Yersinia · Selective isolation
Chromogenic Yersinia enterocolitica Agar – pathogenic strains in colour
Chromogenic Yersinia enterocolitica Agar is a selective medium for the isolation of Yersinia enterocolitica that separates presumptive pathogenic strains from non-pathogenic ones by colony colour. It is completed with a selective supplement.
- Pathogenic strains: purple-red colonies
- Non-pathogenic strains: blue or inhibited
- Incubation at 28 °C
How Chromogenic Yersinia enterocolitica Agar works
Chromogenic substrates reveal enzymes that differ between pathogenic and non-pathogenic biotypes, so presumptive pathogenic Y. enterocolitica grows as light purple to purple-red colonies. Selective agents inhibit E. coli, enterococci and other accompanying bacteria.
Typical colony appearance
| Organism | Colonies |
| Pathogenic Y. enterocolitica | Light purple to purple-red colonies |
| Non-pathogenic Yersinia | Metallic blue colonies or inhibited |
| E. coli, Enterococcus faecalis | Inhibited |
Technical data
| Preparation | 30.4 g/L; boil with stirring until dissolved; cool to about 50 °C and add the selective supplement |
| Final pH | 7.0 ± 0.2 |
| Incubation | 28 ± 1 °C, 48 h |
| Storage | Powder 2–30 °C, dry and dark; prepared plates 2–8 °C up to one week |
| Shelf life | 2 years |
Applications and practical notes
Yersinia enterocolitica grows at refrigeration temperatures and is tested in pork, milk, vegetables and water, for example according to ISO 10273. Typical applications include:
- Pork and pork products
- Raw milk and dairy products
- Vegetables and drinking water
- Veterinary and clinical laboratories
Working with Chromogenic Yersinia enterocolitica Agar: Heat the base only until dissolved, cool to about 50 °C, add the selective supplement as stated on the label and keep prepared plates at 2–8 °C for no more than one week.
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 Shigella and Yersinia methods: ISO 21567 describes the detection of Shigella in food by enrichment in Shigella broth with novobiocin, plating on selective agars such as MacConkey, XLD and Hektoen enteric agar, and biochemical and serological confirmation. ISO 10273 describes the detection of presumptive pathogenic Yersinia enterocolitica by enrichment at 25 °C and plating on CIN agar, followed by tests that separate pathogenic from non-pathogenic strains. COLO.Science offers media, supplements, rapid tests, identification kits and QC strains 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.
Chromogenic Yersinia enterocolitica 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 Chromogenic Yersinia enterocolitica Agar, please send us a request. With every delivery of Chromogenic Yersinia enterocolitica Agar you receive the lot number and expiry date, and on request we send the available documentation for Chromogenic Yersinia enterocolitica Agar.
Where Chromogenic Yersinia enterocolitica Agar fits in Shigella and Yersinia testing
- Enrichment – Shigella broth with selective supplement; for Yersinia a peptone-sorbitol-bile type broth
- Selective isolation – Chromogenic Shigella Agar, Desoxycholate Citrate Agar, XLD; for Yersinia CIN agar and Chromogenic Yersinia enterocolitica Agar
- Screening – qPCR or LAMP kits after enrichment
- Confirmation and QC – biochemical identification kits and reference strains
See all Shigella and Yersinia products in the Microbiology Catalogue →
Ordering information
| Product | COLO code | Pack |
|---|---|---|
| Chromogenic Yersinia enterocolitica Agar | PRO7592 | 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.
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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.
