Polymerase chain reaction-based methods for the rapid identification of Amanita exitialis.

Amanita exitialis, a deadly mushroom found in eastern Asia, causes the highest death rates among all poisonous mushrooms in China. The aim of the present study was to develop an efficient, accurate, and user-friendly PCR-based method for identifying A. exitialis that could facilitate the prevention, diagnosis, and treatment of associated food poisoning. A. exitialis-specific primers and probes were designed based on the internal transcribed spacer region variations of 27 mushroom species. Specificity was confirmed using conventional and real-time PCR for 23 non-target mushroom species, including morphologically similar and closely related species. Compared to conventional PCR, real-time PCR was more sensitive (detectable DNA concentration: 1.36 × 10-2 ng/µL vs. 1.36 × 10-3) and efficient (analysis time: 1 h vs. 40 min). Furthermore, the real-time PCR results could be immediately visualized using amplification curve analysis. The results present two robust PCR-based methods for A. exitialis identification that can facilitate food safety.

Using MALDI-ToF mass spectrometry to identify mushroom species: Proof of concept analysis of Amanita genus specimens.

Food poisoning caused by toxic mushrooms, such as species in the Amanita genus, occurs frequently around the world. To properly treat these patients, it is important to rapidly and accurately identify the causal species. Matrix-assisted laser desorption/ionization time-of-flight (MALDI-ToF) mass spectrometry is a rapid technique that has been used in medical laboratories for the past three decades to identify bacteria, yeasts, and filamentous fungi.Matrix-assisted laser desorption ionization time of flight mass spectrometry (MALDI-Tof MS) is a rapid method used for the past three decades to identify microorganisms. In this study, we created and internally validated a MALDI-Tof MS reference database comprising 15 Amanita species frequently encountered in France, and we challenged this database with 38 Amanita specimens from four French locations, using a free online application for MALDI-ToF spectra identifications.Assessment of the database showed that mass spectra can be obtained by analyzing any portion of a carpophore and that all portions enabled identification of the carpophore at the species level. Most carpophores were correctly identified using our database, with the exception of specimens from the Vaginatae section. Decay tests also demonstrated that decayed portions (like those found in the kitchen garbage can) of Amanita phalloides mushrooms could be properly identified using MALDI-ToF MS.Our findings provide important insight for toxicology laboratories that often rely on DNA sequencing to identify meal leftovers implicated in food poisoning. In future developments, this technique could also be used to detect counterfeit mushrooms by including other genera in the reference database. LAY SUMMARY: MALDI-ToF MS is a powerful identification tool for microorganisms. We demonstrate that the technique can be applied to Amanita specimens. This will prevent food intoxications as a rapid and definite identification can be obtained, and it can also be used for food remnants.

Amanita in the Guineo-Congolian rainforest: Epitypes and new species from the Dja Biosphere Reserve, Cameroon.

Four epitypes and three new species of Amanita (Amanitaceae, Agaricales, Agaricomycetes, Basidiomycota) are described from Guineo-Congolian rainforests of Cameroon. Amanita echinulata, A. fulvopulverulenta, A. robusta, and A. bingensis are epitypified based on collections that are the first since the species were described nearly a century ago. Morphological features of the epitypes are described and enumerated. Amanita minima, Amanita luteolamellata, and A. goossensfontanae are described as new and added to the known macromycota of tropical Africa. Habit, habitat, and known distribution are provided for each species. Sequence data for the internal transcribed spacer (ITS) locus are provided for types and other collections of all taxa, and a molecular phylogenetic analysis across the genus Amanita corroborates morphology-based infrageneric placement for each.

Intragenomic nuclear RNA variation in a cryptic Amanita taxon.

