for selective isolation and differentiation of Vibrio species.
CHROMOGENIC VIBRIO AGAR is used for selective isolation & differentiation of Vibrio species from sea food samples. This medium is highly selective against most major enterobacteriaceae and Gram positive bacteria. For the detection of those bacteria, conventional methods (TCBS, TM 436) are long, require heavy workload and are not very sensitive. On the contrary, the medium Chromegenic Vibrio Agar helps to easily differentiate V. parahaemolyticus, V.vulnificus and V.cholerae from other Vibrio directly at the isolation step by colony colour with sensitivity higher than conventional methods. It also provides enrichment and growth of Vibrio cholerae and other Vibrio species. Peptic digest of animal tissue provides carbonaceous, nitrogeneous and essential nutrients to the organisms. High concentration of sodium chloride in addition to maintaining the osmotic equilibrium also has an inhibitory action on the accompanying microflora. Sodium thiosulphate, sodium citrate and sodium cholate are used in the formulation because they can inhibit the growth of gram positive and some gram negative bacteria, but not members of Enterobacteriaceae. A method for differentiating V. parahaemolyticus from V. alginolyticus in a sample of bacteria of the Vibrio genus, comprising the following steps: a. inoculating a Vibrio culture medium comprising at least one chromogenic agent that is a substrate for beta-glucosidase and sucrose at a concentration of greater than 5 g/l with a sample of bacteria of the Vibrio genus or an inoculum derived from said sample, and b. detecting enzyme activity for V. parahaemolyticus and an absence of β-glucosidase activity for V. alginolyticus in this culture medium, thereby differentiating V. parahaemolyticus from V. alginolyticus. Presumptive identification of V.cholerae through the Blue-Green colouration of β Galactosidase producing colonies while V. alginolyticus colonies are colourless. Vibrio species are mainly responsible for causing cholera and food poisoning in humans. Presumptive identification of V. parahaemolyticus: Pink colonies through Arabinose assimilation. On Chromogenic Vibrio Agar, the colour