Rapid on-site identification of Lepiota brunneoincarnata-induced mushroom poisoning by simple DNA extraction and loop-mediated isothermal amplification strategy

Lepiota brunneoincarnata-induced mushroom poisoning has occurred widely in some areas of the world in recent years, resulting in high mortality and posing potential health risks to humans and pets. However, a rapid and sensitive method for the identification of L. brunneoincarnata is scarce. Loop-mediated isothermal amplification (LAMP) combined with visual dye reaction or lateral flow dipstick (LFD) was established for rapid on-site detection of L. brunneoincarnata. Simple DNA extraction was completed by the heating lysis method within 15 min. In addition, a specific LAMP primer set was designed targeting the internal transcribed spacer (ITS) sequence of L. brunneoincarnata, with no cross-reactivity against 22 other mushroom species. Sensitivity evaluation showed that the detection limits of visual LAMP and LAMP-LFD assays were 10 and 0.1 pg/mu L genomic DNA of L. brunneoincarnata, respectively. Moreover, the developed method was successfully applied to cooked mushroom and simulated vomitus, with detection limits of 1% admixture for the visual LAMP assay and 0.1% admixture for the LAMP-LFD assay. The whole detection protocol can be completed in 60 min without expensive instruments, which is suitable for the rapid identification of Lepiota brunneoincarnata-induced mushroom poisoning in the field.