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1.
Toxins (Basel) ; 16(5)2024 May 18.
Artigo em Inglês | MEDLINE | ID: mdl-38787083

RESUMO

The fungal infestation of crops can cause major economic losses. Toxins produced by the causative fungi (mycotoxins) represent a potential safety hazard to people and livestock consuming them. One such mycotoxin is deoxynivalenol (DON, also known as vomitoxin), a trichothecene associated with Fusarium Head Blight of wheat. DON is commonly found in cereal crops worldwide. A group of trichothecene mycotoxins closely related to DON, the NX toxins, have been reported to occur in the northeastern United States and southern Canada. While many commercial immunoassays are available to detect DON, there are no rapid screening assays for the NX toxins. We describe the development and isolation of three monoclonal antibodies (mAbs) specific towards two NX toxins: NX-2 and NX-3. The mAbs did not recognize DON or several other closely related trichothecenes. One of the mAbs was selected for development of an enzyme-linked immunosorbent assay (ELISA) for NX-2 and NX-3 in wheat. The dynamic ranges for the assay were 7.7 to 127 µg/kg for NX-2 and 59 µg/kg to 1540 µg/kg for NX-3 in wheat. Recoveries from spiked wheat averaged 84.4% for NX-2 and 99.3% for NX-3, with RSDs of 10.4% and 11.3%, respectively (n = 24). The results suggest that this assay can be used to screen for NX toxins in wheat at levels relevant to human food and animal feed safety.


Assuntos
Anticorpos Monoclonais , Ensaio de Imunoadsorção Enzimática , Tricotecenos , Triticum , Triticum/química , Triticum/microbiologia , Anticorpos Monoclonais/imunologia , Ensaio de Imunoadsorção Enzimática/métodos , Animais , Tricotecenos/análise , Tricotecenos/imunologia , Contaminação de Alimentos/análise , Micotoxinas/análise , Micotoxinas/imunologia , Camundongos Endogâmicos BALB C
2.
Biosens Bioelectron ; 233: 115339, 2023 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-37126866

RESUMO

Strains of Penicillium spp. are used for fungi-ripened cheeses and Aspergillus spp. routinely contaminate maize and other crops. Some of these strains can produce toxic secondary metabolites (mycotoxins), including the neurotoxin α-cyclopiazonic acid (CPA). In this work, we developed a homogeneous upconversion-resonance energy transfer (UC-RET) immunoassay for the detection of CPA using a novel epitope mimicking peptide, or mimotope, selected by phage display. CPA-specific antibody was used to isolate mimotopes from a cyclic 7-mer peptide library in consecutive selection rounds. Enrichment of antibody binding phages was achieved, and the analysis of individual phage clones revealed four different mimotope peptide sequences. The mimotope sequence, ACNWWDLTLC, performed best in phage-based immunoassays, surface plasmon resonance binding analyses, and UC-RET-based immunoassays. To develop a homogeneous assay, upconversion nanoparticles (UCNP, type NaYF4:Yb3+, Er3+) were used as energy donors and coated with streptavidin to anchor the synthetic biotinylated mimotope. Alexa Fluor 555, used as an energy acceptor, was conjugated to the anti-CPA antibody fragment. The homogeneous single-step immunoassay could detect CPA in just 5 min and enabled a limit of detection (LOD) of 30 pg mL-1 (1.5 µg kg-1) and an IC50 value of 0.36 ng mL-1. No significant cross-reactivity was observed with other co-produced mycotoxins. Finally, we applied the novel method for the detection of CPA in spiked maize samples using high-performance liquid chromatography coupled to a diode array detector (HPLC-DAD) as a reference method.


Assuntos
Técnicas Biossensoriais , Micotoxinas , Imunoensaio/métodos , Micotoxinas/análise , Peptídeos/química , Transferência de Energia
3.
Toxins (Basel) ; 15(3)2023 03 16.
Artigo em Inglês | MEDLINE | ID: mdl-36977113

RESUMO

T-2 toxin is a mycotoxin routinely found as a contaminant of cereal grains worldwide. A portable mass spectrometer was adapted to enable the detection of T-2 toxin in wheat and maize by APCI-MS. In order to facilitate rapid testing, a rapid cleanup was used. The method was able to detect T-2 toxin in soft white wheat, hard red wheat, and yellow dent maize and could be used to screen for T-2 at levels above 0.2 mg/kg. The HT-2 toxin was only detectable at very high levels (>0.9 mg/kg). Based on these results, the sensitivity was not sufficient to allow the application of the screening method to these commodities at levels recommended by the European Commission. With a cut-off level of 0.107 mg/kg, the method correctly classified nine of ten reference samples of wheat and maize. The results suggest that portable MS detection of T-2 toxin is feasible. However, additional research will be needed to develop an application sensitive enough to meet regulatory requirements.


