Molecular identification of Amanita ibotengutake from patient vomit specimens in mushroom poisoning.

Abstract

Background: Mushroom poisoning remains a global public health challenge, with morphological identification accuracy limited to 17%. This study aimed to demonstrate molecular identification from vomit specimens in a patient with mushroom poisoning.

Methods: Following a mushroom poisoning incident in Yamagata Prefecture, Japan (September 2018), we collected four vomit specimens from a female patient. Deoxyribonucleic acid analysis targeting the internal transcribed spacer region using polymerase chain reaction and sequencing was performed on three of four specimens, while liquid chromatography-tandem mass spectrometry or toxin quantification was conducted on all four specimens. Species identification was conducted through sequence homology analysis.

Results: Polymerase chain reaction amplification of the 185 base pair target sequence was successful from three vomit specimens collected 7 h post-ingestion, yielding identical sequences. Sequence analysis identified Amanita ibotengutake (100% homology), contradicting the initial morphological identification of Amanita pantherina. Liquid chromatography-tandem mass spectrometry detected a total of 0.053 mg ibotenic acid and 0.0043 mg muscimol in vomit specimens, consistent with the patient's neurological symptoms.

Discussions: The discrepancy between morphological (Amanita pantherina) and molecular (Amanita ibotengutake) identification demonstrates limitations of conventional methods, particularly significant as these species were considered identical until 2002. Successful deoxyribonucleic acid amplification 7 h post-ingestion, despite technical challenges from gastric degradation, suggests clinical feasibility. This integrated molecular-toxicological approach strengthens scientific understanding of species-specific toxicities and contributes to improved epidemiological investigation of mushroom poisoning.

Conclusions: We report the successful molecular identification from patient vomit specimens in a patient with mushroom poisoning. Although limited to a single case, this methodology may contribute to strengthening mushroom poisoning reports in the scientific literature to improve understanding of species-specific toxicities. Further validation in additional cases is needed for broader scientific applications.