Intended Use

For the detection of Salmonella spp. in food, animal feed and in environmental samples from the food production area as described in ISO 6579-1:2017.

Principle and Interpretation

Meat extract and casein provide a source of nitrogen and amino acids and sodium chloride maintain theosmotic balance. Ox bile and brilliant green act as selective agents against non-target microorganisms. Tetrathionate is generated from the sodium thiosulfate. Iodine and calcium carbonate buffer the sulfuric acid generated from tetrathionate reduction.

Formulation

Ingredients	/liter
Meat extract	4.3g
Enzymatic digest of casein	8.6g
Sodium chloride	2.6g
Calcium carbonate	38.7g
Sodium Thiosulfate (anhydrous)	30.4g
Ox bile	4.78g
pH8.0±0.2 at 25°C

Preparation

Suspend 89.4g in 1 L of purified water. Heat with frequent agitation and boil to completely dissolve the powder. Distribute into flasks，and then cool to below 45°C. Add a vial of novobiocin sodium salt (SR0640), a vial of iodine solution and a vial of brilliant green (SR0040) into 100 mL of base medium. Mix thoroughly.

Quality Control

Cultural characteristics observed after incubation at 35-37°C for 24 hours

Quality control strains	Approx. Inoculum(CFU)	Expected Results
Salmonella typhimurium  ATCC14028	10 – 100	≥ 10 cfu on XLD
Escherichia coli  ATCC25922	> 104	≤100 cfu on TSA
Enterococcus faecalis ATCC29212	> 104	<10 cfu on TSA

Storage and Shelf Life

2-30℃，Keep container tightly closed, avoid direct sunlight.

Use before expiry date on the label.

 Precautions

1. When weighing the dehydrated medium, please wear masks to avoid causing respiratory system discomfort

2. Keep container tightly closed after using to prevent clumping.

Waste Disposal

Microbiological contamination was disposed by autoclaving at 121°C for 30 minutes.

Revision

On June 14, 2024

References

ISO 6579:2017 Microbiology of food and animal feeding stuffs – Horizontal method for the detection, enumeration and serotyping of Salmonella spp.