Detection of Aflatoxin B1-producing strains from pistachio orchards soil in Iran by multiplex polymerase chain reaction method.

BACKGROUND AND PURPOSE

The current study aimed to report a multiplex polymerase chain reaction (PCR) assay as a monitoring technique to differentiate aflatoxigenic from non-aflatoxigenic strains of isolated from pistachio orchards soil.

MATERIALS AND METHODS

In total, 25 strains were isolated from soil samples of pistachio orchards. To test the strains for Aflatoxin B (AFB)-producing ability, thin-layer chromatography (TLC) was used and the amounts of AFB were measured by high-performance liquid chromatography (HPLC). Multiplex PCR was used as a genome-based method to detect genes responsible for AFB production by and the results were analyzed in terms of speed and specificity of detection. A set of four primers was designed specifically for the , , , and genes which are commonly present in aflatoxin biosynthetic pathways.

RESULTS

The AFB production by the strains ranged from 0 to 321 ρg/μl. Four-band patterns of the primer sets were observed only in AFB-producing strains. Moreover, 18 out of the 25 strains showed all four bands belonging to , , , and , whereas 7 strains did not display , or -related bands, in non-toxigenic and low toxin-producing .

CONCLUSION

The multiplex PCR is a supplementary strategy to current conventional mycotoxin analytical techniques, such as TLC and HPLC. It could be used as an efficient method to differentiate aflatoxigenic from non-aflatoxigenic strains of . This achievement is crucial to minimize fungal contamination of food, feed, and agricultural commodities, thereby reducing the risk of subsequent aflatoxin consumption.