【 Principle 】

Protein peptone, yeast extract, and beef extract provide nitrogen sources, vitamins, and minerals; Sorbitol and glucose provide fermentable carbon sources; Sodium thiosulfate can be reduced by certain bacteria to hydrogen sulfide, which reacts with iron ions to form black ferrous sulfide; Phenol red is a pH indicator, which turns fermented sugar yellow when producing acid and red when producing alkali; Sodium chloride maintains a balanced osmotic pressure; Agar is a coagulant for culture media.

Main components

Composed of peptone, yeast extract, beef extract, sorbitol, glucose, phenol red, sodium chloride, ammonium citrate, sodium thiosulfate, agar, and distilled water.

Storage conditions and expiration date

Storage conditions: This product should be stored in a dark environment at 2-8 ℃.

Validity period: The unopened original packaging has a validity period of 3 months.

This product is a disposable product.

Yersinia biochemical screening: Inoculate suspected colonies of CIN-1 and improved Y plates, and perform rapid screening through glucose, lactose fermentation, urease, and motility.

Distinguish other intestinal pathogenic bacteria: urease positive, non fermenting lactose, glucose producing acid and gas, no H ₂ S, exclude Escherichia coli, Salmonella, Shigella, and Proteus.

Temperature dependent dynamic identification: Dynamic at 25 ℃ and non dynamic at 37 ℃ serve as key identification criteria for Yersinia pestis.

Review of foodborne outbreak strains: Unified biochemical typing of diarrhea related strains isolated from refrigerated food to assist in epidemiological tracing.

Bacterial strain confirmation of mesenteric lymphadenitis: Rapid biochemical screening of fecal isolates from patients with abdominal pain and suspected appendicitis to assist clinical diagnosis.

Complete testing process: Connect with cold enrichment and selective plate separation to complete the first step of biochemical screening for suspicious strains.

Distinguishing Yersinia species: Based on differences in sugar fermentation and urea reaction, preliminary differentiation was made between Yersinia enterocolitica and Yersinia pseudotuberculosis and other closely related species.

Yersinia enterocolitis

Biological characteristics: Gram negative short ball bacillus, with both ends heavily stained; Powered at 25 ℃, unpowered at 37 ℃; Cold loving, capable of proliferation at 4 ℃; Fermentation of glucose produces acid but not gas, and does not ferment lactose; The vast majority of strains are urease positive; Not producing hydrogen sulfide. Cold stored food contamination can cause acute enteritis and mesenteric lymphadenitis; Tolerant to the environment of this culture medium, it can metabolize carbohydrates and urea normally.

Improved Krebs disaccharide culture reaction: can be read at 25 ℃/37 ℃;

Bottom layer (glucose): yellow (fermented glucose produces acid), no bubbles, no gas production;

Slope (lactose): red (unfermented lactose);

Urea layer: The entire culture medium turns pink/dark red (urease positive, producing alkali by decomposing urea);

No black sediment (does not produce H ₂ S); Cultivate the puncture line at 25 ℃ and spread it in a cloud like pattern around (with flagella and positive motility); At 37 ℃, only the puncture line grows without diffusion.