Research article - Peer-reviewed, 2009
Experimental Challenge of Mallards (Anas platyrhynchos) with Brachyspira hyodysentetiae and "Brachyspira suanatina" Isolated from Pigs and Mallards
Jansson, Monica Desiree Seger; Råsbäck, Therese; Fellström, Claes; Feinstein, RAbstract
Brachyspira hyodysenteriae, the aetiological agent of swine dysentery, and a recently proposed and closely related enteropathogenic spirochaete "Brachyspira suanatina", originally isolated from pigs or mallards (Anas platyrhynchos), were used to inoculate week-old mallard ducklings orally or cloacally. The colonization rate, clinical outcome, faecal dry matter content, blood leucocyte counts and gross, microscopical and electron microscopical features 14-16 days post-inoculation were investigated at necropsy examination. Strains of "B. suanatina" of pig and mallard origin and B. hyodysenteriae of mallard origin colonized the ducklings by oral inoculation, and colonization was also established by cloacal inoculation with a "B. suanatina" strain of mallard origin. The porcine reference strain of B. hyodysenteriae (13204 R) failed to colonize the birds. Unchallenged contact birds in one of the challenge groups were readily colonized by a strain of "B. suanatina" of mallard origin. The proportion of colonized birds differed significantly between the challenge groups (P < 0.0001). For each challenge group, the inoculum and a randomly selected subset of recovered isolates had an identical biochemical profile and banding pattern by randomly amplified polymorphic DNA (RAPD) analysis. None of the birds developed clinical signs of gastrointestinal disease during the trial. The faecal dry weight contents, body weights and total leucocyte and heterophal counts did not differ between the various groups of birds. At the microscopical and electron microscopical levels, the caecal mucosa in some of the Brachyspira culture-positive birds had sharply demarcated epithelial cell changes and there were features of irreversible cell damage in crypt necks coinciding with spirochaetal infiltration of the mucosa. The crypts in Brachyspira culture-positive birds were deeper than in culture-negative birds (median: 237 mu m and 218 mu m, respectively, P = 0.019). This challenge model was well suited for use in mallards and consistent with previous findings that strongly haemolytic Brachyspira spp. may cross the species barrier between pigs and birds. (C) 2009 Elsevier Ltd. All rights reserved.Keywords
Brachyspira spp.; intestina spirochaete; mallard; swine dysenteryPublished in
Journal of Comparative Pathology2009, volume: 141, number: 4, pages: 211-222
Publisher: ELSEVIER SCI LTD
Authors' information
Jansson, Monica Desiree Seger (Jansson, Desirée)
Swedish University of Agricultural Sciences, Department of Clinical Sciences
Råsbäck, Therese
Swedish University of Agricultural Sciences, Department of Clinical Sciences
Feinstein, R
UKÄ Subject classification
Veterinary Science
Animal and Dairy Science
Publication Identifiers
DOI: https://doi.org/10.1016/j.jcpa.2009.03.007
URI (permanent link to this page)
https://res.slu.se/id/publ/48997