PREVALENCE OF AFLATOXIN BIOSYNTHESIS GENES ACCORDING TO AFLATOXIN LEVELS IN FEEDSTUFF SAMPLES

Background and Aim:Aflatoxins are amongst the major mycotoxins produced by various species of Aspergillus, particularly A. flavus and A. parasiticus. This study aims to study the effect of aflatoxin genes aflPand aflQ on aflatoxigenic species of A. flavus and A. parasiticus in cattle feed.Methods:To conduct the study, 121 samples of cattle feed were collected and then were isolated and cultured based on macroscopic and microscopic methods. Moreover, PCR technique was also used to undertake a molecular examination of the isolated Aspergillus. To identify the aflatoxigenic species, 10 Aspergillus fungi, containing one or two positive aflatoxin genes were randomly selected and examined under the ultraviolet light. Finally, their aflatoxin content was evaluated based on High Performance Liquid Chromatography.Results:The results indicate that 55.37% of 121 samples of the cattle feeds contaminated by Aspergillus fungi. Among these isolated samples, 67.16% has aflP and 70.14% has aflQ, and the findings of HPLC also confirms that aflatoxigenic isolates are more common than their non-aflatoxigenic counterparts. Among 10 species of A. flavus and A. parasiticus collected from cattle feeds, wheat bran produced the highest amount of aflatoxin, in which aflatoxin B1 accounted for the highest amount and aflatoxins G1 and G2 accounted for the least amount. It is noteworthy that aflatoxin B1 was produced in all species while aflatoxin G2 was not produced. Aflatoxins B2 and G1 were produced in all species of A. parasiticus and some species of A. flavus.Conclusion:Controlling cattle feeds contaminated by Aspergillus fungi can secure them against aflatoxin contamination and prevent them from entering the human and animal health cycle

Keywords:

Aflatoxin , Aspergillus flavus , Aspergillus parasiticus , PCR , HPLC , feedstuff