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Acid-fast
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] |
Ziehl–Neelsen Stain
The Ziehl-Neelsen stain, also known as the acid-fast stain, is a bacteriological staining technique used in cytopathology and microbiology to identify acid-fast bacteria under microscopy, particularly members of the ''Mycobacterium'' genus. This staining method was initially introduced by Paul Ehrlich (1854–1915) and subsequently modified by the German bacteriologists Franz Ziehl (1859–1926) and Friedrich Neelsen (1854–1898) during the late 19th century. The acid-fast staining method, in conjunction with auramine phenol staining, serves as the standard diagnostic tool and is widely accessible for rapidly diagnosing tuberculosis (caused by ''Mycobacterium tuberculosis'') and other diseases caused by atypical mycobacteria, such as leprosy (caused by ''Mycobacterium leprae'') and ''Mycobacterium avium-intracellulare'' infection (caused by ''Mycobacterium avium'' complex) in samples like sputum, gastric washing fluid, and bronchoalveolar lavage fluid. These acid-fast bact ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kinyoun Stain
The Kinyoun method or Kinyoun stain (cold method), developed by Joseph J. Kinyoun, is a procedure used to stain acid-fast species of the bacterial genus ''Mycobacterium''. It is a variation of a method developed by Robert Koch in 1882. Certain species of bacteria have a waxy lipid called mycolic acid, in their cell walls which allow them to be stained with Acid-Fast better than a Gram-Stain. The unique ability of mycobacteria to resist decolorization by acid-alcohol is why they are termed acid-fast. It involves the application of a primary stain ( basic fuchsin), a decolorizer (acid-alcohol), and a counterstain (methylene blue). Unlike the Ziehl–Neelsen stain (Z-N stain), the Kinyoun method of staining does not require heating. In the Ziehl–Neelsen stain, heat acts as a physical mordant while phenol ( carbol of carbol fuchsin) acts as the chemical mordant. Modification The Kinyoun method can be modified as a weak acid fast stain, which uses 0.5–1.0% sulfuric acid ins ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carbol Fuchsin
Carbol fuchsin, carbol-fuchsin, carbolfuchsin, or Castellani's paint is a mixture of phenol and basic fuchsin that is used in bacterial staining procedures. It is commonly used in the staining of mycobacteria because it has an affinity for the mycolic acids found in their cell membranes. It is a component of Ziehl–Neelsen stain, a differential staining, differential stain. Carbol fuchsin is used as the primary stain dye to detect acid-fast, acid-fast bacteria because it is more soluble in the cells' wall lipids than in the acid alcohol. If the bacteria is acid-fast the bacteria will retain the initial red color of the dye because they are able to resist the destaining by acid alcohol (0.4–1% HCl in 70% EtOH). Additionally, it can be used for the staining of bacterial spores. Carbol-fuchsin is also used as a topical antiseptic and antifungal. References {{Stains Microscopy Microbiology techniques Laboratory techniques Histopathology Histotechnology Staining dyes Staini ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leprosy
Leprosy, also known as Hansen's disease (HD), is a Chronic condition, long-term infection by the bacteria ''Mycobacterium leprae'' or ''Mycobacterium lepromatosis''. Infection can lead to damage of the Peripheral nervous system, nerves, respiratory tract, skin, and eyes. This nerve damage may result in a lack of ability to feel pain, which can lead to the loss of parts of a person's Appendicular skeleton, extremities from repeated injuries or infection through unnoticed wounds. An infected person may also experience muscle weakness and poor eyesight. Leprosy symptoms may begin within one year, but for some people symptoms may take 20 years or more to occur. Leprosy is spread between people, although extensive contact is necessary. Leprosy has a low pathogenicity, and 95% of people who contract or who are exposed to ''M. leprae'' do not develop the disease. Spread is likely through a cough or contact with fluid from the nose of a person infected by leprosy. Genetic factors and i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nocardia
''Nocardia'' is a genus of weakly staining Gram-positive, catalase, catalase-positive, rod-shaped bacteria. It forms partially acid-fast beaded branching filaments (appearing similar to fungi, but being truly bacteria). It contains a total of 85 species. Some species are nonpathogenic, while others are responsible for nocardiosis. ''Nocardia'' species are found worldwide in soil rich in organic matter. In addition, they are oral microflora found in healthy human Gums, gingiva, as well as periodontal pockets. Most ''Nocardia'' infections are acquired by inhalation of the bacteria or through traumatic introduction through openings in Epithelium, epithelial barriers. Culture and staining ''Nocardia'' colonies have a variable appearance, but most species appear to have aerial hyphae when viewed with a dissecting microscope, particularly when they have been grown on nutritionally limiting media. ''Nocardia'' grow slowly on nonselective culture media, and are strict Aerobic metaboli ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mycobacterium Tuberculosis Ziehl-Neelsen Stain 640
''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 (''Mycobacterium tuberculosis, M. tuberculosis'') and leprosy (''Mycobacterium leprae, M. leprae'') in humans. The Greek language, Greek prefix ''myco-'' means 'fungus', alluding to this genus' Mold (fungus), mold-like colony surfaces. Since this genus has cell walls with a waxy lipid-rich outer layer containing high concentrations of mycolic acid, acid-fast staining is used to emphasize their resistance to acids, compared to other cell types. Mycobacterial species are generally aerobic, non-motile, and capable of growing with minimal nutrition. The genus is divided based on each species' pigment production and growth rate. While most ''Mycobacterium'' species are non-pathogenic, the genus' characteristic complex cell wall contributes to evasion from host defenses. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gram Stain
