|Beasley, J - UNIV OF ARKANSAS|
|Johnson, M - UNIV OF ARKANSAS|
|Nannapaneni, R - UNIV OF ARKANSAS|
Submitted to: Poultry Science Association Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: May 17, 2004
Publication Date: July 25, 2004
Citation: Huff, G.R., Huff, W.E., Beasley, J.N., Johnson, M.J., Nannapaneni, R., Balog, J.M., Rath, N.C. 2004. Pathology of listeriosis resulting from respiratory infection of turkey poults with Listeria monocytogenes Scott A [abstract]. Poultry Science Association Annual Meeting, July 25-29, 2005, St. Louis, Missouri. p. 86. Technical Abstract: The pathogenesis of a human epidemic strain of Listeria monocytogenes, Scott A, was studied by challenging day-old turkey poults with air sac inoculation of 10F0 (Control), 10F4, 10F5, 10F6, 10F7, or 10F8 cfu. Respiratory challenge with all levels resulted in listeriosis. Mortality at 2 wk post-infection ranged from 25-100% and was directly correlated with level of challenge. Gross pathology included enlarged gall bladders and pale livers, some of which were also yellowish, mottled, or cooked in appearance. Ruptured yolk sacs were common. Lungs were necrotic and hearts were swollen and surrounded by fluid. Sections of liver, heart, spleen, bursa, lung, and brain were fixed in 10% buffered formalin. Paraffin-embedded sections were cut at 5u, stained with hematoxylin and eosin as well as Gram stain and were examined for histological lesions. Lesions were observed in liver, heart, spleen, bursae, and lung, however no significant changes were present in brain. The myocardial lesions consisted of large infiltrations of mononuclear cells deep in the myocardium and were associated with Gram positive rods. In the liver, focal infiltrations of mononuclear cells were small and scattered and were also associated with Gram positive rods. Congestion and reticuloendothelial hyperplasia were prominent in the spleen and there was necrosis of scattered cells. Lymphocytes and mononuclear cells infiltrated areas surrounding bronchi in the lung. In the bursae there was depletion of lymphocytes in bursal follicles. Listeria challenge also resulted in significantly decreased relative weight of the bursa of Fabricius and increased relative weight of the spleen. L. monocytogenes was isolated by direct plating of liver, gall bladder, pericardium, brain, yolk sac, lung, cecal tonsil, and both left and right knee synovium cultures on UVM Listeria selective agar. These results suggest that respiratory infection with L. monocytogenes can be invasive in young turkeys and may be responsible for some unexplained cases of early poult mortality as well as the initiation of chronic infection leading to product contamination.