For performance of Kanagawa test to identify virulent Vibrio parahaemolyticus strains. Dissolve 113.00 gms in 1000ml of distilled water. Gently heat to boiling with gentle swirling and dissolve the medium completely. Steam for 30 minutes. Cool to 50°C. Add 2 ml of a suspension of freshly drawn citrated human red blood cells (previously washed 3 times in saline) to100 ml. Appearance: Very light bluish coloured clear to slightly opalescent- : PH (at 25°C): 8.0 ± 0.2
WAGATSUMA AGAR BASE is used for performance of Kanagawa test to identify virulent Vibrio parahaemolyticus strains. Wagatsuma Agar is formulated as described by Wagatsuma. Vibrio parahaemolyticus is a well-demonstrated cause of acute gastroenteritis. Pathogenic strains of V.parahaemolyticus are differentiated from non-pathogenic strains by the ability of the former to produce a thermostable direct haemolysin whose production is termed as Kanagawa phenomenon. The extensive investigation in animal model suggests that Kanagawa haemolysin is the primary virulence factor in V.parahaemolyticus. It has been well established that enteropathogenic V.parahaemolyticus strains are always Kanagawa positive and seafood isolates are almost always Kanagawa negative. Yeast extract and peptic digest of animal tissue provide nitrogen and other growth factors. Mannitol serves as a energy and carbon source. Crystal violet is inhibitory to most of the gram positive bacteria. Alkaline pH and high salt concentration makes the medium selective for V. parahaemolyticus. Enteropathogenic V. parahaemolyticus strains are Kanagawa positive and produce haemolysin, which forms a transparent, clearing zone of blood cells around the colony.