Gram stain (Gram staining or Gram's method), is a method of staining used to classify bacterial species into two large groups: gram-positive bacteria and gram-negative bacteria. It may also be used to diagnose a fungal infection. The name comes from the Danish bacteriologist Hans Christian Gram, who developed the technique in 1884. Gram staining differentiates bacteria by the chemical and physical properties of their Cell wall#Bacterial cell walls, cell walls. Gram-positive cells have a thick layer of peptidoglycan in the cell wall that retains the primary stain, crystal violet. Gram-negative cells have a thinner peptidoglycan layer that allows the crystal violet to wash out on addition of ethanol. They are stained pink or red by the counterstain, commonly safranin or fuchsine. Lugol's iodine solution is always added after addition of crystal violet to form a stable complex with crystal violet that strengthens the bonds of the stain with the cell wall. Gram staining is almost al ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mycobacteria
''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 a waxy lipid-rich outer layer containing high concentrations of mycolic acid, acid-fast staining is used to emphasize their resistance to acids, compared to other cell types. Mycobacterial species are generally aerobic, non-motile, and capable of growing with minimal nutrition. The genus is divided based on each species' pigment production and growth rate. While most ''Mycobacterium'' species are non-pathogenic, the genus' characteristic complex cell wall contributes to evasion from host defenses. Microbiology Morphology Mycobacteria are aerobic with 0.2-0.6 ... [...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 (''Mycobacterium tuberculosis, M. tuberculosis'') and leprosy (''Mycobacterium leprae, M. leprae'') in humans. The Greek language, Greek prefix ''myco-'' means 'fungus', alluding to this genus' Mold (fungus), mold-like colony surfaces. Since this genus has cell walls with a waxy lipid-rich outer layer containing high concentrations of mycolic acid, acid-fast staining is used to emphasize their resistance to acids, compared to other cell types. Mycobacterial species are generally aerobic, non-motile, and capable of growing with minimal nutrition. The genus is divided based on each species' pigment production and growth rate. While most ''Mycobacterium'' species are non-pathogenic, the genus' characteristic complex cell wall contributes to evasion from host defenses. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tuberculosis
Tuberculosis (TB), also known colloquially as the "white death", or historically as consumption, is a contagious disease usually caused by ''Mycobacterium tuberculosis'' (MTB) bacteria. Tuberculosis generally affects the lungs, but it can also affect other parts of the body. Most infections show no symptoms, in which case it is known as inactive or latent tuberculosis. A small proportion of latent infections progress to active disease that, if left untreated, can be fatal. Typical symptoms of active TB are chronic cough with hemoptysis, blood-containing sputum, mucus, fever, night sweats, and weight loss. Infection of other organs can cause a wide range of symptoms. Tuberculosis is Human-to-human transmission, spread from one person to the next Airborne disease, through the air when people who have active TB in their lungs cough, spit, speak, or sneeze. People with latent TB do not spread the disease. A latent infection is more likely to become active in those with weakened I ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mycolic Acid
Mycolic acids are long fatty acids found in the cell walls of Mycobacteriales taxon, a group of bacteria that includes ''Mycobacterium tuberculosis'', the causative agent of the disease tuberculosis. They form the major component of the cell wall of many Mycobacteriales species. Despite their name, mycolic acids have no biological link to fungi; the name arises from the filamentous appearance their presence gives Mycobacteriales under high magnification. The presence of mycolic acids in the cell wall also gives Mycobacteriales a distinct gross morphological trait known as " cording". Mycolic acids were first isolated by Stodola ''et al.'' in 1938 from an extract of ''M. tuberculosis''. Mycolic acids are composed of a longer beta-hydroxy chain with a shorter alpha-alkyl side chain. Each molecule contains between 60 and 90 carbon atoms. The exact number of carbons varies by species and can be used as an identification aid. Most mycolic acids also contain various functional gr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Auramine Phenol Stain
Auramine phenol stain is a stain used in clinical microbiology and histology to identify tuberculosis mycobacteria. There are two types of auramine phenol stains, 1 and 2 to stain mycobacterium species and cryptosporidium respectively. Both are fluorescent Fluorescence is one of two kinds of photoluminescence, the emission of light by a substance that has absorbed light or other electromagnetic radiation. When exposed to ultraviolet radiation, many substances will glow (fluoresce) with color ... stains. The bacteria or the parasites appear brilliant greenish yellow against dark background. Mycolic acids of the mycobacteria keep this stain when decolorising with the acid alcohol. The method is more rapid and sensitive than ZN technique. Method * Smears are prepared just like that for ZN staining * Stain with Auramine-Phenol for 20 mins * Rinse with water * Decolourise in acid alcohol * Rinse with water * Counterstain with 0.1% potassium permanganate for 30 seconds * Rinse ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
