Listeria monocytogenes
Scientific classification
Kingdom: Bacteria Division: Firmicutes Class: Bacilli Order: Bacillales Family: Listeriaceae Genus: Listeria Species: L. monocytogenes
Binomial name
Listeria monocytogenes Murray et al. (1926)

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). Image File history File links Size of this preview: 480 × 600 pixelsFull resolution (700 × 875 pixel, file size: 64 KB, MIME type: image/jpeg) File historyClick on a date/time to view the file as it appeared at that time. ... For other uses, see Scientific classification (disambiguation). ... Phyla Actinobacteria Aquificae Chlamydiae Bacteroidetes/Chlorobi Chloroflexi Chrysiogenetes Cyanobacteria Deferribacteres Deinococcus-Thermus Dictyoglomi Fibrobacteres/Acidobacteria Firmicutes Fusobacteria Gemmatimonadetes Lentisphaerae Nitrospirae Planctomycetes Proteobacteria Spirochaetes Thermodesulfobacteria Thermomicrobia Thermotogae Verrucomicrobia Bacteria (singular: bacterium) are unicellular microorganisms. ... Classes Bacilli Clostridia Mollicutes The Firmicutes are a division of bacteria, most of which have Gram-positive cell wall structure. ... Orders Bacillales Lactobacillales The term bacilli (singular bacillus) is used to refer to any rod-shaped bacteria. ... Families Alicyclobacillaceae Bacillaceae Caryophanaceae Listeriaceae Paenibacillaceae Planococcaceae Sporolactobacillaceae Staphylococcaceae Thermoactinomycetaceae Turicibacteraceae The Bacillales are an order of Gram-positive bacteria, placed within the Firmicutes. ... Genera Brochothrix Listeria The Listeriaceae are a family of Gram positive bacteria. ... Species Listeria monocytogenes Listeria ivanovii Listeria innocua Listeria welshimeri Listeria seegligeri Listeria grayi Listeria innocua Listeria is a bacterial genus containing six species. ... This article does not cite any references or sources. ... Gram-positive bacteria are those that are stained dark blue or violet by gram staining, in contrast to gram-negative bacteria, which are not affected by the stain. ... Phyla/Divisions Actinobacteria Aquificae Bacteroidetes/Chlorobi Chlamydiae/Verrucomicrobia Chloroflexi Chrysiogenetes Cyanobacteria Deferribacteres Deinococcus-Thermus Dictyoglomi Fibrobacteres/Acidobacteria Firmicutes Fusobacteria Gemmatimonadetes Nitrospirae Omnibacteria Planctomycetes Proteobacteria Spirochaetes Thermodesulfobacteria Thermomicrobia Thermotogae Bacteria (singular, bacterium) are a major group of living organisms. ... Classes Bacilli Clostridia Mollicutes The Firmicutes are a division of bacteria, most of which have Gram-positive cell wall structure. ... Joseph Lister, 1st Baron Lister (April 5, 1827-February 10, 1912) was a famous British surgeon who promoted the idea of sterile surgery while working at the Glasgow Infirmary. ... Motility is a biological term which refers to the ability to move spontaneously and independently. ... A flagellum (plural, flagella) is a whip-like organelle that many unicellular organisms, and some multicellular ones, use to move about. ... Kingdoms Animalia - Animals Fungi Plantae - Plants Chromalveolata Protista Alternative phylogeny Unikonta Opisthokonta Metazoa Choanozoa Eumycota Amoebozoa Bikonta Apusozoa Cabozoa Rhizaria Excavata Corticata Archaeplastida Chromalveolata Animals, plants, fungi, and protists are eukaryotes (IPA: ), organisms whose cells are organized into complex structures by internal membranes and a cytoskeleton. ... An example of alkene polymerisation, in which each Styrene monomer units double bond reforms as a single bond with another styrene monomer and forms polystyrene. ... G-Actin (PDB code: 1j6z). ...

