Genes and evolutionary fates of the amanitin biosynthesis pathway in poisonous mushrooms.

The deadly toxin α-amanitin is a bicyclic octapeptide biosynthesized on ribosomes. A phylogenetically disjunct group of mushrooms in Agaricales (Amanita, Lepiota, and Galerina) synthesizes α-amanitin. This distribution of the toxin biosynthetic pathway is possibly related to the horizontal transfer of metabolic gene clusters among taxonomically unrelated mushrooms with overlapping habitats. Here, our work confirms that two biosynthetic genes, P450-29 and FMO1, are oxygenases important for amanitin biosynthesis. Phylogenetic and genetic analyses of these genes strongly support their origin through horizontal transfer, as is the case for the previously characterized biosynthetic genes MSDIN and POPB. Our analysis of multiple genomes showed that the evolution of the α-amanitin biosynthetic pathways in the poisonous agarics in the Amanita, Lepiota, and Galerina clades entailed distinct evolutionary pathways including gene family expansion, biosynthetic genes, and genomic rearrangements. Unrelated poisonous fungi produce the same deadly amanitin toxins using variations of the same pathway. Furthermore, the evolution of the amanitin biosynthetic pathway(s) in Amanita species generates a much wider range of toxic cyclic peptides. The results reported here expand our understanding of the genetics, diversity, and evolution of the toxin biosynthetic pathway in fungi.

Using a DNA mini-barcode within the ITS region to identify toxic Amanita in mushroom poisoning cases.

Mushroom poisoning contributes significantly to global foodborne diseases and related fatalities. Amanita mushrooms frequently cause such poisonings; however, identifying these toxic species is challenging due to the unavailability of fresh and intact samples. It is often necessary to analyze residues, vomitus, or stomach extracts to obtain DNA sequences for the identification of species responsible for causing food poisoning. This usually proves challenging to obtain usable DNA sequences that can be analyzed using conventional molecular biology techniques. Therefore, this study aimed to develop a DNA mini-barcoding method for the identification of Amanita species. Following the evaluation and optimization of universal primers for DNA mini-barcoding in Amanita mushrooms, we found that the internal transcribed spacer (ITS) gene sequence primer ITS-a was the most suitable DNA barcode primer for identifying Amanita species. Forty-three Amanita samples were subsequently amplified and sequenced. The sequences obtained were analyzed for intra- and inter-species genetic distances, and a phylogenetic tree was constructed. The findings indicated that the designed primers had strong universality among the Amanita samples and could accurately identify the target gene fragment with a length of 290 bp. Notably, the DNA mini-barcode accurately identified the 43 Amanita samples, demonstrating high consistency with the conventional DNA barcode. Furthermore, it effectively identified DNA from digested samples. In summary, this DNA mini-barcode is a promising tool for detecting accidental ingestion of toxic Amanita mushrooms. It may be used as an optimal barcode for species identification and traceability in events of Amanita-induced mushroom poisoning. KEY POINTS: • Development of a DNA mini-barcoding method for Amanita species identification without fresh samples. • The ITS-a primer set was optimized for robust universality in Amanita samples. • The mini-barcode is suitable for screening toxic mushroom species in mushroom poisoning cases.

Historical biogeography and diversification of ringless Amanita (section Vaginatae) support an African origin and suggest niche conservatism in the Americas.

