For isolation and enrichment of Salmonella from faeces, urine or other pathological materials (Part II). SELENITE F BROTH (VEG.) is used for isolation and enrichment of Salmonella from faeces, urine or other pathological material. Selenite Broth is used as a selective enrichment for the cultivation of Salmonella spp. that may be present in small numbers and competing with intestinal flora. Selenite Broth was devised by Leifson, who demonstrated that selenite was inhibitory for coliforms and certain other microbial species, such as fecal streptococci, present in fecal specimens and, thus, was beneficial in the recovery of Salmonella species. He found that the inhibited strains would eventually break through, but if subcultures were made from the enrichment broth after 8-12 hours of incubation, the isolation of Salmonella was possible without overwhelming growth of many members of the intestinal flora. Casein enzymic hydrolysate provides nitrogenous substances and other essential ingredients. Lactose maintains the pH of medium. Selenite is reduced by bacterial growth and alkali is produced. An increase in pH lessens the toxicity of the selenite and results in overgrowth of other bacteria. The acid produced by bacteria due to lactose fermentation serves to maintain a neutral pH. The function of the phosphate is two-fold; it serves to maintain a stable pH and lessens the toxicity of the selenite, thus increasing the capacity of the medium. Sodium selenite inhibits many species of gram-positive and gram-negative bacteria including enterococci and coliforms. Do not incubate the broth longer than 24 hours as inhibitory effect of selenite decreases after 6 - 12 hours of incubation.