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Salmonella in pigs

infection dynamics of different serotypes

Österberg, Julia (2010). Salmonella in pigs. Diss. (sammanfattning/summary) SLU : Sveriges lantbruksuniv., Acta Universitatis agriculturae Sueciae, 1652-6880 ; 2010:75
ISBN 978-91-576-7520-0
[Doctoral thesis]

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Abstract

In recent years several incidents of feed-borne spread of Salmonella spp. have been documented in Swedish pig herds, including serotypes previously not associated with pigs. In this thesis two feed-associated serotypes (S Cubana and S Yoruba) were compared with two serotypes commonly detected in pigs (S Typhimurium and S Derby). The overall aim of the thesis was to increase knowledge about the feed-associated serotypes, with special focus on their infection dynamics in pigs. In 2003, a contamination in a feed mill caused the spread of S Cubana via feed to a number of pig herds. Questions raised during that outbreak led to the design of the present PhD project. The outbreak was analysed and in experimental studies pigs were inoculated orally with one of four serotypes, in three different doses (103, 106 or 109 colony forming units). Pigs were then monitored for eight weeks in order to determine differences among serotypes in faecal shedding, serological response and body distribution. Differences among serotypes were revealed as regards infectious dose, serological response and distribution to extra-intestinal organs and tissues. The data obtained were used for a mathematical modelling approach on the dynamics of faecal salmonella shedding and the immune response in pigs. The results showed that the dynamics of faecal shedding during infection were strongly associated with the challenge dose but weakly associated with the infection serotype. In order to investigate transmission of the four serotypes, uninfected pigs were introduced to salmonella-shedding pigs in a late stage of infection as well as to contaminated pens. All four serotypes were transmitted to at least one of the naïve pigs, but the overall transmission was low in both experimental settings. In conclusion, these studies showed that S Cubana may differ in some aspects regarding infection dynamics in pigs. However, the inoculation dose had a larger impact than the serotype. Thus, the level of infection in a herd infected with Salmonella spp. may be more indicative of what control measures that are needed, than the serotype involved.

Authors/Creators:Österberg, Julia
Title:Salmonella in pigs
Subtitle:infection dynamics of different serotypes
Year of publishing :2010
Volume:2010:75
Number of Pages:73
Papers/manuscripts:
NumberReferences
ALLI. Österberg, J., Vågsholm, I., Boqvist, S. & Sternberg Lewerin, S. (2006). Feed-borne outbreak of Salmonella Cubana in Swedish pig farms: Risk factors and factors affecting the restriction period in infected farms. Acta Veterinaria Scandinavica 47, 13-22. II. Österberg, J. & Wallgren, P. (2008) Effects of a challenge dose of Salmonella Typhimurium or Salmonella Yoruba on the patterns of excretion and antibody responses of pigs. Veterinary Record 162, 580-586. III. Österberg, J., Sternberg Lewerin, S. & Wallgren P. (2009). Patterns of excretion and antibody responses of pigs inoculated with Salmonella Derby and Salmonella Cubana. Veterinary Record 165, 404-408. IV. Österberg, J., Sternberg Lewerin, S. & Wallgren P. (2010). Direct and indirect transmission of four Salmonella enterica serotypes in pigs. Acta Veterinaria Scandinavica 52, 30 (10 May 2010). V. Ivanek, R., Österberg, J., Gautam, R. & Sternberg Lewerin, S. (2010 ). Dose- and serotype- dependent dynamics of fecal shedding and immune response post Salmonella inoculation in pigs. In manuscript. Papers I-IV are reproduced with the permission of the publishers.
Place of Publication:SLU
ISBN for printed version:978-91-576-7520-0
ISSN:1652-6880
Language:English
Publication Type:Doctoral thesis
Full Text Status:Public
Agrovoc terms:swine, salmonella, serotypes, disease transmission, feeds, faeces, meat animals, sweden
Keywords:Salmonella spp., pigs, serotypes, feed, feed-borne, infection dynamics, shedding, transmission
URN:NBN:urn:nbn:se:slu:epsilon-3114
Permanent URL:
http://urn.kb.se/resolve?urn=urn:nbn:se:slu:epsilon-3114
ID Code:2387
Department:(VH) > Dept. of Clinical Sciences
Deposited By: Julia Österberg
Deposited On:02 Nov 2010 00:00
Metadata Last Modified:02 Dec 2014 10:18

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