Brilliant Green Agar w/ 1.2% Agar

 

Specifications

Ingredients Gms / Litre :
Proteose peptone 10.000
Yeast extract 3.000
Lactose 10.000
Sucrose 10.000
Sodium chloride 5.000
Phenol red 0.080
Brilliant green 0.0125
Agar 12.000
Final pH (25oC) 6.9±0.2

Principle & Interpretation :
Salmonella species is responsible for many types of infections, ranging from mild self-limiting gastroenteritis to life threatening typhoid fever. The most common form of Salmonella disease is self-limiting gastroenteritis with fever lasting less than 2 days and diarrhoea lasting less than 7 days (7)
Brilliant Green Agar as a primary plating medium for isolation of Salmonella species was first described by Kristensen et al (1) and further modified by Kauffmann (2) and recommended by APHA (3, 4) FDA (5) and USP (6)
These media contain brilliant green which inhibits growth of most of gram-negative and gram- positive bacteria. There are Salmonella Typhi, Shigella species, Escherichia coli, Proteus species, Pseudomonas species Staphylococcus aureus. Clinical specimens can be directly plated on this medium.
However, to increase the chances of recovery, it is recommended that this medium should be used alongwith a less inhibitory medium Often cultures enriched in Selenite (DM1025A) or Tetrathionate Broth (DM1032) are plated on Brilliant Green Agar as well as Bismuth Sulphite Agar (DM1027), SS Agar (DM1108) and MacConkey Agar (DM1081). Phenol red serves as an acid base indicator giving yellow colour to lactose and or sucrose fermenting bacteria. Lactose non-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.