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KM0034 Blood Agar Base No. 2 is a general-purpose medium with is designed to be enriched with various concentrations of horse or sheep blood and is suitable for the isolation of most organisms including many fastidious anaerobes of clinical significance. Blood Agar Base No. 2, frequently shortened to BAB No.2, was developed to meet the demand for an especially nutritious blood agar base which would permit the maximum recovery of delicate organisms, such as streptococci, pneumococci, and other fastidious microorganisms, without interfering with their haemolytic reactions. Haemolysis observations may vary with the type of blood being used and previous studies have shown that sheep blood provides the most reliable colony and haemolysis characteristics. When the blood is chocolated the medium gives good recovery of Haemophilus species. KM0034, when prepared with required blood type, is recommended as a non-selective blood agar by UK Standards for Microbiology Investigations and is tested in accordance with the principals of ISO 11133:2014 . Related Supplements : Defibrinated Sheep Blood, Defibrinated Horse Blood, LS0008 Staph/Strep Selective Supplement, LS0017 Neomycin Selective Supplement -
Brain heart infusion agar is very nutritious general-purpose medium and is suitable for the isolation of most micro-organisms including many fastidious organisms. The formulation is a modification of that from Rosenow and Hayden. The medium is not recommended for the determination of haemolytic reactions because of the glucose content. The nitrogen, vitamin and carbon sources are supplied by the Brain-Heart infusion solids and peptone. Glucose serves as the carbohydrate source and sodium chloride aids in maintaining the osmotic balance. A phosphate buffer, disodium hydrogen phosphate, is incorporated to help neutralize any acids produced as a result of glucose utilization and thus maintain viability of the organisms. NB: Organisms that produce large amounts of acid in the medium may overwhelm the buffering system and as a result may ‘auto-sterilize’ the culture.
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Brain heart infusion broth is very nutritious isotonic medium with a low concentration of glucose to stimulate early growth. The formulation is a modification of that from Rosenow and Hayden. Brain heart infusion broth is suitable for the isolation of most micro-organisms including many fastidious organisms and, with the appropriate enrichment, is suitable as a base for blood culture medium. The nitrogen, vitamin and carbon sources are supplied by the Brain-Heart infusion solids and peptone. Glucose serves as the carbohydrate source and sodium chloride aids in maintaining the osmotic balance. A phosphate buffer, disodium hydrogen phosphate, is incorporated to help neutralize any acids produced as a result of glucose utilization and thus maintain viability of the organisms. NB: Organisms that produce large amounts of acid in the medium may overwhelm the buffering system and as a result may auto-sterilize the culture.
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KM0057 Campylobacter (CCDA) Agar is a selective medium for the isolation of Campylobacter spp., particularly C. jejuni and C. coli, from clinical specimens and foodstuffs. Campylobacter (CCDA) Agar was described by Bolton et al. and formulated to replace blood with a combination of charcoal, ferrous sulphate, and sodium pyruvate. This product is recommended for the isolation of Campylobacter spp. and complies with the requirements of ISO 10272-1:2017, ISO 10272-2:2017, is tested in accordance with ISO 11133:2014, and is a recommended medium in the UK Standards for Microbiology Investigations for isolation of Campylobacter spp. from clinical specimens such as faeces. Bolton et al. recommended incubating inoculated plates at 37°C to improve isolation rates, but incubation at 41.5°C is recommended for the isolation of the commonly encountered thermophilic species (C. jejuni and C. coli). Selectivity is achieved through the addition of E&O LS0010 Campylobacter CCDA Selective Supplement, which includes a broad-spectrum antibiotic, cefoperazone, and amphotericin B to inhibit yeast and fungi.
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Charcoal agar is used for the cultivation of fastidious organisms, particularly Bordetella pertussis. Charcoal agar is prepared according to the formulation developed by Mishulow, Sharpe and Cohen. This medium is an efficient substitute for Bordet-Gengou agar in the production of B. pertussis vaccines and can be used as a maintenance medium for stock cultures of Bordetella spp. Beef extract and peptone provide the required nitrogen, carbon and vitamins. Sodium chloride maintains the osmotic balance. Starch and charcoal help in absorbing toxic metabolites that are produced during growth of the organism. Nicotinic acid is an essential growth factor for the growth of Bordetella spp. The addition of cephalexin (LS0018) inhibits accompanying contamination in the samples. NB: This is a basic medium only and contains no additional supplement. If cephalexin is added, it should be noted, that although coliforms are inhibited by this medium, Pseudomonas aeruginosa and some fungi will grow. Related Supplements : LS0018 Bordetella Selective Supplement
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Clostridium difficile agar, when supplemented, is used for the isolation of C. difficile from samples. This formulation is a modification of CCFA (Cycloserine-Cefoxitin-Fructose agar) developed by George et al. The proteose peptone act as carbon, nitrogen and vitamin source in this medium. Fructose is a fermentable carbohydrate. Sodium chloride maintains the osmotic balance of the medium. Disodium hydrogen phosphate and potassium dihydrogen phosphate are buffering agents. The magnesium sulfate acts as a source of inorganic ions and the agar is the solidifying agent. This media requires the addition of defibrinated horse blood and Clostridium difficile selective supplement (LS0022).
