Molecular characterization of mycobiota and aflatoxin contamination of retail wheat flours from Jeddah markets.

The mycological profile of the retail wheat flour selling in different markets at Jeddah (Kingdom of Saudi Arabia) was studied. The most common genera were Aspergillus (isolated from 70% of the tested samples), Penicillium (30%), Eurotium (14%), and in a lesser extent Fusarium (20%) and Alternaria (18%). Twenty-nine strains of Aspergillus flavus were screened for their ability to produce aflatoxins (AFs). Four strains produced only aflatoxin B1 (AFB1), two strains produced AFB1 and aflatoxin B2, and one strain produced AFB1, aflatoxin G1, and aflatoxin G2. Random amplified polymorphic DNA-polymerase chain reaction technique could not differentiate between toxigenic and nontoxigenic strains of A. flavus. AF regulatory gene was detected in three flour samples and in seven A. flavus isolates.