Listeria monocytogenes: Difference between revisions

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==Pathology==
==Pathology==
How does this organism cause disease? Human, animal, plant hosts?  Virulence factors, as well as patient symptoms.
''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==
==Application to Biotechnology==

Revision as of 11:06, 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. L. monocytogenes is a intracellular pathogen of both humans and animals. It is also the cause of the food-borne infection Listeriosis. The bacterium can be isolated from the soil, vegetation, and many animal reservoirs. It is also found to be part of the normal gastrointestinal microbiota in healthy individuals. However, due to the fact that it is a intracellular pathogen it is responsible for causing illness in persons with defecient cell-mediated immunity.


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

References

[Sample reference] Takai, K., Sugai, A., Itoh, T., and Horikoshi, K. "Palaeococcus ferrophilus gen. nov., sp. nov., a barophilic, hyperthermophilic archaeon from a deep-sea hydrothermal vent chimney". International Journal of Systematic and Evolutionary Microbiology. 2000. Volume 50. p. 489-500.