DOUBLE MODIFIED LYSINE IRON AGAR BASE

Description

Salmonella is the main agent of foodborne diseases in several parts of the world, belonging to the family Enterobacteriaceae. Most serovars, however, have a wide spectrum of hosts and typically cause gastroenteritis. Double Modified Lysine Iron Agar is used to for isolation and identification of Salmonella from food. Salmonellae are known to decarboxylate lysine rapidly and produce large amounts of hydrogen sulphide. Many strains of this group ferment lactose very rapidly thus suppressing H2S production on Triple Sugar Iron Agar. So there is a possibility that the organisms frequently found in food poisoning outbreaks could be overlooked. Thatcher and Clark described the isolation of Salmonella species from foods from selective agar and to inoculate it on Lysine Iron Agar and Triple Sugar Iron together. Using these two media greater discrimination can be made between coliform organisms e.g. Escherichia and Shigella.