Foodborne illness caused by muscarine-containing mushrooms and identification of mushroom remnants using phylogenetics and LC-MS/MS

A 9-year analysis of wild mushroom consumption in Thailand during 2010–2018 revealed 61 patients from 14 cases exhibiting mushroom poisoning most likely from foraged mushrooms in the family Inocybaceae. Fifty-four patients experienced neurotoxic syndromes, while seven patients presented symptoms relating to gastrointestinal irritant mushroom poisoning. The causative agents for this foodborne illness were primarily recognised based on mushroom samples left from food preparation. These remnants however, lacked sufficient information for accurate taxon identification. Hence, this study aimed to characterise the suspected mushroom samples obtained from clinically reported cases based on multi-locus sequence data and toxic alkaloid diagnosis. Multi-locus phylogenetic analyses were conducted using maximum likelihood and Bayesian approaches. The resulting concatenated phylogenetic trees confirmed that all 26 clinical samples of mushrooms belonged to the family Inocybaceae, and were clustered into highly supported clades of Inocybe, Inosperma and Pseudosperma. In addition, LC-MS/MS detection revealed the presence of alkaloid muscarine as the major toxic substance in all samples of Inosperma and Pseudosperma. Ingestion of these muscarine-containing mushrooms showed a short latent period with signs of perspiration, hypersalivation, lachrymation, bradycardia, diarrhoea and fatigue. Consumption of Inocybe did not reveal these muscarinic symptoms, but the patients experienced similar toxicity effects to gastrointestinal irritant mushroom poisoning, including nausea, vomiting, intestinal colic and xerostomia. Data on molecular annotation and toxic chemical composition of the wild poisonous mushrooms obtained in this study are relevant for food safety and also required for better medical treatment decision making.