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B. Pseudomallei
''Burkholderia pseudomallei'' (also known as ''Pseudomonas pseudomallei'') is a Gram-negative, bipolar, aerobic, motile rod-shaped bacterium. It is a soil-dwelling bacterium endemic in tropical and subtropical regions worldwide, particularly in Thailand and northern Australia. It was reported in 2008 that there had been an expansion of the affected regions due to significant natural disasters, and it could be found in Southern China, Hong Kong, and countries in the Americas. ''B. pseudomallei'', amongst other pathogens, has been found in monkeys imported into the United States from Asia for laboratory use, posing a risk that the pathogen could be introduced into the country. Although it is mainly a soil-dwelling bacterium, one study showed that ''Burkholderia pseudomallei'' survived in distilled water for 16 years, demonstrating that it is capable of living in water if a specific environment is provided. It is resistant to a variety of harsh conditions including nutrient deficie ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ashdown's Agar
Ashdown's medium is a selective culture medium for the isolation and characterisation of ''Burkholderia pseudomallei'' (the bacterium that causes melioidosis). Ashdown's medium was first described by LR Ashdown in 1979. It is used for the selective isolation of ''B. pseudomallei'' from clinical specimens taken from non-sterile sites (e.g., sputum) as well as to produce the characteristic morphology of ''B. pseudomallei''. The medium contains crystal violet and gentamicin as selective agents to suppress the growth of other bacteria. Colonies of ''B. pseudomallei'' also take up neutral red Neutral red (toluylene red, Basic Red 5, or C.I. 50040) is a eurhodin dye used for staining in histology. It stains lysosomes red. It is used as a general stain in histology, as a counterstain in combination with other dyes, and for many stain ... which is present in the medium, and this further helps to distinguish it from other bacteria. Gentamicin slightly inhibits the growth of ''B. p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glucose
Glucose is a sugar with the Chemical formula#Molecular formula, molecular formula , which is often abbreviated as Glc. It is overall the most abundant monosaccharide, a subcategory of carbohydrates. It is mainly made by plants and most algae during photosynthesis from water and carbon dioxide, using energy from sunlight. It is used by plants to make cellulose, the most abundant carbohydrate in the world, for use in cell walls, and by all living Organism, organisms to make adenosine triphosphate (ATP), which is used by the cell as energy. 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 amylose and amylopectin, and in animals as glycogen. Glucose circulates in the blood of animals as blood sugar. The naturally occurring form is -glucose, while its Stereoisomerism, stereoisomer L-glucose, -glucose is produced synthetically in comparatively small amounts and is less biologicall ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Colistin
Colistin, also known as polymyxin E, is an antibiotic medication used as a last-resort treatment for multidrug-resistant Gram-negative infections including pneumonia. These may involve bacteria such as ''Pseudomonas aeruginosa'', ''Klebsiella pneumoniae'', or ''Acinetobacter''. It comes in two forms: colistimethate sodium can be injected into a vein, injected into a muscle, or inhaled, and colistin sulfate is mainly applied to the skin or taken by mouth. Colistimethate sodium is a prodrug; it is produced by the reaction of colistin with formaldehyde and sodium bisulfite, which leads to the addition of a sulfomethyl group to the primary amines of colistin. Colistimethate sodium is less toxic than colistin when administered parenterally. In aqueous solutions, it undergoes hydrolysis to form a complex mixture of partially sulfomethylated derivatives, as well as colistin. Resistance to colistin began to appear as of 2015. Common side effects of the injectable form include kidne ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gram Staining
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 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 always the first step in the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Burkholderia Mallei
''Burkholderia mallei'' is a Gram-negative, bipolar, aerobic bacterium, a human and animal pathogen of genus '' Burkholderia'' causing glanders; the Latin name of this disease (''malleus'') gave its name to the species causing it. It is closely related to '' B. pseudomallei,'' and by multilocus sequence typing it is a subspecies of ''B. pseudomallei.'' ''B. mallei'' evolved from ''B. pseudomallei'' by selective reduction and deletions from the ''B. pseudomallei'' genome. Unlike ''B. pseudomallei'' and other genus members, ''B. mallei'' is nonmotile; its shape is coccobacillary measuring some 1.5–3.0 μm in length and 0.5–1.0 μm in diameter with rounded ends. Discovery and early history Wilhelm Schütz and Friedrich Löffler first isolated ''B. mallei'' in 1882. It was isolated from an infected liver and spleen of a horse. This bacterium is also one of the first to be identified containing a type VI secretion system which is important for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ashdown's Medium
Ashdown's medium is a selective culture medium for the isolation and characterisation of ''Burkholderia pseudomallei'' (the bacterium that causes melioidosis). Ashdown's medium was first described by LR Ashdown in 1979. It is used for the selective isolation of ''B. pseudomallei'' from clinical specimens taken from non-sterile sites (e.g., sputum) as well as to produce the characteristic morphology of ''B. pseudomallei''. The medium contains crystal violet and gentamicin as selective agents to suppress the growth of other bacteria. Colonies of ''B. pseudomallei'' also take up neutral red Neutral red (toluylene red, Basic Red 5, or C.I. 50040) is a eurhodin dye used for staining in histology. It stains lysosomes red. It is used as a general stain in histology, as a counterstain in combination with other dyes, and for many stain ... which is present in the medium, and this further helps to distinguish it from other bacteria. Gentamicin slightly inhibits the growth of ''B. p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eosin Methylene Blue
