TRYPTONE BROTH W/ 10% NACL

Tryptone Broth with 10% NaCl is a selective enrichment medium recommended for counting Staphylococcus aureus, especially in dairy products. It can also be used for enumeration by the Most Probable Number (MPN) method, in which selective conditions applied for growth help recuperation and estimation of the target organism.
The casein was enzymatically hydrolyzed in the presence of the papaic digest of soybean meal, providing the necessary nutrients for microbial growth. Dextrose is an energy source that supports the metabolic activity of S.aureus. Sodium pyruvate protects injured cells and supports their recovery and stimulates the growth of S. aureus during enrichment.
The high concentration of 10% sodium chloride provides the selective property of the medium. Under these conditions, many microorganisms are inhibited, but staphylococci can tolerate the high salt concentration and continue to grow. The selective conditions increase the recovery of S. aureus from samples containing mixed microbial populations.
This formulation is thus useful for laboratory testing of dairy products needing selective enrichment and enumeration of S. aureus.

Selective enrichment broth formulated for the enumeration of Staphylococcus aureus, particularly in dairy products using the MPN technique.