Title: Molecular identification, characterization and assessment of virulence of non-culturable biofilm isolates of L. monocytogenes isolated from chronic infections of turkeys: Implications for product and plant contamination Authors
|Johnson, M - UNIVERSITY OF ARKANSAS|
|Nannapaneni, R - MISSISSIPPI STATE UNIV|
Submitted to: Government Publication/Report
Publication Type: Government Publication
Publication Acceptance Date: August 11, 2007
Publication Date: August 31, 2007
Citation: Huff, G.R., Huff, W.E., Johnson, M.G., Nannapaneni, R. 2007. Molecular identification, characterization and assessment of virulence of non-culturable biofilm isolates of L. monocytogenes isolated from chronic infections of turkeys: Implications for product and plant contamination [CDROM]. Food Saftey Consortium 2006-07 Progress Reports. Version 1. Fayetteville, AR: Food Safety Consortium. Technical Abstract: We have hypothesized that sub-clinical, stress-induced infection of turkeys may be an unrecognized source of processing plant contamination with Listeria monocytogenes (Lm) biofilm. The objectives of this study were to determine the effects of early cold stress and concurrent environmental challenge with Escherichia coli (Ec) on colonization with Lm and to develop a real-time PCR assay for the detection of Lm in turkey synovial tissues. At one week post challenge, using conventional microbiological methods, Lm was isolated from knees of 33%, 43%, and 13% of cold stressed poults challenged with Ec+Lm, Ec alone, and Lm alone respectively. Lm was isolated from 40%, 50% and 20% of non-cold stressed birds challenged with Ec+Lm, Ec and Lm respectively. More Lm positive birds were detected using real time PCR as compared to cultural methods. No Lm was isolated from non-challenged, non-stressed controls at either 1 or 2 weeks post challenge or from any group at 2 weeks post challenge using either method. Early exposure to cold stress did not increase isolation of Lm and appeared to have a protective effect. Challenge of poults with Ec resulted in increased Lm isolation from knee joints, even in birds not directly exposed to the Lm challenge. These data suggest that Lm colonization of turkey synovial tissue can be enhanced by concurrent infection with Ec and real-time PCR can detect Lm in these samples.