A Rapid Extraction Method Combined with a Monoclonal Antibody-Based Immunoassay for the Detection of Amatoxins

Rapid and simultaneous detection of five mycotoxins and their analogs with a gold nanoparticle-based multiplex immuno-strip sensor

Mycotoxins, as secondary metabolites produced by fungi, have been the focus of researchers in various countries and are considered to be one of the major risk factors in agricultural products. There is an urgent need for a rapid, simple and high-performance method to detect residues of harmful mycotoxins in agricultural foods. We have developed a gold nanoparticle-based multiplexed immunochromatographic strip biosensor that can simultaneously detect fifteen mycotoxins in cereal samples. With this optimized procedure, five representative mycotoxins, deoxynivalenol (DON), zearalenone (ZEN), T-2 toxin (T-2), tenuazonic acid (TEA) and alternariol (AOH) were detected in the range of 0.91-4.77, 0.04-0.56, 0.11-0.68, 0.12-1.02 and 0.09-0.75 ng/mL, respectively. The accuracy and stability of these measurements were demonstrated by analysis of spiked samples with recoveries of 91.8%-115.3% and coefficients of variation <8.7%. In addition, commercially available samples of real cereals were tested using the strips and showed good agreement with the results verified by LC-MS/MS. Therefore, Our assembled ICA strips can be used for the simultaneous detection of 5 mycotoxins and their analogs (15 mycotoxins in total) in grain samples, and the results were consistent between different types of cereal foods, this multiplexed immunochromatographic strip biosensor can be used as an effective tool for the primary screening of mycotoxin residues in agricultural products.

[Amatoxin-containing mushroom poisoning: An update]

Amatoxin-containing mushroom poisoning occurs after consumption of certain mushroom species, of the genera Amanita, Lepiota and Galerina. Amanita phalloides is the most implicated species, responsible for over more than 90% of mushroom-related deaths. The α-amanitin is responsible for most of the observed effects. Symptoms are characterized by severe delayed gastrointestinal disorders (more than six hours after ingestion). The liver being the main target organ, outcome is marked by an often severe hepatitis which can evolve towards terminal liver failure, justifying orthotopic liver transplantation. Acute renal failure is common. Diagnosis of amatoxin-containing mushroom poisoning is based primarily on clinical data; it can be biologically confirmed using detection of amatoxins, especially from urine samples. In the absence of an antidote, early hospital management is essential. It is based on supportive care (early compensation of hydroelectrolytic losses), gastrointestinal digestive decontamination, elimination enhancement, amatoxin uptake inhibitors and antioxidant therapy. Combined therapy associating silibinin and N-acetylcysteine is recommended. Prognosis of this severe poisoning has greatly benefited from improved resuscitation techniques. Mortality is currently less than 10%. In the event of a suspected or confirmed case, referral to a Poison Control Center is warranted in order to establish the diagnosis and guide the medical management of patients in an early and appropriate way.

Molecular Recognition Mechanism of an Anti-Amatoxins mAb and Its Application in Centrifugal Disk-Based Immunoassay

Amatoxins are polypeptides that cause 90% of fatalities from accidental ingestion of poisonous mushrooms. Unfortunately, there are no specific antidotes against amatoxins poisoning, hence preparation of high-affinity antibodies, understanding the receptor (amatoxins) and ligand (antibody) mechanism, and establishing a straightforward screening approach are of great significance for confirming poison agents and clinical diagnosis. Here, anti-amatoxins monoclonal antibody (mAb) 9B2 was prepared and the recognition mechanism was investigated. The approach is useful for designing desirable immunogens, developing new antibodies with improved performance, and constructing effective immunoassays. Based on the mAb, we designed a centrifugal disk-like microfluidics chip and developed a fully automated immunoassay capable of detecting amatoxins poisoning in various samples including serum, urine, and mushrooms. The whole detection process could be automatically accomplished within 30 min, with a limit of detection of 0.08 to 0.12 μg/L for real samples, ∼30-fold more sensitive than conventional enzyme-linked immunosorbent assay (ELISA). Our platform not only provided a practical approach for performing poison agent confirmation and clinical diagnosis but also had important implications for improving the survival of patients with mushroom poisoning.

New preservation and detection technologies for edible mushrooms: A review

Edible mushrooms are nutritious, tasty, and have medicinal value, which makes them very popular. Fresh mushrooms have a high water content and a crisp texture. They demonstrate strong metabolic activity after harvesting. However, they are prone to textural changes, microbial infestation, and nutritional and flavor loss, and they therefore require appropriate post-harvest processing and preservation. Important factors affecting safety and quality during their processing and storage include their quality, source, microbial contamination, physical damage, and chemical residues. Thus, these aspects should be tested carefully to ensure safety. In recent years, many new techniques have been used to preserve mushrooms, including electrofluidic drying and cold plasma treatment, as well as new packaging and coating technologies. In terms of detection, many new detection techniques, such as nuclear magnetic resonance (NMR), imaging technology, and spectroscopy can be used as rapid and effective means of detection. This paper reviews the new technological methods for processing and detecting the quality of mainstream edible mushrooms. It mainly introduces their working principles and application, and highlights the future direction of preservation, processing, and quality detection technologies for edible mushrooms. Adopting appropriate post-harvest processing and preservation techniques can maintain the organoleptic properties, nutrition, and flavor of mushrooms effectively. The use of rapid, accurate, and non-destructive testing methods can provide a strong assurance of food safety. At present, these new processing, preservation and testing methods have achieved good results but at the same time there are certain shortcomings. So it is recommended that they also be continuously researched and improved, for example through the use of new technologies and combinations of different technologies. © 2023 Society of Chemical Industry.

