VIBRIO CHROMOGENIC AGAR 500 grams/bottle

Vibrio Chromogenic Agar is recommended for the selective isolation and differentiation of Vibrio species based on colony colors, due to the enzymatic activities of ß-galactosidase and ß-glucosidase. The Vibrio genus consists of micro-organisms whose natural habitat is marine and fluvial ecosystems. They are frequently isolated from marine water, especially in warmer months and when the water temperature is higher than 17 ºC. Vibrio species are mainly responsible for causing cholera and food poisoning in humans. The medium contains yeast extract and peptones which are the source of nitrogen, vitamins (particularly the B-group essential for bacterial growth), minerals and amino acids. Special Bilis inhibits Gram-positive organisms. Sucrose, glucose and lactose are the fermentable carbohydrates, which provide carbon and energy. Sodium chloride supplies essential electrolytes for transport and osmotic balance. Sodium citrate, sodium thiosulfate and sodium cholate are the selective agents, inhibiting the Gram-positive bacteria. Chromogenic substrate is added to detect Vibrio species by means of a color change in the colonies. This medium is designed for the development and diferentation of 3 types of Vibrio depending on the enzyme activity of each strain. ß-glucosidase activity will appear as blue-green colonies, as in the case of V. parahaemoliticus. The activity of ß-galactosidase enzyme will show red or pink colonies in the case of V. cholerae. And finally, the yellowish-white colonies will be V. alginolyticus, which has ß-galactosidase, but is not expressed due to the high concentration of sugars. The alkaline pH of the medium enhances the recovery of V. cholerae. ISO 21872: Microbiology of the food chain - Horizontal method for the detection of potentially enteropathogenic species Vibrio spp. Detection of Vibrio parahaemolyticus, Vibrio cholerae and Vibrio vulnificus (ISO 21872-1: 2017), recommends an alternative selective medium to TCBS for the detection of Vibrio enteropathogenic species.