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Pasteurella Agar Base is an non-selective medium capable of supporting the growth of Pasteurella spp. Pasteurella spp.are spherical, ovoid or rod-shaped cells 0.3-1.0μm in diameter and 1.0-2.0μm in length. Cells are Gram negative, and occur singly, or in pairs or short chains. Bipolar staining may be seen and capsules may be present. All species are non-motile, and are facultatively anaerobic.(1) With further enrichment using 5-10% blood and selective antimicrobials, most Pasteurella spp. can be isolated. There is no haemolysis on blood agar for Pasteurella spp. and the organism will not regularly exhibit satellitism around colonies of Staphylococcus spp. The peptones act as carbon, nitrogen and vitamin sources in this medium. Sodium chloride maintains the osmotic balance and the agar is a solidifying agent. The medium is made selective through the addition of LS0057, Pasteurella agar selective supplement. REFERENCE (1) Standards Unit, Microbiology Services, PHE. 1995. UK Standards for Microbiology Investigations. Identification of Pasteurella species and Morphologically Similar Organisms. 3, 1-28. -
Peptone water is a general-purpose medium that supports thecultivation of non-fastidious organisms. This non-selective medium can be used a basal medium for biochemical tests such as carbohydrate fermentation and production of indole. Tryptone and peptone act as sources of carbon, nitrogen and vitamins in this medium and sodium chloride maintains osmotic balance.
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Perfringens Agar Base is a base medium that allows the enumeration of Clostridium perfringens from food samples. As a base medium, Perfringens Agar Base can have several supplementary and selective agents added to increase selectivity. The addition of Eye Yolk Emulsion (BM0140) allows the detection of lecithinase activity as precipitates are formed by C. perfringens. The addition of D-cycloserine (LS0023) can be used to inhibit other facultative anaerobes, as used in Tryptose-Sulphite-Cycloserine (TSC) agar. (1&2) Alternately, kanamycin and polymyxin B (LS0025) can be used to inhibit other coliforms generally found in food samples, as used in Shahidi-Ferguson Perfringens (SFP) agar.(3) The tryptose and soy peptone provide the required nitrogen, carbon and minerals. Yeast extract provide the essential vitamins, including the vitamin B group, needed for growth. The ferric ammonium citrate and sodium metabisulphite allows the reduction of sulphites to hydrogen sulphide by C. perfringens, which produces black colonies. References (1) ISO- 7937:2004. Microbiology of food and animal feeding stuffs- Horizontal method for the enumeration of Clostridium perfringens - Colony count technique (2) Harmon, S.M., Kauttar, D.A. and Peeler, J.T. 1971. Improved Medium for Enumeration of Clostridium perfringens. Appl. Microbiol. 22:688-692. (3) Shahidi S. A. and Ferguson A. R. 1971 New Quantitative, Qualitative, and Confirmatory Media for Rapid Analysis of Food for Clostridium perfringens. Appl. Microbiol. 21:500-506
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Phosphate-buffered saline (PBS) is a buffer solution used in biological research. It is a water-based salt solution containing sodium phosphate, sodium chloride and, in some formulations, it contains potassium chloride and potassium phosphate. The osmolality and ion concentrations of the solutions match those of the human body (isotonic) and are non-toxic to most cells. This balanced salt solution is issued to meet the requirements of those tissue culture workers who use the Dulbecco Solution with and without calcium and magnesium.
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Plate Count Agar is formulated to the A.P.H.A. specification developed by Buchbinder et al. This medium is intended for use in food, dairy and water bacteriology to perform Total Viable Counts. Tryptone and yeast extract provide the required carbon, nitrogen and vitamins. Glucose is a fermentable carbohydrate.
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KM0058 Primary Listeria Agar is a selective medium for the isolation, enumeration and presumptive identification of Listeria species and L. monocytogenes from food and environmental samples. Listeria monocytogenes is commonly found in soil, sewage, and faeces. It is difficult to eradicate, and can cause serious food poisoning; therefore, L. monocytogenes is frequently tested for in food processing facilities to avoid contamination. Contamination can occur at all steps of the food manufacturing chain from raw materials to point of consumption. Primary Listeria Agar is used for the detection and presumptive identification of Listeria spp. and the specific differentiation of L. monocytogenes. Based on the method of Ottaviani et al (1 2), this medium allows detection and enumeration of Listeria spp. as early as 24 hours. Primary Listeria Agar is recommended by ISO 11290-1:2017 (3) and ISO 11290-2:2017 (4) and tested in accordance with ISO 11133:2014 (5). References:- Ottaviani, F., Ottaviani, M., and Agosti M. (1997) Differential agar medium for Listeria monocytogenes. Quimper Froid Symposium Proceedings, P6 ADRIA Quimper, France, 16-18 June.
- Ottaviani, F., Ottaviani, M.G., and Agosti, M. (1997). Esperienze su un agar selettivo e differenziale per Listeria monocytogenes. Industrie Alimentari, 36: 888-889.
- International Organization for Standardization (2017) 11290-1:2017 Microbiology of the food chain – Horizontal method for the detection and enumeration of Listeria monocytogenes and of Listeria spp. – Part 1: Detection method. Geneva, ISO.
- International Organization for Standardization (2017) 11290-2:2017 Microbiology of the food chain – Horizontal method for the detection and enumeration of Listeria monocytogenes and of Listeria spp. – Part 2: Enumeration method. Geneva, ISO.
- International Organization for Standardization (2014) 11133:2014 Microbiology of food, animal feed and water – Preparation, production, storage and performance testing of culture media. Geneva, ISO.
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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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KM0007 Primary UTI Agar is a chromogenic agar that has been developed to allow differentiation and presumptive identification of organisms typically found in urinary tract infections. Urinary Tract Infections (UTI’s) account for 35-40% of all hospital acquired infections in the UK. Gram negative aerobic bacteria are responsible for a considerable proportion of UTI’s with Escherichia coli isolation rates at 80-90% of first-time infections. Various other opportunistic bacterial species can cause UTI’s. KM0007 may be used as a chromogenic medium for the quantification and presumptive identification of bacteria in urine from clinical samples in line with the UK Standards for Microbiology Investigations and tested in accordance with the principles of ISO 11133:2014. Related Supplements : SHS500 Sterile Horse Serum 500ml