Amanita cf. lavendula collections in eastern North America, Mexico, and Costa Rica were found to consist of four cryptic taxa, one of which exhibited consistently unreadable nuclear rDNA ITS1-5.8S-ITS2 (fungal barcode) sequences after ITS1 base 130. This taxon is designated here as Amanita cf. lavendula taxon 1. ITS sequences from dikaryotic basidiomata were cloned, but sequences recovered from cloning did not segregate into distinct haplotypes. Rather, there was a mix of haplotypes that varied among themselves predominantly at 28 ITS positions. Analysis of each of these 28 variable bases showed predominantly two alternate bases at each position. Based on these findings and additional sequence data from the nuclear rDNA 28S, RNA polymerase II subunit 2 (RPB2) and mitochondrial rDNA small subunit (SSU) and 23S genes, we speculate that taxon 1 represents an initial hybridization event between two divergent taxa followed by failure of the ribosomal repeat to homogenize. Homogenization failure may be a result of repeated hybridization between divergent internal transcribed spacer (ITS) types with inadequate time for concerted evolution of the ribosomal repeat or, alternately, a complete failure of the ribosomal homogenization process. To our knowledge, this finding represents the first report of a geographically widespread taxon (Canada, eastern USA, Costa Rica) with apparent homogenization failure across all collections. Findings such as these have implications for fungal barcoding efforts and the application of fungal barcodes in identifying environmental sequences.

Notes on Amanita section Caesareae from Malaysia.

Some Amanita specimens collected from Malaysia are critically investigated by morphological examination and molecular analysis of two gene fragments, the nuc rDNA partial 28S (28S) gene and the internal transcriber spacer (ITS1-5.8S-ITS2 = ITS) regions. Six phylogenetic species of Amanita section Caesareae are recognized among the studied collections. One of them is described as new, A. malayensis. Four of the phylogenetic species correspond with existing morphology-based taxa: A. aporema, A. javanica, A. princeps, and A. similis. The remaining species is not described because of the paucity of material. Detailed descriptions and the distribution of these southeastern Asian species are provided, along with a key to the species of section Caesareae from Malaysia.

Study of three interesting Amanita species from Thailand: Morphology, multiple-gene phylogeny and toxin analysis.

Amanita ballerina and A. brunneitoxicaria spp. nov. are introduced from Thailand. Amanita fuligineoides is also reported for the first time from Thailand, increasing the known distribution of this taxon. Together, those findings support our view that many taxa are yet to be discovered in the region. While both morphological characters and a multiple-gene phylogeny clearly place A. brunneitoxicaria and A. fuligineoides in sect. Phalloideae (Fr.) Quél., the placement of A. ballerina is problematic. On the one hand, the morphology of A. ballerina shows clear affinities with stirps Limbatula of sect. Lepidella. On the other hand, in a multiple-gene phylogeny including taxa of all sections in subg. Lepidella, A. ballerina and two other species, including A. zangii, form a well-supported clade sister to the Phalloideae sensu Bas 1969, which include the lethal "death caps" and "destroying angels". Together, the A. ballerina-A. zangii clade and the Phalloideae sensu Bas 1969 also form a well-supported clade. We therefore screened for two of the most notorious toxins by HPLC-MS analysis of methanolic extracts from the basidiomata. Interestingly, neither α-amanitin nor phalloidin was found in A. ballerina, whereas Amanita fuligineoides was confirmed to contain both α-amanitin and phalloidin, and A. brunneitoxicaria contained only α-amanitin. Together with unique morphological characteristics, the position in the phylogeny indicates that A. ballerina is either an important link in the evolution of the deadly Amanita sect. Phalloideae species, or a member of a new section also including A. zangii.

The Gondwanan connection - Southern temperate Amanita lineages and the description of the first sequestrate species from the Americas.

Amanita is a diverse and cosmopolitan genus of ectomycorrhizal fungi. We describe Amanita nouhrae sp. nov., a new hypogeous ('truffle-like') species associated with Nothofagus antarctica in northern Patagonia. This constitutes the first report of a sequestrate Amanita from the Americas. Thick-walled basidiospores ornamented on the interior spore wall ('crassospores') were observed consistently in A. nouhrae and its sister epigeous taxon Amanita morenoi, a rarely collected but apparently common species from northern Patagonia that has sometimes been misidentified as the Australian taxon Amanita umbrinella. Nuclear 18S and 28S ribosomal DNA and mitochondrial 16S and 26S DNA placed these two species in a southern temperate clade within subgenus Amanita, together with other South American and Australian species. Based on a dated genus-level phylogeny, we estimate that the southern temperate clade may have originated near the Eocene/Oligocene boundary (ca. 35 Ma ± 10 Ma). This date suggests a broadly distributed ancestor in the Southern Hemisphere, which probably diversified as a result of continental drift, as well as the initiation of the Antarctic glaciation. By comparison, we show that this clade follows an exceptional biogeographic pattern within a genus otherwise seemingly dominated by Northern Hemisphere dispersal.

