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Bile Esculin Agar
Bile Esculin Agar (BEA) is a selective differential agar used to isolate and identify members of the genus ''Enterococcus'', formerly part of the "group D streptococci" (enterococci were reclassified in their own genus in 1984). Composition and process Bile salts are the selective ingredient, while esculin is the differential component. ''Enterococcus'' hydrolyze esculin to products that react with ferric citrate in the medium to produce insoluble iron salts, resulting in the blackening of the medium. Test results must be interpreted in conjunction with gram stain morphology. Uses Bile Esculin Agar is used primarily to differentiate ''Enterococcus'' from ''Streptococcus''. Members of the genus ''Enterococcus'' are capable of growing in the presence of 40% bile (oxgall) and hydrolyzing esculin to glucose and esculetin. Esculetin combines with ferric ions to produce a black complex. For some purposes, certain bacteria are able to hydrolyze aesculin Aesculin, also called æscu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Esculin
Aesculin, also called æsculin or esculin, is a coumarin glucoside that naturally occurs in the trees Horse-chestnut (tree), horse chestnut (''Aesculus hippocastanum''), California buckeye (''Aesculus californica''), prickly box (''Bursaria spinosa''), and daphnin (the dark green resin of ''Daphne mezereum''). It is also found in dandelion coffee. Medical uses As medication, aesculin is sometimes used as a vasoprotective agent. Aesculin is also used in a microbiology laboratory to aid in the identification of bacterial species (especially Enterococcus, ''Enterococci'' and ListeriaQadri, S. M., Smith, J. C., Zubairi, S., & DeSilva, M. I. (1981). Esculin hydrolysis by Gram positive bacteria. A rapid test and it's comparison with other methods. Medical microbiology and immunology, 169(2), 67–74. https://doi.org/10.1007/BF02171773 . PMID 6783825). In fact, all strains of Group D Streptococci hydrolyze æsculin in 40% bile. Aesculin hydrolysis test Aesculin is incorporated into ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Agar
Agar ( or ), or agar-agar, is a jelly-like substance consisting of polysaccharides obtained from the cell walls of some species of red algae, primarily from ogonori (''Gracilaria'') and "tengusa" (''Gelidiaceae''). As found in nature, agar is a mixture of two components, the linear polysaccharide agarose and a heterogeneous mixture of smaller molecules called agaropectin. It forms the supporting structure in the cell walls of certain species of algae and is released on boiling. These algae are known as agarophytes, belonging to the Rhodophyta (red algae) phylum. The processing of food-grade agar removes the agaropectin, and the commercial product is essentially pure agarose. Agar has been used as an ingredient in desserts throughout Asia and also as a solid substrate to contain culture media for microbiological work. Agar can be used as a laxative; an appetite suppressant; a vegan substitute for gelatin; a thickener for soups; in fruit preserves, ice cream, and other ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Enterococcus
''Enterococcus'' is a large genus of lactic acid bacteria of the phylum Bacillota. Enterococci are gram-positive cocci that often occur in pairs (diplococci) or short chains, and are difficult to distinguish from streptococci on physical characteristics alone. Two species are common commensal organisms in the intestines of humans: '' E. faecalis'' (90–95%) and '' E. faecium'' (5–10%). Rare clusters of infections occur with other species, including ''E. casseliflavus'', '' E. gallinarum'', and ''E. raffinosus''. Physiology and classification Enterococci are facultative anaerobic organisms, i.e., they are capable of cellular respiration in both oxygen-rich and oxygen-poor environments. Though they are not capable of forming spores, enterococci are tolerant of a wide range of environmental conditions: extreme temperature (10–45 °C), pH (4.6–9.9), and high sodium chloride concentrations. Enterococci typically exhibit gamma-hemolysis on sheep's blood agar. His ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Genus
Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nomenclature, the genus name forms the first part of the binomial species name for each species within the genus. :E.g. '' Panthera leo'' (lion) and '' Panthera onca'' (jaguar) are two species within the genus '' Panthera''. ''Panthera'' is a genus within the family Felidae. The composition of a genus is determined by taxonomists. The standards for genus classification are not strictly codified, so different authorities often produce different classifications for genera. There are some general practices used, however, including the idea that a newly defined genus should fulfill these three criteria to be descriptively useful: # monophyly – all descendants of an ancestral taxon are grouped together (i.e. phylogenetic analysis should cl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bile Esculin Agar
Bile Esculin Agar (BEA) is a selective differential agar used to isolate and identify members of the genus ''Enterococcus'', formerly part of the "group D streptococci" (enterococci were reclassified in their own genus in 1984). Composition and process Bile salts are the selective ingredient, while esculin is the differential component. ''Enterococcus'' hydrolyze esculin to products that react with ferric citrate in the medium to produce insoluble iron salts, resulting in the blackening of the medium. Test results must be interpreted in conjunction with gram stain morphology. Uses Bile Esculin Agar is used primarily to differentiate ''Enterococcus'' from ''Streptococcus''. Members of the genus ''Enterococcus'' are capable of growing in the presence of 40% bile (oxgall) and hydrolyzing esculin to glucose and esculetin. Esculetin combines with ferric ions to produce a black complex. For some purposes, certain bacteria are able to hydrolyze aesculin Aesculin, also called æscu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Esculin
