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This is an established medium, with a neutral pH, used for the enumeration of Yeasts and Moulds -
This is a selective differential medium for the isolation of Listeria monocytogenes from food, clinical and environmental specimens. -
This medium is recommended for the detection and enumeration of yeasts and fungi in a variety of sample types. The low pH (5.6) and addition of streptomycin will ensure that the growth of most bacterial species is inhibited and the low mineral content ensures good pigment production by fungi where appropriate. -
Chromogenic Coliform Agar (CCA) Chromogenic Coliform Agar (CCA) conforms to the ISO 9308-1 guidelines for the detection, enumeration and isolation of coliforms and more specifically Escherichia coli in water samples by the membrane-filtration technique. The colonial differentiation is provided by the chromogenic substrates, Salmon-GAL and X-glucuronide. Salmon-GAL is used for the detection of β-D-galactosidase enzymatic activity. X-glucuronide is used for the detection of β-D-Glucoronidase enzymatic activity. β-D-galactosidase, expressed by all coliforms, cleaves the Salmon-GAL substrate and producing red/pink coloured colonies. Unlike other coliforms, Escherichia coli leaves both Salmon-GAL and X-glucuronide producing a violet/blue coloured colonies. Tryptophan is used to increase detection reliability by improving the indole reaction. The peptones, sodium pyruvate and sorbitol support bacterial growth and simple recovery of sub-lethal thermally injured coliforms. Sodium di-hydrogen phosphate and di-sodium hydrogen phosphate phosphate buffer the medium and sodium chloride is used to achieve osmotic balance. The selectivity is attained by the addition of Tergitol® 7 as it inhibits the growth of Gram positive bacteria. -
Tryptone Bile X (TBX) - Glucuronide Agar Recent developments in culture media have given rise to the use of chromogenic substrates as a means of differentiating bacteria particularly among the coliform group of organisms. This is one such medium and has been developed as a selective medium for the isolation and enumeration of Escherichia coli in food samples. Based on Tryptone Bile Agar it incorporates the chromogenic agent X-glucuronide, which detects glucuronidase activity, the same enzyme as is detected by MUG reagent. Escherichia coli can be differentiated from other coliform organisms by the presence of glucuronidase resulting in the colonies being blue/green while the other coliforms are colourless. For information on the full technical detail as to the functionality of this medium reference should be made to the many publications available. -
Pseudomonas Agar Base with 1% Glycerol, Cephalothin, Fucidin & Cetrimide (CFC) This is a selective medium for the isolation of Pseudomonas spp primarily in food, water and environmental samples. The medium uses Magnesium and Potassium salts to enhance pigment production and is made selective by the addition of CFC supplement. The presence of blue/green or brown pigmentation or fluorescence is indicative of presumptive Pseudomonas spp. It should be noted however that further testing must be carried out to confirm the full identity of the organism. -
Pseudomonas Agar Base with 1% Glycerol & CN Supplement A selective medium for the isolation of Pseudomonas aeruginosa the medium is made selective by the inclusion of Cetrimide and Naladixic Acid (CN) supplement to significantly reduce the enteric organisms particularly Proteus and Klebsiella spp. Magnesium and Potassium salts are included to enhance the production of the pigments pyocyanin and fluorescein. -
A selective medium for the isolation of Pseudomonas spp. primarily in food, water and environmental samples the medium is made selective by the addition of CFC supplement (cetrimide, at a concentration of 10mg/L which is said to allow the growth of all pseudomonads, cephalothin and fucidin). The presence of blue/green or brown pigmentation or fluorescence is indicative of presumptive Pseudomonas spp. It should be noted however that further testing must be carried out to confirm the full identity of the organism. -
R2A medium was developed to determine the bacterial count including heterotrophic bacteria in potable waters during treatment and distribution. This medium has a low nutritional content and therefore requires extended incubation times. It is recommended by the Environmental Agency, Methods for the Examination of Waters and Associated Materials, and Standard Methods for the Enumeration of Water and Wastewater. -
Originally intended as a medium for the enumeration of enterococci in water using Membrane Filtration, this medium has become more popular in many other areas such as food bacteriology. The medium contains Tetrazolium Chloride, which is reduced by enterococci to the insoluble red dye Formazan resulting in dark red colonies of enterococci on the agar. It should be noted that this reaction is not exclusive to enterococci and colonies should be confirmed by additional testing e.g. Aesculin hydrolysis. -
This is a differential medium for the isolation of Escherichia coli 0157:H7. It differs from other MacConkey media in that lactose has been replaced by sorbitol. As Escherichia coli 0157:H7 does not ferment sorbitol, it produces pale translucent colonies whereas most other strains of Escherichia coli do ferment sorbitol and produce pink colonies. -
Sorbitol MacConkey with Cefixime & Tellurite (CT-Smac) This is a selective differential medium for the isolation of Escherichia coli 0157:H7. It differs from other MacConkey medium in that Lactose has been replaced by Sorbitol. As Escherichia coli 0157:H7 does not ferment Sorbitol it produces pale translucent colonies whereas most other strains of Escherichia coli are Sorbitol positive and produce pink colonies. The medium is made more selective by the addition of the antimicrobial Cefixime and Potassium Tellurite. -
Thiosulphate Citrate Bile Salts Sucrose (TCBS) Agar TCBS is a selective isolation medium for culture of pathogenic Vibrio spp. from clinical samples. The formulation was developed by Kobayashi, Enomoto, Skazaki and Kuwahara. This medium inhibits most enterobacteriacae for at least 24 hours. For the isolation of Vibrio spp. other than V.cholerae in environmental bacteriology, it is advisable to incubate at the lower temperature range of 20°C – 30°C. NB - It is not recommended to perform an oxidase test on any presumptive positive isolates directly from TCBS medium. -
Triphenyltetrazolium Chloride Soya Tryptone (TSAT) Agar Complete Triphenyltetrazolium Chloride (TTC) has been added as an indicator to various media, and recommended by several workers as being helpful in the early recognition and identification of a variety of bacteria including Escherichia coli, Vibrio parahaemolyticus and enterococci. This particular formulation is based on a Tryptone Soya Agar with added Sucrose and is particularly useful when performing counts on food and food product samples. Many of the enterobacteriaceae and enterococci will reduce the TTC to a formazan which colours the colonies deep red making them easier to distinguish and identify. The presence of the Sucrose can also assist in the differentiation of Sucrose fermenting and non-fermenting strains. -
This is a plate count agar originally suggested by the American public Health Association for the estimation of total viable counts in food and dairy products. -
This is a general-purpose medium which supports the growth of a wide range of organisms. It is suitable for Phage Typing, Colicine Typing and for testing the X and V requirements of Haemophilus spp as well as many other areas of bacteriological investigation and conforms to the requirements of the United States Pharmacopeia for sterility testing of pharmaceutical products.
