EIJKMAN LACTOSE BROTH

Coliform organism is a term used to designate the lactose-fermenting Enterobacteria such as Escherichia coli and Enterobacter. Enterobacteriaceae forms a large group of gram-negative bacteria that inhabit intestinal tract of warm-blooded animals. Therefore, they constitute the major microbial flora of human faeces. Since coliforms are readily isolated and identified, they are used as indicator organisms to check faecal contamination of food, water and other samples. E. coli is one of the common organisms involved in gram-negative sepsis and endotoxin-induced shock. Eijkman described a method for selective isolation of E. coli from faeces of warm-blooded and cold-blooded animals. This method had limitations due to the inability to obtain growth after subculturing from positive tubes incubated at 46?C, as acidity and high temperature resulted in death of the culture within 24-48 hours. Perry and Hajna modified Eijkmans original method by decreasing carbohydrate content and adding a phosphate buffer enabling to subculture E. coli after incubation at 46?C for 96 hours or longer where pH was 5.6 unlike 4.5 of Eijkman Medium. Perry modified Eijkman Medium using lactose for isolation of E. coli. This medium can also be used for bacteriological examination in water filtration control work.

for di?erentiating E. coli from other coliforms based on their ability to liberate gas from lactose

Escherichia coli

Water

500 gm