Listeria monocytogenes
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: João André Alves Silva, M.D. [2]
Overview
Listeria monocytogenes is a Gram-positive bacterium, in the division Firmicutes, named for Joseph Lister. Motile via flagella, L. monocytogenes can move within eukaryotic cells by explosive polymerization of actin filaments (known as comet tails or actin rockets). The name monocitogenes derives from the strong monocytic activity this organism produces in rabbits, which however does not happen in humans. Despite the name, more that half the patients present with increased levels of neutrophils in CSF.[1] Studies suggest that up to 10% of human gastrointestinal tracts may be colonized by L. monocytogenes.
Taxonomy
Bacteria; Firmicutes; Bacilli; Bacillales; Listeriaceae; Listeria; Listeria monocytogenes
Biology
Listeria monocytogenes is a Gram-positive, facultative anaerobe, nonsporulating bacillus with polar flagellae. It is a catalase-positive organism and exhibits motility, more specifically tumbling motility. Listeria produces acid but not gas in a variety of carbohydrates.[2] It has the ability to grow at temperatures as low as 0°C, which allow it to survive in a diverse array of environments such as soil, water, food products, and host cells.
Listeria uses the cellular machinery to move inside the host cell. It induces directed polymerization of actin by the ActA transmembrane protein, thus pushing the bacterial cell inside the host cell.
Structure
Tropism
Natural Reservoir
- L. monocytogenes has been associated with such foods as raw milk, pasteurized fluid milk[3], cheeses (particularly soft-ripened varieties), ice cream, raw vegetables, fermented raw-meat sausages, raw and cooked poultry, raw meats (of all types), and raw and smoked fish.
- Its ability to grow at temperatures as low as 0°C permits multiplication in refrigerated foods. In refrigeration temperature such as 4°C the amount of ferric iron promotes the growth of L. monocytogenes.[4]
References
- ↑ Mandell, Gerald L.; Bennett, John E. (John Eugene); Dolin, Raphael. (2010). Mandell, Douglas, and Bennett's principles and practice of infectious disease. Philadelphia, PA: Churchill Livingstone/Elsevier. ISBN 0-443-06839-9.
- ↑ Chapter 13. Non-Spore-Forming Gram-Positive Bacilli: Corynebacterium, Propionibacterium, Listeria, Erysipelothrix, Actinomycetes, & Related Pathogens ,Jawetz, Melnick, & Adelberg's Medical Microbiology, 24th Edition ,The McGraw-Hill Companies
- ↑ Fleming, D. W., S. L. Cochi, K. L. MacDonald, J. Brondum, P. S. Hayes, B. D. Plikaytis, M. B. Holmes, A. Audurier, C. V. Broome, and A. L. Reingold. 1985. Pasteurized milk as a vehicle of infection in an outbreak of listeriosis. N. Engl. J. Med. 312:404-407.
- ↑ Dykes, G. A., Dworaczek (Kubo), M. 2002. Influence of interactions between temperature, ferric ammonium citrate and glycine betaine on the growth of Listeria monocytogenes in a defined medium. Lett Appl Microbiol. 35(6):538-42.