KLIGLER IRON AGAR SLANT (10 Slants)

Kligler Iron Agar is a combination of the lead acetate medium described by Kligler and Russels Double Sugar Agar and is used as a differentiation medium for typhoid, dysentery and allied bacilli. Bailey and Lacey substituted phenol red for andrade indicator previously used as pH indicator. Kligler Iron Agar differentiates lactose fermenters from the non-fermenters. It differentiates Salmonella typhi from other Salmonellae and also Salmonella paratyphi A from Salmonella scottmuelleri and Salmonella enteritidis. Fermentation of dextrose results in production of acid, which turns the indicator from red to yellow. Since there is little sugar i.e. dextrose, acid production is very limited and therefore a reoxidation of the indicator is produced on the surface of the medium, and the indicator remains red. However, when lactose is fermented, the large amount of acid produced, avoids reoxidation and therefore the entire medium turns yellow.

for di?erential identi?cation of Gram-negative enteric bacilli on the basis of the fermentation of dextrose, lactose and H2S Production