Listeria monocytogenes
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Template:Seealso 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 facultative intracellular, anaerobic, nonsporulating, Gram-positive bacillus. Listeria is commonly found in soil, water, vegetation and fecal material.[1]
Taxonomy
Bacteria; Firmicutes; Bacilli; Bacillales; Listeriaceae; Listeria; Listeria monocytogenes
Microbiological Characteristics
- Listeria monocytogenes is a facultative intracellular, anaerobic, nonsporulating, Gram-positive bacillus.
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Listeria monocytogenes is a Gram-positive, facultative intracellular parasite, anaerobe, nonsporulating bacillus, with polar flagellae. It is a catalase-positive organism that exhibits motility, more specifically tumbling motility (between 20-25ºC). At 35 ºC the bacterium looses its motility.
Listeria produces acid and not gas in a variety of carbohydrates.[3] It has the ability to grow at temperatures between 0°C and 45ºC, which allows it to survive in a diverse array of environments such as soil, water, food products, and within the host cells. It can grown in an environment where the pH level ranges from 4.4 and 9.4.
- Listeria uses the cellular machinery of the host cell to migrate intracellularly.
- It induces directed polymerization of actin by the ActA transmembrane protein, thus pushing the bacterial cell inside the host cell.
Natural Reservoir
- In the environment, Listeria monocytogenes is commonly found in soil, water, vegetation and fecal material.
- Animals may be asymptomatic carriers of Listeria.[1]
- L. monocytogenes has been associated with foods such as raw milk, pasteurized fluid milk, cheeses (particularly soft-ripened varieties), ice cream, raw vegetables, fermented raw-meat sausages, raw and cooked poultry, raw meats, and raw and smoked fish.[4]
- Listeria has the ability to grow at temperatures as low as 0°C, allows its multiplication in refrigerated foods. At refrigerated temperature such as 4°C, the amount of ferric iron in the environment promotes the growth of L. monocytogenes.[5]
References
- ↑ 1.0 1.1 "Risk assessment of Listeria monocytogenes in ready-to-eat foods" (PDF).
- ↑ 2.0 2.1 2.2 "Public Health Image Library (PHIL), Centers for Disease Control and Prevention".
- ↑ 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.