Mycobacterium leprae: Difference between revisions

From Citizendium
Jump to navigation Jump to search
imported>Meg Taylor
m (spelling: alot -> a lot)
mNo edit summary
 
(One intermediate revision by one other user not shown)
Line 1: Line 1:
{{Subpages}}
{{Subpages}}
 
{{TOC|left}}
{{Taxobox
{{Taxobox
| color = pink
| color = pink
Line 16: Line 16:
}}
}}


 
'''''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.
'''''Mycobacterium leprae''''' causes the disease [[leprosy]], also called [[Hansen's disease]] after the scientist that discovered the organism in the skin nodules of leprosy patient. For a long time this disease was seen as a curse , an hereditary disease and its patients used to be stimatized. Cases of this disease has been reported as early as 650 BCE and the Christian Bible talks a lot 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==
''M. leprae'' is an aerobic, rod-shaped bacterium, technically [[Gram stain|Gram-positive]] but often difficult to stain without an [[acid-fast]] procedure such as the [[Ziehl-Neelsen stain]]. It is believed that the pseudogenes used to be involved in metabolic patgways but now this bacteria lost its metabolic capability, making it an obligate parasite that depends on its host for most of its nutritional and functional needs.  <ref>{{citation
| author - Cole ST, Eiglmeier K, Parkhill J, et al
| year = 2001
| title = Massive gene decay in the leprosy bacillus
| journal = Nature | volume = 409 | issue = 6823 |pages = 1007-11 |doi=10.1038/35059006 | PMID 11234002}}</ref>


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.
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.
Line 40: Line 34:


==Pathology==
==Pathology==
M.leprae is responsible for the disease leprosy, 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.  
Transmission of the disease is not fully understood, 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.
 
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==
==Current Research==
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.
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 research is being done on the mechanism of transmission of leprosy. This research was done in India.
"Study of rifampin and dapsone resistance in three patients with recurring leprosy".Rev Panam Salud Publica. 2008 Feb;23(2):73-7.</ref>
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.<ref>{{citation
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.  
| 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
  | title = Use of Short Tandem Repeat Sequences to Study Mycobacterium leprae in Leprosy Patients in Malawi and India
Line 54: Line 52:


==References==
==References==
1.[ "The discovery of the leprosy bacillus". Tidsskr Nor Laegeforen 122 (7): 708-9. PMID 11998735]
{{reflist|2}}[[Category:Suggestion Bot Tag]]
 
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://microbewiki.kenyon.edu/index.php/Mycobacterium_leprae
 
==References==
{{reflist}}

Latest revision as of 07:01, 22 September 2024

This article is a stub and thus not approved.
Main Article
Discussion
Related Articles  [?]
Bibliography  [?]
External Links  [?]
Citable Version  [?]
 
This editable Main Article is under development and subject to a disclaimer.
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