Multi-locus phylogenies revealed a new record of Entoloma species (Basidiomycota, Agaricales) responsible for gastrointestinal poisoning

Abstract

The frequency of mushroom poisoning has increased worldwide. In Thailand, reports on mycetism between 2013 and 2021 included 18 cases of Entoloma poisoning. Incorrect identification of toxic Entoloma species occurs during wild mushroom foraging, and their consumption results in gastrointestinal irritation. Morphological distinction of mushroom leftovers is difficult; however, we aimed to characterize 40 clinical samples to the genus level using macroscopic and microscopic analyses. Furthermore, species identification of the poisonous Entoloma was performed based on multi-locus phylogenetic analyses of the nuclear internal transcribed spacer region, nuclear large subunit ribosomal DNA, and mitochondrial small subunit ribosomal DNA. Phylogenetic trees reconstructed using maximum likelihood and Bayesian methods demonstrated that forty samples of mushroom remnants formed eight robust clades with six identified species. The findings confirmed the taxonomic identity of E. griseolazulinum as a new record of species causing gastrointestinal poisoning. The use of molecular annotation provided a foundation for the development of accurate methods for identification of toxic mushrooms.