Defining the phylogenetic position of Amanita species from Andean Colombia.

Amanita is a worldwide-distributed fungal genus, with approximately 600 known species. Most species within the genus are ectomycorrhizal (ECM), with some saprotrophic representatives. In this study, we constructed the first comprehensive phylogeny including ECM species from Colombia collected in native Quercus humboldtii forests and in introduced Pinus patula plantations. We included 8 species (A. brunneolocularis, A. colombiana, A. flavoconia, A. fuligineodisca, A. muscaria, A. rubescens, A. sororcula, and A. xylinivolva) out of 16 species reported for the country, two new reports: A. citrina and A. virosa, and a new variety A. brunneolocularis var. pallida. Morphological taxonomic keys together with a phylogenetic approach using three nuclear gene regions: partial nuc rDNA 28S nuc rDNA internal transcribed spacers ITS1 and ITS2 and partial translation elongation factor 1-α gene (TEF1), were used to classify the specimens. Several highly supported clades were obtained from the phylogenetic hypotheses obtained by Bayesian inference and maximum likelihood approaches, allowing us to position the Colombian collections in a coherent infrageneric level and to contribute to the knowledge of local Amanita diversity.

Determination of cyclopeptide toxins in Amanita subpallidorosea and Amanita virosa by high-performance liquid chromatography coupled with high-resolution mass spectrometry.

Amanita subpallidorosea is a recently discovered lethal Amanita sect. Phalloideae species found in China that is clustered with A. virosa in the same clade based on molecular phylogenetic analysis. However, the cyclopeptide toxin contents of these lethal mushrooms remain poorly studied. In this study, the cyclopeptide toxins in A. subpallidorosea were reported for the first time and the cyclopeptide compositions of A. subpallidorosea and A. virosa species were systematically analyzed. Thirteen cyclopeptides and two unknown compounds were identified or observed from these two lethal mushrooms by high-performance liquid chromatography coupled with high-resolution mass spectrometry. Of the known cyclopeptides, the virotoxins alaviroidin, viroisin, and viroidin, which were previously thought to be restricted to A. virosa, were identified in A. subpallidorosea. The cyclopeptide compositions showed that there are diversities in the kinds and levels of amatoxins, phallotoxins, and virotoxins between A. subpallidorosea and A. virosa species, and that the amount of total toxins in the tested A. subpallidorosea is significantly higher than that in the tested A. virosa. Furthermore, consistency of the cyclopeptide toxins with the molecular phylogenetic relationships was demonstrated.

Cyclopeptide toxins of lethal amanitas: Compositions, distribution and phylogenetic implication.

Lethal amanitas (Amanita sect. Phalloideae) are responsible for 90% of all fatal mushroom poisonings. Since 2000, more than ten new lethal Amanita species have been discovered and some of them had caused severe mushroom poisonings in China. However, the contents and distribution of cyclopeptides in these lethal mushrooms remain poorly known. In this study, the diversity of major cyclopeptide toxins in seven Amanita species from Eastern Asia and three species from Europe and North America were systematically analyzed, and a new approach to inferring phylogenetic relationships using cyclopeptide profile was evaluated for the first time. The results showed that there were diversities of the cyclopeptides among lethal Amanita species, and cyclopeptides from Amanita rimosa and Amanita fuligineoides were reported for the first time. The amounts of amatoxins in East Asian Amanita species were significantly higher than those in European and North American species. The analysis of distribution of amatoxins and phallotoxins in various Amanita species demonstrated that the content of phallotoxins was higher than that of amatoxins in Amanita phalloides and Amanita virosa. In contrast, the content of phallotoxins was significantly lower than that of amatoxins in all East Asian lethal Amanita species tested. However, the distribution of amatoxins and phallotoxins in different tissues showed the same tendency. Eight cyclopeptides and three unknown compounds were identified using cyclopeptide standards and high-resolution MS. Based on the cyclopeptide profiles, phylogenetic relationships of lethal amanitas were inferred through a dendrogram generated by UPGMA method. The results showed high similarity to the phylogeny established previously based on the multi-locus DNA sequences.

