Salmonella detecting board

1. Principle & application scope

Salmonella is a kind of intestinal bacteria that can cause food poisoning, gastroenteritis and typhoid, etc. People who infected salmonella have the symptom of nausea, vomit and diarrhea that could last for a week. It will lead to death without taking antibiotics medicine in time. Salmonella enteritidis infection usually comes from dairy, poultry and meat products, especially chicken and eggs. Salmonella detecting board which contains selective culture medium, special chromogenic reagent and bibulous gel could get the results after cultivation for 15-24 hours. This product is very suitable for food manufacturers and institute of food hygiene inspection. 

Executive standard: National Food Safety Standard, Microbiological Examination of Food Hygiene, Salmonella Test(GB 4789.4)

2. Using method

2.1 Sample preparation: Prepare the 1:10 solution by placing 25g or 25mL sample into 225mL sterile phosphate buffer solution or sterile saline. According to the pollution level of sample, prepare solutions of tenfold increasing dilution ratios if necessary.

2.2 Inoculation: Place the salmonella detecting board on a flat experiment table, Uncover the upper film of detecting board. Suck 1mL solution with sterile pipette, and then drop it slowly and evenly onto the filter paper. Cover the film quickly and shake the detecting board horizontally to let the solution be absorbed by filter paper. Stand it for 10s until the solution is adsorbed completely. Inoculate two detecting board for each sample solution.

2.3 Culture: Superimpose the detecting board; place them upside down in the incubator in the temperature of 36℃±1℃ for 15-24 hours.

3. Result

Colony of salmonella would show purplish red color while other colony would show blue after culture. Positive results should be tested again with other detection methods.

4. Additional explanatory note

4.1 The verification test shows that inoculating pure bacterium (including hydrogen sulfide negative strain) on detecting board will generate typical purplish red bacterial plaque; while other enterobacters show blue color and staphylococcus will not grow.

4.2 Dispose the used detecting boards according to the biology safety waste treatment rule, because there are live bacteria on them.