Abstract
The genus Listeria contains ten species of Gram-positive bacteria, L. monocytogenes, L. fleischmannii, L. grayi, L. innocua, L. ivanovii, L. marthii, L. rocourtiae, L. seeligeri, L. weihenstephanensis, and L. welshimeri, and has been classified (along with members of the genus Brochothrix: B. thermosphacta and B. campestris) within the family Listeriaceae. Members of this family produce short rods that may form filaments. Cells stain Gram-positive, and the cell walls contain meso-diaminopimelic acid. The major lipid components include saturated straight-chain and methyl-branched fatty acids. Endospores are not produced; menaquinones are the sole respiratory quinones. Growth is aerobic and facultatively anaerobic; glucose is fermented to lactate and other products. L. monocytogenes (and to a lesser extent L. ivanovii) which are pathogenic to humans and a range of other animals, and the disease is primarily transmitted by consumption of contaminated food or feed. Human listeriosis is an opportunistic infection which most often affects those with severe underlying illness, the elderly, pregnant women, and both unborn and newly delivered infants. The reported incidence of human listeriosis varies between countries from <1 to >10 cases per million of the total population. Because of the severity of infection, listeriosis is one of the major causes of death from a preventable foodborne illness. Studies of the molecular biology of L. monocytogenes have identified a number of virulence factors that promote uptake into nonprofessional phagocytic cells and the process of movement from cell-to-cell by recruiting host cell proteins and remodeling the host cell cytoskeleton. This has made L. monocytogenes also of interest both as a tool to help understand eukaryotic cell biology and as a potential therapeutic agent for intracellular delivery of drugs and as a cancer vaccine. The presence of L. monocytogenes remains a major challenge for the food industry. Its psychrotrophic nature means that it can grow at or below refrigeration temperatures and it is also relatively tolerant of high solute concentrations, resists desiccation, and therefore can overcome mild food preservation techniques. L. monocytogenes is able to form biofilms and can colonize food processing equipment and environments, leading to cross-contamination of processed foods. Hence it is of particular concern in ready-to-eat foods.
Original language | English |
---|---|
Title of host publication | The Prokaryotes |
Subtitle of host publication | Firmicutes and Tenericutes |
Publisher | Springer-Verlag Berlin Heidelberg |
Pages | 241-259 |
Number of pages | 19 |
ISBN (Electronic) | 9783642301209 |
ISBN (Print) | 3642301193, 9783642301193 |
DOIs | |
Publication status | Published - 1 Nov 2013 |
Bibliographical note
Publisher Copyright:© 2014 Springer-Verlag Berlin Heidelberg. All rights are reserved.