Pathogenesis and pathologic changes of experimentally induced listeriosis in newborn pigs
Busch, R.H.; Barnes, D.M.; Sautter, J.H.
American Journal of Veterinary Research 32(9): 1313-1320
1971
ISSN/ISBN: 0002-9645 PMID: 4999330 Document Number: 35343
Pigs 10 days of age were resistant to 109 Listeria monocytogenes given by mouth simultaneously with modified live swine fever virus vaccine s/c or with prednisolone i/m. New-born pigs less than 24 hours old consistently developed listeriosis when dosed by mouth with 106 or 109 organisms. The clinical characteristics of experimentally induced listeriosis were inconsistent. Listeria organisms administered orally to new-born pigs were distributed throughout the lumen of the intestine and were demonstrable in mesenteric lymph nodes 1-2 hours after inoculation. Lesions first appeared in parenchymatous organs with a reticulo-endothelial component, such as liver and lungs. Other tissues affected were bone marrow, lymph nodes, Peyer's patches, the choroid of the eye, mesentery, and brain blood vessels. The lesions were characterized by focal necrosis with inflammatory cell infiltration and by necrotizing phlebitis, occasionally with thrombosis.