COMPOSITION
Ingredients Gms / Ltr
Peptic digest of animal tissue 10.000
Yeast extract 5.000
Sodium taurocholate 5.000
Sodium thiosulphate 10.000
Sodium chloride 20.000
Sodium lauryl sulphate 0.200
Sodium citrate 10.000
Sucrose 20.000
Bromo thymol blue 0.040
Thymol blue 0.040
Agar 20.000
Instruction for use :
ï‚· Dissolve 100.28 grams in 1000 ml distilled water.
ï‚· Heat to boiling to dissolve the medium completely, do not autoclave.
ï‚· Mix well and pour into sterile Petri plates
Principle
The medium contains peptic digest of animal tissue and yeast extract, which provide nitrogenous compounds, vitamin B
complex and other essential growth nutrients. Sucrose is added as a fermentable sugar. Sodium citrate, sodium lauryl
sulphate, sodium taurocholate and sodium thiosulphate as well as high alkalinity of the medium inhibit most of the
contaminating organisms. Bromothymol blue and thymol blue are the pH indicators. The alkaline pH of the medium and
higher concentration of sodium chloride improves the recovery of Vibrio parahaemolyticus. Sucrose fermenting
organisms like V. cholerae and V. alginolyticus produces yellow coloured colonies. Vibrio parahaemolyticus is a sucrose
non-fermenting organism and produces blue-green colonies, as does V. vulnificus. Occasionally a few enteric sucrose nonfermenters may exhibit growth e.g. Proteus group.