Description
Brilliant Green Agar medium is recommended as a primary plating medium for isolation of Salmonella species was first described by Kristensen et al as medium for differentiation of paratyphoid B from other Gram negative enteric bacteria. Kauffmann further modified it for isolation of Salmonella from stool samples. Brilliant green agar is also recommended by APHA FDA and is in accordance with United States Pharmacopoeia. This medium is employed in testing clinical specimens. Heavy inocula and heavily contaminated samples can be analyzed due to the outstanding selectivity of this medium. Brilliant Green Agar is used in the microbial limits test and with novobiocin for testing food and pharmaceutical products. Salmonella Typhi, Shigella species, Escherichia coli, Proteus species, Pseudomonas species, Staphylococcus aureus are mostly inhibited. However, being highly selective, it is recommended that this medium should be used along with a less inhibitory medium to increase the chances of recovery. Often cultures enriched in Selenite or Tetrathionate Broth are plated on Brilliant Green Agar along with Bismuth Sulphite Agar, SS Agar, MacConkey Agar. Non-lactose fermenting bacteria develop white to pinkish red colonies within 18-24 hours of incubation. Salmonella typhi and Shigella species may not grow on this medium, moreover Proteus, Pseudomonas and Citrobacter species may mimic enteric pathogens by producing small red colonies.
