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Mycobacterium Tuberculosis
''Mycobacterium tuberculosis'' (M. tb) is a species of pathogenic bacteria in the family Mycobacteriaceae and the causative agent of tuberculosis. First discovered in 1882 by Robert Koch, ''M. tuberculosis'' has an unusual, waxy coating on its cell surface primarily due to the presence of mycolic acid. This coating makes the cells impervious to Gram staining, and as a result, ''M. tuberculosis'' can appear weakly Gram-positive. Acid-fast stains such as Ziehl–Neelsen, or fluorescent stains such as auramine are used instead to identify ''M. tuberculosis'' with a microscope. The physiology of ''M. tuberculosis'' is highly aerobic and requires high levels of oxygen. Primarily a pathogen of the mammalian respiratory system, it infects the lungs. The most frequently used diagnostic methods for tuberculosis are the tuberculin skin test, acid-fast stain, culture, and polymerase chain reaction. The ''M. tuberculosis'' genome was sequenced in 1998. Microbiology In 2019, M. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Robert Koch
Heinrich Hermann Robert Koch ( , ; 11 December 1843 – 27 May 1910) was a German physician and microbiologist. As the discoverer of the specific causative agents of deadly infectious diseases including tuberculosis, cholera (though the bacterium itself was discovered by Filippo Pacini in 1854), and anthrax, he is regarded as one of the main founders of modern bacteriology. As such he is popularly nicknamed the father of microbiology (with Louis Pasteur), and as the father of medical bacteriology. His discovery of the anthrax bacterium (''Bacillus anthracis'') in 1876 is considered as the birth of modern bacteriology. His discoveries directly provided proofs for the germ theory of diseases, and the scientific basis of public health. While working as a private physician, Koch developed many innovative techniques in microbiology. He was the first to use the oil immersion lens, condenser, and microphotography in microscopy. His invention of the bacterial culture method using ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polymerase Chain Reaction
The polymerase chain reaction (PCR) is a method widely used to rapidly make millions to billions of copies (complete or partial) of a specific DNA sample, allowing scientists to take a very small sample of DNA and amplify it (or a part of it) to a large enough amount to study in detail. PCR was invented in 1983 by the American biochemist Kary Mullis at Cetus Corporation; Mullis and biochemist Michael Smith, who had developed other essential ways of manipulating DNA, were jointly awarded the Nobel Prize in Chemistry in 1993. PCR is fundamental to many of the procedures used in genetic testing and research, including analysis of ancient samples of DNA and identification of infectious agents. Using PCR, copies of very small amounts of DNA sequences are exponentially amplified in a series of cycles of temperature changes. PCR is now a common and often indispensable technique used in medical laboratory research for a broad variety of applications including biomedical resear ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Motility
Motility is the ability of an organism to move independently, using metabolic energy. Definitions Motility, the ability of an organism to move independently, using metabolic energy, can be contrasted with sessility, the state of organisms that do not possess a means of self-locomotion and are normally immobile. Motility differs from mobility, the ability of an object to be moved. The term vagility encompasses both motility and mobility; sessile organisms including plants and fungi often have vagile parts such as fruits, seeds, or spores which may be dispersed by other agents such as wind, water, or other organisms. Motility is genetically determined, but may be affected by environmental factors such as toxins. The nervous system and musculoskeletal system provide the majority of mammalian motility. In addition to animal locomotion, most animals are motile, though some are vagile, described as having passive locomotion. Many bacteria and other microorganisms, and multic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Obligate Aerobe
