Occurrence and chemotaxonomical analysis of amatoxins in Lepiota spp. (Agaricales)

Lepiota castanea mushroom growing in Turkiye does not contain phallotoxins and amatoxins

The number of poisoning cases caused by the Lepiota genus is globally increasing. This genus has more poisonous species than the Amanita genus, and many Lepiota species can cause severe toxicity and death if ingested. As recognized in the literature, L. castanea is a toxic species containing amatoxin. Although crude analytical methods have shown that L. castanea contains amatoxins, more recent and sensitive analyses suggest otherwise. Toxin concentrations can vary even among the same fungal species due to geographical and climatic differences. Therefore, this confusion can be resolved by analyzing L. castanea toxins from different geographical regions. This study aimed to demonstrate the toxin levels of L. castanea collected from forests in different regions of Turkiye (Istanbul and Kocaeli) using sensitive methods. The collected mushrooms were analyzed for alpha amanitin, beta amanitin, gamma amanitin, amanin, phallacidin, and phalloidin levels using RP-HPLC-UV and LC-ESI-MS/MS methods. L. castanea mushroom was found to be free of amatoxin and phallotoxin. Our study revealed for the first time that L. castanea mushrooms from different geographical regions of Turkiye do not contain amatoxin and phallotoxin. Supporting these findings with new studies from different parts of the world would be appropriate.

A guide to mycetisms: A toxicological and preventive overview

Fungi are often considered a delicacy and are primarily cultivated and harvested, although numerous species are responsible for intoxication due to toxin content. Foodborne diseases are a significant public health concern, causing approximately 420 000 deaths and 600 million morbidities yearly, of which mushroom poisoning is one of the leading causes. Epidemiological data on non-cultivated mushroom poisoning in individual countries are often unrepresentative, as intoxication rarely requires emergency intervention. On the other hand, the lack of specialist knowledge among medical personnel about the toxicological manifestations of mushroom consumption may result in ineffective therapeutic interventions. This work aims to provide an easy-to-consult and wide-ranging tool useful for better understanding the variability of mushroom intoxications, the associated symptoms, and the main treatments for the most severe cases, given the absence of a complete species mapping tool toxic. Moreover, we establish an effective collection network that describes the incidence of mushroom poisonings by reporting the species and associated toxicological manifestations for each case. In conclusion, we highlight the need to establish appropriate primary prevention interventions, such as training the affected population and increasing consultancy relationships between mycological experts and specialised healthcare personnel.

Family matters inside the order Agaricales: systematic reorganization and classification of incertae sedis clitocyboid, pleurotoid and tricholomatoid taxa based on an updated 6-gene phylogeny