Studies suggest that up to 10% of human gastrointestinal tracts may be colonized by L. monocytogenes.^{[citation needed]} Upper and Lower gastrointestinal tract The gastrointestinal tract (GI tract), also called the digestive tract, or the alimentary canal, is the system of organs within multicellular animals that takes in food, digests it to extract energy and nutrients, and expels the remaining waste. ...

Pathogenesis

Infection by L. monocytogenes causes the disease listeriosis. The manifestations of listeriosis include septicemia^[1], meningitis (or meningoencephalitis)^[1], encephalitis^[2], corneal ulcer^[3], Pneumonia^[4], and intrauterine or cervical infections in pregnant women, which may result in spontaneous abortion (2nd/3rd trimester) or stillbirth. Surviving neonates of Fetomaternal Listeriosis may suffer granulomatosis infantiseptica - pyogenic granulomas distributed over the whole body, and may suffer from physical retardation. Influenza-like symptoms, including persistent fever, usually precede the onset of the aforementioned disorders. Gastrointestinal symptoms such as nausea, vomiting, and diarrhea may precede more serious forms of listeriosis or may be the only symptoms expressed. Gastrointestinal symptoms were epidemiologically associated with use of antacids or cimetidine. The onset time to serious forms of listeriosis is unknown but may range from a few days to three weeks. The onset time to gastrointestinal symptoms is unknown but probably exceeds 12 hours. An early study suggeseted that L. monocytogenes was unique among Gram-positive bacteria in that it possessed lipopolysaccharide^[5], which served as an endotoxin. A later study did not support these findings^[6]. An infection is the detrimental colonization of a host organism by a foreign species. ... Sepsis (in Greek Σήψις) is a serious medical condition caused by a severe systemic infection leading to a systemic inflammatory response. ... Meningitis is the inflammation of the protective membranes covering the central nervous system, known collectively as the meninges. ... Meningoencephalitis is a type of infection that simultaneously resembles both meningitis, which is an infection or inflammation of the meninges, and encephalitis, which is an infection or inflammation of the brain. ... Encephalitis is an acute inflammation of the brain, commonly caused by a viral infection. ... This article is about female reproductive anatomy. ... The cervix (from Latin neck) is the lower, narrow portion of the uterus where it joins with the top end of the vagina. ... This article or section is in need of attention from an expert on the subject. ... Pyogenic refers to bacterial infections that make pus. ... In medicine (anatomical pathology), a granuloma is a group of epithelioid macrophages surrounded by a lymphocyte cuff. ... Influenza, commonly known as flu, is an infectious disease of birds and mammals caused by an RNA virus of the family Orthomyxoviridae (the influenza viruses). ... Types 5-7 on the Bristol Stool Chart are often associated with diarrhea Diarrhea (in American English) or diarrhoea (in British English) is a condition in which the sufferer has frequent watery, loose bowel movements (from the Greek word διάρροια; literally meaning through-flowing). Acute infectious diarrhea is a common cause... A bottle of antacid tablets An antacid is any substance, generally a base, which counteracts stomach acidity. ... Cimetidine is a histamine H2-receptor antagonist that inhibits the production of acid in the stomach. ... Gram-positive bacteria are those that are stained dark blue or violet by gram staining, in contrast to gram-negative bacteria, which are not affected by the stain. ... Lipopolysaccharide (captions are in French) Lipopolysaccharide (LPS) is a large molecule consisting of a lipid and a polysaccharide (carbohydrate) joined by a covalent bond. ... Endotoxins are potentially toxic, natural compounds found inside pathogens such as bacteria. ...

The infective dose of L. monocytogenes varies with the strain and with the susceptibility of the victim. From cases contracted through raw or supposedly pasteurized milk, one may safely assume that in susceptible persons, fewer than 1,000 total organisms may cause disease. L. monocytogenes may invade the gastrointestinal epithelium. Once the bacterium enters the host's monocytes, macrophages, or polymorphonuclear leukocytes, it becomes blood-borne (septicemic) and can grow. Its presence intracellularly in phagocytic cells also permits access to the brain and probably transplacental migration to the fetus in pregnant women. The pathogenesis of L. monocytogenes centers on its ability to survive and multiply in phagocytic host cells. Monocyte A monocyte is a leukocyte, part of the human bodys immune system that protect against blood-borne pathogens and move quickly to sites of infection in the tissues. ... A macrophage of a mouse stretching its arms to engulf two particles, possibly pathogens Macrophages (Greek: big eaters, makros = long, phagein = eat) are white blood cells, more specifically phagocytes, acting in the nonspecific defense as well as the specific defense system of vertebrate animals. ... Granulocytes are a category of white blood cells, characterised by the fact that all types have differently staining granules in their cytoplasm on light microscopy. ... Steps of a macrophage ingesting a pathogen: a. ...

