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ARS Home » Southeast Area » Fayetteville, Arkansas » Poultry Production and Product Safety Research » Research » Publications at this Location » Publication #216655
Title: Isolation of Listeria monocytogenes from challenged turkeys using real time PCR

Author
item DUTTA, VIKRANT - UNIV OF ARKANSAS
item HUFF, GERALDINE
item SAYLER, R - UNIV OF ARKANSAS
item HUFF, WILLIAM
item JOHNSON, M - UNIV OF ARKANSAS
item NANNAPANENI, R - MISSISSIPPI STATE UNIV

Submitted to: World Poultry Congress Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 6/30/2008
Publication Date: 6/30/2008
Citation: Dutta, V., Huff, G.R., Sayler, R.J., Huff, W.E., Johnson, M.G., Nannapaneni, R. 2008. Isolation of Listeria monocytogenes from challenged turkeys using real time PCR. In: Proceedings of the 23rd World Poultry Congress, June 30 - July 4, 2008, Queensland, Brisbane, Australia. 2008 CDROM.

Interpretive Summary: Stress-induced subclinical infection of turkeys with L. monocytogenes (Lm) may be a source of processing plant contamination. The objective of this work was to compare conventional culture methods and Taqman® real time PCR (RTi PCR) for isolation of Lm from joints of challenged turkeys. Male turkeys were exposed to Escherichia coli and Lm Scott A using coarse spray and feed inclusion and positive controls were also injected with a compound that mimics stress. At 15 weeks of age a sample of birds was held and transported for 12 hours and all birds were necropsied the following morning. Knee and hip joints were sampled using duplicate transport swabs. Swabs were directly plated and pre-enriched using conventional methods. Another set was subjected to DNA extraction and amplification of an Lm specific gene using RTi PCR. Using pre enrichment Lm was isolated from 71%, 44% and 23%, and using RTi PCR Lm was isolated from 60%, 40% and 22% of Lm-Dex treated, Lm control, and Lm-transport stressed birds respectively. No Lm was isolated upon direct plating of swabs. These data suggest that RTi PCR can be useful for direct isolation of Lm from joint tissues.

Technical Abstract: We have hypothesized that stress-induced subclinical infection of turkeys with L. monocytogenes (Lm) may be a source of processing plant contamination. The objective of this work was to compare conventional culture methods and Taqman® real time PCR (RTi PCR) for isolation of Lm from joints of challenged turkeys. Male turkeys were exposed to Escherichia coli and Lm Scott A using coarse spray and feed inclusion and positive controls were also injected with dexamethasone (Dex). At 15 wks of age a sample of birds was subjected to a 12 h transport stress and all birds were necropsied the following morning. Knee and hip joints were sampled using duplicate transport swabs. Swabs were directly plated and pre-enriched using conventional methods. Another set was subjected to DNA extraction and amplification of the 64 bp hly gene of Lm using RTi PCR. Using pre enrichment Lm was isolated from 71%, 44% and 23%, and using RTi PCR Lm was isolated from 60%, 40% and 22% of Lm-Dex treated, Lm control, and Lm-transport stressed birds respectively. No Lm was isolated upon direct plating of swabs. These data suggest that RTi PCR can be useful for direct isolation of Lm from synovial tissues.