Assuntos
Micotoxinas , Toxina T-2 , Toxina T-2/análise , Triticum , Zea mays , Micotoxinas/análise , Espectrometria de Massas , Grão Comestível/química , Contaminação de Alimentos/análise
4.
Food Addit Contam Part B Surveill ; 16(1): 14-23, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35997046

RESUMO

Strains of Penicillium camemberti and P. roqueforti are used in the production of soft-ripened and blue-veined cheeses. However, some strains can produce toxic secondary metabolites (mycotoxins), including α-cyclopiazonic acid (CPA), a neurotoxin. Data on the levels of CPA in cheeses marketed in the USA are extremely limited. An enzyme-linked immunosorbent assay was adapted for measuring CPA in soft-ripened and blue-veined cheeses. Recoveries from cheese curds were 103 ± 27% (n = 30). A total of 254 samples of soft-ripened, blue and miscellaneous cheeses were examined. CPA was detected in 36/79 (45.6%) of soft-ripened cheeses and in 41/168 (24.4%) of blue-veined cheeses. Median levels in positive samples were 48.5 µg/kg and 30 µg/kg, respectively. The highest levels found were 3,820 µg/kg (in a Brie), 1,250 µg/kg (in a blue) and 7,900 µg/kg (in a Monte Enebro). The implication of such exposures is unknown, as a consensus on acceptable intake remains to be established.


Assuntos
Queijo , Micotoxinas , Penicillium , Queijo/análise , Contaminação de Alimentos , Micotoxinas/análise , Indóis/metabolismo
5.
Toxins (Basel) ; 14(8)2022 07 30.
Artigo em Inglês | MEDLINE | ID: mdl-36006185

RESUMO

Fumonisins are a group of mycotoxins that routinely contaminate maize. Their presence is monitored at multiple stages from harvest to final product. Immunoassays are routinely used to screen commodities in the field while laboratory-based methods, such as mass spectrometry (MS), are used for confirmation. The use of a portable mass spectrometer unlocks the potential to conduct confirmatory analyses outside of traditional laboratories. Herein, a portable mass spectrometer was used to measure fumonisins in maize. Samples were extracted with aqueous methanol, cleaned up on an immunoaffinity column, and tested with the portable MS. The limits of detection were 0.15, 0.19, and 0.28 mg/kg maize for fumonisins B1 (FB1), FB2/FB3, and total fumonisins, respectively. The corresponding limits of quantitation in maize were 0.33, 0.59, and 0.74 mg/kg. Recoveries ranged from 93.6% to 108.6%. However, RSDs ranged from 12.0 to 29.8%. The method was applied to the detection of fumonisins in 64 samples of maize collected as part of the Illinois Department of Agriculture's monitoring program. Good correlations were observed between the portable MS and a laboratory-based LC-MS method (r2 from 0.9132 to 0.9481). Results suggest the portable MS can be applied to the measurement of fumonisins in maize at levels relevant to international regulations.


Assuntos
Fumonisinas , Micotoxinas , Contaminação de Alimentos/análise , Fumonisinas/análise , Espectrometria de Massas/métodos , Micotoxinas/análise , Água/análise , Zea mays/química
6.
J Fungi (Basel) ; 8(1)2021 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-35049943

RESUMO

Fungal volatile organic compounds (VOCs) are low-molecular weight fungal metabolites that have high vapor pressure at ambient temperatures and can function as airborne signals. Here, we report a VOC study of several different species of Fusarium. Direct analysis in real time mass spectrometry (DART-MS) was applied for non-invasive VOC fingerprinting of Fusarium isolates growing under standardized conditions. A large number of ions were detected from the headspaces of the Fusarium species sampled here. Ions were detected with distinctively high concentrations in some species. While there were few VOCs produced by only one species, the relative concentrations of VOCs differed between species. The methodology has potential for convenient detection and identification of Fusarium contamination in agricultural commodities.

