Disinfectant Test Broth (Staphylococcus aureus Enrichment Broth)

Ingredients

Final pH (at 25°C) 6.8±0.2

**Formula adjusted, standardized to suit performance parameters

Directions

Suspend 20 grams in 1000 ml distilled water. Heat if necessary to dissolve the medium completely. Dispense as desired. Sterilize by autoclaving at 15 lbs pressure (121°C) for 15 minutes.

Principle And Interpretation

Bacteria in the genus Staphylococcus are pathogens of man and other mammals. Traditionally they were divided into two groups on the basis of their ability to clot blood plasma (the coagulase reaction). The coagulase-positive Staphylococci constitute the most pathogenic species Staphylococcus aureus. The presence of Staphylococci in a lesion might first be suspected after examination of a direct gram stain. However, small numbers of bacteria in blood preclude microscopic examination and require culturing first (1). Staphylococcus Aureus Enrichment Broth (Disinfectant Test Broth) is recommended for enrichment of S.aureus and Disinfectant testing as per ISI Specifications.

Peptic digest of animal tissue and meat infusion provide carbonaceous, nitrogenous compounds and other necessary nutrients for the growth of the test organisms. Yeast extract provides vitamins and other trace nutrients. Sodium chloride maintains the osmotic equilibrium

Quality Control

Appearance: Cream to yellow homogeneous free flowing powder

Colour and Clarity of prepared medium: Yellow coloured, clear solution without any precipitate

Reaction: Reaction of 2.0% w/v aqueous solution at 25°C. pH: 6.8±0.2

pH: 6.60-7.00

Cultural Response

M464: Cultural characteristics observed after an incubation at 35-37°C for 18-24 hours.

Storage and Shelf Life

Store below 30°C in a tightly closed container and prepared medium at 2-8°C. Use before expiry period on the label.

Reference

1. Easmon C. S. F., Adlam C., Staphylococci and staphylococcal infections. Vol. I & II, 1983, Academic Press, London