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This is a selective medium for the isolation of Salmonella spp. and Shigella spp. from clinical specimens and environmental samples. This formulation was developed by Hynes through a modification of Leifson’s DCA medium. The peptone provides the required carbon, nitrogen and vitamins. Lactose is a fermentable carbohydrate and neutral red is a pH indicator. Sodium thiosulphate and ferric citrate are used to detect hydrogen sulphide production indicated by the black centred colonies of hydrogen sulphite positive organisms. Sodium desoxycholate and sodium citrate inhibit most Gram-positive organisms.
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This is a selective medium for the isolation of Helicobacter pylori from clinical samples. The medium is based on a modification of Campylobacter CCDA Blood Free Medium with charcoal, ferrous sulphate and sodium pyruvate replacing the horse blood. The medium is made selective by the addition of vancomycin and cefsulodin, to suppress other bacteria, and amphoteracin to inhibit yeasts. Horse serum (10%) is also added to promote optimum growth of Helicobacter spp. Related Supplements : LS0031 Helicobacter pylori Selective Supplement, SHS500 Sterile Horse Serum 500ml
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Kligler iron agar is used to differentiate between some of the enterobacteriacae on the basis of three reactions: fermentation of lactose and glucose and the production of hydrogen sulphide. Kligler iron agar is a modification of the original formulation developed by Kligler. It incorporates the principles of Russell’s double sugar agar with Kligler ‘s lead acetate agar. The peptone provides the required nitrogen, carbon and vitamins. Lactose and glucose are carbohydrates. Acid production from their fermentation is detected by the phenol red pH indictor. Sodium thiosulphate is reduced to hydrogen sulphide which is detected by the ferric citrate indicator. Sodium chloride maintains the osmotic balance.
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KM0124 MacConkey Agar with Salt is a selective medium for the isolation and differentiation of bile tolerant Gram-negative (enteric) and Gram-positive (staphylococci and enterococci) organisms in all areas of bacteriology. MacConkey Agar with Salt is based on the formulation by MacConkey in 1900. Staphylococcus and Enterococcus spp. are able to grow due to the omission of crystal violet from this formulation. This medium is recommended by the World Health Organisation and the Department of Health for the bacteriological examination of water, and KM0124 is recommended as a differential primary isolation media by the UK Standards for Microbiology Investigations.
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MacConkey Agar without Salt and Crystal Violet, based on the formulation by Rappaport and Henig, is a differential medium for the isolation and differentiation of lactose and non-lactose fermenting enteric bacteria while also restricting the swarming of Proteus species. KM0011 is recommended as a differential primary isolation media by the UK Standards for Microbiology Investigations, The Microbiology of Drinking Water and tested in accordance with ISO 11133:2014. Related Supplements : LS0189 Cefotaxime Supplement (1mg/L)
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KM0031 Mannitol Salt Agar is a selective medium for the isolation of Staphylococcus aureus from clinical samples, food, cosmetics and water samples. Chapman showed that adding a higher level of sodium chloride to Mannitol Salt Agar allowed for the recovery of pathogenic staphylococci and inhibits most organisms. Coagulase positive staphylococci (e.g., S. aureus) produce yellow colonies and a surrounding yellow medium while coagulase negative staphylococci produce red colonies and no colour change of the phenol red indicator. The medium conforms to the requirements of the Harmonised EP/USP/JP, is recommended as a primary isolation media by the UK Standards for Microbiology Investigations and tested in accordance with ISO 11133:2014 and Clinical and Laboratory Standards Institute. This medium is also included in the Bacteriological Analytical Manual for cosmetics testing.
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Membrane Lauryl Sulphate Agar is used for the enumeration of Escherichia coli and other coliforms found in filter membranes used in water sample testing. The broth base, originally named Membrane Enriched Teepol broth,(1) was updated when Teepol 610 was removed from the formulation and replaced by sodium lauryl sulphate.(2&3) The peptones, yeast extract and lactose act as carbon, nitrogen and vitamin sources in this medium. The phenol red is added as a pH indicator to detect the fermentation of lactose to differentiate the coliforms. Sodium lauryl sulphate is an inhibitory agent. References (1) Burman, N. P., 1967. Development of membrane filter techniques. II. Adaptation to routine and special requirements. Proc. Soc. Wat. Treat. Exam., 16:40 (2) Joint Committee of PHLS and the Standing Committee of Analysis. 1980. J. Hyg. Camb., 85:181 (3) Stanfield, G. and Irving, T. E., 1981. A suitable replacement for Teepol 610 in the selective isolation of coliforms from marine waters and sewage. Water Research. 15:469-474
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Membrane Lauryl Sulphate Broth is used for the enumeration of Escherichia coli and other coliforms found in filter membranes used in water sample testing. Originally named Membrane Enriched Teepol broth,(1) this recipe was updated when Teepol 610 was removed from the formulation and replaced by sodium lauryl sulphate.(2&3) The peptones, yeast extract and lactose act as carbon, nitrogen and vitamin sources in this medium. The phenol red is added as a pH indicator to detect the fermentation of lactose to differentiate the coliforms. Sodium lauryl sulphate is an inhibitory agent. References (1) Burman, N. P., 1967. Development of membrane filter techniques. II. Adaptation to routine and special requirements. Proc. Soc. Wat. Treat. Exam., 16:40 (2) Joint Committee of PHLS and the Standing Committee of Analysis. 1980. J. Hyg. Camb., 85:181 (3) Stanfield, G. and Irving, T. E., 1981. A suitable replacement for Teepol 610 in the selective isolation of coliforms from marine waters and sewage. Water Research. 15:469-47
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A basic general-purpose medium suitable for use in the cultivation of the less fastidious organisms particularly those that do not require the addition of blood or other enrichment. When used to prepare agar slopes or agar butts, the medium can be used to maintain control organisms. The peptone provides the required carbon, nitrogen and vitamins. Sodium chloride maintains osmotic balance.
