EDWARDS AND BRUNER SEMISOLID MEDIUM

Description

Edwards and Bruner formulated a semisolid medium, which is used in routine identification of enteric bacilli by means of motility and separation of H and O phases. Salmonella is found in nature and occurs in the intestinal tract of many animals, both wild and domestic. Infection in humans occurs through consumption of contaminated vegetables, raw meat and other food products. Serotypes of Salmonella are defined based on the antigenic structure of both somatic cell wall antigen (O) and flagellar antigen (H). Complete identification of Salmonella involves isolation on selective media, biochemical characterization and then confirmation by serotyping. Serological confirmation involves the procedure in which the microorganism (antigen) reacts with its corresponding antibody. Salmonella can be recovered when samples are processed to recover injured microorganisms. The purity of the cultures and their biochemical test reactions should be determined. These aid in the identification of the organisms as a Salmonella species. After these criteria have been met, serological identification can be performed. It is often necessary to increase the motility of the test organism. To accomplish this, make several consecutive transfers in motility medium.