Culture methods and conventional PCR for detection the aflatoxigenicity of Aspergillus flavus in local isolates samples

Abstract

Abstract: One of the main carcinogenic aflatoxins producers belong to Aspergillus section Flavi is Aspergillus flavus. Not all fungi from Aspergillus section Flavi produce aflatoxins. It is important to use reliable and accurate methods to differentiate Aspergillus species in to toxigenic and nontoxigenic strain. Soil and maize grains of Sulaimani governorate were subjected for our study. Primary isolation and identification of isolates performed based on using the morphological features of Aspergillus flavus on selective and differential media. PCR-based protocol used for more accurate identification of isolates as Aspergillus flavus, which based on the multi-copy internal transcribed region of the rDNA unit (ITS1-5.8S-ITS2 rDNA). Different culture and highly specific sensitive methods used for determining aflatoxigenicity of our isolates. As a culture methods, colony fluorescence, ammonia vapor test and characteristics of Aspergillus flavus on aspergillus differentiation media have been used. Accurate detection of aflatoxigenicity of our isolates confirmed by using conventional PCR for detection of the potential gene markers (aflD and aflO),in the aflatoxin biosynthesis. Out of eighteen isolates of Aspergillus flavus, aflatoxigenicity seven of them have been detected and confirmed by both culture and molecular methods. In conclusion both culture and molecular methods could be used for rapid detection of aflatoxigenicity of Aspergillus flavus.