Selective isolation of coagulase positive Staphylococci in food.
Description:Baird-Parker modified the Tellurite Glycine Medium of Zebovitz, Evans and Niven. It is recommended for microbial limit tests by the USP. Potassium Tellurite and Lithium Chloride selectively suppresses the growth of most bacteria but allows the growth of Staphylococcus aureus. The addition of pyruvate and glycine enhances the growth of Staphylococci. The differentiation of coagulase-positive staphylococci is noted by the reduction of Potassium Tellurite which results in a black colony. Staphylococcus that contain lecithinase break down the egg yolk and cause a clear zone. An opaque zone may be formed due to lipase activity.
Directions:Dissolve 60g. in 800ml of ddH2O, heating to boiling with stirring until completely solubilized. Dispense into appropriate containers, loosen caps and autoclave for 15-30 minutes at 121ºC (15 psi). After cooling to 45-50°C add 10ml of a sterile I% Potassium Tellurite solution and 50ml of sterile egg yolk emulsion.
Storage and Stability:Store powdered media at RT. Opened bottles should be capped tightly and kept in a dark, low humidity environment. Prepared media should be kept refrigerated and used within a short period of time.
Appearance:Light beige, homogeneous and free flowing
Solubility:Light to medium amber and opaque
Canary yellow with the egg yolk addition
pH: 7.0 ± 0.2
Important Note: This product as supplied is intended for research use only, not for use in human, therapeutic or diagnostic applications without the expressed written authorization of United States Biological.
