【 Principle 】

Tryptone provides the carbon source, nitrogen source, vitamins, and growth factors required for bacterial growth; Bile salt No. 3 can selectively inhibit the growth of Streptococcus and Gram positive bacilli; Phosphates act as acid-base buffering agents to maintain pH stability; Sodium chloride maintains the osmotic pressure equilibrium of the system; Neomycin can inhibit the growth of some non target bacteria.

Main components

Composed of tryptone, bile salt 3, lactose, potassium dihydrogen phosphate, dipotassium dihydrogen phosphate, sodium chloride, sodium neomycin, 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 6 months.

This product is a disposable product.

Food induced diarrhea bacteria: National standard method, screening trace pathogenic Escherichia coli in meat, eggs, aquatic products and other samples at 44.5 ℃ high temperature.

Water source hygiene monitoring: Increase bacteria in drinking water, surface water, sewage, etc., screen for heat-resistant Escherichia coli and diarrheal Escherichia coli.

Processing environment screening: detecting the coating samples of the operating table, cutting tools, and cold chain equipment, tracing the sources of pollution, and controlling cross contamination.

Enrichment of food poisoning: The patient's feces, vomit, and leftover food are enriched with bacteria, and pathogenic Escherichia coli such as O157: H7 are isolated.

Secondary separation and enrichment: When suspicious colonies are detected on ordinary plates, mEC high-temperature enrichment is used to improve the sensitivity of pathogenic bacteria detection.

Laboratory quality control: Use diarrheal Escherichia coli as a positive control to verify the antibacterial and high-temperature screening performance of bile salts.

Escherichia coli O157: H7

Biological characteristics: Gram negative short rod bacteria, flagella, facultative anaerobic, no spores;

Belonging to the heat-resistant coliform group, tolerant to bile salts and high temperatures of 44.5 ℃; Sorbitol does not ferment, most strains ferment lactose and produce acid and gas; Carrying Shiga like toxin, it is hemorrhagic Escherichia coli EHEC; It can survive for a long time at low temperatures, tolerate conventional refrigeration environments, and can stably proliferate under high temperature screening conditions of 44.5 ℃. It can tolerate the antibacterial components of bile salts in improved EC broth.

Cultivation characteristics: 44.5 ℃, 18-24h, overall uniform and obvious turbidity of the liquid, and massive proliferation of bacterial cells; Fermentation of lactose produces acid and gas, and clear bubbles can be seen in the small tubes of Dursley fermentation; The original light yellow background color of the culture medium has no obvious discoloration or sediment layering; Bile salt and high temperature synergistically inhibit the growth of miscellaneous bacteria such as Staphylococcus, Streptococcus, and Salmonella, with only heat-resistant Escherichia coli such as O157: H7 showing dominant growth.