What is the method to detect total colony and E.coli in seafood oyster?

The total number of colonies is measured by the Petri dish method, the unit is one/ml (how many complete colonies are there in each milliliter or milligram), the method is: under the premise of aseptic operation, absorb 1ml of the original liquid and add it to the 9cm Petri dish, pour in 3-5ml of nutrient agar (at 37℃), cultivate it for 24 hours at 37℃ in a warm box and then take out to calculate the total number of its colony units.

Escherichia coli with fermentation method, the unit is MPN/100ml (per 100 milliliters or milligrams of the sample inside the maximum possible colony-forming units) method is 15 tubes (suitable for food) or 9 tubes (suitable for non-food, such as swimming pool water) with lactose bile salt fermentation tube.

Pathogenic bacteria with culture method, as long as the corresponding chemical, biological tests can be judged as a pathogenic are positive.

Expanded information:

Coliforms, E. coli and Staphylococcus aureus are routine items in food microbiological testing, and the traditional methods usually used require a great deal of manpower and resources and long incubation times, whereas the use of Petrifilm Coliform and E. coli Counting Papers (PEC) and Petrifilm Staphylococcus aureus Test Pieces (STX) is not. Staphylococcus test piece (STX) only takes 24~48 hours.

The Coliform and E. coli Test Sheets contain a modified VRB (Violet Red Bile) medium and a glucopurinidase indicator. The vast majority of E. coli can produce R a glucopuricase, which reacts with the indicator in the medium to produce a blue precipitate surrounding the E. coli colonies, and the surface is covered with a gelatinous film that retains the gas produced by the fermentation of lactose, forming blue and dark blue colonies with gas bubbles attached.

Baidu Encyclopedia - Rapid Test Piece Method