Eosin methylene blue (EMB, also known as "Levine's formulation") is a selective and differential media used for the identification of Gram-negative bacteria, specifically the Enterobacteriaceae. EMB inhibits the growth of most Gram-positive bacteria. EMB is often used to confirm the presence of coliforms in a sample. It contains two dyes, eosin and methylene blue in the ratio of 6:1. EMB is a differential microbiological media, which inhibits the growth of Gram-positive bacteria and differentiates bacteria that ferment lactose (e.g., '' E. coli'') from those that do not (e.g., ''Salmonella'', ''Shigella''). Organisms that ferment lactose appear dark/black or green often with "nucleated colonies"—colonies with dark centers. Organisms that do not ferment lactose will appear pink and often mucoid. This culture media is important in medical laboratories by allowing the identification of enteric bacteria microbes in a short period of time. *Rapid lactose fermentation produces aci ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MacConkey Agar
MacConkey agar is a selective and differential culture medium for bacteria. It is designed to selectively isolate gram-negative and enteric (normally found in the intestinal tract) bacteria and differentiate them based on lactose fermentation. Lactose fermenters turn red or pink on MacConkey agar, and nonfermenters do not change color. The media inhibits growth of gram-positive organisms with crystal violet and bile salts, allowing for the selection and isolation of gram-negative bacteria. The media detects lactose fermentation by enteric bacteria with the pH indicator neutral red. Contents It contains bile salts (to inhibit most gram-positive bacteria), crystal violet dye (which also inhibits certain gram-positive bacteria), and neutral red dye (which turns pink if the microbes are fermenting lactose). Composition: * Peptone – 17 g * Proteose peptone – 3 g * Lactose – 10 g * Bile salts – 1.5 g * Sodium chloride – 5 g * Neutral red – 0.03 g * Crystal violet – ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Blood Agar
An agar plate is a Petri dish that contains a growth medium solidified with agar, used to Microbiological culture, culture microorganisms. Sometimes selective compounds are added to influence growth, such as antibiotics. Individual microorganisms placed on the plate will grow into individual colony (biology), colonies, each a cloning, clone genetically identical to the individual ancestor organism (except for the low, unavoidable rate of mutation). Thus, the plate can be used either to estimate the concentration of organisms in a Microbiological culture, liquid culture or a suitable dilution of that culture using a colony counter, or to generate genetically pure cultures from a mixed culture of genetically different organisms. Several methods are available to plate out cells. One technique is known as "Streaking (microbiology), streaking". In this technique, a drop of the culture on the end of a thin, sterilization (microbiology), sterile loop of wire, sometimes known as an inocu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fastidious
A fastidious organism is any organism that has complex or particular nutritional requirements. In other words, a fastidious organism will only grow when specific nutrients are included in its medium. The more restrictive term fastidious microorganism is used in microbiology to describe microorganisms that will grow only if special nutrients are present in their culture medium. Thus fastidiousness is often practically defined as being difficult to culture, by any method yet tried. Examples An example of a fastidious bacterium is ''Neisseria gonorrhoeae'', which requires blood or hemoglobin and several amino acids and vitamins to grow.Todar, Kenneth''Neisseria gonorrhoeae'', the Gonococcus, and Gonorrhea. Lectures in Microbiology. 2009. Retrieved 2013-03-05. Other examples include ''Campylobacter'' spp. and ''Helicobacter'' spp., which are capnophilic – require elevated CO2 – among other requirements. Fastidious organisms are not inherently "weak"—they can flourish and t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Endotoxin
Lipopolysaccharide (LPS), now more commonly known as endotoxin, is a collective term for components of the outermost membrane of the cell envelope of gram-negative bacteria, such as '' E. coli'' and ''Salmonella'' with a common structural architecture. Lipopolysaccharides are large molecules consisting of three parts: an outer core polysaccharide termed the O-antigen, an inner core oligosaccharide and Lipid A (from which toxicity is largely derived), all covalently linked. In current terminology, the term endotoxin is often used synonymously with LPS, although there are a few endotoxins (in the original sense of toxins that are inside the bacterial cell that are released when the cell disintegrates) that are not related to LPS, such as the so-called delta endotoxin proteins produced by '' Bacillus thuringiensis''. Lipopolysaccharides can have substantial impacts on human health, primarily through interactions with the immune system. LPS is a potent activator of the immune sys ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Exotoxin
An exotoxin is a toxin secreted by bacteria. An exotoxin can cause damage to the host by destroying cells or disrupting normal cellular metabolism. They are highly potent and can cause major damage to the host. Exotoxins may be secreted, or, similar to endotoxins, may be released during lysis of the cell. Gram negative pathogens may secrete outer membrane vesicles containing lipopolysaccharide endotoxin and some virulence proteins in the bounding membrane along with some other toxins as intra-vesicular contents, thus adding a previously unforeseen dimension to the well-known eukaryote process of membrane vesicle trafficking, which is quite active at the host–pathogen interface. They may exert their effect locally or produce systemic effects. Well-known exotoxins include: botulinum toxin produced by ''Clostridium botulinum''; ''Corynebacterium diphtheriae'' toxin, produced during life-threatening symptoms of diphtheria; tetanospasmin produced by '' Clostridium tetani''. The t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
