Enterococci · Detection in water
Azide Dextrose Broth – faecal streptococci in water and sewage
Azide Dextrose Broth is a selective broth for the detection and MPN count of faecal streptococci and enterococci in water and sewage.
- Sodium azide selective broth
- For faecal streptococci
- Water and sewage
How Azide Dextrose Broth works
Sodium azide inhibits Gram-negative bacteria, while dextrose and peptones support the growth of enterococci and streptococci. Turbidity indicates presumptive growth, which is confirmed on bile esculin azide agar.
Technical data
| Final pH | 7.2 ± 0.2 |
| Storage | Cool, dry place away from bright light; keep the container tightly closed |
| Shelf life | 3 years |
Applications and practical notes
Enterococci and streptococci are indicators of faecal contamination in water and sewage. Typical applications include:
- Drinking and recreational water
- Waste water and sewage
- Environmental samples
- Food and dairy products
Working with Azide Dextrose Broth: Use multiple tubes for an MPN count and confirm turbid tubes on Bile Esculin Azide Agar.
Good practice with dehydrated media: keep the bottle tightly closed in a cool, dry place, weigh the powder quickly to avoid moisture uptake, and use fresh distilled or deionised water. Check the pH of each new batch after preparation and before use, and label prepared media with the date. Performance of each lot can be verified with reference strains according to ISO 11133, the standard for the preparation, production, storage and performance testing of culture media.
About the Enterococcus methods: intestinal enterococci are indicators of faecal contamination of water. ISO 7899-2 counts them by membrane filtration on Slanetz and Bartley Agar, where typical colonies are red, maroon or pink, and confirms them by transferring the membrane to Bile Esculin Azide Agar, where esculin hydrolysis turns the medium black. In food, enterococci are counted on bile esculin azide media. Streptococci are cultivated on blood agar, where the type of haemolysis is read, and grouped by Lancefield antigens. COLO.Science offers media, supplements, rapid tests and identification kits for these methods.
Complete sets from one supplier: COLO.Science supplies culture media, supplements, rapid tests, identification kits and QC strains as complete sets for the method you follow. Send us your sample types and standards, and we will prepare an offer with the matching products and documentation.
Azide Dextrose Broth is supplied by COLO.Science in the pack sizes listed under Ordering information. For larger quantities, regular deliveries or method-specific sets that include Azide Dextrose Broth, please send us a request. With every delivery of Azide Dextrose Broth you receive the lot number and expiry date, and on request we send the available documentation for Azide Dextrose Broth.
Where Azide Dextrose Broth fits in Enterococcus and Streptococcus testing
- Enumeration in water – membrane filtration on Slanetz and Bartley Agar
- Confirmation – transfer of the membrane to Bile Esculin Azide Agar; Bile Esculin Agar for single colonies
- Streptococci – Blood Agar Base with blood for haemolysis, Mitis Salivarius Agar with potassium tellurite
- Identification – Lancefield grouping latex, qPCR or LAMP for Enterococcus faecalis
See all Enterococcus and Streptococcus products in the Microbiology Catalogue →
Ordering information
| Product | COLO code | Pack |
|---|---|---|
| Azide Dextrose Broth | PRO8180 | 250 g |
Product notice: preparation, storage conditions and shelf life are given on the label. Technical data on this page are for orientation; the label and the lot documentation apply. B2B prices are quoted net, excluding VAT.
Sales and technical support
COLO LabExperts
Polje ob Sotli 4, SI-3255, Slovenia
Quotations and technical support for culture media and microbiology products across our international sales territory. B2B prices are net, excluding VAT.
COLO.SCIENCE | MICROBIOLOGY SUPPORT
Need the complete set for your method?
Send the sample type, target organism and the standard you follow. COLO.Science will put together the media, supplements, QC strains and confirmation tests for the whole procedure.
