Streptococci · Selective isolation
Mitis Salivarius Agar – selective medium for oral streptococci
Mitis Salivarius Agar is a selective medium for the isolation of Streptococcus mitis, S. salivarius and other streptococci and enterococci from mixed samples. It is completed with the Potassium Tellurite Supplement.
- Selective for streptococci
- Completed with potassium tellurite
- Incubation in 5 % CO₂
How Mitis Salivarius Agar works
Trypan blue, crystal violet and potassium tellurite inhibit most Gram-negative and many Gram-positive bacteria. S. salivarius forms blue gum-drop colonies, and enterococci form black colonies by reducing tellurite.
Typical colony appearance
| Organism | Colonies |
| Streptococcus salivarius | Light blue gum-drop colonies |
| Enterococcus faecalis | Blue-black colonies |
| Escherichia coli | Inhibited |
Technical data
| Preparation | 90.0 g/L; boil, autoclave 121 °C 15 min; cool to 50–55 °C and add 1 vial Potassium Tellurite Supplement per 500 mL |
| Final pH | 7.0 ± 0.2 |
| Incubation | 36 °C, 5 % CO₂, 24–48 h |
| Storage | Dry, dark place; keep the container tightly closed |
| Shelf life | 3 years |
Applications and practical notes
Enterococci and streptococci are tested in drinking, bathing and waste water, in food and in clinical and dairy laboratories, for example according to ISO 7899-2. Typical applications include:
- Drinking, bathing and recreational water
- Waste water and environmental samples
- Food and dairy products
- Clinical and veterinary microbiology
Working with Mitis Salivarius Agar: Add one vial of the Potassium Tellurite Supplement per 500 mL to the base cooled to 50–55 °C and incubate the plates in 5 % CO₂.
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.
Mitis Salivarius Agar is supplied by COLO.Science in the pack sizes listed under Ordering information. For larger quantities, regular deliveries or method-specific sets that include Mitis Salivarius Agar, please send us a request. With every delivery of Mitis Salivarius Agar you receive the lot number and expiry date, and on request we send the available documentation for Mitis Salivarius Agar.
Where Mitis Salivarius Agar 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 |
|---|---|---|
| Mitis Salivarius Agar | PRO7556 | 500 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
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Quotations and technical support for culture media and microbiology products across our international sales territory. B2B prices are net, excluding VAT.
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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.
