VIOLET RED BILE BROTH

Violet Red Bile Broth, a modification of MacConkeys original formulation is used for the enumeration of coli-aerogens bacterial group. It relies on the use of the selective inhibitory components crystals violet and bile salts and the indicator system lactose, and neutral red. Thus, the growth of many unwanted organisms is suppressed, while tentative identification of sought bacteria can be made. Lactose non-fermenters and late lactose fermenters produce pale coloured medium. Other related gram- negative bacteria can be suppressed by incubation at > 42?C or by anaerobic incubation. Incubation may be carried out at > 42?C for 18 hours, 32?C for 24-48 hours or 4?C for 10 days depending on the temperature characteristics of the organisms to be recovered. Violet red bile Broth is similar to VRBA, except agar that is recommended by APHA.

for detection and enumeration of coliform bacteria in water and food