Screening of selected grains and cashew nuts in South East Nigeria for aflatoxigenic fungi by multiplex PCR technique

*Corresponding Author Email: ikennatex@yahoo.com; ikenna.nwachukwu@futo.edu.ng Contamination of feeds by aflatoxins has been of global concern as a result of their noxious effects on human and animal health as well as their importance in international trade. Timely assessment of fungal contaminants, characterization and identification of the mycotoxigenic species are very necessary, not just for assessing food quality, but also for the development of strategies to control and ensure food safety. In this study, fungal species isolated from selected grains and cashew nut samples from south east Nigeria were screened for aflatoxigenic potential by Multiplex PCR Technique. Primers were designed specifically for the amplification of genes responsible for aflatoxigenic biosynthesis pathways. The necessary experimental conditions were standardized to achieve optimum mPCR result. The DNA extracted from seven fungal isolates were subjected to multiplex PCR using nor-1 (F&R), ver-1 (F&R), omtA (F&R) and aflR (F&R) as the primer pairs. DNA samples from AF4 and AP1 possessed the four genes needed for aflatoxigenic biosynthesis pathways. AF1 and AP3 did not show any positive reaction to the four genes after amplification following PCR. However, AF2 and AF3 showed positive response to the two structural genes (nor-1and ver-1) and also for the regulatory gene (aflR) but were negative to the omtA structural gene. The DNA sample of AP3 was only reactive to the structural gene aflR but, did not have the 3 structural genes. Multiple PCR assay has proven to a more reliable, accurate and sensitive molecular tool for the detection and characterization of mycotoxinproducing fungi from agricultural commodities.