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Dey & Engley Broth has the ability to neutralise antimicrobial chemicals and is used for environmental sampling for the detection and enumeration of microorganisms present in cosmetic and/or environmental samples. In this formulation the broth has been modified by the addition of Tween 80 (Polysorbate 80), Lecithin, Sodium thioglycollate, Sodium thiosulphate and Sodium bisulphite. It is recommended for use in environmental testing, particularly in areas subjected to surface disinfection, and conforms to the requirements of the British Pharmacopeia for sterility testing of appropriate pharmaceutical products. The product also conforms to ISO 21149 to act as a diluent in the method for the enumeration of aerobic bacteria from cosmetic samples. Lecithin and Polysorbate 80 (Tween 80) inactivate surface disinfectants (Lecithin neutralises quaternary ammonium compounds and Tween 80 neutralises phenols, formalin, hexachlorophene and in combination with the Lecithin ethanol). Sodium thioglycollate neutralises mercurials, Sodium thiosulphate neutralises iodine and chlorine and Sodium bisulphite neutralises aldehydes. Bromocresol purple is incorporated into the medium to indicate glucose utilisation. -
Glucose agar allows for the detection of glucose fermentation (with or without gas production) as an identification test for Enterobacteriaceae (ISO 21528) and B.cereus (ISO 7932). It is further enriched by the addition of Yeast Extract. Bromocresol Purple is also included and acts as an indicator of glucose fermentation. -
A selective medium for the enrichment of Enterobacteriaceae and the detection of Escherichia coli in pharmaceutical products. The inclusion of Bromocresol Purple indicator makes the colour change caused by acid production from the fermentation of lactose easy to read with gas formation. The presence of Ox bile helps to suppress the growth of Gram positive and non-enteric bacterial species. This formulation complies with the Harmonized USP/EP/JP. -
A modification of Violet Red Bile agar designed to give a ‘coliform’ count. In this medium lactose is substituted with glucose. Glucose is fermented by all members of the Enterobacteriaceae thus V.R.B.G.A gives a presumptive Enterobacteriaceae count. Bile salts and crystal violet are used to inhibit Gram positive and non-enteric organisms. The growth of non-fermentative Gram negative bacteria can be suppressed by using the agar overlay method.
