edu.au., McGregor H; Redefining Agriculture Pty Ltd, PO Box 723, Brunswick Lower, VIC 3056, Australia., Marenda M; University of Melbourne, Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, 250 Princes Highway, Werribee, VIC 3030, Australia., Morton JM; Jemora Pty Ltd., PO Box 2277, Geelong 3220, VIC, Australia., Larsen JWA; Mackinnon Project, Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, 250 Princes Highway, Werribee, VIC 3030, Australia.
Jazyk: angličtina
Zdroj: Preventive veterinary medicine [Prev Vet Med] 2018 May 01; Vol. 153, pp. 30-41. Date of Electronic Publication: 2018 Mar 01.
DOI: 10.1016/j.prevetmed.2018.02.016
Abstrakt: A prospective longitudinal study was conducted to investigate potential risk factors for faecal shedding of Yersinia enterocolitica and Y. pseudotuberculosis by Merino lambs in four flocks in south-eastern Australia. The primary aims of the study were to determine the seasonal patterns of shedding of pathogenic Y. enterocolitica and Y. pseudotuberculosis, and to evaluate putative risk factors for faecal shedding of these organisms, including worm egg count, live-weight and growth rate. The risk of shedding varied markedly between Yersinia spp., farms, seasons and years. Shedding of Y. pseudotuberculosis occurred predominately in winter, whereas Y. enterocolitica was commonly isolated from faeces throughout the year. Moderate to high prevalences of shedding of each organism occurred in the absence of outbreaks of yersiniosis. In general, for shedding of Y. pseudotuberculosis, animals with moderate or high worm egg counts were at increased risk of shedding compared with animals with low worm egg counts. Sheep with higher average daily weight gains were at decreased risk of shedding Y. enterocolitica but at increased risk of shedding Y. pseudotuberculosis. Live-weight was not significantly associated with risk of shedding either species. This study highlighted that exposure to determinants of shedding Y. enterocolitica and Y. pseudotuberculosis differ between farms and over time within farms. Shedding is likely influenced by environmental, animal and management factors. Our results indicate that different or additional risk factors are required for yersiniosis over those that cause faecal shedding of Yersinia spp., because moderate to high prevalences of shedding were not always associated with outbreaks of clinical disease.
(Copyright © 2018 Elsevier B.V. All rights reserved.)
Databáze: MEDLINE
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