1. Principle & application scope

E.coli STEC can produce Non O157:H7 Escherichia coliform, including E.coli O111 appears in Japan and E.coli O104 appears in German and other countryies in Europe. This kind of E.coli which parasitizes cows, sheep and other animal can cause diarrhea, colitis, and uremia. There are 60 kinds of STEC coliform serotypes are found all over the world, and some non O157 are verified that they are relevant to some food-borne disease. Therefore, these kind of microorganism should be paid attention to and supervised. E.coli STEC count plate which adopts imported selective medium and specific enzyme chromogenic reagent is a kind of disposable rapid test product that can greatly simplify detection process and the result can be got after culture for 15-24h. It is suitable to inspection institutes and food industries.

2.  Using method

2.1 Sample preparation: Prepare the 1:10 solution by placing 25g or 25mL sample into 225mL sterilized saline. Them prepare 1:100 solution by sucking 1ml 1:10 dilution with sterile pipette into 9ml sterile saline.

2.2 Inoculation: Place the E.coli STEC count plate onto sterile experiment table, uncover the film on the surface. Suck 1mL solution with sterile pipette ,and then drop it slowly and evenly onto the plate. Then cover the film gently and stand it for 10s to let the medium solidify. At last press it lightly by hand .Inoculate two count plates for each dilute ratio sample solution, and do a blank control test.  

2.3 Culture: Pile up the plates together and place them back to ziplock bags  and seal them well. Then place them in the incubator with transparent side up . The quantity of superimposed count plates is no more than 12. The temperature of culture is 36℃±1℃, and the time of culture is 15-24h.

3. Results

E.coliSTEC would show purplish red while other coliform would show blue after the culture. Tje sample which shows positive results should be veritified by other detection methods or take the sample to do at least one more test using E.coli STEC count plate..

4. Additional explanatory note

Pay attention that unused count plates should be disposed timely according to biology safety waste treatment rule because there are live bacteria on them.