Protein expression by Listeria monocytogenes grown on a RTE-meat matrix

Little is known about whether the growth of L. monocytogenes on a ready-to-eat (RTE) meat matrix has an impact on the bacterium's pathogenic capabilities. In this report, we examined protein expression by L, monocytogenes grown on RTE sliced turkey meat, using L monocytogenes grown on brain-heart-infusion agar as a control. Total protein fractions of L. monocytogenes from both growth conditions were extracted and compared by two-dimensional gel electrophoresis. Seventy-seven proteins expressed by turkey meat-grown L. monocytogenes were identified by MALDI-TOF/TOF mass spectrometry analysis. The identified proteins include proteins known to be involved in virulence and stress adaptation such as CIpB. CIpC, CIpP, and surface antigen. This is the first report describing the proteome expressed by L monocytogenes grown on a meat matrix. Our results suggest that certain proteins that are expressed by RTE meat-grown L. monocytogenes may contribute to the virulence of the bacterium. (C) 2008 Elsevier B.V. All rights reserved.