|
M. Gastri
''Mycobacterium gastri'' is a species of the phylum Actinomycetota (Gram-positive bacteria with high guanine and cytosine content, one of the dominant phyla of all bacteria), belonging to the genus '' Mycobacterium''. Description Moderately long to long, Gram-positive, aerobic, nonmotile and acid-fast rods. Colony characteristics *Nonchromogenic, smooth to rough, white colonies on Löwenstein-Jensen medium and smooth or somewhat granular on Middlebrook 7H10 agar. Physiology *Growth on Löwenstein-Jensen medium or on Middlebrook 7H10 agar at 37 °C, (temperature range 25 °C-40 °C), within 7 or more days. *Does not grow in the presence of ethambutol or isoniazid. Differential characteristics *Closely related to '' M. kansasii'' * M. gastri and '' M. kansasii'' share an identical 16S rDNA sequence. Species differentiation is possible by differences in the ITS and hsp65 sequences. *'' M. kansasii'' produces a photochromogenic The Timpe and Runyon classific ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Actinomycetota
The ''Actinomycetota'' (or ''Actinobacteria'') are a phylum of all gram-positive bacteria. They can be terrestrial or aquatic. They are of great economic importance to humans because agriculture and forests depend on their contributions to soil systems. In soil they help to decompose the organic matter of dead organisms so the molecules can be taken up anew by plants. While this role is also played by fungi, ''Actinomycetota'' are much smaller and likely do not occupy the same ecological niche. In this role the colonies often grow extensive mycelia, like a fungus would, and the name of an important order of the phylum, ''Actinomycetales'' (the actinomycetes), reflects that they were long believed to be fungi. Some soil actinomycetota (such as '' Frankia'') live symbiotically with the plants whose roots pervade the soil, fixing nitrogen for the plants in exchange for access to some of the plant's saccharides. Other species, such as many members of the genus ''Mycobacterium ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gram-positive
In bacteriology, gram-positive bacteria are bacteria that give a positive result in the Gram stain test, which is traditionally used to quickly classify bacteria into two broad categories according to their type of cell wall. Gram-positive bacteria take up the crystal violet stain used in the test, and then appear to be purple-coloured when seen through an optical microscope. This is because the thick peptidoglycan layer in the bacterial cell wall retains the stain after it is washed away from the rest of the sample, in the decolorization stage of the test. Conversely, gram-negative bacteria cannot retain the violet stain after the decolorization step; alcohol used in this stage degrades the outer membrane of gram-negative cells, making the cell wall more porous and incapable of retaining the crystal violet stain. Their peptidoglycan layer is much thinner and sandwiched between an inner cell membrane and a bacterial outer membrane, causing them to take up the counterstain ( s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bacteria
Bacteria (; singular: bacterium) are ubiquitous, mostly free-living organisms often consisting of one Cell (biology), biological cell. They constitute a large domain (biology), domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria were among the first life forms to appear on Earth, and are present in most of its habitats. Bacteria inhabit soil, water, Hot spring, acidic hot springs, radioactive waste, and the deep biosphere of Earth's crust. Bacteria are vital in many stages of the nutrient cycle by recycling nutrients such as the nitrogen fixation, fixation of nitrogen from the Earth's atmosphere, atmosphere. The nutrient cycle includes the decomposition of cadaver, dead bodies; bacteria are responsible for the putrefaction stage in this process. In the biological communities surrounding hydrothermal vents and cold seeps, extremophile bacteria provide the nutrients needed to sustain life by converting dissolved compounds, such as hydrogen sulp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
G+C Ratio
G, or g, is the seventh letter in the Latin alphabet, used in the modern English alphabet, the alphabets of other western European languages and others worldwide. Its name in English is ''gee'' (pronounced ), plural ''gees''. History The letter 'G' was introduced in the Old Latin period as a variant of ' C' to distinguish voiced from voiceless . The recorded originator of 'G' is freedman Spurius Carvilius Ruga, who added letter G to the teaching of the Roman alphabet during the 3rd century BC: he was the first Roman to open a fee-paying school, around 230 BCE. At this time, ' K' had fallen out of favor, and 'C', which had formerly represented both and before open vowels, had come to express in all environments. Ruga's positioning of 'G' shows that alphabetic order related to the letters' values as Greek numerals was a concern even in the 3rd century BC. According to some records, the original seventh letter, 'Z', had been purged from the Latin alphabet somewhat ea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mycobacterium
''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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Middlebrook 7H10 Agar
