ENTEROCOCCUS SELECTIVE BROTH (ENTEROCCOSEL BROTH) 500 grams/bottle

Enterococcus Selective Broth (Emterococcosel Broth) is a sensitive enrichment medium for the isolation of enterococci from specimens containing numerous other flora. Many organisms such as saprophytic Neisseria, Staphylococcus, Haemophilus, non-hemolytic streptococci, and a certain number of Enterobacteriaceae are inhibited wholly or partially. Casein and Soy peptones provide essential nutrients for growth. Dextrose is the fermentable carbohydrate energy source. Sodium chloride maintains the osmotic balance. Sodium citrate provides additional carbon. Sodium azide is an inhibitor. Sodium sulfite when reduced produces H2S. L-Cystine lowers the oxidation-reduction potential by removing oxygen to maintain a low Eh. Crystal violet is a pH indicator. Clinical material is inoculated into this selective medium and tubes are incubated at 35 °C for 18-24 hours in a normal atmosphere. The growth of streptococci can be determined by the formation of a granular precipitate at the bottom of the tube, with the liquid above being clean or slightly turbid. At this point, perform a Gram stain and restreak on Trypticasein Soy Agar (Cat. 1068) blood plates or Blood Agar Base (Cat. 1108) to determine the type of hemolysis and to purify the culture. The presence of variable length chains of gram-positive cocci inhibited by bacitracin in a low concentration, catalase negative and insoluble in bile or bile salts, constitute a valid presumptive identification of Group A beta-hemolytic streptococci. The definitive identification of the streptococci groups can be made by performing other biochemical tests such as esculin hydrolysis, pyruvate hydrolysis, etc. Also, serological typing, using Lancefield antisera methods, or more conveniently, the techniques of co-agglutination of Edwards and Larson can be performed.