7.
Artigo em Inglês | MEDLINE | ID: mdl-32730172

RESUMO

Roquefortine, also known as roquefortine C (ROQC) is a fungal secondary metabolite (mycotoxin) that is produced by some of the same Penicillia as the tremorgen penitrem-A (PEN-A). The two mycotoxins have been linked to sporadic cases of toxicosis in dogs, cattle, and humans, leading some to consider ROQC as a biomarker of PEN-A. Reported here are the development of a monoclonal antibody (mAb) and associated competitive enzyme-linked immunosorbent assay (ELISA) for the screening of ROQC in extracts of nuts (nut "milks"), and dog serum. The ELISA was sensitive for ROQC, with a level of 0.117 ng ml-1 inhibiting colour development by 50% (IC50), a limit of detection of 0.026 ng ml-1, and a dynamic range (IC20 to IC80) of 0.038 to 0.289 ng ml-1 in buffer. The assay was tolerant to significant levels of methanol. Recoveries from 4 types of nut milks spiked over the range of 0.25 to 2 ng ml-1 were in the range of 83.5% to 116%. A small survey of commercial nut "milks" and "creamers" indicated 4 of 35 samples contained ROQC at levels so low that they are unlikely to be significant to human health (<0.6 ng ml-1). The assay was also applied to canine serum. Recoveries from serum spiked over the range of 0.2 to 5 ng ml-1 ranged from 98.1% to 123%. The results suggest the ELISA can be applied to the screening of food products, such as nut extracts, as well as for the screening of serum from dogs suspected to be suffering from mycotoxin-induced tremors.


Assuntos
Anticorpos Monoclonais/química , Indóis/análise , Anticorpos Monoclonais/metabolismo , Ensaio de Imunoadsorção Enzimática , Compostos Heterocíclicos de 4 ou mais Anéis/análise , Conformação Molecular , Piperazinas/análise
8.
Toxins (Basel) ; 11(11)2019 10 30.
Artigo em Inglês | MEDLINE | ID: mdl-31671523

RESUMO

Citreoviridin (CTV) in an inhibitor of mitochondrial ATPase that has been isolated from molded yellow rice and linked to the human disease Shoshin-kakke (acute cardiac beriberi). The disease results from a deficiency of thiamine, however, purified CTV can reproduce the symptoms in experimental animals. The link between CTV and Shoshin-kakke has been difficult to resolve, in part because cases of the disease are rare. In addition to rice, CTV has been found in maize, pecan nuts, and wheat products. A method to screen for CTV and its geometric isomer, iso-CTV, in commodities was developed, based upon the isolation of two novel monoclonal antibodies (mAb). In an antigen-immobilized competitive enzyme-linked immunosorbent assay format (CI-ELISA), the observed IC50s for CTV were 11 ng/mL and 18 ng/mL (mAbs 2-2 and 2-4, respectively). The assays were relatively tolerant to methanol and acetonitrile, which allowed their application to the detection of CTV in spiked polished white rice. For quantification, a standard mixture of CTV and iso-CTV was used, along with matrix matched calibration. The dynamic range of the ELISA using mAb 2-4 was equivalent to 0.23 to 2.22 mg/kg in rice. Recoveries over the range of 0.36 to 7.23 mg/kg averaged 97 ± 10%. The results suggest that the mAb 2-4-based immunoassay can be applied to the screening of white rice for CTV. Both mAbs were also observed to significantly enhance the fluorescence of the toxin.


Assuntos
Anticorpos Monoclonais/análise , Aurovertinas/análise , Aurovertinas/toxicidade , Beriberi/imunologia , Micotoxinas/análise , Micotoxinas/imunologia , Oryza/microbiologia , Beriberi/fisiopatologia , Ensaio de Imunoadsorção Enzimática/métodos , Imunoensaio/métodos
9.
Toxins (Basel) ; 11(7)2019 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-31266143