Analytical methods for amatoxins: A comprehensive review

Amatoxins are toxic bicyclic octapeptides found in certain wild mushroom species, particularly Amanita phalloides. These mushrooms contain predominantly α- and β-amanitin, which can lead to severe health risks for humans and animals if ingested. Rapid and accurate identification of these toxins in mushroom and biological samples is crucial for diagnosing and treating mushroom poisoning. Analytical methods for the determination of amatoxins are critical to ensure food safety and prompt medical treatment. This review provides a comprehensive overview of the research literature on the determination of amatoxins in clinical specimens, biological and mushroom samples. We discuss the physicochemical properties of toxins, highlighting their influence on the choice of the analytical method and the importance of sample preparation, particularly solid-phase extraction with cartridges. Chromatographic methods are emphasised with a focus on liquid chromatography coupled to mass spectrometry as one of the most relevant analytical method for the determination of amatoxins in complex matrices. Furthermore, current trends and future perspectives in amatoxin detection are also suggested.

Smartphone-based paper microfluidic competitive immunoassay for the detection of α-amanitin from mushrooms

α-Amanitin is often considered the most poisonous mushroom toxin produced by various mushroom species, which are hard to identify from edible, non-toxic mushrooms. Conventional detection methods require expensive and bulky equipment or fail to meet high analytical sensitivity. We developed a smartphone-based fluorescence microscope platform to detect α-amanitin from dry mushroom tissues. Antibody-nanoparticle conjugates were captured by immobilized antigen-hapten conjugates while competing with the free analytes in the sample. Captured fluorescent nanoparticles were excited at 460 nm and imaged at 500 nm. The pixel numbers of such nanoparticles in the test zone were counted, showing a decreasing trend with increasing analyte concentration. The detection method exhibited a low detection limit (1 pg/mL), high specificity, and selectivity, allowing us to utilize a simple rinsing for toxin extraction and avoiding the need for high-speed centrifugation. In addition, this assay's short response time and portable features enable field detection of α-amanitin from amanitin-producing mushrooms.

Ultrasensitive paper sensor for simultaneous detection of alpha-amanitin and beta-amanitin by the production of monoclonal antibodies

Amanitin (AMA) is responsible for human fatalities after ingestion of poisonous mushrooms, thus, a rapid and accurate detection method is urgently needed. Here, gold nanoparticle-based immunosensor with monoclonal antibody against AMA was constructed for rapid detection of alpha- and beta-amanitin (α- and β-AMA) in mushroom, serum and urine samples. Under optimized conditions, the visual limits of detection (vLOD) and calculated LOD for α-AMA and β-AMA in mushroom were 10 ng/g, 20 ng/g, and 0.1 ng/g, 0.2 ng/g, respectively. Analysis of wild mushroom samples was also performed using a strip scan reader in the 10 min range. Furthermore, in mushrooms containing amatoxins results were confirmed and compared with those determined by liquid chromatography tandem mass spectrometry. Thus, this immunosensor provided a useful monitoring tool for rapid detection and screening of mushroom samples and in serum and urine from subjects who accidentally consumed AMA-containing mushrooms.

Lateral flow immunoassay (LFIA) for the detection of lethal amatoxins from mushrooms

The mushroom poison that causes the most deaths is the class of toxins known as amatoxins. Current methods to sensitively and selectively detect these toxins are limited by the need for expensive equipment, or they lack accuracy due to cross-reactivity with other chemicals found in mushrooms. In this work, we report the development of a competition-based lateral flow immunoassay (LFIA) for the rapid, portable, selective, and sensitive detection of amatoxins. Our assay clearly indicates the presence of 10 ng/mL of α-AMA or γ-AMA and the method including extraction and detection can be completed in approximately 10 minutes. The test can be easily read by eye and has a presumed shelf-life of at least 1 year. From testing 110 wild mushrooms, the LFIA identified 6 out of 6 species that were known to contain amatoxins. Other poisonous mushrooms known not to contain amatoxins tested negative by LFIA. This LFIA can be used to quickly identify amatoxin-containing mushrooms.

Rapid, Sensitive, and Accurate Point-of-Care Detection of Lethal Amatoxins in Urine

Globally, mushroom poisonings cause about 100 human deaths each year, with thousands of people requiring medical assistance. Dogs are also susceptible to mushroom poisonings and require medical assistance. Cyclopeptides, and more specifically amanitins (or amatoxins, here), are the mushroom poison that causes the majority of these deaths. Current methods (predominantly chromatographic, as well as antibody-based) of detecting amatoxins are time-consuming and require expensive equipment. In this work, we demonstrate the utility of the lateral flow immunoassay (LFIA) for the rapid detection of amatoxins in urine samples. The LFIA detects as little as 10 ng/mL of α-amanitin (α-AMA) or γ-AMA, and 100 ng/mL of β-AMA in urine matrices. To demonstrate application of this LFIA for urine analysis, this study examined fortified human urine samples and urine collected from exposed dogs. Urine is sampled directly without the need for any pretreatment, detection from urine is completed in 10 min, and the results are read by eye, without the need for specialized equipment. Analysis of both fortified human urine samples and urine samples collected from intoxicated dogs using the LFIA correlated well with liquid chromatography-mass spectrometry (LC-MS) methods.