KANAMYCIN AESCULIN AZIDE AGAR

Selective media used for the isolation, differentiation and enumeration of enterococci and faecal streptococci in foodstuffs and water.

Description

Kanamycin Aesculin Broth and Agar, AM 73 and AM 74, are based on the formulation of Mossel et al1 for the detection of enterococci and faecal streptococci in foodstuffs. The selective agents incorporated into the media, Kanamycin Sulphate and Sodium Azide, are both inhibitory to a wide range of micro-organisms other than streptococci and enterococci, Kanamycin a member of the broad spectrum aminoglycoside group of antimicrobial substances, while Sodium Azide is particularly active against gram negative organisms.

The media also contain an indicator system for the detection of aesculin hydrolysing organisms such as enterococci and faecal streptococci which have the capacity to hydrolyse the glycoside aesculin to produce dextrose and aesculitin. The latter substance then reacts with ferric ions to produce a black halo around the colonies or a black colouration of the fluid medium due to the formation of iron phenolic derivitives.

Nitrogen and other growth factors are contained in the peptone and yeast extract, while sodium citrate provides a carbon source. Sodium chloride maintains osmotic equilibrium.

Additional information

Size

100gm, 2500gm, 500gm