RESUMO

T-2 and HT-2 toxins and their main modified forms (T-2 glucoside and HT-2 glucoside) may co-occur in cereals and cereal-based products. A fluorescence polarization immunoassay (FPIA) was developed for the simultaneous determination of T-2 toxin, HT-2 toxin and relevant glucosides, expressed as sum. The developed FPIA, using a HT-2-specific antibody, showed high sensitivity (IC50 = 2.0 ng/mL) and high cross-reactivity (100% for T-2 toxin and 80% for T-2 and HT-2 glucosides). The FPIA has been used to develop two rapid and easy-to-use methods using two different extraction protocols, based on the use of organic (methanol/water, 90:10, v/v) and non-organic (water) solvents, for the determination of these toxins in wheat. The two proposed methods showed analytical performances in terms of sensitivity (LOD 10 µg/kg) recovery (92-97%) and precision (relative standard deviations ≤13%), fulfilling the criteria for acceptability of an analytical method for the quantitative determination of T-2 and HT-2 toxins established by the European Union. Furthermore, the methods were then validated in accordance with the harmonized guidelines for the validation of screening methods included in the Regulation (EU) No. 519/2014. The satisfactory analytical performances, in terms of intermediate precision (≤25%), cut-off level (80 and 96 µg/kg for the two methods) and rate of false positives (<0.1%) confirmed the applicability of the proposed methods as screening method for assessing the content of these toxins in wheat at the EU indicative levels reported for T-2 and HT-2 toxins.


Assuntos
Grão Comestível/química , Glucosídeos/análise , Toxina T-2/análogos & derivados , Toxina T-2/análise , Triticum , Anticorpos Monoclonais/imunologia , Monitoramento Ambiental , Imunoensaio de Fluorescência por Polarização , Glucosídeos/imunologia , Itália , Toxina T-2/imunologia
10.
Mycotoxin Res ; 35(3): 279-292, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-30949954

RESUMO

The ability of several chelating mycotoxins to form coordination complexes with the lanthanide metals europium and terbium was explored. The mycotoxins examined included ochratoxin A, citrinin, cyclopiazonic acid (CPA), kojic acid, and tenuazonic acid (TeA). Of these compounds, TeA and CPA resulted in the greatest luminescence. Parameters influencing luminescence of TeA were investigated further. These included the type of lanthanide and its concentration, certain environmental factors, and the effect of competing metal cations. Of the two lanthanide metals, the terbium coordination complex (TeA-Tb3+) showed greater luminescence relative to the europium complex (TeA-Eu3+). The effects of solvent type, water content, and pH on the TeA-Tb3+ system suggested that optimal conditions for luminescence were in 90% methanol with 10% aqueous buffer at pH 3. In competitive assays, the luminescence of the TeA-Tb3+ complex decreased as the concentration of competing metal cations increased. Among the cations tested, Cu2+ was the best inhibitor followed by Al3+, Au3+, Fe3+, Co2+, Mn2+, Mg2+, and Ca2+. Two cations, Na+ and K+, showed no significant inhibition. This is the first report to describe the coordination of the metal-chelating mycotoxin TeA with lanthanides and the ability of TeA to serve as an "antenna" for the efficient transfer of energy to the lanthanide with resulting luminescence. Understanding the ability of mycotoxins such as TeA to chelate metals provides insight into how they exert their toxic effects.


Assuntos
Complexos de Coordenação/química , Elementos da Série dos Lantanídeos/química , Luminescência , Micotoxinas/química , Quelantes/química , Európio/química , Indóis/química , Metais/química , Ácido Tenuazônico/química , Térbio/química
11.
Anal Bioanal Chem ; 411(16): 3543-3552, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31025179

RESUMO

α-Cyclopiazonic acid (CPA) is a tremorgenic mycotoxin produced by Aspergillus and Penicillium fungal species, commonly found on agricultural commodities or fermented food products. A sensitive and rapid imaging surface plasmon resonance (iSPR) assay was developed to detect CPA in maize and cheese by combining an indirect competitive immunoassay and signal amplification based upon a secondary antibody (Ab2) conjugated with gold nanoparticles. Matrix-matched calibration curves were used to determine CPA content in maize and cheese samples. Recoveries, at two spiking levels in maize and cheese, were 89 to 126%, with standard deviations of repeatability (RSDr) of less than 16%. The limits of detection were 17 and 6 µg/kg in maize and cheese, respectively. To separate the CPA-contaminated samples from uncontaminated samples, a cutoff validation level of 40 µg/kg was introduced. The assay was applied to samples of naturally contaminated maize and was compared with competitive inhibition enzyme-linked immunosorbent assay (CI-ELISA). This is the first report to detect CPA using an immuno-biosensor iSPR format.