Lethal Amanita species in China.

Lethal amanitas (Amanita sect. Phalloideae) cause many casualties worldwide. Recent molecular phylogenetic studies revealed diverse lethal Amanita spp. in China. Here a 5-gene phylogeny (nuc rDNA region encompassing the internal transcribed spacers 1 and 2 with the 5.8S rDNA, the D1-D3 domains of nuc 28S rDNA, and partial RNA polymerase II second largest subunit, translation elongation factor 1-α and ß-tubulin genes) is used to investigate the phylogenetic lineages and species delimitation in this section. Thirteen species are recognized, including four new species, namely A. griseorosea, A. molliuscula, A. parviexitialis, and A. subfuliginea They are documented with morphological, multigene phylogenetic, and ecological evidence, line drawings, and photographs and compared with similar species. A key to the Chinese lethal Amanita species is provided.

Amanita diemii singer y amanita merxmellueri bresinsky & garrido (agaricales, basidiomycota), las amanitas comestibles de Chile / Amanita diemii singer and amanita merxmuelleri Bresinsky & garrido (agaricales, basiodiomycota), the edible amanitas of Chile

Se presenta una breve revisión del género Amanita Pers. y posteriormente, se describen los caracteres macromorfológicos de las especies nativas comestibles Amanita diemii Singer y Amanita merxmuelleri Bresinsky & Garrido, las cuales se encuentran distribuidas desde la Región del Maule hasta la Región de Magallanes asociadas a especies del género Nothofagus Blume.

A brief review of the genus Amanita Pers. is presented and then the characters macromorphological of edible native species Amanita diemii Singer and Amanita merxmuelleri Bresinsky & Garrido, which are distributed from the Maule Region to the Magallanes Region described associated with Nothofagus Blume species.

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.

In and out of refugia: historical patterns of diversity and demography in the North American Caesar's mushroom species complex.

Some of the effects of past climate dynamics on plant and animal diversity make-up have been relatively well studied, but to less extent in fungi. Pleistocene refugia are thought to harbour high biological diversity (i.e. phylogenetic lineages and genetic diversity), mainly as a product of increased reproductive isolation and allele conservation. In addition, high extinction rates and genetic erosion are expected in previously glaciated regions. Some of the consequences of past climate dynamics might involve changes in range and population size that can result in divergence and incipient or cryptic speciation. Many of these dynamic processes and patterns can be inferred through phylogenetic and coalescent methods. In this study, we first delimit species within a group of closely related edible ectomycorrhizal Amanita from North America (the American Caesar's mushrooms species complex) using multilocus coalescent-based approaches; and then address questions related to effects of Pleistocene climate change on the diversity and genetics of the group. Our study includes extensive geographical sampling throughout the distribution range, and DNA sequences from three nuclear protein-coding genes. Results reveal cryptic diversity and high speciation rates in refugia. Population sizes and expansions seem to be larger at midrange latitudes (Mexican highlands and SE USA). Range shifts are proportional to population size expansions, which were overall more common during the Pleistocene. This study documents responses to past climate change in fungi and also highlights the applicability of the multispecies coalescent in comparative phylogeographical analyses and diversity assessments that include ancestral species.

Multi-locus phylogeny of lethal amanitas: implications for species diversity and historical biogeography.

