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Enteropathogenic Yersinia spp. and Salmonella spp. in Swedish wild boars

the presence and molecular epidemiology

Sannö, Axel (2018). Enteropathogenic Yersinia spp. and Salmonella spp. in Swedish wild boars. Diss. (sammanfattning/summary) Uppsala : Sveriges lantbruksuniv., Acta Universitatis Agriculturae Sueciae, 1652-6880 ; 2018:46
ISBN 978-91-7760-232-3
eISBN 978-97-7760-233-0
[Doctoral thesis]

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Wild boars are reported as carriers of several zoonotic agents. The aims of this thesis was to investigate the presence of the foodborne enteropathogens Salmonella spp., Yersinia (Y.) spp. and E. coli O157:H7 in Swedish wild boars, the influence of potential risk factors presumably associated with their occurrence, the presence of Yersinia spp. and Salmonella spp. in minced meat, and to establish a method for molecular epidemiological studies (MLVA).
The thesis includes studies on lymphatic tissue and faeces from 178 wild boars and 32 samples of wild-boar minced meat. MLVA was evaluated on 254 isolates of Y. enterocolitica from several sources. Further, the wild boar populations were characterized with respect to four factors that possibly may be associated with the presence of enteropathogens in the wild boar.
A PCR-based protocol for the detection of enteropathogenic Yersinia spp. and Salmonella spp. was developed and evaluated. The protocol offered the possibility to obtain molecular epidemiological data of Yersinia spp. by MLVA on enrichment broths.
In total, 91 (51.1%) of the sampled wild boars carried the enteropathogens investigated and 46, 37 and 32 animals were PCR-positive for the presence of Y. enterocolitica, Y. pseudotuberculosis, and Salmonella spp., respectively. The subsequent cultivation yielded a total of 28 isolates of Salmonella spp., 10 isolates of Y. enterocolitica and 13 isolates of Y. pseudotuberculosis. None of the investigated risk factors were associated with the presence of these enteropathogens. However, a strong association between high levels of artificial feeding and high population densities was seen and the practice of leaving slaughter waste out in nature was found to be common among the hunters. In the new protocol, a positive selection for motile bacteria was used and seemed favourable in the detection of Y. enterocolitica and Salmonella spp. but not in the detection of Y. pseudotuberculosis. Further, MLVA performed directly on the enrichment broth seemed promising. MLVA on the isolates demonstrated a close resemblance between two human isolates and those obtained from domestic pigs whereas one rodent isolate was identical to that from pigs in the same farm.
In conclusion, human enteropathogens are present in a majority of the Swedish wild boars which may be of concern for the public health. The findings warrants further surveillance on the enteropathogens present and the new protocol presented within this thesis may be useful to obtain molecular epidemiological data for future reference in e.g. outbreak investigations.

Authors/Creators:Sannö, Axel
Title:Enteropathogenic Yersinia spp. and Salmonella spp. in Swedish wild boars
Subtitle:the presence and molecular epidemiology
Series Name/Journal:Acta Universitatis Agriculturae Sueciae
Year of publishing :2018
Depositing date:17 August 2018
Number of Pages:73
ISannö A., Aspán A., Hestvik G. & Jacobson M. (2014). Presence of Salmonella spp., Yersinia enterocolitica, Yersinia pseudotuberculosis and Escherichia coli O157:H7 in wild boars. Epidemiology & Infection, 142 (12), pp. 2542-2547.
IISannö A., Jacobson M., Sterner S., Thisted-Lambertz S. & Aspán A. (2018). The development of a screening protocol for Salmonella spp. and enteropathogenic Yersinia spp. in samples from wild boar (Sus scrofa) also generating MLVA–data for Y. enterocolitica and Y. pseudotuberculosis. Journal of Microbiological Methods, 150, pp. 32-38.
IIISannö A., Rosendal T., Aspán A., Backhans A. & Jacobson M. (2018). Distribution of enteropathogenic Yersinia spp. and Salmonella spp. in the Swedish wild boar population, and assessment of risk factors that may affect the prevalence of these zoonotic agents. Acta Veterinaria Scandinavica, 60 (40).
IVSannö A., Rosendal T., Aspán A., Backhans A. & Jacobson M. Comparison of Multiple-Locus Variable number tandem repeat Analysis profiles of enteropathogenic Yersinia spp. obtained from humans, domestic pigs, wild boars, rodents, red fox, pork, dog food and jack daws. (In manuscript)
Place of Publication:Uppsala
Publisher:Department of Clinical Sciences, Swedish University of Agricultural Sciences
ISBN for printed version:978-91-7760-232-3
ISBN for electronic version:978-97-7760-233-0
Publication Type:Doctoral thesis
Full Text Status:Public
Agris subject categories.:L Animal production > L73 Animal diseases
Subjects:(A) Swedish standard research categories 2011 > 1 Natural sciences > 106 Biological Sciences (Medical to be 3 and Agricultural to be 4) > Microbiology (Microbiology in the medical area to be 30109)
(A) Swedish standard research categories 2011 > 3 Medical and Health Sciences > 302 Clinical Medicine > Infectious Medicine
(A) Swedish standard research categories 2011 > 4 Agricultural Sciences > 403 Veterinary Science > Clinical Science
Agrovoc terms:Wild boar, Salmonella, Yersinia, zoonoses
Keywords:Wild boars, Enteropathogens, Zoonosis
Permanent URL:
ID Code:15591
Faculty:VH - Faculty of Veterinary Medicine and Animal Science
Department:(VH) > Dept. of Clinical Sciences
External funders:C. F. Lundströms stiftelse and Swedish Environmental Protection Agency and Stiftelsen Ivar & Elsa Sandbergs Stipendiefond för livsmedelshygienisk forskning
Deposited By: Axel Sannö
Deposited On:27 Aug 2018 07:56
Metadata Last Modified:09 Sep 2020 14:17

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