Treatment

When listeric meningitis occurs, the overall mortality may reach 70%; from septicemia 50%, from perinatal/neonatal infections greater than 80%. screw infections during pregnancy, the mother usually survives. Reports of successful treatment with parenteral penicillin or ampicillin exist. Trimethoprim-sulfamethoxazole has been shown effective in patients allergic to penicillin. For the Japanese rock band, see Penicillin (band). ... Ampicillin is a beta-lactam antibiotic that has been used extensively to treat bacterial infections since 1961. ... Co-trimoxazole is a bacteriostatic antibiotic combination of trimethoprim and sulfamethoxazole, in the ratio of 1 to 5, used in the treatment of a variety of bacterial infections. ...

Bacteriophage treatment have been developed by several companies. EBI Food Safety and Intralytix both have products suitable for treatment of the bacteria. The FDA of the United States approved a cocktail of six bacteriophages from Intralytix, and a one type phage product from EBI Food Safety designed to kill the bacteria L. monocytogenes. Uses would potentially include spraying it on fruits and ready-to-eat meats such as sliced ham and turkey. The United States Food and Drug Administration is the government agency responsible for regulating food, dietary supplements, drugs, cosmetics, medical devices, biologics and blood products in the United States. ... A bacteriophage (from bacteria and Greek phagein, to eat) is a virus that infects bacteria. ...

Gene Therapy

L. monocytogenes has been used in studies to deliver genes in vitro. However transfection efficiency remains poor.

other than that, there is no treatment.

Detection

Colonies of typical Listeria monocytogenes as they appear when grown on Listeria selective agar

The methods for analysis of food are complex and time-consuming. The present Food and Drug Administration (FDA) method, revised in September, 1990, requires 24 and 48 hours of enrichment, followed by a variety of other tests. Total time to identification takes from 5 to 7 days, but the announcement of specific nonradiolabled DNA probes should soon allow a simpler and faster confirmation of suspect isolates. Image File history File links File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... Image File history File links File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... This does not adequately cite its references or sources. ... hi “FDA” redirects here. ... Year 1990 (MCMXC) was a common year starting on Monday (link displays the 1990 Gregorian calendar). ... In molecular biology, a hybridization probe is a fragment of DNA of variable length (usually 100-1000 bases long), which is used to detect in DNA or RNA samples the presence of nucleotide sequences that are complementary to the sequence in the probe. ...

Recombinant DNA technology may even permit 2-to-3 day positive analysis in the future. Currently, the FDA is collaborating in adapting its methodology to quantitate very low numbers of the organisms in foods.

Bio-Rad Laboratories (www.bio-rad.com) have come up with media called Rapid'L.Mono Medium which cut short time to 48 hours

Epidemiology

Researchers have found L. monocytogenes in at least 37 mammalian species, both domesticated and feral, as well as in at least 17 species of birds and possibly in some species of fish and shellfish. Laboratories can isolate L. monocytogenes from soil, silage, and other environmental sources. L. monocytogenes is quite hardy and resists the deleterious effects of freezing, drying, and heat remarkably well for a bacterium that does not form spores. Most L. monocytogenes are pathogenic to some degree. Subclasses & Infraclasses Subclass †Allotheria* Subclass Prototheria Subclass Theria Infraclass †Trituberculata Infraclass Metatheria Infraclass Eutheria Mammals (class Mammalia) are warm-blooded, vertebrate animals characterized by the production of milk in female mammary glands and by the presence of: hair, three middle ear bones used in hearing, and a neocortex region in... For other meanings of bird, see bird (disambiguation). ... For other uses, see Fish (disambiguation). ... Cooked mussels Shellfish is a term used to describe shelled molluscs and crustaceans used as food. ... Loess field in Germany Surface-water-gley developed in glacial till, Northern Ireland Technically, soil forms the pedosphere: the interface between the lithosphere (rocky part of the planet) and the biosphere, atmosphere, and hydrosphere. ... Silage (hay) somewhere in Allschwil or Schönenbuch, near Basel, Switzerland. ...

