Location: Warmwater Aquaculture Research UnitTitle: Transcriptpome analysis of Listeria monocytogenes grown on a ready to eat meat matrix Author
Submitted to: Journal of Food Protection
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/11/2011
Publication Date: 7/1/2011
Publication URL: http://handle.nal.usda.gov/10113/55396
Citation: Bae, D., Crowley, M.R., Wang, C. 2011. Transcriptpome analysis of Listeria monocytogenes grown on a ready to eat meat matrix. Journal of Food Protection. 74:1104-1111. Interpretive Summary: The contamination of ready-to-eat (RTE) meat products with Listeria monocytogenes is a major concern for the food industry. However, little is known about how L. monocytogenes adapts and multiplies in a RTE meat matrix and how these adaptive changes affect the ability of this pathogen to cause disease in humans. We compared the gene transcription profiles of L. monocytogenes grown on delicatessen turkey meat to those of the same strain grown on brain heart infusion (BHI) media using transcriptome analysis. Analysis demonstrated that 39 and 45 genes transcriptionally up-regulated and down-regulated, respectively, for from L. monocytogenes grown on RTE compared to BHI. Differentially transcribed genes were primarily related to general cellular processes (metabolism of energy, fatty acids, phospholipid, DNA; biosynthesis of proteins; and regulatory functions). Transcription levels of genes associated with stress responses and virulence were not different between the two growth media. Our data provide a basis for understanding the growth and adaptation of L. monocytogenes when grown on RTE products and may provide insights into controlling this important food pathogen.
Technical Abstract: The contamination of ready-to-eat (RTE) meat products with Listeria monocytogenes is a major concern for the food industry. For a better understanding of the adaptation and survival ability of L. monocytogenes grown on turkey deli meat, the transcriptome of L. monocytogenes strain F2365 was determined using a microarray. Microarray data were validated using a quantitative real time RT-PCR assay. Based on the microarray data, 39 and 45 genes from L. monocytogenes were transcriptionally up-regulated and down-regulated, respectively. The genes regulated at the transcriptional level were mainly involved in energy metabolism, fatty acid and phospholipid metabolism, biosynthesis of proteins, transport and binding proteins, DNA metabolism, cellular processes, and regulatory functions. There was no significant change on the expression of genes encoding for known virulence factors such as sigB, prfA, inlA, inlB, plcA, plcB, and hly. This study suggests that L. monocytogenes grown on RTE deli meat changes its transcription involved in its metabolic pathways to obtain an energy source or an ability to adapt to environmental change without increasing the expression levels of virulence factors. The global transcriptome profiles provide a better understanding of the growth or adaptation of L. monocytogenes in RTE meat products.