BACKGROUND: Lethal amanitas (Amanita section Phalloideae) are a group of wild, fatal mushrooms causing many poisoning cases worldwide. However, the diversity and evolutionary history of these lethal mushrooms remain poorly known due to the limited sampling and insufficient gene fragments employed for phylogenetic analyses. In this study, five gene loci (nrLSU, ITS, rpb2, ef1-α and ß-tubulin) with a widely geographic sampling from East and South Asia, Europe, North and Central America, South Africa and Australia were analysed with maximum-likelihood, maximum-parsimony and Bayesian inference methods. Biochemical analyses were also conducted with intention to detect amatoxins and phalloidin in 14 representative samples. RESULT: Lethal amanitas were robustly supported to be a monophyletic group after excluding five species that were provisionally defined as lethal amanitas based on morphological studies. In lethal amanitas, 28 phylogenetic species were recognised by integrating molecular phylogenetic analyses with morphological studies, and 14 of them represented putatively new species. The biochemical analyses indicated a single origin of cyclic peptide toxins (amatoxins and phalloidin) within Amanita and suggested that this kind of toxins seemed to be a synapomorphy of lethal amanitas. Molecular dating through BEAST and biogeographic analyses with LAGRANGE and RASP indicated that lethal amanitas most likely originated in the Palaeotropics with the present crown group dated around 64.92 Mya in the early Paleocene, and the East Asia-eastern North America or Eurasia-North America-Central America disjunct distribution patterns were primarily established during the middle Oligocene to Miocene. CONCLUSION: The cryptic diversity found in this study indicates that the species diversity of lethal amanitas is strongly underestimated under the current taxonomy. The intercontinental sister species or sister groups relationships among East Asia and eastern North America or Eurasia-North America-Central America within lethal amanitas are best explained by the diversification model of Palaeotropical origin, dispersal via the Bering Land Bridge, followed by regional vicariance speciation resulting from climate change during the middle Oligocene to the present. These findings indicate the importance of both dispersal and vicariance in shaping the intercontinental distributions of these ectomycorrhizal fungi.

[Toxic fungi in Buenos Aires City and surroundings]. / Hongos tóxicos en la Ciudad de Buenos Aires y alrededores.

In Facultad de Ciencias Exactas y Naturales,Universidad de Buenos Aires there is a service called Servicio de Identificación de Hongos Tóxicos, directed by researchers of the Program of Medicinal Plants and Fungi Involved in Biological Degradation (PROPLAME-PRHIDEB, CONICET) that assist hospitals and other health establishments, identifying the different samples of fungi and providing information about their toxicity, so that patients can receive the correct treatment. The objective of the present study was to analyze all the cases received from 1985 to 2012. This analysis permitted the confection of a table identifying the most common toxic species. The information gathered revealed that 47% of the patients were under 18 years of age and had eaten basidiomes; the remaining 53% were adults who insisted that they were able to distinguish edible from toxic mushrooms. Chlorophyllum molybdites turned out to be the main cause of fungal intoxication in Buenos Aires, which is commonly confused with Macrolepiota procera, an edible mushroom. In the second place Amanita phalloides was registered, an agaric known to cause severe symptoms after a long period of latency (6-10 hours), and which can lead to hepatic failure even requiring a transplant to prevent severe internal injuries or even death, is not early and correctly treated.

Hongos tóxicos en la Ciudad de Buenos Aires y alrededores / Toxic fungi in Buenos Aires City and surroundings

En la Facultad de Ciencias Exactas y Naturales de la Universidad de Buenos Aires (FCEN-UBA) funciona el Servicio de Identificación de Hongos Tóxicos. Lo integran los investigadores del Programa de Plantas Medicinales y Programa de Hongos que Intervienen en la Degradación Biológica (PROPLAME-PRHIDEB, CONICET) y colabora con servicios médicos, estatales y privados, identificando los materiales remitidos en casos de intoxicaciones con hongos, permitiendo, en muchos casos, realizar el tratamiento adecuado. El presente trabajo da a conocer los casos atendidos por el servicio desde 1985 hasta 2012 inclusive, además de una tabla para reconocer las especies tóxicas más comunes de la región. Según esta información, el 47% de las consultas que se recibieron correspondieron a pacientes menores de 18 años de edad que ingirieron materiales fúngicos de forma accidental (o al menos se sospechaba que lo hubieran hecho). El 53% restante correspondió a adultos que afirmaron ser capaces de distinguir hongos comestibles de tóxicos. Se determinó que Chlorophyllum molybdites fue la principal especie causante de intoxicaciones, la cual es comúnmente confundida con el hongo comestible Macrolepiota procera. En segundo lugar Amanita phalloides, un hongo altamente tóxico, que se caracteriza por presentar inicio de síntomas en forma tardía (latencia de 6-10 horas), evolucionando a falla hepática con el consiguiente requerimiento de trasplante o la muerte, si no se realiza el tratamiento adecuado en forma oportuna.

In Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires there is a service called Servicio de Identificación de Hongos Tóxicos, directed by researchers of the Program of Medicinal Plants and Fungi Involved in Biological Degradation (PROPLAME-PRHIDEB, CONICET) that assist hospitals and other health establishments, identifying the different samples of fungi and providing information about their toxicity, so that patients can receive the correct treatment. The objective of the present study was to analyze all the cases received from 1985 to 2012. This analysis permitted the confection of a table identifying the most common toxic species. The information gathered revealed that 47% of the patients were under 18 years of age and had eaten basidiomes; the remaining 53% were adults who insisted that they were able to distinguish edible from toxic mushrooms. Chlorophyllum molybdites turned out to be the main cause of fungal intoxication in Buenos Aires, which is commonly confused with Macrolepiota procera, an edible mushroom. In the second place Amanita phalloides was registered, an agaric known to cause severe symptoms after a long period of latency (6-10 hours), and which can lead to hepatic failure even requiring a transplant to prevent severe internal injuries or even death, is not early and correctly treated.

Hongos tóxicos en la Ciudad de Buenos Aires y alrededores / Toxic fungi in Buenos Aires City and surroundings

En la Facultad de Ciencias Exactas y Naturales de la Universidad de Buenos Aires (FCEN-UBA) funciona el Servicio de Identificación de Hongos Tóxicos. Lo integran los investigadores del Programa de Plantas Medicinales y Programa de Hongos que Intervienen en la Degradación Biológica (PROPLAME-PRHIDEB, CONICET) y colabora con servicios médicos, estatales y privados, identificando los materiales remitidos en casos de intoxicaciones con hongos, permitiendo, en muchos casos, realizar el tratamiento adecuado. El presente trabajo da a conocer los casos atendidos por el servicio desde 1985 hasta 2012 inclusive, además de una tabla para reconocer las especies tóxicas más comunes de la región. Según esta información, el 47% de las consultas que se recibieron correspondieron a pacientes menores de 18 años de edad que ingirieron materiales fúngicos de forma accidental (o al menos se sospechaba que lo hubieran hecho). El 53% restante correspondió a adultos que afirmaron ser capaces de distinguir hongos comestibles de tóxicos. Se determinó que Chlorophyllum molybdites fue la principal especie causante de intoxicaciones, la cual es comúnmente confundida con el hongo comestible Macrolepiota procera. En segundo lugar Amanita phalloides, un hongo altamente tóxico, que se caracteriza por presentar inicio de síntomas en forma tardía (latencia de 6-10 horas), evolucionando a falla hepática con el consiguiente requerimiento de trasplante o la muerte, si no se realiza el tratamiento adecuado en forma oportuna.(AU)

In Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires there is a service called Servicio de Identificación de Hongos Tóxicos, directed by researchers of the Program of Medicinal Plants and Fungi Involved in Biological Degradation (PROPLAME-PRHIDEB, CONICET) that assist hospitals and other health establishments, identifying the different samples of fungi and providing information about their toxicity, so that patients can receive the correct treatment. The objective of the present study was to analyze all the cases received from 1985 to 2012. This analysis permitted the confection of a table identifying the most common toxic species. The information gathered revealed that 47% of the patients were under 18 years of age and had eaten basidiomes; the remaining 53% were adults who insisted that they were able to distinguish edible from toxic mushrooms. Chlorophyllum molybdites turned out to be the main cause of fungal intoxication in Buenos Aires, which is commonly confused with Macrolepiota procera, an edible mushroom. In the second place Amanita phalloides was registered, an agaric known to cause severe symptoms after a long period of latency (6-10 hours), and which can lead to hepatic failure even requiring a transplant to prevent severe internal injuries or even death, is not early and correctly treated.(AU)