The phylogenetic position of several clitocyboid/pleurotoid/tricholomatoid genera previously considered incertae sedis is here resolved using an updated 6-gene dataset of Agaricales including newly sequenced lineages and more complete data from those already analyzed before. Results allowed to infer new phylogenetic relationships, and propose taxonomic novelties to accommodate them, including up to ten new families and a new suborder. Giacomia (for which a new species from China is here described) forms a monophyletic clade with Melanoleuca (Melanoleucaceae) nested inside suborder Pluteineae, together with the families Pluteaceae, Amanitaceae (including Leucocortinarius), Limnoperdaceae and Volvariellaceae. The recently described family Asproinocybaceae is shown to be a later synonym of Lyophyllaceae (which includes also Omphaliaster and Trichocybe) within suborder Tricholomatineae. The families Biannulariaceae, Callistosporiaceae, Clitocybaceae, Fayodiaceae, Macrocystidiaceae (which includes Pseudoclitopilus), Entolomataceae, Pseudoclitocybaceae (which includes Aspropaxillus), Omphalinaceae (Infundibulicybe and Omphalina) and the new families Paralepistaceae and Pseudoomphalinaceae belong also to Tricholomatineae. The delimitation of the suborder Pleurotineae (= Schizophyllineae) is discussed and revised, accepting five distinct families within it, viz. Pleurotaceae, Cyphellopsidaceae, Fistulinaceae, Resupinataceae and Schizophyllaceae. The recently proposed suborder Phyllotopsidineae (= Sarcomyxineae) is found to encompass the families Aphroditeolaceae, Pterulaceae, Phyllotopsidaceae, Radulomycetaceae, Sarcomyxaceae (which includes Tectella), and Stephanosporaceae, all of them unrelated to Pleurotaceae (suborder Pleurotineae) or Typhulaceae (suborder Typhulineae). The new family Xeromphalinaceae, encompassing the genera Xeromphalina and Heimiomyces, is proposed within Marasmiineae. The suborder Hygrophorineae is here reorganized into the families Hygrophoraceae, Cantharellulaceae, Cuphophyllaceae, Hygrocybaceae and Lichenomphaliaceae, to homogenize the taxonomic rank of the main clades inside all suborders of Agaricales. Finally, the genus Hygrophorocybe is shown to represent a distinct clade inside Cuphophyllaceae, and the new combination H. carolinensis is proposed. Taxonomic novelties: New suborder: Typhulineae Vizzini, Consiglio & P. Alvarado. New families: Aphroditeolaceae Vizzini, Consiglio & P. Alvarado, Melanoleucaceae Locq. ex Vizzini, Consiglio & P. Alvarado, Paralepistaceae Vizzini, Consiglio & P. Alvarado, Pseudoomphalinaceae Vizzini, Consiglio & P. Alvarado, Volvariellaceae Vizzini, Consiglio & P. Alvarado, Xeromphalinaceae Vizzini, Consiglio & P. Alvarado. New species: Giacomia sinensis J.Z. Xu. Stat. nov.: Cantharellulaceae (Lodge, Redhead, Norvell & Desjardin) Vizzini, Consiglio & P. Alvarado, Cuphophyllaceae (Z.M. He & Zhu L. Yang) Vizzini, Consiglio & P. Alvarado, Hygrocybaceae (Padamsee & Lodge) Vizzini, Consiglio & P. Alvarado, Lichenomphaliaceae (Lücking & Redhead) Vizzini, Consiglio & P. Alvarado. New combination: Hygrophorocybe carolinensis (H.E. Bigelow & Hesler) Vizzini, Consiglio & P. Alvarado. New synonyms: Sarcomyxineae Zhu L. Yang & G.S. Wang, Schizophyllineae Aime, Dentinger & Gaya, Asproinocybaceae T. Bau & G.F. Mou. Incertae sedis taxa placed at family level: Aphroditeola Redhead & Manfr. Binder, Giacomia Vizzini & Contu, Hygrophorocybe Vizzini & Contu, Leucocortinarius (J.E. Lange) Singer, Omphaliaster Lamoure, Pseudoclitopilus Vizzini & Contu, Resupinatus Nees ex Gray, Tectella Earle, Trichocybe Vizzini. New delimitations of taxa: Hygrophorineae Aime, Dentinger & Gaya, Phyllotopsidineae Zhu L. Yang & G.S. Wang, Pleurotineae Aime, Dentinger & Gaya, Pluteineae Aime, Dentinger & Gaya, Tricholomatineae Aime, Dentinger & Gaya. Resurrected taxa: Fayodiaceae Jülich, Resupinataceae Jülich. Citation: Vizzini A, Alvarado P, Consiglio G, Marchetti M, Xu J (2024). Family matters inside the order Agaricales: systematic reorganization and classification of incertae sedis clitocyboid, pleurotoid and tricholomatoid taxa based on an updated 6-gene phylogeny. Studies in Mycology 107: 67-148. doi: 10.3114/sim.2024.107.02.

Acute hepatic and kidney injury after ingestion of Lepiota brunneoincarnata: Report of 2 cases

Lepiota brunneoincarnata is a highly toxic mushroom species known to cause acute liver failure. However, there are limited reports investigating L. brunneoincarnata causing acute hepatic and renal damage. The present article reports 2 cases of L. brunneoincarnata poisoning in a mother and son from Chuxiong City, Yunnan Province, China. Both patients presented with gastrointestinal symptoms approximately 8-9 h after ingesting the suspect mushrooms and sought medical attention 27-28 h post-ingestion, both exhibiting acute hepatic and kidney injuries. Morphological and molecular biology studies confirmed the species of the mushrooms as L. brunneoincarnata. Liquid chromatography-tandem mass spectrometry analysis revealed mean fresh-weight concentrations of 123.5 μg/g α-amanitin and 45.7 μg/g β-amanitin in the mushrooms. The patients underwent standard treatments, including multiple-dose activated charcoal, oral silibinin capsules, N-acetylcysteine, penicillin G, hemoperfusion, and plasma exchange. One patient recovered completely and was discharged after 16 days of hospitalization. The other patient exhibited gradual improvement in liver and renal function; however, renal function deteriorated 9 days after ingestion, and the patient declined renal replacement therapy and returned home 14 days post-ingestion. The patient was then re-hospitalized due to oliguria and edema in both lower extremities. Renal biopsy revealed acute tubular necrosis, inflammatory cell infiltration, minor glomerular capsular fibrosis, loss of microvilli in the renal tubular epithelial cells, and interstitial edema. The patient underwent 2 rounds of continuous renal replacement therapy, which eventually resulted in improvement, and was discharged 31 days after mushroom consumption. It is noteworthy that this patient had already progressed to chronic kidney insufficiency 11 months after intoxication.