Routes of infection

L. monocytogenes has been associated with such foods as raw milk, pasteurized fluid milk^[7], 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.^[8] A glass of cows milk. ... Cheese is a solid food made from the milk of cows, goats, sheep, and other mammals. ... Missing image Ice cream is often served on a stick Boxes of ice cream are often found in stores in a display freezer. ... Vegetables on a market Vegetable is a nutritional and culinary term denoting any part of a plant that is commonly consumed by humans as food, but is not regarded as a culinary fruit, nut, herb, spice, or grain. ... This article is about the prepared meat. ... This article does not cite any references or sources. ... For other uses, see Fish (disambiguation). ...

Infectious Cycle

The primary site of infection is the intestinal epithelium where the bacteria invade non-phagocytic cells via the "zipper" mechanism. Uptake is stimulated by the binding of listerial internalins (Inl) to host cell adhesion factors such as E-cadherin or Met. This binding activates certain Rho-GTPases which subsequently bind and stabilize Wiskott Aldrich Syndrome Protein (WASp). WASp can then bind the Arp2/3 complex and serve as an actin nucleation point. Subsequent actin polymerization extends the cell membrane around the bacterium, eventually engulfing it. The net effect of internalin binding is to exploit the junction forming-apparatus of the host into internalizing the bacterium. Note that L. monocytogenes can also invade phagocytic cells (e.g. macrophages) but only requires internalins for invasion of non-phagocytic cells. Cadherins are a class of proteins which are expressed on the surface of cells. ... The Wiskott-Aldrich Syndrome Protein (WASp) is a 502 amino acid protein dependent upon Cdc42 and PIP2 for activation. ... Atomic structure of bovine Arp2/3 complex (PDB code: 1k8k). ... G-Actin (PDB code: 1j6z). ... Macrophages (Greek: big eaters) are cells found in tissues that are responsible for phagocytosis of pathogens, dead cells and cellular debris. ...

Following internalisation, the bacterium must escape from the vacuole/phagosome before fusion with a lysosome can occur. Two main virulence factors which allow the bacterium to escape are listeriolysin O (LLO - encoded by hly) and phospholipase C B (plcB). Secretion of LLO and PlcB disrupts the vacuolar membrane and allows the bacterium to escape into the cytoplasm where it may proliferate. Organelles. ... Listeriolysin O (LLO) is a hemolysin produced by the bacterium Listeria monocytogenes, the pathogen responsible for causing listeriosis. ... Phospholipase C is a key enzyme in phosphatidylinositol (PIP2) metabolism and lipid signaling pathways. ...

Once in the cytoplasm, L. monocytogenes exploits host actin for the second time. ActA proteins associated with the old bacterial cell pole (being a bacilli, L. monocytogenes septates in the middle of the cell and thus has one new pole and one old pole) are capable of binding the Arp2/3 complex and thus induce actin nucleation at a specific area of the bacterial cell surface. Actin polymerization then propels the bacterium unidirectionally into the host cell membrane. The protrusion which is formed may then be internalised by a neighbouring cell, forming a double-membrane vacuole from which the bacterium must escape using LLO and PlcB. G-Actin (PDB code: 1j6z). ... Atomic structure of bovine Arp2/3 complex (PDB code: 1k8k). ...

References

External links

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Listeria monocytogenes

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Listeria monocytogenes

• U.S. Food and Drug Administration. Foodborne Pathogenic Microorganisms and Natural Toxins Handbook: Listeria monocytogenes