Assuntos
Queijo/análise , Imunoensaio/métodos , Indóis/análise , Ressonância de Plasmônio de Superfície/métodos , Zea mays/química , Técnicas Biossensoriais , Calibragem , Limite de Detecção , Reprodutibilidade dos Testes
12.
Toxins (Basel) ; 10(7)2018 07 10.
Artigo em Inglês | MEDLINE | ID: mdl-29996475

RESUMO

Cycopiazonic acid (CPA) is a neurotoxin that acts through inhibition of the sarco(endo)plasmic reticulum Ca2+-ATPase (SERCA). CPA blocks the calcium access channel of the enzyme. The inhibition may involve the binding of CPA with a divalent cation such as Mg2+. The potential for CPA to act as a chelator also has implications for methods to detect this toxin. Certain of the lanthanide metals undergo a dramatic increase in luminescence upon coordination with small molecules that can transfer excitation energy to the metal. This report is the first to describe the coordination of CPA with lanthanide metals, resulting in a substantial enhancement of their luminescence. The luminescence expressed was dependent upon the type of lanthanide, its concentration, and the environment (solvent, water content, pH). Based upon the phenomenon, a competitive assay was also developed wherein terbium (Tb3+) and a series of metal cations competed for binding with CPA. With increasing cation concentration, the luminescence of the CPA/Tb3+ complex was inhibited. The chlorides of ten metals were tested. Inhibition was best with Cu2+, followed by Co2+, Al3+, Fe3+, Mn2+, Au3+, Mg2+, and Ca2+. Two cations in oxidation state one (Na⁺, K⁺) did not inhibit the interaction significantly. The interaction of CPA with lanthanides provides a novel recognition assay for this toxin. It also provides a novel way to probe the binding of CPA to metals, giving insights into CPA’s mechanism of action.


Assuntos
Európio/química , Indóis/química , Micotoxinas/química , Neurotoxinas/química , Térbio/química , Luminescência , Metais Pesados/química
13.
Toxins (Basel) ; 10(3)2018 03 10.
Artigo em Inglês | MEDLINE | ID: mdl-29534452

RESUMO

A sensitive, rapid, and reproducible imaging surface plasmon resonance (iSPR) biosensor assay was developed to detect T-2 toxin and T-2 toxin-3-glucoside (T2-G) in wheat. In this competitive assay, an amplification strategy was used after conjugating a secondary antibody (Ab2) with gold nanoparticles. Wheat samples were extracted with a methanol/water mixture (80:20 v/v), then diluted with an equal volume of primary antibody (Ab1) for analysis. Matrix-matched calibration curves were prepared to determine T-2 toxin and T2-G. Recovery studies were conducted at three spiking levels in blank wheat. Mean recoveries ranged from 86 to 90%, with relative standard deviations for repeatability (RSDr) of less than 6%. Limits of detection were 1.2 ng/mL of T-2 toxin and 0.9 ng/mL of T2-G, equivalent to their levels in wheat, of 48 and 36 µg/kg, respectively. The developed iSPR assay was rapid and provided enough sensitivity for the monitoring of T-2 toxin/T2-G in wheat. This is the first iSPR assay useful for detecting the "masked" T2-G in wheat.


Assuntos
Técnicas Biossensoriais , Contaminação de Alimentos/análise , Glucosídeos/análise , Toxina T-2/análise , Triticum/química , Anticorpos Monoclonais/química , Anticorpos Monoclonais/imunologia , Antígenos/química , Antígenos/imunologia , Glucosídeos/química , Ouro/química , Nanopartículas Metálicas/química , Ovalbumina/química , Ovalbumina/imunologia , Soroalbumina Bovina/química , Soroalbumina Bovina/imunologia , Ressonância de Plasmônio de Superfície , Toxina T-2/química
14.
Toxins (Basel) ; 10(3)2018 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-29494529

RESUMO

MycoKey, an EU-funded Horizon 2020 project, includes a series of "Roundtable Discussions" to gather information on trending research areas in the field of mycotoxicology. This paper includes summaries of the Roundtable Discussions on Chemical Detection and Monitoring of mycotoxins and on the role of genetics and biodiversity in mycotoxin production. Discussions were managed by using the nominal group discussion technique, which generates numerous ideas and provides a ranking for those identified as the most important. Four questions were posed for each research area, as well as two questions that were common to both discussions. Test kits, usually antibody based, were one major focus of the discussions at the Chemical Detection and Monitoring roundtable because of their many favorable features, e.g., cost, speed and ease of use. The second area of focus for this roundtable was multi-mycotoxin detection protocols and the challenges still to be met to enable these protocols to become methods of choice for regulated mycotoxins. For the genetic and biodiversity group, both the depth and the breadth of trending research areas were notable. For some areas, e.g., microbiome studies, the suggested research questions were primarily of a descriptive nature. In other areas, multiple experimental approaches, e.g., transcriptomics, proteomics, RNAi and gene deletions, are needed to understand the regulation of toxin production and mechanisms underlying successful biological controls. Answers to the research questions will provide starting points for developing acceptable prevention and remediation processes. Forging a partnership between scientists and appropriately-placed communications experts was recognized by both groups as an essential step to communicating risks, while retaining overall confidence in the safety of the food supply and the integrity of the food production chain.


