Phylogenetic evidence revealed Cantharocybe virosa (Agaricales, Hygrophoraceae) as a new clinical record for gastrointestinal mushroom poisoning in Thailand.

Epidemiological data showed increasing incidence rates of gastrointestinal (GI) mushroom syndrome in Thailand. This study therefore, aimed to identify suspected GI toxin-containing mushrooms using DNA sequence analyses of the internal transcribed spacer (ITS) region and the large subunit (LSU) of nuclear ribosomal DNA. GI toxins were also identified using liquid chromatography quadrupole time-of-flight mass spectrometry (LC-QTOF-MS). 39 patients presented with poisoning symptoms, including nausea, vomiting, fatigue, abdominal pain, circulatory disturbances and diarrhea after ingesting wild mushrooms. The latent periods varied from 30 min to 4 h, but mostly between 1 and 2 h. Results of the ITS sequence-based identification revealed high similarities for the obtained clinical mushroom samples with the genus Cantharocybe H.E. Bigelow & A.H. SM. Maximum likelihood and Bayesian summary trees of combined ITS and LSU data confirmed that these toxic mushroom samples ingested by the patients belonged to Cantharocybe virosa (Manim. & K.B. Vrinda) T.K.A. Kumar. Detection of GI toxins using LC-QTOF-MS method revealed the presence of coprine in C. virosa. This study described the first outbreak of C. virosa poisoning in Thailand which resulted in severe cases of gastrointestinal irritation. To prevent such poisoning cases it is essential to educate the public not to gather any unidentified or unfamiliar wild mushrooms.

Molecular identification of poisonous mushrooms using nuclear ITS region and peptide toxins: a retrospective study on fatal cases in Thailand.

Cases of mushroom poisoning in Thailand have increased annually. During 2008 to 2014, the cases reported to the National Institute of Health included 57 deaths; at least 15 died after ingestion of amanitas, the most common lethal wild mushrooms inhabited. Hence, the aims of this study were to identify mushroom samples from nine clinically reported cases during the 7-year study period based on nuclear ITS sequence data and diagnose lethal peptide toxins using a reversed phase LC-MS method. Nucleotide similarity was identified using BLAST search of the NCBI database and the Barcode of Life Database (BOLD). Clade characterization was performed by maximum likelihood and Bayesian phylogenetic approaches. Based on BLAST and BOLD reference databases our results yielded high nucleotide similarities of poisonous mushroom samples to A. exitialis and A. fuliginea. Detailed phylogenetic analyses showed that all mushroom samples fall into their current classification. Detection of the peptide toxins revealed the presence of amatoxins and phallotoxins in A. exitialis and A. fuliginea. In addition, toxic α-amanitin was identified in a new provisional species, Amanita sp.1, with the highest toxin quantity. Molecular identification confirmed that the mushrooms ingested by the patients were members of the lethal amanitas in the sections Amanita and Phalloideae. In Thailand, the presence of A. exitialis was reported here for the first time and all three poisonous mushroom species provided new and informative data for clinical studies.

A cross-sectional study of exposure to mercury in schoolchildren living near the eastern seaboard industrial estate of Thailand.

BACKGROUND: Industrial activity in Thailand's coastal areas has significantly increased mercury concentrations in seawater, causing accumulation through the food chain. Continuous exposure to mercury has been linked to bioaccumulation in living organisms and potential adverse health effects in children. METHODS: Blood samples were collected from 873 schoolchildren aged 6-13 years living in four sites near the eastern seaboard industrial estates of the Gulf of Thailand in 2011. Total mercury level in whole blood (Hg-B) was compared with standard reference values. RESULTS: Mean (± standard deviation) concentrations of Hg-B from schoolgirls (2.19 ± 0.5 µg/L; n = 405) and schoolboys (2.29 ± 0.3 µg/L; n = 468) did not exceed the regulatory limits of the United States Environmental Protection Agency (US EPA), the German Commission on Human Biological Monitoring (HBM I, II) or Clarke's analysis of drugs and poisons reference values. Nevertheless, 67 children (34 girls and 33 boys) had individual values that exceeded the lowest of these standards (4 µg/L). CONCLUSION: The relatively low concentrations of Hg-B detected in this study suggested a relatively low risk for schoolchildren. However, 67 children had elevated mean total Hg-B concentrations, especially in the two sites located nearest the industrial area. This information may serve as an early warning of the potential for pollution to affect children living around industrial areas. Further regular monitoring, including studies assessing the health impact of mercury pollution in this region of Thailand, is to be encouraged.