Ectomycorrhizal fungi (ECM) sustain nutrient recycling in most terrestrial ecosystems, yet we know little about what major biogeographical events gave rise to present-day diversity and distribution patterns. Given the strict relationship between some ECM lineages and their hosts, geographically well-sampled phylogenies are central to understanding major evolutionary processes of fungal biodiversity patterns. Here, we focus on Amanita sect. Vaginatae to address global diversity and distribution patterns. Ancestral-state-reconstruction based on a 4-gene timetree with over 200 species supports an African origin between the late Paleocene and the early Eocene (ca. 56 Ma). Major biogeographic "out-of-Africa" events include multiple dispersal events to Southeast Asia (ca. 45-21 Ma), Madagascar (ca. 18 Ma), and the current Amazonian basin (ca. 45-36 Ma), the last two likely trans-oceanic. Later events originating in Southeast Asia involve Nearctic dispersal to North America (ca. 20-5 Ma), Oceania (Australia and New Zealand; ca. 15 Ma), and Europe (ca. 10-5 Ma). Subsequent dispersals were also inferred from Southeast Asia to East Asia (ca. 4 Ma); from North America to East Asia (ca. 11-8 Ma), Southeast Asia (ca. 19-2 Ma), Northern Andes (ca. 15 Ma), and Europe (ca. 15-2 Ma), respectively; and from the Amazon to the Caribbean region (ca. 25-20 Ma). Finally, we detected a significant increase in the net diversification rates in the branch leading to most northern temperate species in addition to higher state-dependent diversification rates in temperate lineages, consistent with previous findings. These results suggest that species of sect. Vaginatae likely have higher dispersal ability and higher adaptability to new environments, in particular compared to those of its sister clade, sect. Caesareae. Overall, the much wider distribution of A. sect. Vaginatae, from pan-tropical to pan-arctic, provides a unique window to understanding niche conservatism across a species-rich clade of ECM fungi.

Mechanism and treatment of α-amanitin poisoning.

Amanita poisoning has a high mortality rate. The α-amanitin toxin in Amanita is the main lethal toxin. There is no specific detoxification drug for α-amanitin, and the clinical treatment mainly focuses on symptomatic and supportive therapy. The pathogenesis of α-amanitin mainly includes: α-amanitin can inhibit the activity of RNA polymeraseII in the nucleus, including the inhibition of the largest subunit of RNA polymeraseII, RNApb1, bridge helix, and trigger loop. In addition, α-amanitin acts in vivo through the enterohepatic circulation and transport system. α-Amanitin can cause the cell death. The existing mechanisms of cell damage mainly focus on apoptosis, oxidative stress, and autophagy. In addition to the pathogenic mechanism, α-amanitin also has a role in cancer treatment, which is the focus of current research. The mechanism of action of α-amanitin on the body is still being explored.

Analysis of the Ibotenic Acid, Muscimol, and Ergosterol Content of an Amanita Muscaria Hydroalcoholic Extract with an Evaluation of Its Cytotoxic Effect against a Panel of Lung Cell Lines In Vitro.

The fungus Amanita muscaria is universally recognizable for its iconic appearance; it is also widely regarded as poisonous, inedible, and even deadly. In spite of that, there have been documented cases of use of A. muscaria-containing preparations against various diseases, including cancer, to no apparent ill effect. The search for compounds that can be used to treat cancer among various plants and fungi has been intensifying in recent years. In light of this, we describe an HPLC HILIC analytical method for the evaluation of the content of the anticancer compound ergosterol (ERG) and the neuroactive alkaloids ibotenic acid (IBO) and muscimol (MUS) that contribute significantly to the unpleasant physiological syndrome associated with A. muscaria consumption. A 'homemade' A. muscaria tincture made using 80-proof rye vodka as the solvent, an A. muscaria extract made with a standardized water-ethanol solution as the solvent, and fractions obtained from the second extract via liquid-liquid extraction with nonpolar solvents were analyzed. The study also presents the results of capillary zone electrophoresis with contactless conductivity detection and UHPLC-MS/MS analyses of the IBO and MUS content of the two native A. muscaria extracts and an evaluation of the standardized extract's cytotoxic effect against a small panel of lung cell cultures in vitro. Our results show that the standardized extract has a significant cytotoxic effect and does not contain the compounds of interest in any significant quantity.

Cytotoxicity of 4 Wild Mushrooms in a Case of Yunnan Sudden Unexplained Death.

