Oxford Listeria Selective Supplement
Description:
Listeria Agar Base Oxford is a selective medium for Listeria according to the Oxford formula and it is recommended for the detection of Listeria monocytogenes from clinical samples and food products. It is used for a direct sample inoculation or for confirmation after using Listeria Enrichment Broth Base.
All Listeria species hydrolyze the esculin to esculetin, which reacts with the iron ions producing black colonies and a blackening of the medium. Another advantage of this medium is that peptones and maize starch provides a rich nutrient base for growth, and the addition of Ferric ammonium citrate improves the growth of L. monocytogenes. Lithium chloride is an inhibiting
agent, together with the other antibiotics from the supplement, which inhibit the growth of gram-negative bacteria and a large part of Gram-positive ones. Cycloheximide inhibits yeasts.
Technique:
Aseptically reconstitute 1 vial with 9 ml of 1:1 sterile distilled water/Ethanol. Mix gently until complete dissolution. Aseptically add to 500 ml of Listeria Agar Base Oxford, autoclaved and cooled to 50 ºC. Mix well and distribute into sterile containers.