An obligate aerobe is an organism that requires oxygen to grow. Through cellular respiration, these organisms use oxygen to metabolise substances, like sugars or fats, to obtain energy. In this type of respiration, oxygen serves as the terminal electron acceptor for the electron transport chain. Aerobic respiration has the advantage of yielding more energy ( adenosine triphosphate or ATP) than fermentation or anaerobic respiration, but obligate aerobes are subject to high levels of oxidative stress."Obligate aerobe - definition from Biology-Online.org." ''Biology Online.'' Biology-Online, n.d. Web. 12 Dec 2009. Examples Among organisms, almost all animals, most fungi, and several bacteria are obligate aerobes. Examples of obligately aerobic bacteria include ''Mycobacterium tuberculosis'' (acid-fast), '' Pseudomonas aeruginosa'' ( Gram-negative), ''Bacillus'' ( Gram-positive), and '' Nocardia asteroides'' ( Gram-positive). With the exception of the yeasts, most fungi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mycobacterium Orygis
''Mycobacterium orygis'' is a species of the tuberculosis complex of the genus ''Mycobacterium''. It causes tuberculosis in oryx, rhinos, dairy cattle, rhesus monkeys, and humans. Morphology ''Mycobacterium orygis'' is similar in morphology to species in the tuberculosis complex of ''Mycobacterium''. It is a non-motile, acid fast bacterium. The cell walls are composed primarily of Mycolic acids. The cells are irregular rods, 0.3–0.5 um in diameter and 2–3 um in length. Metabolism ''Mycobacterium orygis'' is an obligate aerobe, and a facultative intracellular pathogen. It has a doubling time of 15–20 hours within cells, and longer when outside cells. ''Mycobacterium orygis'' uses the host's cells internal fatty acids for both a carbon source and an energy source. These molecules include cholesterol, triacylglycerides, and glycosphingolipids. The optimum growing range for this species is 32 degrees Celsius. Genome Strain 51145, obtained from a human diagno ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mycobacterium Mungi
''Mycobacterium'' is a genus of over 190 species in the phylum Actinomycetota, assigned its own family, Mycobacteriaceae. This genus includes pathogens known to cause serious diseases in mammals, including tuberculosis ('' M. tuberculosis'') and leprosy (''M. leprae'') in humans. The Greek prefix ''myco-'' means 'fungus', alluding to this genus' mold-like colony surfaces. Since this genus has cell walls with Gram-positive and Gram-negative features, acid-fast staining is used to emphasize their resistance to acids, compared to other cell types. Metabolism and Morphology Mycobacteria are aerobic with 0.2-0.6 µm wide and 1.0-10 µm long rod shapes. They are generally non-motile, except for the species ''Mycobacterium marinum'', which has been shown to be motile within macrophages. Mycobacteria possess capsules and most do not form endospores. ''M. marinum'' and perhaps ''M. bovis'' have been shown to sporulate; however, this has been contested by further research. The disting ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mycobacterium Pinnipedii
''Mycobacterium pinnipedii'' is a member of the Mycobacterium tuberculosis complex which primarily infects seals. It is a slowly growing Mycobacterium. The species is named after the Pinniped Pinnipeds (pronounced ), commonly known as seals, are a widely distributed and diverse clade of carnivorous, fin-footed, semiaquatic, mostly marine mammals. They comprise the extant families Odobenidae (whose only living member is the ...s, the organisms from which ''M. pinnipedii'' was first isolated. In 2014, a genetic study showed that Peruvian human skeleton dating to 1000 CE had been infected with a form of tuberculosis most closely related to ''M. pinnipedii'', suggesting that seals had served as a vector for transmission of tuberculosis from the Old World to the New. References External links * Acid-fast bacilli pinnipedii Bacteria described in 2003 {{Mycobacterium-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mycobacterium Microti
''Mycobacterium microti'' *Member of the Mycobacterium tuberculosis complex (MTBC) *Also known as the 'Vole bacillus' *Etymology: microtus is a genus that includes small field rodents such as the vole. This mycobacterium species was first described as a pathogen of field voles in England Description Gram-positive, nonmotile, acid-fast rods. Colony characteristics *Variable colony morphology, buff in colour, either rough or smooth. Physiology *Slow growth on glycerol-free egg media at 37 °C often requiring incubation for 28–60 days. May adapt tolerance to glycerol. May fail to grow in liquid media. *Usually susceptible to the first line anti tuberculosis antibiotics isoniazid, ethambutol, rifampin, streptomycin and pyrazinamide. Differential characteristics Commercially available nucleic acid hybridisation assays are widely used to identify members of the M. tuberculosis complex.. Differentiation between individual members of the M tuberculosis complex is possible us ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mycobacterium Caprae