Simple and rapid detection of three amatoxins and three phallotoxins in human body fluids by UPLC-MS-MS and its application in 15 poisoning cases

Amatoxins and phallotoxins are toxic cyclopeptides found in the genus Amanita and are among the predominant causes of foodborne sickness and poisoning-related fatalities in China. This study introduces and validates a simple, rapid and cost-effective ultra-performance liquid chromatography-mass spectrometry method for the simultaneous determination and quantification of α-amanitin, β-amanitin, γ-amanitin, phallisacin, phallacidin and phalloidin in human blood and urine. Quick therapeutic decision-making is supported by a 9 min chromatographic separation performed on a Waters Acquity UPLC HSS T3 column (100 mm × 2.1 mm, 1.8 µm) using a gradient of high-performance liquid chromatography (HPLC)-grade water and methanol:0.005% formic acid. The analyte limit of quantification was 1-3 ng/mL in blood and 0.5-2 ng/mL in urine. Calibrations curves, prepared by spiking drug-free blood and urine, demonstrated acceptable linearity with mean correlation coefficients (r) greater than 0.99 for all phallotoxins and amatoxins. Acceptable intraday and interday precision (relative standard deviation <15%) and accuracy (bias, -4.8% to 13.0% for blood and-9.0% to 14.7% for urine) were achieved. The validated method was successfully applied to analyze 9 blood samples and 2 urine samples testing positive for amatoxins and/or phallotoxins. Amatoxins and/or phallotoxins were identified in each whole blood sample at a range of 1.12-5.63 ng/mL and in two urine samples from 1.01-9.27 ng/mL. The method has the benefits of simple sample preparation (protein precipitation) and wide analyte coverage, making it suitable for emergency quantitative surveillance toxicological analysis in clinics and forensic poisoning practice.

Amanitins: The Most Poisonous Molecules of the Fungal World

Among the toxic metabolites of the fungal world, those that, due to their strong biological effect, can seriously (even fatally) damage the life processes of humans (and certain groups of animals) stand out. Amatoxin-containing mushrooms and the poisonings caused by them stand out from the higher fungi, the mushrooms. There are already historical data and records about such poisonings, but scientific research on the responsible molecules began in the middle of the last century. The goals of this review work are as follows: presentation of the cosmopolitan mushroom species that produce amanitins (which are known from certain genera of four mushroom families), an overview of the chemical structure and specific properties of amanitins, a summary of the analytical methods applicable to them, a presentation of the "medical history" of poisonings, and a summary of the therapeutic methods used so far. The main responsible molecules (the amanitins) are bicyclic octapeptides, whose structure is characterized by an outer loop and an inner loop (bridge). It follows from the unusual properties of amanitins, especially their extreme stability (against heat, the acidic pH of the medium, and their resistance to human, and animal, digestive enzymes), that they are absorbed almost without hindrance and quickly transported to our vital organs. Adding to the problems is that accidental consumption causes no noticeable symptoms for a few hours (or even 24-36 h) after consumption, but the toxins already damage the metabolism of the target organs and the synthesis of nucleic acid and proteins. The biochemical catastrophe of the cells causes irreversible structural changes, which lead to necrotic damage (in the liver and kidneys) and death. The scientific topicality of the review is due to the recent publication of new data on the probable antidote molecule (ICR: indocyanine green) against amanitins. Further research can provide a new foundation for the therapeutic treatment of poisonings, and the toxicological situation, which currently still poses a deadly threat, could even be tamed into a controllable problem. We also draw attention to the review conclusions, as well as the mycological and social tasks related to amanitin poisonings (prevention of poisonings).

Amanita Section Phalloideae Species in the Mediterranean Basin: Destroying Angels Reviewed

Simple Summary

Whitish lethal species of Amanita sect. Phalloideae (‘destroying angels’) are known to be among the most poisonous fungi worldwide due to their production of amatoxins. The taxonomy of species occurring in the Mediterranean region is here revised, clarifying the identity of several names. Amanita decipiens, A. porrinensis, and A. virosa var. levipes are here considered later heterotypic synonyms of A. verna, A. phalloides, and A. amerivirosa, respectively, while a new name, A. vidua, is proposed for a spring-occurring taxon. The amatoxins and phallotoxins present in Mediterranean destroying angels were characterized, and their epidemiology discussed on the basis of the case study of available data from Spain.

Abstract

In Europe, amatoxin-containing mushrooms are responsible for most of the deadly poisonings caused by macrofungi. The present work presents a multidisciplinary revision of the European species of Amanita sect. Phalloideae based on morphology, phylogeny, epidemiology, and biochemistry of amatoxins and phallotoxins. Five distinct species of this section have been identified in Europe to date: A. phalloides, A. virosa, A. verna, the recently introduced North American species A. amerivirosa, and A. vidua sp. nov., which is a new name proposed for the KOH-negative Mediterranean species previously described as A. verna or A. decipiens by various authors. Epitypes or neotypes are selected for species lacking suitable reference collections, namely A. verna and A. virosa. Three additional taxa, Amanita decipiens, A. porrinensis, and A. virosa var. levipes are here considered later heterotypic synonyms of A. verna, A. phalloides, and A. amerivirosa, respectively.