Mycobacterium leprae: Difference between revisions

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imported>Alphonse Guylsda
imported>Howard C. Berkowitz
(Splitting off disease article for leprosy. While this article is correct that it is no longer a treat to the U.S., I don't think that's what was meant)
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{{Taxobox
{{Taxobox
| color = pink
| color = pink
| name =  ''Mycobacterium leprae''
| name =  ''Mycobacterium leprae''
| image =  
| image = leprosy1.jpg
| regnum = Eubacteria
| regnum = Eubacteria
| phylum = Actinobacteria  
| phylum = Actinobacteria  
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==Description and significance==
'''''Mycobacterium leprae''''' is an obligate parasite that causes the disease [[leprosy]], also called [[Hansen's disease]] or [[Hansenitis]]. Its infectivity is quite low; while the mechanism of transmission is not completely understood, it requires prolonged contact.
[[Image: leprosy1.jpg]]
This [[M.leprae]] causes the disease [[leprosy]]. It's also called the [[Hansen's disease]] after the scientist that discovered the bacteria in the skin nodules of leprosy patient. For a long time this disease was seen as a curse , an hieredietery disease and its patients used to be stimatized. Cases of this disease has been reported as early as 650 bc and  the Christian Bible talk alot about it.But it's not as contagious as the Bible stories make us believed. Patients of this disease used to be stunned. This disease no longer cause a treat to the United States but is a major problems in the third countried specially India, Brazil and some parts of Africa.
M.leprae is an obligate parasite that once it atttacks the human body can take a long time to show symptoms.


==Genome structure==
==Genome structure==
It was discovered in 1873 by Gerhard Armauer Hansen. He discovered it in the skin nodules of patients with leprosy.
It was discovered in 1873 by Gerhard Armauer Hansen.<ref>
"The discovery of the leprosy bacillus". Tidsskr Nor Laegeforen 122 (7): 708-9. PMID 11998735</ref> He discovered it in the skin nodules of patients with leprosy.


Mycobactrium M.leprae has about 3,268,203 base pairs. Only 49% of the genome encode for proteins. The rest is composed of pseudogenes.
M.leprae has about 3,268,203 base pairs. Only 49% of the genome encode for proteins. The rest is composed of pseudogenes.
In size and shape M.leprae resemble the M. tuberculosis.
In size and shape M.leprae resemble the M. tuberculosis.


==Cell structure and metabolism==
==Cell structure and metabolism==
It’s a gram positive ,aerobic rod-shaped acid fast. Scientists believe that the pseudogenes used to be involed in metabolic patways but now this bacteria lost its metabolic capability. Because of this lost the M.leprae is now an obligate parasite that depends on its host for most of its nutritional and functional needs.  They have a waxy coating which is caused by the [[mycolic acid]]. That coating is unique to mycobacterium. The mycolic acid is composed of large lipids that are covalently bonded to each other to form the waxy coating. It's solid at room temperature. That's one of the causing why this bacteia is so hard to fight and destroyed.
 
Mycobacteria have a waxy coating of [[mycolic acid]], which is made up of large lipids that are covalently bonded to each other to form the waxy coating. The coating is solid at room temperature, resisting most [[disinfectant]]s except those certified as tuberculocides.


==Ecology==
==Ecology==
This bacteria is believed to live in the soil. Scientists think that the reservoir for this bacteria is the new world armadillos and African primates.
This bacteria is believed to live in the soil. Scientists think that the reservoir for this bacteria is the new world armadillos and African primates.
At the beginning the idea that the habitat of this bacteria was in soil was just an hypothesis but some research were done and DNA of the m.leeprae was found in soil close to where peope were infected with leprosy. Its ideal temperature is about 30-33 degres C
At the beginning the idea that the habitat of this bacteria was in soil was just an hypothesis but some research were done and DNA of the m.leeprae was found in soil close to where peope were infected with leprosy. Its ideal temperature is about 30-33 degrees C


==Pathology==
==Pathology==
M.leprae is responsible for the disease leprosy. It's a chronic disease that infects the peripheral nerves, the skin, the nervous system  and the mucous membranes of the nose , throat and eyes. It has a slow growth rate and also a long incubation time. The symptoms of leprosy are skin lesions, pain and weakness. If left untreated it can cause nerve damage that can lead to numbness, deformities of extremeties.It can also cause blindness. It can be treated with multiple drug therapy but some strands are becaming resistant to some of the drugs.
M.leprae is responsible for the disease [[leprosy]]. It has a slow growth rate and also a long incubation time. The symptoms of leprosy are skin lesions, pain and weakness. If left untreated it can cause nerve damage that can lead to numbness, deformities of extremeties.It can also cause blindness.  
The tranmission of the disease is not yet undrestood and current research are being done on that. But scientists believe that it might be transmitted from infected individuals to uninfected ones through close contacts.


==Current Research==
Due to the development of resistant forms, [[multidrug therapy]] is the standard of care.