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A general-purpose medium for the cultivation of organisms that are less fastidious in their nutritional requirements. The beef extract, peptone and yeast extract act as carbon, nitrogen and vitamin sources in this medium. Sodium chloride maintains osmotic balance.
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Primary Membrane Lactose Glucuronide Agar (mLGA) is used for the differentiation and enumeration of Escherichia coli and other coliforms through a single membrane filtration technique. The peptone and yeast extract provide the required nitrogen, carbon and vitamins. Sodium pyruvate protects injured cells enhancing recovery and growth of coliforms. Sodium lauryl sulphate is a selective agent that inhibits Gram-positive organisms. Lactose is a fermentable carbohydrate and phenol red is a pH indicator. Lactose fermentation will result in yellow colonies. X-glucuronide is a chromogenic substrate which can be cleaved by the enzyme ß-glucuronidase present in E. coli. This results in a blue colony, but in combination with lactose fermentations colonies will appear green. NB: Prepared plates stored at 28°C may show formation of surface crystals which will disappear when plates are warmed to >20°C Related Supplements :
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Triple sugar iron agar is used to differentiate between some of the enterobacteriacae on the basis of four reactions: fermentation of lactose, glucose and sucrose and the production of hydrogen sulphide. Beef extract, yeast extract and peptone provide the required nitrogen, carbon and vitamins. Lactose, sucrose and glucose are carbohydrates. Acid production from their fermentation is detected by the phenol red pH indictor. Sodium thiosulphate is reduced to hydrogen sulphide which is detected by the ferric citrate indicator. Sodium chloride maintains osmotic balance.
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Violet Red Bile Agar is a medium for the enumeration of coliform organisms in food and dairy products and conforms to American Public Health Association (APHA). Yeast extract and enzymatic digest of gelatin provides the required carbon, nitrogen and vitamins. Sodium chloride maintains the osmotic balance. The medium is made selective by the inclusion of bile salts and crystal violet to inhibit Gram-positive and non-enteric organisms. Lactose is a fermentable carbohydrate and neutral red is a pH indicator. Lactose fermenters produce red/purple colonies often surrounded by a halo of the same colour. Non lactose fermenters produce pale colonies. Selectivity can be increased by incubation at 42-44ºC.
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Violet Red Bile Glucose Agar (VRBGA) is a selective medium for the isolation and enumeration of Enterobacteriaceae in food products. It is a modification of the original Violet Red Bile Agar with the lactose being replaced with glucose. As all Enterobacteriaceae ferment glucose VRBGA allows for a wider range of organisms to be detected. This medium conforms to the requirements of the Harmonised USP/EP/JP. Yeast extract and pancreatic digest of gelatin provide the required carbon, nitrogen and vitamins. Glucose is a fermentable carbohydrate and neutral red is a pH indicator. Sodium chloride maintains the osmotic balance. The medium is made selective by the inclusion of bile salts and crystal violet to inhibit Gram-positive and non-enteric organisms.
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KM0013 Xylose Lysine Deoxycholate (XLD) Agar is used for the isolation and detection of Salmonella and Shigella spp. in clinical specimens, food, and environmental samples. Xylose Lysine Deoxycholate (XLD) Agar is used for the isolation of Salmonella from food and animal feedstuffs when used according to ISO 6579:2017, ISO 11133:2014. The formulation conforms to CLSI M22 and European, United States and Japanese Pharmacopeia requirements. KM0013 is recommended for clinical specimens as a standard, supplementary or primary isolation medium by the UK Standards for Microbiology Investigations. Xylose Lysine Deoxycholate (XLD) Agar has a pH of 7.4, leaving it with a bright red appearance due to the indicator phenol red. Sugar fermentation lowers the pH and the phenol red indicator registers this by changing to yellow. Most gut bacteria, including Salmonella spp., can rapidly ferment the sugar xylose to produce acid; Shigella spp. cannot do this and therefore remain red. Once the xylose has been used, Salmonella spp. decarboxylate lysine leading to a reversion to an alkaline pH. Additionally, Salmonella spp. (but not Shigella species) are able to reduce thiosulphate to hydrogen sulphide which reacts with ferric ions to produce the black pigment iron sulphide. Salmonella spp. may, therefore, be differentiated since colonies have a black centre on this medium.
