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This medium is used to detect and/or confirm the presence of coli-aerogenes group of organisms in water, food and dairy laboratories. Bile and Brilliant Green are included in the medium to inhibit gram positive organisms while the coli-aerogenes organisms are identified by the formation of gas during the fermentation of Lactose. The medium can also be used for the confirmation of Escherichia coli by incubating at 44°C. -
A modification of UVM Medium, Fraser Broth is a secondary selective enrichment broth for the isolation of Listeria spp primarily from food and environmental specimens. The medium is made selective by the inclusion of Nalidixic Acid and Acriflavine. Darkening of the broth following incubation, due to the presence of Aesculin and Ferric Ammonium Citrate, is indicative of the presence of Listeria spp. Lithium Chloride is also included to inhibit the growth of enterococci that would otherwise hydrolyse the Aesculin. This medium is generally used in conjunction with Fraser Broth Half-Strength (BM0647). NB: It should be noted that the lack of darkening of the broth should not be taken as a final negative result and all Fraser Broth enrichment cultures should be sub-cultured onto an appropriate selective agar medium irrespective of colour. -
Palcam agar is a selective differential medium for the isolation of Listeria monocytogenes from food, clinical and environmental specimens. The Columbia peptone mix and starch provide the required carbon, nitrogen and vitamins. Glucose is a fermentable carbohydrate. Differentiation of Listeria spp. from enterococci and staphylococci occurs through aesculin hydrolysis and mannitol fermentation. Listeria monocytogenes will hydrolyse aesculin and the associated reaction with the ferric ammonium citrate gives rise to a brown/black precipitate around the colonies. Listeria spp. do not however ferment mannitol. Mannitol fermentation is seen through a colour change of the colony or the area around the colony from red to yellow due to the production of acidic end products. Phenol red is the pH indicator in the medium. Lithium chloride is included to inhibit enterococci. The associated Palcam selective supplement, LS0038, contains polymyxin B, acriflavine and ceftazidime to inhibit other Gram-positive and Gram-negative organisms that may be present in specimens. Related Supplements : LS0038 PALCAM Selective Supplement -
This medium is based on the formula described by Kupferburg, Johnson and Sprince for the selective isolation of Trichomonas spp. The medium is selective due to the inclusion of two selective agents namely, Chloramphenicol and Nystatin, to inhibit a wide range of both Gram-positive and Gram-negative bacterial species as well as yeasts and fungi. The inclusion of methylene blue as a redox indicator allows for the visualisation of any significant oxygen diffusion in the medium. Cultures may be examined microscopically after 48 hours incubation at 37°C for the presence of flagellate protozoans. If a negative result is obtained then the culture may be re-incubated for a further 72 hours.
