Description
TS20114
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Description
AZIDE DEXTROSE BROTH is a selective medium for the detection of enterococci in water and sewage. The presence of enterococci serves as indicator for faecal contamination, particularly when this took place a long time ago and the less resistant coliform bacteria, including E.coli, may be already dead when the analysis is carried out.
Principle
Beef extract and tryptose are sources of nitrogen, carbon, vitamins, minerals and amino acids. Glucose is the fermentable carbohydrate. Sodium chloride maintains the osmotic balance of the medium. Sodium azide inhibits cytochrome oxidase in gram-negative bacteria.
Preparation
Check the content of the tube is homogeneous and clear and fermentation vials are inverted.
Technique
- Small sample volumes (up to 1 mL) can be added to the normal strength broth
- Incubate at 35 +/-2°C for 24 hours
- If no growth has occurred continue incubation for further 24 hours.
Interpretation of Results
If the broth becomes turbid due to microbial growth it is likely that enterococci are present. Confirm the presumptive result with a subculture in E.V.A. BROTH (code 20101). If the broth does not become turbid enterococci are not present.
Specifications
- Form: Glass tubes containing
- Storage: 10-25°C
- Shelf life: 2 years
- Incubation: 2°C, 24 hours
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