Aesculin, also called æsculin or esculin, is a coumarin glucoside that naturally occurs in the trees Horse-chestnut (tree), horse chestnut (''Aesculus hippocastanum''), California buckeye (''Aesculus californica''), prickly box (''Bursaria spinosa''), and daphnin (the dark green resin of ''Daphne mezereum''). It is also found in dandelion coffee. Medical uses As medication, aesculin is sometimes used as a vasoprotective agent. Aesculin is also used in a microbiology laboratory to aid in the identification of bacterial species (especially Enterococcus, ''Enterococci'' and ListeriaQadri, S. M., Smith, J. C., Zubairi, S., & DeSilva, M. I. (1981). Esculin hydrolysis by Gram positive bacteria. A rapid test and it's comparison with other methods. Medical microbiology and immunology, 169(2), 67–74. https://doi.org/10.1007/BF02171773 . PMID 6783825). In fact, all strains of Group D Streptococci hydrolyze æsculin in 40% bile. Aesculin hydrolysis test Aesculin is incorporated into ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gram Stain
In microbiology and bacteriology, 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. 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 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 strengthen the bonds of the stain with the cell membrane. Gram staining is almost always the first step in the preliminary identification of a bacterial organism. While Gram ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Streptococcus
''Streptococcus'' is a genus of gram-positive ' (plural ) or spherical bacteria that belongs to the family Streptococcaceae, within the order Lactobacillales (lactic acid bacteria), in the phylum Bacillota. Cell division in streptococci occurs along a single axis, so as they grow, they tend to form pairs or chains that may appear bent or twisted. This differs from staphylococci, which divide along multiple axes, thereby generating irregular, grape-like clusters of cells. Most streptococci are oxidase-negative and catalase-negative, and many are facultative anaerobes (capable of growth both aerobically and anaerobically). The term was coined in 1877 by Viennese surgeon Albert Theodor Billroth (1829–1894), by combining the prefix "strepto-" (from ), together with the suffix "-coccus" (from Modern , from .) In 1984, many bacteria formerly grouped in the genus ''Streptococcus'' were separated out into the genera ''Enterococcus'' and '' Lactococcus''. Currently, over 50 speci ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glucose
Glucose is a simple sugar with the molecular formula . Glucose is overall the most abundant monosaccharide, a subcategory of carbohydrates. Glucose is mainly made by plants and most algae during photosynthesis from water and carbon dioxide, using energy from sunlight, where it is used to make cellulose in cell walls, the most abundant carbohydrate in the world. In energy metabolism, glucose is the most important source of energy in all organisms. Glucose for metabolism is stored as a polymer, in plants mainly as starch and amylopectin, and in animals as glycogen. Glucose circulates in the blood of animals as blood sugar. The naturally occurring form of glucose is -glucose, while -glucose is produced synthetically in comparatively small amounts and is less biologically active. Glucose is a monosaccharide containing six carbon atoms and an aldehyde group, and is therefore an aldohexose. The glucose molecule can exist in an open-chain (acyclic) as well as ring (cyclic) fo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Esculetin
Aesculetin (also known as esculetin, 6,7-dihydroxycoumarin and cichorigenin) is a derivative of coumarin. It is a natural lactone that derives from the intramolecular cyclization of a cinnamic acid derivative. It is present in chicory and in many toxic and medicinal plants, in form of glycosides and caffeic acid conjugates. This compound is used in some sunscreens, but there is evidence that it acts as a photosensitizer for DNA damage. The sodium salt of its methyl-derivative is used in dermatology for the treatment of varicose veins. It is a blue fluorescence compound found in plants. Aesculin, the glucoside of aesculetin, will fluoresce under long wave ultraviolet light (360 nm). The hydrolysis of aesculin results in loss of this fluorescence. Aesculetin has the ability to quench the inner fluorescence of bovine serum albumin. Aesculetin can be transformed into scopoletin (7-hydroxy-6-methoxycoumarin) and isoscopoletin (6-hydroxy-7-methoxycoumarin) through incubation w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aesculin
Aesculin, also called æsculin or esculin, is a coumarin glucoside that naturally occurs in the trees horse chestnut (''Aesculus hippocastanum''), California buckeye (''Aesculus californica''), prickly box (''Bursaria spinosa''), and daphnin (the dark green resin of '' Daphne mezereum''). It is also found in dandelion coffee. Medical uses As medication, aesculin is sometimes used as a vasoprotective agent. Aesculin is also used in a microbiology laboratory to aid in the identification of bacterial species (especially ''Enterococci'' and ListeriaQadri, S. M., Smith, J. C., Zubairi, S., & DeSilva, M. I. (1981). Esculin hydrolysis by Gram positive bacteria. A rapid test and it's comparison with other methods. Medical microbiology and immunology, 169(2), 67–74. https://doi.org/10.1007/BF02171773 . PMID 6783825). In fact, all strains of Group D Streptococci hydrolyze æsculin in 40% bile. Aesculin hydrolysis test Aesculin is incorporated into agar with ferric citrate and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
