Mycobacterium leprae
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Mycobacterium leprae in Ziehl-Neelsen staining |
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| ( Hansen 1880) Lehmann & Neumann 1896 |
Mycobacterium leprae , discovered in 1873 by the Norwegian Gerhard Armauer Hansen , is the causative agent of leprosy ("leprosy"), which still affects over 200,000 people every year in the tropics. The genome of this bacterial species was completely sequenced in 2001.
features
The rod-shaped bacterium, 1–5 μm long, 0.2–0.8 μm thick, grows in macrophages and Schwann cells and forms tumors that lead to tissue dissolution in the face and extremities and destroy the nerves . Due to the high lipid content in the cell wall, it is very resistant to environmental influences. The reduplication is very slow and takes between two and three weeks. In nutrient the bacterium is not be cultured. Mycobacterium leprae is the only species of the genus Mycobacterium that has so far not been able to be cultivated in nutrient media, in cell cultures or in the otherwise common guinea pigs .
carrier
In addition to humans and immunocompromised rats and mice, armadillos are one of the few groups of mammals that can carry the bacterium of the leprosy disease . This makes it difficult to do without when researching vaccines and new antibiotic combinations. A connection between the unusually low body temperature and the multiplication of mycobacteria in the armadillo is considered likely.
In Great Britain, Mycobacterium leprae has also been detected in squirrels ( Sciurus vulgaris ), where they sometimes lead to fatal diseases. According to the research of the working group, the bacteria detected are probably a strain that has stayed with the squirrels and developed after an epidemic among humans.
Evolution and systematics
The closest relative of Mycobacterium leprae is Mycobacterium lepromatosis , the causative agent of lepromatosis , a rare disease similar to leprosy that is mainly found in Central America today . The decoding of the genome of Mycobacterium lepromatosis and a comparison of the genome with the nucleotide sequence of Mycobacterium leprae was interpreted in 2015 to mean that both had a common ancestor approximately 13.9 million years ago. "Since both diseases cause similar symptoms, it can be assumed that the ancestors of the two pathogens who lived millions of years ago already caused a leprosy-like disease," explained one of the researchers involved, Johannes Krause from the Eberhard Karls University in Tübingen , director of the Max Planck Institute for the History of Human History in Jena , this finding. Leprosy is therefore probably one of the oldest human diseases.
Within the genus Mycobacterium , therefore, M. tuberculosis together with M. bovis (including the live vaccine M. bovis BCG ), M. lepromatosis and M. caprae (formerly M. bovis subsp. Capra ) are assigned to the "Mycobacterium tuberculosis complex".
Reporting requirement
In Germany, direct or indirect evidence of Mycobacterium leprae must be reported by name in accordance with Section 7 of the Infection Protection Act , if the evidence indicates an acute infection.
Web links
swell
literature
- Helmut Hahn, Stefan HE Kaufmann, Thomas F. Schulz, Sebastian Suerbaum (eds.): Medical microbiology and infectiology . 6th edition. Springer Verlag, Heidelberg 2009, ISBN 978-3-540-46359-7 , p. 367-369 .
Individual evidence
- ↑ Global leprosy update, 2018: moving towards a leprosy-free world . In: World Health Organization (Ed.): Weekly epidemiological record . tape 94 , no. 35/36 , August 30, 2019, pp. 389-412 ( who.int [PDF]).
- ^ Cole, ST et al .: Massive gene decay in the leprosy bacillus. In: Nature. Volume 409, 2001, pp. 1007-1011, doi: 10.1038 / 35059006 .
- ^ Hermann Feldmeier: Leprosy . In Hans Schadewaldt (ed.): About the return of epidemics. Robugen GmbH, Esslingen 1994, p. 43.
- ↑ a b H. Hof, RL Müller, R. Dörries: Microbiology. Georg Thieme Verlag, Stuttgart 2000, ISBN 3-13-125311-8 , p. 342 ff.
- ↑ a b Charlotte Avanzi, Jorge del-Pozo, Andrej Benjak, Karen Stevenson, Victor R. Simpson, Philippe Busso, Joyce McLuckie, Chloé Loiseau, Colin Lawton, Janne Schoening, Darren J. Shaw, Jérémie Piton, Lucio Vera-Cabrera, Jesùs S. Velarde-Felix, Fergal McDermott, Stephen V. Gordon, Stewart T. Cole, Anna L. Meredith: Red squirrels in the British Isles are infected with leprosy bacilli. Science 354 (6313), Nov. 11, 2016; Pp. 744-747. doi : 10.1126 / science.aah3783 .
- ↑ Pushpendra Singh et al. : Insight into the evolution and origin of leprosy bacilli from the genome sequence of Mycobacterium lepromatosis. In: PNAS . Volume 112, No. 14, 2015, pp. 4459-4464, doi: 10.1073 / pnas.1421504112 .
- ↑ Leprosy identified as one of the oldest diseases of mankind. On: idw.de from March 25, 2015.