OBJECTIVES: To explore the cytotoxicity of four wild mushrooms involved in a case of Yunnan sudden unexplained death (YNSUD), to provide the experimental basis for prevention and treatment of YNSUD. METHODS: Four kinds of wild mushrooms that were eaten by family members in this YNSUD incident were collected and identified by expert identification and gene sequencing. Raw extracts from four wild mushrooms were extracted by ultrasonic extraction to intervene HEK293 cells, and the mushrooms with obvious cytotoxicity were screened by Cell Counting Kit-8 (CCK-8). The selected wild mushrooms were prepared into three kinds of extracts, which were raw, boiled, and boiled followed by enzymolysis. HEK293 cells were intervened with these three extracts at different concentrations. The cytotoxicity was detected by CCK-8 combined with lactate dehydrogenase (LDH) Assay Kit, and the morphological changes of HEK293 cells were observed under an inverted phase contrast microscope. RESULTS: Species identification indicated that the four wild mushrooms were Butyriboletus roseoflavus, Boletus edulis, Russula virescens and Amanita manginiana. Cytotoxicity was found only in Amanita manginiana. The raw extracts showed cytotoxicity at the mass concentration of 0.1 mg/mL, while the boiled extracts and the boiled followed by enzymolysis extracts showed obvious cytotoxicity at the mass concentration of 0.4 mg/mL and 0.7 mg/mL, respectively. In addition to the obvious decrease in the number of HEK293 cells, the number of synapses increased and the refraction of HEK293 cells was poor after the intervention of Amanita manginiana extracts. CONCLUSIONS: The extracts of Amanita manginiana involved in this YNSUD case has obvious cytotoxicity, and some of its toxicity can be reduced by boiled and enzymolysis, but cannot be completely detoxicated. Therefore, the consumption of Amanita manginiana is potentially dangerous, and it may be one of the causes of the YNSUD.

[Study on 4 cases of mushroom poisoning with amanita and identification of poison].

Different kinds of poisonous mushrooms contain different toxic components. Acute liver injury caused by amanita mushroom is the main cause of death from poisonous mushroom poisoning in China. Consumption of poisonous mushrooms has an incubation period, there is a false recovery period in the clinical process, and the early performance is slight and does not attract enough attention from doctors, and it is easy to miss the treatment opportunity. The clinical characteristics, treatment and identification of mushrooms containing amanita in 4 patients were analyzed in order to improve clinicians' understanding of the diagnosis and treatment of mushroom poisoning and early species identification.

[The research of liver failure in Banna miniature pigs caused by amanita exitialis].

Objective: To explore the characteristics of Banna miniature pig liver failure induced by amanita exitialis. Methods: From September to October 2020, a reverse high performance liquid chromatography (RP-HPLC) method was used to determine the toxin content of amanita exitialis solution, and 2.0 mg/kg amanita exitialis solution (α-amanitins+ß-amanitins) was administered orally to Banna miniature pigs. Toxic symptoms, blood biochemical indexes and histopathological changes of liver, heart and kidney were observed at each time point. Results: All Banna miniature pigs died within 76 h of exposure, and different degrees of digestive tract symptoms such as nausea, vomiting and diarrhea appeared between 6 and 36 h. The biochemical indexes of alanine aminotransferase, aspartate aminotransferase, total bilirubin, lactate dehydrogenase, myoglobin, creatine kinase isoenzyme, blood urea nitrogen and creatinine increased significantly at 52 h after exposure, and the differences were statistically significant compared with 0 h (P<0.05). The bleeding of liver and heart was obvious under macroscopic and microscopic observation, hepatocyte necrosis, renal tubule epithelial cell swelling. Conclusion: Large dose of amanita exitialis can cause acute liver failure of Banna miniature pigs, which is in line with the pathophysiological characteristics of acute liver failure, and lays a foundation for further research on the toxic mechanism and detoxification drugs of amanita exitialis induced liver failure.

[Investigation on a case of Amanita neoovoidea poisoning].