''Mycobacterium caprae'' is a species of bacteria in the genus ''Mycobacterium'' and a member of the Mycobacterium tuberculosis complex. The species is named after the caprines, the organisms from which M. caprae was first isolated. Prior to 2003, the species was referred to as ''Mycobacterium tuberculosis'' subsp. caprae. It is also synonymous with the name ''Mycobacterium bovis'' subsp. caprae. ''M. caprae'' is a causative agent of tuberculosis in humans. The species has also been isolated from tuberculous lesions in cattle, pigs, deer, and wild boars, as well as from camels and bison. References External links * Acid-fast bacilli Mycobacteria, caprae Tuberculosis Bacteria described in 2003 {{Mycobacterium-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mycobacterium Bovis
''Mycobacterium bovis'' is a slow-growing (16- to 20-hour generation time) aerobic bacterium and the causative agent of tuberculosis in cattle (known as bovine TB). It is related to ''Mycobacterium tuberculosis'', the bacterium which causes tuberculosis in humans. ''M. bovis'' can jump the species barrier and cause tuberculosis-like infection in humans and other mammals. Bacterium morphology and staining The bacteria are curved or straight rods. They sometimes form filaments, which fragment into bacilli or cocci once disturbed. In tissues they form slender rods, straight or curved, or club-shaped. Short, relatively plump bacilli (rods) in tissue smears, large slender beaded rods in culture. They have no flagella or fimbria, and no capsule. ''Mycobacterium tuberculosis'' group bacteria are 1.0-4.0 µm long by 0.2-0.3 µm wide in tissues. In culture, they may appear as cocci, or as bacilli up to 6-8 µm long. The bacteria stain Gram-positive, acid-fast. Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mycobacterium Canetti
''Mycobacterium canettii'', a novel pathogenic taxon of the ''Mycobacterium tuberculosis'' complex (MTBC), was first reported in 1969 by the French microbiologist Georges Canetti, for whom the organism has been named. It formed smooth and shiny colonies, which is highly exceptional for the MTBC. It was described in detail in 1997 on the isolation of a new strain from a 2-year-old Somali patient with lymphadenitis. It did not differ from ''Mycobacterium tuberculosis'' in the biochemical tests and in its 16S rRNA sequence. It had shorter generation time than clinical isolates of ''M. tuberculosis'' and presented a unique, characteristic phenolic glycolipid and lipo-oligosaccharide. In 1998, Pfyffer described abdominal lymphatic TB in a 56-year-old Swiss man with HIV infection who lived in Kenya. Tuberculosis caused by ''M. canettii'' appears to be an emerging disease in the Horn of Africa The Horn of Africa (HoA), also known as the Somali Peninsula, is a large peninsula and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mycobacterium Africanum
''Mycobacterium africanum'' is a species of ''Mycobacterium'' that is most commonly found in West African countries, where it is estimated to cause up to 40% of pulmonary tuberculosis. The symptoms of infection resemble those of ''M. tuberculosis''. It is a member of the Mycobacterium tuberculosis complex. Taxonomy There are seven major lineages in the Mycobacterium tuberculosis complex (MTBC), with lineages 5 and 6 classified as ''Mycobacterium africanum''. MTBC lineage 5 is ''M. africanum'' type 1, West African 1 (MAF1), and is classified based on a characteristic deletion of Region of Differentiation (RD) 711. MAF1 is commonly found around the Gulf of Guinea. MTBC lineage 6 is also known as ''M. africanum'' type 1, West African 2 (MAF2), and is classified based on a deletion of RD702. MAF2 is prevalent in Western Africa. ''M. africanum'' type 2, East African, was previously recognized as a strain of ''Mycobacterium africanum''; it was recently reclassified as ''Mycobacterium ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
