Evaluation of the Optimal Multiplex PCR Method for the Detection of Aspergillus Flavus and Aspergillus Parasiticus on Dried Peanut

摘要

Aspergillus flavus and Aspergillus parasiticus are the common aflatoxin producing species that usually infect on foodstuff in their production line from the field to the storage place such as peanut, corn, cereal, etc., especially in tropical country like Vietnam. Aflatoxins which are considered as derived secondary metabolites assigned as a group of mycotoxins produced by several species of the Aspergillus spp are potent hepatotoxins, immunosuppression, carcinogen that lead to mortality or reducing the productivity of farm animals. There has been a demand for effective method to detect these two species on dried food. In previous study, a multiplex PCR method were designed to improve the detection process of A. flavus and A. parasiticus and that method showed high sensitivity and specificity by being applied on artificially infected dried peanut. In this study, that multiplex PCR method would be evaluated by testing the presence of A. flavus and A. parasiticus on natural dried peanut kernels. On this purpose, the presence of A. flavus and A. parasiticus on the collected peanut from the market was determined using two method, the conventional culturing method in Institute of Hygiene and Public Health (THPH) and the mentioned multiplex PCR. The efficiency of multiplex PCR method would be evaluated by comparing fungi detection result of two methods using appropriate statistical tests. Next, fungal enrichment with distilled water overnight was applied to increase the detection percentage if the first analysis do not get the expected result The result showed that 54% results from PCR method was the same with culturing method, and after fungal enrichment, this percentage increased to 76% which suggested that these two method was not significantly different with each other. Therefore, this multiplex PCR method could have more advanced points than the culturing method in detection of A. flavus and A. parasiticus on foodstuff.