Transmission of the disease is not fully understood, but it appears t be transmitted from infected individuals to uninfected ones through close contacts over prolonged periods. While it is primarily


Recent research  are being done on strains of rifampin-resistant. In this reseaserch samples were taking from patients with reocurring leprosy. A punctual mutation was found in nucleotide 1367 of the rpoBgene. That mutation show strains  of rifampin-resistant M.leprae in two of the three patients that were tested. This study took place in Agua de Dios in Colombia.
==Current Research==
Another research is being done on the mechanism of transmission of leprosy. This research was done in India.
Recent research  are being done on strains of [[rifampin]]-resistant organisms. I. A punctual mutation was found in nucleotide 1367 of the rpoBgene. That mutation show strains  of rifampin-resistant M.leprae in two of the three patients that were tested. This study took place in Agua de Dios in Colombia.<ref>Hernández E, Cardona-Castro N, Rodríguez G, Villegas S, Beltrán C, Kimura M, Vissa VD, Gómez Y.
Another one is done to study M.leprae in leprosy patient in Malawi and India. In this research the scientist used short tandem repeat sequence to help them undrestand M.leprae.
"Study of rifampin and dapsone resistance in three patients with recurring leprosy".Rev Panam Salud Publica. 2008 Feb;23(2):73-7.</ref>
Studies of  M.leprae in leprosy patient in Malawi and India investigate short tandem repeat sequences.<ref>{{citation
| author = Young SK, Ponnighaus JM, Jain S, Lucas S, Suneetha S, Lockwood DN, Young DB, Fine PE.
| title = Use of Short Tandem Repeat Sequences to Study Mycobacterium leprae in Leprosy Patients in Malawi and India
| journal =  PLoS Negl Trop Dis.  
| date = 2008 Apr 9 | volume = 2 | issue =4 | page = e214 |PMID= 18398487]
}}</ref>


==References==
==References==
1.[ "The discovery of the leprosy bacillus". Tidsskr Nor Laegeforen 122 (7): 708-9. PMID 11998735]
{{reflist|2}}
 
 
2.[Cole ST, Eiglmeier K, Parkhill J, et al (2001). "Massive gene decay in the leprosy bacillus". Nature 409 (6823): 1007-11. doi:10.1038/35059006. PMID 11234002.]
 
 
3.[Hernández E, Cardona-Castro N, Rodríguez G, Villegas S, Beltrán C, Kimura M, Vissa VD, Gómez Y.
"Study of rifampin and dapsone resistance in three patients with recurring leprosy".Rev Panam Salud Publica. 2008 Feb;23(2):73-7.]
 
 
4.[http://en.wikipedia.org/wiki/Leprosy.]
 
 
5.[http://microbewiki.kenyon.edu/index.php/Mycobacterium_leprae]
 
 
6.[http://www.who.org]
 
 
7.[http://www.cdc.gov/search.do?queryText=leprosy&action=search]
 
 
8.[Young SK, Ponnighaus JM, Jain S, Lucas S, Suneetha S, Lockwood DN, Young DB, Fine PE. "Use of Short Tandem Repeat Sequences to Study Mycobacterium leprae in Leprosy Patients in Malawi and India."  PLoS Negl Trop Dis. 2008 Apr 9;2(4):e214.][PMID: 18398487]
 
9.[http://www.britannica.com/eb/article-248483/leprosy]

Revision as of 16:04, 18 August 2010

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Mycobacterium leprae
Leprosy1.jpg
Scientific classification
Kingdom: Eubacteria
Phylum: Actinobacteria
Order: Actinomycetales
Family: Mycobacteriaceae
Genus: Mycobacterium
Species: leprae
Binomial name
Mycobacterium leprae

Mycobacterium leprae is an obligate parasite that causes the disease leprosy, also called Hansen's disease or Hansenitis. Its infectivity is quite low; while the mechanism of transmission is not completely understood, it requires prolonged contact.

Genome structure

It was discovered in 1873 by Gerhard Armauer Hansen.[1] He discovered it in the skin nodules of patients with leprosy.

M.leprae has about 3,268,203 base pairs. Only 49% of the genome encode for proteins. The rest is composed of pseudogenes. In size and shape M.leprae resemble the M. tuberculosis.

Cell structure and metabolism

Mycobacteria have a waxy coating of mycolic acid, which is made up of large lipids that are covalently bonded to each other to form the waxy coating. The coating is solid at room temperature, resisting most disinfectants except those certified as tuberculocides.

Ecology

This bacteria is believed to live in the soil. Scientists think that the reservoir for this bacteria is the new world armadillos and African primates. At the beginning the idea that the habitat of this bacteria was in soil was just an hypothesis but some research were done and DNA of the m.leeprae was found in soil close to where peope were infected with leprosy. Its ideal temperature is about 30-33 degrees C

Pathology

M.leprae is responsible for the disease leprosy. It has a slow growth rate and also a long incubation time. The symptoms of leprosy are skin lesions, pain and weakness. If left untreated it can cause nerve damage that can lead to numbness, deformities of extremeties.It can also cause blindness.

Due to the development of resistant forms, multidrug therapy is the standard of care.

Transmission of the disease is not fully understood, but it appears t be transmitted from infected individuals to uninfected ones through close contacts over prolonged periods. While it is primarily

Current Research

Recent research are being done on strains of rifampin-resistant organisms. I. A punctual mutation was found in nucleotide 1367 of the rpoBgene. That mutation show strains of rifampin-resistant M.leprae in two of the three patients that were tested. This study took place in Agua de Dios in Colombia.[2]

Studies of M.leprae in leprosy patient in Malawi and India investigate short tandem repeat sequences.[3]

References

  1. "The discovery of the leprosy bacillus". Tidsskr Nor Laegeforen 122 (7): 708-9. PMID 11998735
  2. Hernández E, Cardona-Castro N, Rodríguez G, Villegas S, Beltrán C, Kimura M, Vissa VD, Gómez Y. "Study of rifampin and dapsone resistance in three patients with recurring leprosy".Rev Panam Salud Publica. 2008 Feb;23(2):73-7.
  3. Young SK, Ponnighaus JM, Jain S, Lucas S, Suneetha S, Lockwood DN, Young DB, Fine PE. (2008 Apr 9), "Use of Short Tandem Repeat Sequences to Study Mycobacterium leprae in Leprosy Patients in Malawi and India", PLoS Negl Trop Dis. 2 (4): e214