This paper reported a case of poisoning caused by ingestion of Amanita neoovoidea. The patient experienced nausea, vomiting, oliguria, acute renal function injury, and was discharged after symptomatic support treatment and blood purification treatment. Given the different toxicity of different mushrooms, species identification of poisonous mushrooms can help clinicians in diagnosis and treatment.

Intracellular sequestration of cadmium and zinc in ectomycorrhizal fungus Amanita muscaria (Agaricales, Amanitaceae) and characterization of its metallothionein gene.

Amanita muscaria is an ectomycorrhizal mushroom that commonly grows at metal-polluted sites. Sporocarps from the lead smelter-polluted area near Príbram (Central Bohemia, Czech Republic) showed elevated concentrations of Cd and Zn. Size exclusion chromatography of the cell extracts of the sporocarps from both polluted and unpolluted sites indicated that substantial part of intracellular Cd and Zn was sequestered in 6-kDa complexes, presumably with metallothionein(s) (MT). When the cultured mycelial isolates were compared, those from Príbram were more Cd-tolerant and accumulated slightly less Cd and Zn than those from the unpolluted site. The analysis of the available A.muscaria sequence data returned a 67-amino acid (AA) MT encoded by the AmMT1 gene. Weak Cd and Zn responsiveness of AmMT1 in the mycelia suggested its metal homeostasis function in A.muscaria, rather than a major role in detoxification. The AmMT1 belongs to a ubiquitous peptide group in the Agaricomycetes consisting of 60-70-AA MTs containing seven cysteinyl domains and a conserved histidyl, features observed also in a newly predicted, atypical 45-AA RaMT1 of the Zn-accumulator Russula bresadolae in which the C-terminal cysteinyl domains VI and VII are missing. Heterologous expression in metal-sensitive yeast mutants indicated that AmMT1 and RaMT1 encode functional peptides that can protect cells against Cd, Zn, and Cu toxicity. The metal protection phenotype observed in yeasts with mutant variants of AmMT1 and RaMT1 further indicated that the conserved histidyl seems to play a structural, not metal binding role, and the cysteinyls of the C-terminal domains VI and VII are important for Cu binding. The data provide an important insight into the metal handling of site-associated ectomycorrhizal species disturbed by excess metals and the properties of MTs common in Agaricomycetes.

[An investigation of a food poisoning incident caused by Amanita fuliginea].

Mistakenly picking and eating poisonous mushrooms can cause acute poisoning. In August 2020, Qingdao Hospital of Traditional Chinese Medicine handled a poisonous mushroom poisoning incident, conducted epidemiological investigation on all poisoned patients, collected suspicious food, clinical manifestations, clinical test results and treatment conditions, and identified the mushrooms as Amanita fuliginea poisoning after morphological identification. In this incident, 6 people ate grey goose paste, of which 4 were sick with a incubation period of 6~12 h. The clinical manifestations were gastrointestinal symptoms such as nausea, vomiting and diarrhea, liver and kidney damage. After symptomatic support treatment, hemoperfusion or continuous hemofiltration treatment, the patients were cured and discharged. It is suggested to strengthen the popular science education on poisonous mushroom poisoning and improve the ability of identification and clinical treatment of poisonous mushrooms in grass-roots medical institutions.

CLIF-OF >9 predicts poor outcome in patients with Amanita phalloides poisoning.

PURPOSE: Amanita phalloides poisoning with high mortality is rare but serious. The aim of this study is to identify the risk indicators of death in patients with Amanita phalloides poisoning and a good score tool to predict prognosis. METHODS: In this respective study (1/2009-12/2018), the patients (n = 105) with Amanita phalloides poisoning from two hospitals of China Medical University who met the inclusion/exclusion criteria were included. The laboratory markers and the clinical scoring systems including Child-Turcotte-Pugh (CTP), Sequential organ failure assessment (SOFA), Liver injury and Failure evaluation (LiFe), Chronic liver failure-organ failure score system (CLIF-OF), King's College criteria (KCH criteria), Model for end-stage liver disease (MELD) and Platelet-bilirubin-albumin (PALBI) within 24 h of admission to the two hospitals were analyzed and area under the curve (AUC) analyses were also performed regarding the prediction of death. RESULTS: The data analysis indicated that high international normalized ratio (INR) (>3.6, AUC = 0.941) and plasma ammonia (>95.1 µmol/L, AUC = 0.805) were closely associated with mortality after multivariate logistic regression. CLIF-OF (>9) within 24 h with really good diagnostic accuracy (>90%) significantly outperformed the other scores in predicting mortality. CONCLUSION: CLIF-OF (>9) within 24 h of admission is considered as a satisfactory and practical tool to predict a poor outcome of Amanita phalloides poisoning.

