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Mycobacterium leprae

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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