Listeria monocytogenes: Difference between revisions
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==Description and significance== | ==Description and significance== | ||
''Listeria Monocytogenes'' is a gram positive, rod | ''Listeria Monocytogenes'' is a gram positive, rod shaped bacterium that can be found in the soil, vegetation, and many animal reservoirs. It is also found to be part of the normal gastrointestinal microbiota in healthy individuals. ''L.'' ''monocytogenes'' is an intracellular pathogen of both humans and animals. It is the cause of the major food born infection Listeriosis. It is mainly obtained from the consumption of contaminated dairy and meat products. Due to the fact that is an intracellular pathogen it is responsible for causing illnesses in persons with deficient cell-mediated immunity. | ||
''L. Monocytogenes'' is a psychrotroph and can grow at low temperature of 0-7 degrees Celsius. It’s optimum temperature is between 20 and 30 degrees Celsius and it holds its maximum temperature at 35 degrees Celsius | |||
Revision as of 11:50, 2 April 2008
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Classification
Higher order taxa
Kingdom: Bacteria
Division: Firmicutes
Class: Bacilli
Order: Bacillales
Family: Listeriaceae
Species
Genus: Listeria
Species: L. monocytogenes
Description and significance
Listeria Monocytogenes is a gram positive, rod shaped bacterium that can be found in the soil, vegetation, and many animal reservoirs. It is also found to be part of the normal gastrointestinal microbiota in healthy individuals. L. monocytogenes is an intracellular pathogen of both humans and animals. It is the cause of the major food born infection Listeriosis. It is mainly obtained from the consumption of contaminated dairy and meat products. Due to the fact that is an intracellular pathogen it is responsible for causing illnesses in persons with deficient cell-mediated immunity.
L. Monocytogenes is a psychrotroph and can grow at low temperature of 0-7 degrees Celsius. It’s optimum temperature is between 20 and 30 degrees Celsius and it holds its maximum temperature at 35 degrees Celsius
Describe the appearance, habitat, etc. of the organism, and why it is important enough to have its genome sequenced. Describe how and where it was isolated.
Include a picture or two (with sources) if you can find them.
Genome structure
Describe the size and content of the genome. How many chromosomes? Circular or linear? Other interesting features? What is known about its sequence? Does it have any plasmids? Are they important to the organism's lifestyle?
Cell structure and metabolism
Describe any interesting features and/or cell structures; how it gains energy; what important molecules it produces.
Ecology
Describe any interactions with other organisms (included eukaryotes), contributions to the environment, effect on environment, etc.
Pathology
Listeria Monocytogenes is an intracellular pathogen of both humans and animals. It is the cause of the food born infection Listeriosis. Outbreaks of the disease are found to be caused by consumption of contaminated milk, soft cheese, and meat products. Symptoms include gastrointestinal symptoms of vomiting and diarrhea as well as patient symptoms of influenza. Individuals that are more highly susceptible of acquiring the infection Listeriosis are pregnant women and people who are immune-suppressed due to illness or medication. For one, the reason that there is such an increased risk in pregnant women is that it may be related to both systematic and local immunological changes associated with pregnancy. In immune-suppressed individuals the invasion, intracellular multiplication, and cell to cell spread of bacterium appears to be mediated through proteins such as internalin, the hemolysin O, listeriolysin, and phospholipase C. Also bear in mind that since Listeria Monocytogenes is an intracellular pathogen it will affect immune-suppressed individuals more.
Unlike the several other food-borne pathogens which are the cause of gastrointestinal illness, L. monocytogenes is causes serious disease such as meningitis, sepsis, encephalitis, corneal ulcer, pneumonia, and stillbirth. The diagnosis of Listeria is by the culture of the bacterium. Also, the treatment method of this disease is intravenous administration of either ampicillin or penicillin.
However, it must be noted that L. monocytogenes is found to be part of the normal gastrointestinal microbiota in healthy individuals resulting in no symptoms. The effect of the pathogen depends not only on the individual but also the strain of bacterium.
Application to Biotechnology
Does this organism produce any useful compounds or enzymes? What are they and how are they used?
Current Research
Enter summaries of the most recent research here--at least three required