Abstract:
To eliminate the negative effects of aerosol contamination in the detection of aflatoxin-producing bacteria and to achieve rapid and visual detection of aflatoxin-producing bacteria, an anti-contamination loop-mediated isothermal amplification (LAMP) based on the heat-sensitive uracil-DNA glycosylase (UDG enzyme) and the lateral flow dipsticks (LFD) was developed. Rapid and visual detection of aflatoxin-producing bacteria was achieved by the UDG-LAMP-LFD system. Specific LAMP primers were designed for the key regulatory genes of aflatoxin synthesis,
omt-1,
ver-1, and
aflR. The amplification products of
aflR,
omt-1, and
ver-1 genes corresponding to a 10
8 dilution of U-base-containing amplification products were eliminated by this system, thus achieving anti-contamination effects. The sensitivity of this system for the three target genes was determined to be 1×10
−3, 1×10
−5, and 1×10
−6 ng/μL, respectively, and the precision was measured to be less than 5%, with strong specificity and anti-interference ability being demonstrated. Aflatoxin-producing bacteria were detected with high sensitivity, specificity, and visualisation by the UDG-LAMP-LFD assay system, while false positives caused by aerosol contamination were avoided. The UDG-LAMP-LFD system was demonstrated to be suitable for the timely detection of aflatoxin-producing bacteria in grain and oil raw materials prior to processing and storage, so that the risk of contamination was predicted in advance, prevention and control measures were implemented, and loss reduction and quality improvement were achieved.