Title: Update: Molecular identification, characterization and assessment of virulence of non-culturable biofilm isolates of Listeria monocytogenes isolated from chronic infections of turkeys Authors
Submitted to: Government Publication/Report
Publication Type: Other
Publication Acceptance Date: August 18, 2008
Publication Date: August 18, 2008
Citation: Huff, G.R., Huff, W.E., Johnson, M.G., Nannapaneni, R. 2008. Update: Molecular identification, characterization and assessment of virulence of non-culturable biofilm isolates of Listeria monocytogenes isolated from chronic infections of turkeys CDROM. Food Safety Consortium 2007-08 Progress Report.Version 1. University of Arkansas, Agricultural Building, Fayetteville, AR: Food Safety Consortium. Technical Abstract: Conventional culture methods and Taqman real time PCR (RTi PCR) were used for isolation of Listeria monocytogenes (Lm) from knee and hip joints of processing-age turkeys in a transport stress model. Male turkeys were exposed to an Escherichia coli and Lm Scott A co-challenge using coarse spray and feed inclusion and were either injected with dexamethasone (Dex, positive control) or were subjected to a 12 h transport stress protocol. Knee and hip joints were sampled using duplicate transport swabs. One set of swabs was subjected to cultural Lm detection methods and the other set was subjected to RTi PCR for the amplification of the 64 bp hly gene of Lm. Using pre-enrichment Lm was isolated from 50, 75, and 18.2%, and using RTi PCR Lm was isolated from 12.5%, 75, and 45.5% of Lm-Control, Lm-Dex treated, and Lm-transport stressed birds respectively. No Lm was isolated upon direct plating of swabs. Lm was not isolated from non-challenged birds except for the Rti-PCR isolation from 33% of transported but not-challenged birds. These data suggest that severe stress, as modeled by Dex treatment, can increase carcass contamination with environmentally acquired Lm, while the effects of transport stress were variable and that RTi PCR can be useful for direct isolation of Lm from turkey synovial tissues.