1. Principle & application scope

Vibrio parahaemolyticus which widely exist in seafood is the main cause for food poisoning and acute diarrhea. According to the statistics of Foodborne Disease Monitoring Network, in recent China, there is a significant upward trend of food poisoning that caused by vibrio parahaemolyticus. Vibrio parahaemolyticus 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 (the whole process takes less than 24 hours). Vibrio parahaemolyticus count plate which is easy to use and very convenient could be widely used in institutes of Food hygiene inspection and food factories.  

Executive standard : Food safety microbiology test, vibro parahaemolyticus test (GB/T 4789.7-2008)

2. Using method

2.1 Sample preparation: Prepare the 1:10 solution by placing 25g or 25mL sample into 225mL 3.5% sodium chloride solution.

2.2 Inoculation: Place the vibrio parahaemolyticus 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 count plate. Then cover the film gently and stand it for 10s to let the medium solidify. Inoculate two count plates for each sample and do a blank control test.

2.3 Culture: Pile up the count plates together and place them back to the ziplock bags and seal them well. Place them in the incubator with transparent side up. The quantity of superimposed count plates should not be more than 12. The temperature of culture is 36℃±1℃, and the time of culture is 15-24h.

3. Results

Colony of vibrio parahaemolyticus would show purplish red after the culture. Some types of non-objective bacteria such as vibrio cholerae and vibrio vulnificus can grow on the plate with the blue color. The sample shows positive result should be veritified by other detection methods or take the sample to do at least one more test using vibrio parahaemolyticus count plate.

4. Report

Detect whether there is any vibrio parahaemolyticus in 25g or 25mL sample.

5.Additional explanatory note

5.1 Vibrio parahaemolyticus count plate has passed the test of import and export inspection and quarantine bureau. Sensitivity of vibrio parahaemolyticus count plate reaches 8CFU/mL, consistent rate is more than 90% with industry standard of Chinese import and export inspection and quarantine.

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