Yolk Agar Base , 250g

Description: 

Clostridium perfringens food poisoning is one of the most common types of human food borne illness (1). The foods usually involved are cooked meat or poultry products containing large numbers of viable cells. A heat-labile enterotoxin produced only by sporulating cells (2) induces the major symptoms of diarrhea in perfringens poisoning. Egg Yolk Agar Base is a slight modification (3) of McClung Toabe Agar Base (4) used for isolation and detection of Clostridium perfringens .

Egg Yolk Agar Base differs from the original formula by the inclusion of hemin. Proteose peptone provide the essential nutrients along with carbonaceous and nitrogenous substances. Phosphates buffer the medium whereas sodium chloride maintains the osmotic equilibrium. Magnesium sulphate serves as a source of divalent cations along with sulphates. Glucose serves as a source of energy.

Hemin help to enhance the growth of anaerobic organisms. Organisms producing lecithinase break d own lecithin present in the egg yolk emulsion producing an insoluble opaque precipitate around the colonies. Lipase -producing organisms break down free fatty acids (in the egg yolk emulsion) forming an iridescent sheen on the surface of the colonies. Lipas e activity may be delayed, therefore plates should not be discarded as negative before incubation for a week. Proteolytic activity is seen as clear zones around the colonies (5).

The media should be directly inoculated with the test specimen. Prior to inoculation, media plates should be reduced by placing in an anaerobic jar for 18-24 hours . An enrichment broth should be simultaneously inoculated with the test sample to detect small number of anaerobic organisms. Standard procedures for the isolation of organism should be referred. Incubation should be carried out for 18-48 hours and continued for 7 days. 

Specification: 

250g