1. Principle & application scope

Enterobacter sakazakiiis a kind of serious pathogenic bacteria that can result in neonatal meningitis, enterocolitis, and bacteremia etc, also these diseases can cause neurological sequelae.and hypotrophy. Mortality rate is more than 50% to infants who suffer from these diseases. Enterobacter sakazaii count plate which adopted 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). Enterobacter sakazaii 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 national standard ,

                                 Food microbiology examination: enterobacter sakazakii (GB4789.40)

2. Using method

2.1 Sample preparation: Prepare the 1:10 solution by placing 100g or 100mL sample into 900mL sterile saline. Prepare the 1:100 sample solution by sucking 1:10 sample solution into 9mL sterile saline.

2.2 Inoculation: Place the enterobacter sakazaii count plate onto sterile experiment table, uncover the film on the surface. Suck 1mL solution with sterile pipette , then drop it slowly and evenly onto the count plate. Cover the film gently and standing for 10s to let the medium solidify. Inoculate two count plates for each sample solution. 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 less than 12. The temperature of culture is 36℃±1℃, and the time of culture is 15-24h.

3. Results

Colony of enterobacter sakazaii would show bluish green after the culture. The sample which shows positive result should be veritified by other detection methods or take the sample to do at least one more test using enterobacter sakazaii count plate.

4. Report

Detect whether there is any enterobacter sakazakii in 100ml or 100g samples.

5.Additional explanatory note

5.1Enterobacter sakazaii count plate could test enterobacter sakazaii with high sensitivity and specificity, other colonies such as E.coli and salmonella will show purple after the culture. While staphylococcus aureus ,Escherichia coliform and vibrio parahaemolyticus are restrained.

5.2 Consistent rate of enterobacter sakazaii count plate is more than 80% with traditional agar plate method. Lower detection limit of this product is 4CFU/ml.

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