TRYPTONE SOYA BROTH W/ 10% NACL AND 1% SODIUM PYRUVATE

Staphylococcal food poisoning ranks as one of the most prevalent causes of gastroenteritis worldwide. Staphylococci ferment glucose to produce acid from glucose. Tryptone Soya Broth with 10% sodium chloride and 1% sodium pyruvate is used for enumeration of Staphylococcus aureus in dairy products and is recommended for enumeration by MPN technique.
For MPN Technique: Inoculate 3 tubes of Tryptone Soya Broth w/ 10% NaCl and 1% sodium pyruvate of each test dilution with 1 ml aliquots of decimal dilutions of sample. Incubate at 35-37?C for 48 hours. Following incubation, transfer a loopful from each positive growth tube to Baird-Parker Agar plates. Colonies of S.aureus on Baird Parker Agar are typically circular, smooth, convex, moist, 2-3 mm in diameter, grey-black to jet black and surrounded by an opaque zone.

for enumeration of Staphylococcus aureus in dairy products by MPN technique