Development Of Rapid Test Tablet Matrix For Staphylococcus Aureus In Food

In recent years,with the people's living standard rising,food safety incidents are increasing,so food safety incidents has attracted more and more attention,which is an important cause of microbial contamination,Staphylococcus aureus widely exists in nature,caused by food poisoning incidents.Staphylococcus aureus is not high on the nutritional requirements,and high salt tolerance,easy contamination of milk and dairy products,meat,aquatic products and other food,is a kind of important food borne pathogens,which produces a heat stable enterotoxin can cause food poisoning,the resulting harm after Salmonella and Vibrio parahaemolyticus.At present,the quantitative detection method of Staphylococcus aureus in food is mainly based on traditional plate culture method,and at the same time,subsequent biochemical identification is needed.The operation is time-consuming and laborious,and can not meet the needs of on-site detection.Secondly,there are test film method,color culture medium counting method,PCR technique,fluorescent PCR method,immunological method and so on.In this paper,the formula of Staphylococcus aureus test film culture medium was screened,and the performance of the test film medium was verified at last.Objective: according to the enzyme and substrate of Staphylococcus aureus produced with the chromogenic reaction medium,preparation of Staphylococcus aureus test piece,the medium is to add some nutrients,accelerant and inhibitor and chromogenic substrate based on the nutrient agar.Methods: Based on nutrient agar,respectively adding nutrients(peptone,yeast),accelerator(sodium pyruvate and glycine)and inhibitor(sodium chloride,lithium chloride,potassium tellurite,glycine),through the single factor experiment selected a range of values,the optimum ratio.Finally,different concentrations of chromogenic substrates(5-bromine,-4-,chlorine,-3-indole phosphates)were added to the basal medium to observe its color effect,and the final Staphylococcus aureus test medium was obtained.The 24 h time was cultured at 37 ?,and the effect of Staphylococcus aureus test medium was tested from specificity,sensitivity,culture time,stability,bacterial yield,and the comparison between different food detection and national standard BP tablet.Results: through single factor experiment and the experiment was Staphylococcus aureus test culture medium formula: peptone 20g/L,yeast 3g/L,sodium pyruvate 8g/L,glycine 12.5g/L,sodium chloride 30g/L,3g/L lithium chloride,potassium tellurite 30mg/L,benzene alcohol 3ml/L,pH value is 7.4.The test media had a good specificity for Staphylococcus aureus,Staphylococcus aureus colonies were blue,and other bacteria were not growing,so they were very easy to observe.The sensitivity can reach a digit,37 degrees in the best training time is about 24 h,at 4 degrees and 28 degrees for different time showed no difference detection,36 ? storage time is longer,the greater the impact on the test results,test medium isolated rate was 81.2 ± 2.90%,than the national standard method contrast positive detection the rate of increase of 7%.Conclusion: Staphylococcus aureus test piece has strong specificity,high sensitivity,good stability,short time and easy operation.It is suitable for rapid detection of staphylococcus aureus in food.