Acute liver failure caused by Amanita verna: a case series and review of the literature.

BACKGROUND: Amanita verna is one of the most harmful wild fungi in China. Amanita verna poisoning occurs every year, and the mortality is as high as 50%. However, its clinical manifestations are complex and diverse. CASE PRESENTATION: In March 2019, three patients took a large amount of Amanita, and one of them received liver transplantation in Zhongshan hospital, Sun Yat-sen University. All patients had vomiting and diarrhea 8-12 h after eating wild mushrooms (Amanita). The patients were initially diagnosed with Amanita poisoning. One case (case 3) was complicated and diagnosed as mushroom poisoning (fatal Amanita), toxic hepatitis, acute liver failure, toxic encephalopathy, hemorrhagic colitis, toxic myocarditis, disseminated intravascular coagulation (DIC) and pregnancy. The general clinical data of all patients were recorded, who received early treatment such as hemodialysis, artificial liver plasma exchange, hormone shock and anti-infection. One case (case 1) recovered smoothly after liver transplantation, and the indexes of liver, kidney, coagulation function and infection were improved. The other two cases died of intracerebral hemorrhage. CONCLUSION: Liver transplantation is an effective method for the treatment of acute liver failure caused by mushroom poisoning and can improve the survival rate of patients with toxic liver failure.

Amanita phalloides intoxication: mechanism of toxicity, clinical manifestations and therapeutic approaches.

Ingestion of Amanita phalloides is the most common cause of fatal mushroom poisoning. The clinical picture of intoxication varies from mild subclinical manifestation to lethal fulminant course with the development of acute liver failure. Early diagnosis of Amanita phalloides poisoning is crucial for the outcome but i tis difficult because it is often mistaken as gastroenteritis or due to other mushroom poisoning. The diagnosis is based on the history of recent mushroom ingestion followed by gastrointestinal symptoms, typical time course and laboratory markers and is proven with mycological examination or toxicological examination. Specific treatment consists of detoxification procedures, supportive measures, administration of drugs and therapy in the specialized intensive care unit in the case of acute liver failure. In selected patients with acute liver failure urgent liver transplantation is the only life-saving option.

Diversity of MSDIN family members in amanitin-producing mushrooms and the phylogeny of the MSDIN and prolyl oligopeptidase genes.

BACKGROUND: Amanitin-producing mushrooms, mainly distributed in the genera Amanita, Galerina and Lepiota, possess MSDIN gene family for the biosynthesis of many cyclopeptides catalysed by prolyl oligopeptidase (POP). Recently, transcriptome sequencing has proven to be an efficient way to mine MSDIN and POP genes in these lethal mushrooms. Thus far, only A. palloides and A. bisporigera from North America and A. exitialis and A. rimosa from Asia have been studied based on transcriptome analysis. However, the MSDIN and POP genes of many amanitin-producing mushrooms in China remain unstudied; hence, the transcriptomes of these speices deserve to be analysed. RESULTS: In this study, the MSDIN and POP genes from ten Amanita species, two Galerina species and Lepiota venenata were studied and the phylogenetic relationships of their MSDIN and POP genes were analysed. Through transcriptome sequencing and PCR cloning, 19 POP genes and 151 MSDIN genes predicted to encode 98 non-duplicated cyclopeptides, including α-amanitin, ß-amanitin, phallacidin, phalloidin and 94 unknown peptides, were found in these species. Phylogenetic analysis showed that (1) MSDIN genes generally clustered depending on the taxonomy of the genus, while Amanita MSDIN genes clustered depending on the chemical substance; and (2) the POPA genes of Amanita, Galerina and Lepiota clustered and were separated into three different groups, but the POPB genes of the three distinct genera were clustered in a highly supported monophyletic group. CONCLUSIONS: These results indicate that lethal Amanita species have the genetic capacity to produce numerous cyclopeptides, most of which are unknown, while lethal Galerina and Lepiota species seem to only have the genetic capacity to produce α-amanitin. Additionally, the POPB phylogeny of Amanita, Galerina and Lepiota conflicts with the taxonomic status of the three genera, suggesting that underlying horizontal gene transfer has occurred among these three genera.

