Anatomy_Presentation - Mycobacterium leprae Mycobacterium...

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Mycobacterium leprae Mycobacterium leprae , one of the causative agents of leprosy. As acid-fast bacteria, M. leprae appear red when a Ziehl-Neelsen stain is used. Main article: Mycobacterium leprae Mycobacterium leprae and Mycobacterium lepromatosis are the causative agents of leprosy. M. lepromatosis is only the causative agent in diffuse lepromatous leprosy, which can be lethal. [2] [3] An intracellular, acid-fast bacterium , M. leprae is aerobic and rod-shaped, and is surrounded by the waxy cell membrane coating characteristic of Mycobacterium species. [31] Due to extensive loss of genes necessary for independent growth, M. leprae and M. lepromatosis are unculturable in the laboratory, a factor which leads to difficulty in definitively identifying the organism under a strict interpretation of Koch's postulates . [2] [32] The use of non-culture-based techniques such as molecular genetics has allowed for alternative establishment of causation. The most widely held belief is that the disease is transmitted by contact between infected persons and healthy persons. [37] In general, closeness of contact is related to the dose of infection, which in turn is related to the occurrence of disease. Of the various situations that promote close contact, contact within the household is the only one that is easily identified, although the actual incidence among contacts and the relative risk for them appear to vary considerably in different studies. In incidence studies , infection rates for contacts of lepromatous leprosy have varied from 6.2 per 1000 per year in Cebu , Philippines [38] to 55.8 per 1000 per year in a part of Southern India . [39] Two exit routes of M. leprae from the human body often described are the skin and the nasal mucosa, although their relative importance is not clear. It is true that lepromatous cases show large numbers of organisms deep down in the dermis . However, whether they reach the skin surface in sufficient numbers is doubtful. Although there are reports of acid-fast bacilli being found in the desquamating epithelium (sloughing of superficial layer of skin) of the skin, Weddell et al. had reported in 1963 that they could not find any acid-fast bacilli in the epidermis , even after examining a very large number of specimens from patients and contacts. [40] In a recent study, Job et al. found fairly large numbers of M. leprae in the superficial keratin layer of the skin of lepromatous leprosy patients, suggesting that the organism could exit along with the sebaceous secretions
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Treatment MDT patient packs and blisters Until the development of promin in the 1940s, there was no effective treatment for leprosy. The efficacy of promin was first discovered by Guy Henry Faget and his co-workers in 1943. Later dapsone was developed. However, it is only weakly bactericidal against M. leprae and it was considered necessary for patients to take the drug indefinitely. Moreover, when dapsone was used alone, the M. leprae population quickly
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Anatomy_Presentation - Mycobacterium leprae Mycobacterium...

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