Brilliant Green Sulpha Agar M492
Brilliant Green Sulpha Agar is used for the selective isolation and detection of Salmonella species in foods especially from eggs and egg products
Ingredients Gms / Litre Yeast extract 3.000 Proteose peptone 10.000 Lactose 10.000 Sucrose 10.000 Sodium sulphapyridine 1.000 Sodium chloride 5.000 Brilliant green 0.0125 Phenol red 0.080 Agar 20.000 Final pH ( at 25°C) 6.9±0.2 **Formula adjusted, standardized to suit performance parameters
Suspend 59.09 grams in 1000 ml distilled water. Heat to boiling to dissolve the medium completely. Sterilize by autoclaving at 15 lbs pressure (121°C) for 15 minutes. To maintain selectivity of the medium, DO NOT OVER STERILIZE OR OVERHEAT the medium.
Principle And Interpretation
Salmonella species are ubiquitous in the environment. These enter the gastrointestinal tract of animals due to consumption of contaminated feed. Stringent animal husbandry practices are used in the meat (food) industry and inedible raw materials are recycled and discarded. Thus the organisms are further returned to the environment and stay in the global food chain (1, 2). Eggshell and its contents are usually sterile at the time of oviposition. Subsequently it gets contaminated on contact with the nest, the floor and litter of other birds (5-7). Salmonella species are usually the causative agents of a self-limiting gastroenteritis. In some cases they may also cause typhoid fever. Salmonella contamination is most frequently encountered in the poultry industry. Brilliant Green Sulpha Agar is used for the selective isolation and detection of Salmonella species in foods especially from eggs and egg products. Brilliant Green Agar was first formulated by Kristensen, Lester and Jargens (3). This was further modified by Osborne and Stokes (4) by the addition of 0.1% sodium sulphapyridine to the original formulation. This addition helped to increase the selective properties of the medium. Colonies of Salmonella may sometimes vary from red to pink to white depending upon the time and length of incubation and the strain of Salmonella . Do not autoclave the medium for more than 15 minutes as it decreases the selectivity of the medium (8). Yeast extract and proteose peptone provide essential growth nutrients, amino acids and vitamins. Brilliant green used in the medium is inhibitory to gram-positive and most gram-negative lactose/sucrose fermenting bacilli. Sulphapyridine enhances the selectivity of the medium. The medium does not support luxuriant growth of Salmonella Typhi. Shigella species also fail to grow on Brilliant Green Sulpha Agar (8). Since Brilliant Green Sulpha Agar is highly selective, a less inhibitory medium should be simultaneously used to recover organisms from the pre-enriched culture (Selenite Cystine Medium).
Storage and Shelf Life
Store below 30°C in tightly closed container and the prepared medium at 2 - 8°C. Use before expiry date on the label.
1. Doyle M. P., (Ed.), 1989, Foodborne Bacterial Pathogens, Marcel Dekker, Inc., New York. 327- 445 2. DAoust J. Y., 1994, Int. J. Food Microbiol. 24: 11-31. 3. Kristensen M., Lester V., and Jargens A., 1925, Brit. J. Exp. Pathol. , 6:291. 4. Osborne W. W. and Stokes J. L., 1955, Ottawa; Food and Drug Laboratories, 1962. 5. Brooks and Taylor, 1955, Rep. Rd. Invest. Bd. 60, H. M. S. O., London, England. 6. Forsythe, Ayres and Radlo, 1953, Food Technol., 7:49. 7. Stadelman, Ikeme, Roop and Simmons, 1982, Poultry Sci., 61:388. 8. MacFaddin J. F., 1985, Media for Isolation-Cultivation-Identification-Maintenance of Medical Bacteria, Vol. I, Williams & Wilkins, Baltimore, MD.