| Objective:To understand the pollution status and trends of microorganisms in the food and beverage industry in Jilin Province,and to provide theoretical basis for taking effective measures to reduce the risk of microbial contamination in import and export food.Simultaneous establishment and optimization of dd PCR detection of Listeria monocytogenes.Method: 1.In 2014,2015,Jilin Province,entry and exit of 8 kinds of food microbiological testing.(1)The study of 2014,2015,Jilin Province,1668 outbound food for microbiological testing.Samples include meat products,milk and dairy products,soy products,food and food products,beverages and mineral water,water samples,feed and feed additives,instant fruits and vegetables a total of 8 categories.Of which 574 samples in 2014,1094 in 2015.(2)Collection method In accordance with the "Food Safety Sampling Inspection Management Measures"(3)test items include: the total number of bacteria,coliform bacteria,mold and yeast,food-borne pathogens detection.Detection method: According to the "food hygiene microbiology test" GB / T4789-2003 / 2010,the collection of samples of four microbial detection.(4)statistical methods: detection data using SPSS17.0 for input and statistical analysis.The statistical evaluation of each index was carried out,and the X2 test and the four-table exact probability method were used to statistically deduce.α = 0.05.(1)Bacteria culture.(2)To establish a microarray digital PCR(dd PCR)method using the Hly A gene of Listeria monocytogenes as the target gene.(3)Optimize the probe concentration in the dd PCR reaction to verify the specificity,sensitivity,limit,and detection limit of the method.Result:1.1668 categories of food for microbiological testing.Mainly including meat products 727,accounting for 43.6%;milk and dairy products 207,accounting for 12.4%;98 fresh fruit and vegetables,accounting for 5.9%;beans and soy products 97,accounting for 5.8% Accounting for 11.2%;beverage and mineral water 102,accounting for 6.1%;food and its products 178,accounting for 10.7%;feed and additives 72,accounting for 4.3%.2.2014 samples of meat food,drinks and mineral water,and its products,feed and additives,water have different degree of microbial contamination,and milk and dairy ready-to-use fruits and vegetables,beans and bean products pass rate of one hundred percent.2015 samples in meat products,food and its products,water have different degree of microbial contamination,and milk and dairy products,instant fruits and vegetables,beans and bean products,drinks and mineral water,feed and additive pass rate of one hundred percent.1668 samples of total number of colonies of checking out of 48,the percent of pass is 97.12%;Among them,the water percent of pass is lowest,which is 80.75%;Beans and bean products,milk and dairy products,instant fruit and vegetable class qualified rate is highest,which is 100%.3.1596 samples of coliform bacteria(including Escherichia coli,heat-resistant coliform bacteria,E.coli)detection,detection of 15,the total pass rate of 99.06%;meat products with the lowest pass rate of 98.76%;beans and soy products,milk and dairy products and feed and feed products the highest pass rate of 100%.The qualified rate of all kinds of food coliforms increased by 2015 compared with 2014.4.754 samples were tested for mold and yeast,and five copies were detected,and the total rate was 99.34 percent.Milk and dairy products were lowest,at 98.55%;Legumes and soy products,and ready-to-eat fruits and vegetables,are Highest in 100%.The percentage of mold and yeast in all types of food increased in 2015 compared with 2014.2.Detection of Listeria monocytogenes by microarray digital PCR(dd PCR)methodtest items)were six foodborne pathogens detection.Among them,the detection rate ofListeria monocytogenes was 1.21%,followed by Salmonella 1.19%,0.55%Staphylococcus aureus,0.48% Enterobacter sakazakii,Not found EnterohemorrhagicEscherichia coli O157: H7 and Shiga Bacteria.The Fisher exact rate method was usedto compare the detection rate of different foodborne pathogens,the difference wasstatistically significant(F = 20.401,P <0.05).6.1481 samples of food-borne pathogens detection,detection of 28,the totalpass rate of 98.11%;feed and feed additives the lowest pass rate of 94.44%;food andfood products,beans and soy products,ready-to-eat fruits and vegetables Class,beverage and mineral water pass the highest rate of 100%.The food quality of allfood-borne pathogens in 2015 was higher than that in 2014.7.The total pass rate of all kinds of food microbes in 2015 is higher than that of2014,and the qualified rate is 94.97% and 92.51% respectively.(Χ2 = 4.133,P =0.042,P <0.05).Among them,except for feed and additives,the difference wasstatistically significant(P<0.05),and other food microbiological tests werestatistically significant The number of 2015 compared with 2014 have increased,nostatistical differences.8.Specific validation results show that the established dd PCR method is specificfor good.From the results of several experimental methods used in this experimentcan be seen that the most sensitive method is dd PCR method,can reach 10-9.Conclusion:1.The total number of samples of 1668 samples was 48 and the total pass ratewas 97.12%.Among them,the qualified rate of water samples was the lowest,whichwas 80.75%.The qualified rate of beans and soy products,milk and dairy productsand instant fruits and vegetables was the highest of 100 %.2.The total pass rate of the 1668 samples of coliform bacteria was 99.10%;thequalified rate of meat products was the lowest,98.76%;the qualified rate of beans andsoy products,milk and dairy products and feed and feed products was the highest.3.754 copies of mold and yeast detection of the total pass rate of 99.34%;milkand dairy products the lowest pass rate of 98.55%;beans and soy products,ready-to-eat fruits and vegetables qualified the highest rate of 100%.4.The detection rate of Listeria monocytogenes was 1.21% in 1481 samples of foodborne pathogens.Food and food products,beans and soy products,ready-to-eat 5.1481 samples(water samples according to the detection criteria without the fruits and vegetables,beverages and mineral water the highest pass rate of 94.44%;the highest pass rate of 94.84% for feed and feed additives,For 100%.5.In 2005,the total qualified rate of microbiological monitoring of inbound and outbound food in Jilin Province was higher than that in 2014.6.dd PCR method without nucleic acid standard,high sensitivity,specificity,easy operation,can be used for quantitative detection of Listeria monocytogenes gene. |
PDF Full Text Request