Middlebrook 7H10 Agar is a solid growth medium specially used for culture of ''Mycobacterium'', notably ''Mycobacterium tuberculosis''. It has been reported that the 7H10 medium tends to grow fewer contaminants than the egg-based media commonly used for the cultivation of mycobacteria. Composition Ingredients (g/L) * Ammonium sulfate, 0.50 * Monopotassium phosphate, 1.50 * Disodium phosphate, 1.50 * Sodium citrate, 0.40 * Magnesium sulfate, 0.025 * Zinc sulfate, 0.001 * Copper sulfate, 0.001 * L-Glutamic acid, 0.50 * Ferric ammonium citrate, 0.04 * Pyridoxine hydrochloride, 0.001 * Biotin, 0.0005 * Malachite green, 0.00025 * Agar, 15.00 * Calcium chloride, 0.0005 Cultures should be read within 5–7 days after inoculation and once a week thereafter for up to 8 weeks. See also * Lowenstein-Jensen medium * Middlebrook 7H9 Broth Middlebrook 7H9 broth is a liquid growth medium specially used for culture of'' Mycobacterium'' species, notably ''Mycobacterium tuberculosis''. Comp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ethambutol
Ethambutol (EMB, E) is a medication primarily used to treat tuberculosis. It is usually given in combination with other tuberculosis medications, such as isoniazid, rifampicin and pyrazinamide. It may also be used to treat ''Mycobacterium avium'' complex, and ''Mycobacterium kansasii''. It is taken by mouth. Common side effects include problems with vision, joint pain, nausea, headaches, and feeling tired. Other side effects include liver problems and allergic reactions. It is not recommended in people with optic neuritis, significant kidney problems, or under the age of five. Use during pregnancy or breastfeeding has not been found to cause harm. In the United States the FDA has raised concerns about eye issues in the baby if used during pregnancy. Ethambutol is believed to work by interfering with the bacteria's metabolism. Ethambutol was discovered in 1961. It is on the World Health Organization's List of Essential Medicines and is available as a generic medication. C ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Isoniazid
Isoniazid, also known as isonicotinic acid hydrazide (INH), is an antibiotic used for the treatment of tuberculosis. For active tuberculosis it is often used together with rifampicin, pyrazinamide, and either streptomycin or ethambutol. For latent tuberculosis it is often used by itself. It may also be used for atypical types of mycobacteria, such as '' M. avium'', '' M. kansasii'', and ''M. xenopi''. It is usually taken by mouth but may be used by injection into muscle. Common side effects include increased blood levels of liver enzymes and numbness in the hands and feet. Serious side effects may include liver inflammation and acute liver failure. It is unclear if use during pregnancy is safe for the baby. Use during breastfeeding is likely safe. Pyridoxine may be given to reduce the risk of side effects. Isoniazid works in part by disrupting the formation of the bacteria's cell wall which results in cell death. Isoniazid was first made in 1952. It is on the World Heal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Photochromogenic
The Timpe and Runyon classification of nontuberculous mycobacteria based on the rate of growth, production of yellow pigment and whether this pigment was produced in the dark or only after exposure to light. It was introduced by Ernest Runyon in 1959. On these bases, the nontuberculous mycobacteria are divided into four groups: Slowly growing Mycobacteria The first three groups are classified as "Slowly growing Mycobacteria". Runyon I: Photochromogens Runyon I organisms (photochromogens) are slow growing, and produce a yellow-orange pigment when exposed to light. The group includes ''Mycobacterium kansasii'', '' Mycobacterium marinum'', ''Mycobacterium asiaticum'', and ''Mycobacterium simiae''. ''Mycobacterium szulgai'' is a photochromogen when grown at 24 degrees, and a scotochromogen at 37 degrees. In contrast, Runyon classifications III through IV are considered ''nonphotochromogens'', in that exposure to light does not make them produce pigment which they would not deve ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acid-fast Bacilli
Acid-fastness is a physical property of certain bacterial and eukaryotic cells, as well as some sub-cellular structures, specifically their resistance to decolorization by acids during laboratory staining procedures. Once stained as part of a sample, these organisms can resist the acid and/or ethanol-based decolorization procedures common in many staining protocols, hence the name ''acid-fast''. The mechanisms of acid-fastness vary by species, although the most well-known example is in the genus ''Mycobacterium'', which includes the species responsible for tuberculosis and leprosy. The acid-fastness of ''Mycobacteria'' is due to the high mycolic acid content of their cell walls, which is responsible for the staining pattern of poor absorption followed by high retention. Some bacteria may also be partially acid-fast, such as ''Nocardia''. Acid-fast organisms are difficult to characterize using standard microbiological techniques, though they can be stained using concentrated dyes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