A novel chloro-substituted pentenamide from the fruiting bodies of Amanita virgineoides.

One unusual chloro-substituted pentenamide, (3R)-4-chloro-3-hydroxy-4-pentenamide (1), together with 11 known compounds (2-12) were isolated from the fruiting bodies of Amanita virgineoides. The structure of 1 including the absolute configuration was characterized by extensive spectroscopic analyses and quantum calculation. Compound 1 displayed no obvious activity against herpes simplex virus (HSV), human enterovirus 71 (EV71) or coxsackievirus B3 (CVB3).

Significance and outcome of living-donor liver transplantation in acute mushroom intoxication.

INTRODUCTION: Mushroom intoxication (MT) can lead to acute liver injury which may result in Mushroom intoxication-related liver failure (M-ALF) requiring liver transplantation (LT). In the present study, we want to share the experience of our institute regarding living-donor LT (LDLT) due to mushroom poisoning. AIM: The aim of this study is to identify the predictors of poor prognosis in patients with ALF secondary to mushroom intoxication requiring LDLT. MATERIALS AND METHODS: All patients with MT between 2008 and 2016 were evaluated. Demographics, symptoms, interval between symptoms and admission to our institute, laboratory data, model for end-stage liver disease (MELD)/pediatric end-stage liver disease (PELD) scores, clinical course, and outcomes of supportive therapy and LT were evaluated. There were two groups in the study: Group A = responsive to supportive therapy (n = 9) versus Group B = unresponsive to supportive therapy (n = 9). RESULTS: During the study, a total of 18 patients were admitted with M-ALF. Twelve (66.7%) of them were female, and the mean age was 39.9 ± 18.2 years. All of the nine patients in Group A fully recovered with supportive therapy. In Group B, one patient died during waiting period for LT and 8 patients received LDLT LDLT. Three of the eight patients who were transplanted died in the postoperative early period within postoperative 5 days. The patients in Group B had significantly higher MELD/PELD scores and encephalopathy rate than in Group A (P < 0.05). International normalized ratio (INR), bilirubin, ammonium levels, and platelet count were significantly different between groups (P < 0.05). The patients in Group B had significantly longer interval before admission to our institute (P < 0.05). CONCLUSION: The presence of encephalopathy, higher MELD/PELD, INR, bilirubin, ammonium levels, and lower platelet count was related to poor prognosis in MT. LDLT provides a good therapeutic option in patients with M-ALF. The time is a crucial factor in successful treatment of MT. Early admission to a tertiary referral center with expertise in LT results in a better prognosis and increased survival following M-ALF.

Features of Patients With Severe Hepatitis Due to Mushroom Poisoning and Factors Associated With Outcome.

