A Comparison of Four Molecular Methods for Detection of Aflatoxin-Producing Aspergillus in Peanut and Dried Shrimp Samples Collected from Local Markets around Pathum Thani Province, Thailand

Abstract

Aspergillus flavus is an aflatoxin-producing fungus which is poisonous to humans and animals when consumed. Detecting the fungus can help to prevent this danger. The four molecular methods, namely, conventional isothermal amplification (LAMP), PCR, quantitative LAMP (qLAMP), and qPCR, were compared to determine their efficiency for A. flavus detection. Thirty samples of peanut and dried shrimp were collected from 15 markets around Pathum Thani Province in Thailand. The samples were artificially infected with 108 conidia/ml of A. flavus for 1 hr and enriched for one day to represent real contamination. The results show that the sensitivity detection for A. flavus in PCR, LAMP, qPCR, and qLAMP was 50 ng, 5 ng, 5 pg, and 5 pg, respectively. Aspergillus in 30 peanut and dried shrimp from the market was detected by all four methods. The detection rate was about 20%, 60%, 100%, and 100% with PCR, LAMP, qPCR, and qLAMP, respectively. The molecular detection technique, especially LAMP, qPCR, and qLAMP, can detect this pathogenic fungi very rapidly with high sensitivity and reliability in comparison to conventional PCR.

Comparison of Time Course Detection of Human Male DNA from Blood Stains on Various Objects on Surface in a Natural Environment and in a Laboratory Using Loop-Mediated Isothermal Amplification (LAMP)

“…While outside the laboratory on day 45, none of the LAMP product was observed on all surfaces. However, when all DNA samples buried outside the laboratory were analyzed using qLAMP, the LAMP product was detected which agrees with the work of Kumsiri and Kanchanaphum [ 7 ] and Vichaibun and Kanchanaphum [ 8 ]. Their results indicated that the efficiency and sensitivity of qLAMP were better than those of conventional LAMP.…”

Microbial Contamination in the Coffee Industry: An Occupational Menace besides a Food Safety Concern?

“…These differences between molecular and culture-based methods have been observed previously where the low growth speed of fungal species was pinpointed as the main reason for the lack of their detection in culture systems, on the one hand, and high spore prevalent fungi as being on the basis of preferential detection by molecular-based methods, on the other hand [ 51 ]. Importantly, qPCR allows the detection of toxigenic species which are not possible to distinguish microscopically [ 52 ]. The presence of the Aspergillus sections Nidulantes and Circumdati also identified by molecular biology tools, reveals an important contamination by potential toxigenic fungi.…”

Aflatoxin's Toll on Health: Insights into Human and Animal Impact

“…These methods can provide rapid screening for aflatoxin-producing moulds in food and feed samples. For the conventional PCR and multiplex PCRbased detection, different housekeeping genes coding for ribosomal RNA and or genes, viz., aflM, aflP, aflR, and aflOinvolved in the aflatoxins biosynthesis (Adetunji et al, 2019) can be amplified to detect the contamination of Aspergillus flavus in food grains Mangal et al, 2016); whereas for the quantitative estimation using real-time PCR (qPCR) the Aspergillus norsolorinic acid reductase gene (NOR1) can be selected (Sardiñas et al, 2011;Kumsiri and Kanchanaphum, 2020). Similarly, LAMP-based strategy was developed to amplify the Norsolorinic Acid gene (nor1) to distinguish aflatoxigenic and non-aflatoxigenic fungal strains in rice grain (Douksouna et al, 2020).…”