Author
Palumbo, Jeffrey - Jeff | |
KANEKO, AYA - INTNL.INTERN PROG.TOKYO | |
Nguyen, Kimanh | |
Gorski, Lisa |
Submitted to: Applied and Environmental Microbiology
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 3/23/2005 Publication Date: 9/9/2005 Citation: Palumbo, J.D., Kaneko, A., Nguyen, K.D., Gorski, L.A. 2005. Identification of genes induced in listeria monocytogenes during growth and attachment to cut cabbage using differential display.. Applied and Environmental Microbiology.AEM(71)9:5236-5346 Interpretive Summary: The foodborne pathogen Listeria monocytogenes is an ubiquitous soil bacterium with the potential to contaminate fresh produce during cultivation and postharvest processing. In order to identify potential mechanisms by which L. monocytogenes may successfully attach to and colonize fresh produce, gene expression in L. monocytogenes cells inoculated onto fresh-cut cabbage was compared to that in cells grown under control conditions. Using a technique called differential display thirty-two genes were identified as over-expressed by L. monocytogenes when it was grown with cabbage tissue. Genes involved in carbohydrate, amino acid and nucleic acid metabolism, motility and cell division, and transport were identified, as well as a number of regions encoding putative proteins with no known function. Site-directed mutations constructed in two genes encoding potential cell surface-associated proteins and a third gene encoding a putative regulatory protein had no effect on the mutants' capacity to attach to fresh-cut cabbage. Nevertheless, the differential display approach represents an important step in characterizing the genetic factors potentially involved in L. monocytogenes-plant interactions. Technical Abstract: The foodborne pathogen Listeria monocytogenes is an ubiquitous soil bacterium with the potential to contaminate fresh produce during cultivation and postharvest processing. In order to identify potential mechanisms by which L. monocytogenes may successfully attach to and colonize fresh produce, gene expression in L. monocytogenes cells inoculated onto fresh-cut cabbage was compared to that in cells grown under control conditions. Differential display of RT-PCR fragments amplified with a set of 81 arbitrary primers allowed the isolation and identification of 32 L. monocytogenes gene fragments observed to be more highly expressed under cabbage-associated conditions. Genes involved in carbohydrate, amino acid and nucleic acid metabolism, motility and cell division, and transport were identified, as well as a number of ORFs encoding putative proteins with no known function. Site-directed mutations constructed in two ORFs encoding potential cell surface-associated proteins and a third ORF encoding a putative regulatory protein had no effect on the mutants' capacity to attach to fresh-cut cabbage. Nevertheless, the differential display approach represents an important step in characterizing the genetic factors potentially involved in L. monocytogenes-plant interactions. |