-
Bacillius cereus Selective Agar (PEMBA) This is a medium for the selective isolation and enumeration of Bacillus cereus in food samples. It is said to be particularly suitable for the detection of small numbers of Bacillus cereus particularly in the presence of other contaminating organisms. The medium is made selective by the inclusion of Polymixin and Sodium Pyruvate is also present which is said to improve Egg Yolk precipitation and enhance sporulation. As Bacillus cereus is Mannitol Negative the colonies are bluish in colour, due to the presence of the Bromothymol Blue Indicator, with a surrounding precipitate of the same colour due to Lecithinase production (from the Egg Yolk). NB: It should be noted that some Proteus spp. and gram positive cocci may grow on this medium. -
Dermatophyte Test Medium with Chloramphenicol & Cyclohexamide (Actidione) This is a selective medium for the isolation of dermatophytes that includes a Phenol Red indicator to assist in the differentiation between dermatophytes and other pathogenic fungi. Although the low pH (5.5) of the medium inhibits most bacteria, Chloramphenicol is added to further reduce the risk when processing material that may be more heavily contaminated. Cyclohexamide (Actidione) is also added to suppress the growth of most yeasts and saprophytic fungi. Dermatophytes appear as fluffy white colonies and produce a red colour on the medium while other fungi cause the medium to become yellow due to acid production. Yeasts will also grow on this medium but are readily distinguished by their distinct white/creamy colonies and distinctive smell. NB: Prolonged incubation should be avoided as this may cause fungi other than dermatophytes to turn the medium red -
A sterile concentrated emulsion of premium egg yolks, suitable for incorporation in culture media which detect lecithinase production by bacteria. It can be used in media for Bacillus cereus and Staphylococci. Used with serum and Filde’s extract it may be used to produce Nagler plates for Clostridia. -
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. -
A modification of UVM11 Medium, Fraser Broth Half-Strength is a primary selective enrichment broth for the isolation of Listeria spp. from food and environmental samples and is generally used in conjunction with Fraser Broth (BM0640). Although the base is identical to Fraser Broth it differs in that it contains only half the quantity of selective agents (Nalidixic acid and Acriflavine). -
This buffer is intended primarily for use as a neutralising agent following treatment with alkaline compounds during the decontamination and homogenisation process of Sputum specimens prior to inoculation onto appropriate culture media for the isolation of Mycobacterium spp. -
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. -
This buffer is intended primarily for use as a neutralising agent following treatment with alkaline compounds during the decontamination and homogenisation process of Sputum specimens prior to inoculation onto appropriate culture media for the isolation of Mycobacterium spp.
