Iranian Journal of Toxicology

en Study of the Incidence of Aflatoxin-Producing Genes in Environmental Isolates of Aspergillus flavus by PCR in Southwestern Iran, Yasuj عمومى General پژوهشي Research Background: Aflatoxins are carcinogenic mycotoxins produced by Aspergillus flavus and pose health risks in warm, humid regions. Despite favorable conditions in southwestern Iran, the prevalence of key biosynthesis genes (aflD, aflS, aflR) in local environmental isolates remains unknown. The present study determined the incidence of A. flavus from Yasuj, Iran. Material and Methods: In this cross-sectional study conducted in 2025, a total of 250 environmental specimens were collected from water, soil, air, and food products. A. flavus isolates were identified morphologically and confirmed by calmodulin gene sequencing. The presence of aflD, aflS, and aflR was detected using conventional polymerase chain reaction (PCR) with gene-specific primers. Gene frequencies were compared across environmental sources using Fisher's exact test. Results: A total of 30 A. flavus isolates were confirmed. Prevalence was as follows: aflD (66.7%), aflS (56.7%), aflR (33.3%). Soil yielded the most isolates (n=14), with aflD predominating (85.7%). Distribution of aflD varied significantly across sources (P=0.034), while aflS and aflR did not. Isolates from moldy fruit, bread, and fruit peel lacked all three genes. Conclusions: Structural genes (aflD and aflS) are more conserved than the regulatory gene (aflR) in environmental A. flavus from this region, particularly in soil. Gene absence in certain foods suggests substrate-specific influences on gene maintenance. These findings offer molecular epidemiological insights for targeted aflatoxin control in southwestern Iran.   Aflatoxins, Iran, Mycotoxins, Polymerase Chain Reaction, Public Health 0 0 http://ijt.arakmu.ac.ir/browse.php?a_code=A-10-1538-1&slc_lang=en&sid=1 Sadegh Nouripour Sisakht nooripoor8561@gmail.com 0000-0002-1158-4318 No Cellular and Molecular Research Center, Yasuj University of Medical Sciences, Yasuj, Iran Hadi Ebrahimi hadiebmed@gmail.com 0009-0002-7936-9160 No Student Research Committee, Yasuj University of Medical Sciences, Yasuj, Iran Mahsa Kaveh Mahsakaveh99@yahoo.com No Student Research Committee, Yasuj University of Medical Sciences, Yasuj, Iran Maral Gharaghani maralgharaghani@gmail.com 0000-0002-0144-3407 Yes Medicinal Plants Research Center, Yasuj University of Medical Sciences, Yasuj, Iran