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United States Department of Agriculture

Agricultural Research Service

Research Project: INVESTIGATING THE IMPACT OF STRESS ON FOODBORNE PATHOGEN COLONIZATION IN TURKEYS Title: The effects of stress on respiratory disease and transient colonization of turkeys with Listeria monocytogenes Scott A

Authors
item Dutta, Vik - UNIV OF ARKANSAS
item Huff, Geraldine
item Huff, William
item Johnson, Michael - UNIV OF ARKANSAS
item Nannapaneni, R - MISS STATE UNIV
item Sayler, R - UNIV OF ARKANSAS

Submitted to: Avian Diseases
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: June 19, 2008
Publication Date: December 1, 2008
Citation: Dutta, V., Huff, G.R., Huff, W.E., Johnson, M.G., Nannapaneni, R., Sayler, R.J. 2008. The effects of stress on respiratory disease and transient colonization of turkeys with Listeria monocytogenes Scott A. Avian Diseases. 52(4):581-589.

Interpretive Summary: Listeria monocytogenes contamination in poultry processing plants has been a consistent problem. The ubiquitous nature and high resistance of this organism to disinfection are reasons for its prevalence, but the sources of persistent, strains that tightly attach to surfaces are unknown. The purpose of this study is to determine the effects of stress on colonization of turkey poults with L. monocytogenes, as a possible source of contamination. Male poults housed in floor pens were subjected to cold stress from 4-12 day of age and were unchallenged or were exposed to an aerosol and oral challenge of the Scott-A strain of L. monocytogenes (Lm), an avian pathogenic strain of Escherichia coli (Ec), or the combination (Ec-Lm). Non-challenged, non-cold stressed controls were housed in a separate, bio-secure building. At seven weeks, all cold stressed poults were treated with a compound that decreased immunity and were exposed to the same bacterial challenges. Challenged birds had decreased body weights and signs of clinical disease. Listeria monocytogenes was isolated from a percentage of the liver and knee cultures of all bacteria-challenged groups at one week but not at two weeks post-challenge. The higher percentages of positive birds detected by real time PCR than by culture, and negative results at two weeks post-challenge suggest that this was a transient infection that was cleared by the immune system. These results suggest that environmentally acquired L. monocytogenes can transiently colonize the liver and synovial tissues of stressed turkeys and may be a sporadic source of contamination with strains that persist in the processing plant.

Technical Abstract: Listeria monocytogenes contamination in poultry processing plants has been a consistent problem. The ubiquitous nature and high resistance of this organism to disinfection are reasons for its prevalence, but the sources of persistent, biofilm-forming strains are unknown. The purpose of this study is to determine the effects of stress on colonization of turkey poults with L. monocytogenes, as a possible source of contamination. Male poults housed in floor pens were subjected to cold stress from 4-12 day of age and were unchallenged or were exposed to an aerosol and oral challenge of the Scott-A strain of L. monocytogenes (Lm), an avian pathogenic strain of Escherichia coli (Ec), or the combination (Ec-Lm). Non-challenged, non-cold stressed controls were housed in a separate, bio-secure building. At seven weeks, all cold stressed poults were treated with an immunosuppressive dose of dexamethasone (Dex) and exposed to the same bacterial challenges Birds were necropsied at one and two weeks post-Dex treatment. Percent mortality, body and organ weights, and airsacculitis scores were determined. Liver and knee synovial tissues were sampled using transport swabs and cultured by direct plating, pre-enrichment, and Taqman® real-time PCR. There were no significant differences in cumulative mortality, and airsacculitis scores were variable but tended to be decreased by early cold stress. Relative weights of liver and heart were increased, whereas body weights and spleen and bursa relative weights were decreased due to all challenges. Listeria monocytogenes was isolated from a percentage of liver and knee of all bacteria-challenged groups using pre-enrichment and real time PCR at one week but not at two weeks post-challenge. The higher percentages of positive birds detected by real time PCR than by culture, and negative results at two weeks post-challenge suggest that this was a transient infection that was cleared by the immune system. These results suggest that environmentally acquired L. monocytogenes can transiently colonize the liver and synovial tissues of stressed turkeys may be a sporadic source of contamination with persistent, biofilm-forming strains.

Last Modified: 10/25/2014
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