BACKGROUND & AIMS: Acute liver failure after ingestion of toxic mushrooms is a significant medical problem. Most exposures to toxic mushrooms produce no symptoms or only mild gastroenteritis, but some lead to severe hepatic necrosis and fulminant hepatic failure requiring liver transplantation. We aimed to assess mortality from mushroom poisoning and identify variables associated with survival and liver transplantation. METHODS: We collected information from 27 patients (13 male; median age, 47 years) admitted to the emergency department within 24 hours of ingesting wild mushrooms. They developed severe liver injury (serum levels of transaminases greater than 400 IU/L) and were treated with activated charcoal and N-acetylcysteine at a tertiary medical center in San Francisco, California from January 1997 through December 2014. Viral hepatitis, autoimmune liver disease, acetaminophen, salicylate toxicity, and chronic liver diseases were ruled out for all patients. We analyzed patient demographics, time since ingestion, presenting symptoms, laboratory values, and therapies administered. A good outcome was defined as survival without need for liver transplant. A poor outcome was defined as death or liver transplant. Positive predictive values were calculated, and the χ2 test was used to analyze dichotomous variables. RESULTS: Liver injury was attributed to ingestion of Amanita phalloides in 24 patients and Amanita ocreata in 3 patients. Twenty-four of the patients ingested mushrooms with meals and 3 patients for hallucinogenic purpose. At 24-48 hours after ingestion, all patients had serum levels of alanine aminotransferase ranging from 554 to 4546 IU/L (median, 2185 IU/L). Acute renal impairment developed in 5 patients. Twenty-three patients survived without liver transplantation, and 4 patients had poor outcomes (1 woman underwent liver transplantation on day 20 after mushroom ingestion, and 3 women died of hepatic failure). Of the 23 patients with peak levels of total bilirubin of 2 mg/dL or more during hospitalization, only 4 had a poor outcome. Peak serum level of aspartate aminotransferase less than 4000 IU/L, peak international normalized ratio less than 2, and a value of serum factor V greater than 30% identified patients with good outcomes with 100% positive predictive value; if these peak values were used as a cutoff, 10 of 27 patients (37%), 7 of 27 patients (26%), and 6 of 12 patients (50%), respectively, could have avoided transfer to a transplant center. CONCLUSIONS: In an analysis of 27 patients with hepatocellular damage due to mushroom (Amanita) poisoning and peak levels of total bilirubin greater than 2 mg/dL, the probability of liver transplantation or death is 17%, fulfilling Hy's law. Patients with peak levels of aspartate aminotransferase less than 4000 IU/L can be monitored in a local hospital, whereas patients with higher levels should be transferred to liver transplant centers. Women and older patients were more likely to have a poor outcome than men and younger patients.

Biochemical characteristics of a novel protease from the basidiomycete Amanita virgineoides.

The characterization of a novel protease from Amanita virgineoides is described. The A. virgineoides protease was purified to homogeneity using Q-Sepharose, carboxymethyl-cellulose, diethylaminoethyl-cellulose, and a gel filtration step on Superdex 75. The molecular mass of the purified protease was estimated to be 16.6 kDa. The protease was purified 32.1-fold, and its specific activity was 301.4 U/mg. The optimum pH was 4.0, and the optimum temperature was 50 °C. Kinetic constants (Km , Vmax ) were determined under the optimum reaction conditions, with Km and Vmax , being 3.74 mg/mL and 9.98 µg mL-1 Min-1 , respectively. The activity of the protease was curtailed by Cu2+ , Pb2+ , Fe3+ , Cd2+ , and Hg2+ ions but enhanced by Mg2+ , Ca2+ , and K+ ions at low concentrations. The protease activity was adversely affected by ethylene diamine tetraacetic acid, suggesting that it is a metalloprotease. Four peptide sequences were obtained from liquid chromatography-tandem mass spectrometry, including KQALSGIR, TIAMDGTEGLVR, VALTGLTVAEYFR, and AGAGSATLSMAYAGAR, which showed 86%, 64%, 60%, and 75% identity with peptides of Hypsizygus marmoreus, Dacryopinax sp. DJM-731 SS1, Trametes versicolor FP-101664 SS1, and Paxillus involutus ATCC 200175, respectively. The newly isolated protease showed good hydrolytic activity and biochemical characteristics, which expanded the knowledge of biologically active proteins and provided further insight on this poisonous fungus.

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.