M-Brilliant Green HiVeg™ Broth

Principle and Interpretation

M-Brilliant Green HiVeg Broth is developed by using HiVeg peptone No.3 in place of Proteose peptone which makes the medium free from BSE/TSE risks. Geldreich and Jeter (1) developed membrane screening technique. Kabler and Clark (2) applied M-Brilliant Green Broth for primary screening of Salmonella in polluted water. This selective differential medium is a modification of Brilliant Green Agar without agar in double strength (3). M-Brilliant Green HiVeg Broth serves the same purpose.

In this technique, suitable and known quantity of water is passed through membrane filter and this filter is then kept on a absorbent pad saturated with M-Tetrathionate HiVeg Broth Base (MV1115). It is then incubated in humid atmosphere for 3 hours at 35-37°C and then the membrane is transferred to another absorbent pad saturated with M-Brilliant Green HiVeg Broth and the incubation is continued for 15 more hours at 35°C. After the total of 18 hours incubation, the membrane is transfered to a fresh pad soaked in urease test reagent (20 grams urea, 0.16 grams bromo thymol blue, 0.2 grms phenol red, all components in a litre of distilled water). Urease test reaction is recorded after 20 minutes.

HiVeg peptone No. 3 provides nitrogenous source, Yeast extract is the vitamin source. Lactose and Saccharose are the carbohydrates useful for growth of the bacteria, sodium chloride maintains the osmotic equilibrium where as phenol red is the pH indicator. Brilliant green serves as the selective agent.