Assuntos
Micotoxinas , Animais , Biodiversidade , Monitoramento Ambiental , Humanos , Micotoxinas/análise , Micotoxinas/genética , Pesquisa
15.
Mycotoxin Res ; 34(1): 39-48, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29130148

RESUMO

The major aim of this study was to examine the binding of zearalenone (ZEN) to bovine serum albumin (BSA) by measuring the quenching of the intrinsic fluorescence of the protein under aqueous conditions. The results suggest that ZEN has a strong ability to quench the intrinsic fluorescence of BSA through a static mechanism. The hydrophobicity of the microenvironment around the tyrosine (Tyr) residues in BSA was increased in the presence of ZEN. The quenching constants, ratio of protein with ZEN, and thermodynamic parameters were determined. The collaborative action of hydrophobic and electrostatic interactions was involved in the binding process and the formation of the complex was mainly enthalpy-driven. The average binding distance between ZEN and BSA was calculated to be 2.20 nm. This is much closer in magnitude than the distance reported for the binding of most toxins to HSA and most pharmaceuticals to BSA, indicating a strong affinity.


Assuntos
Estrogênios não Esteroides/metabolismo , Soroalbumina Bovina/metabolismo , Zearalenona/metabolismo , Animais , Bovinos , Fluorometria , Ligação Proteica
16.
Biosens Bioelectron ; 101: 245-252, 2018 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-29096362

RESUMO

A rapid, sensitive and multiplexed imaging surface plasmon resonance (iSPR) biosensor assay was developed and validated for three Fusarium toxins, deoxynivalenol (DON), zearalenone (ZEA) and T-2 toxin. The iSPR assay was based on a competitive inhibition format with secondary antibodies (Ab2) conjugated to gold nanoparticles (AuNPs) used as a signal amplification tag. Signal was amplified nearly 25-fold for DON, 90-fold for ZEA and 12-fold for T-2 toxin assay using Ab2-AuNPs. Analyses, including steps to regenerate the sensor, took 17.5min. The antigen coated sensor chip was used for more than 46 cycles without affecting signal intensity (< 12%). Matrix matched calibration curves were used to determine Fusarium toxins in wheat. The mean recoveries ranged from 87% to 103% with relative standard deviations of repeatability of less than 5%. The limits of detection were 15µg/kg for DON, 24µg/kg for ZEA and 12µg/kg for T-2 toxin. This provided sufficient sensitivity to monitor contamination of these mycotoxins in wheat in accordance with European Commission (EC) limits. Cut off levels for all three Fusarium toxins were validated using blank wheat and wheat spiked either at the EC regulated levels (100µg/kg for ZEA and T-2 toxin) or at one third of the EC level (for DON: 400µg/kg). The assay was successfully applied and further validated with naturally contaminated wheat samples. This is the first reported AuNP enhanced iSPR assay to detect and classify three agriculturally important Fusarium toxins in wheat.


Assuntos
Anticorpos Imobilizados/química , Fusarium/isolamento & purificação , Ouro/química , Nanopartículas Metálicas/química , Micotoxinas/análise , Ressonância de Plasmônio de Superfície/métodos , Triticum/microbiologia , Anticorpos Monoclonais/química , Limite de Detecção , Triticum/química
17.
J AOAC Int ; 99(4): 849-860, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-27455928

RESUMO

Significant progress has been made in the development of biosensors that can be used to detect low-MW toxins produced by fungi (mycotoxins). The number of formats that have been investigated is impressive and is an indication of the importance attached to finding easy-to-use, accurate, and rapid methods for detecting these toxins in commodities and foods. This review explores the details of multiplexed biosensors based on many formats, including multiplexed immunoassays, suspension arrays, membrane-based devices (flow-through and immunochromatographic), and planar microarrays. Each assay format has its own strengths and areas that need improvement. Certain formats, such as multiplexed immunochromatographic devices, are well developed and relatively easy to use, and in some cases, commercial products are being sold. Others, such as the suspension arrays and microarrays, are laboratory-based assays that, although more complicated, are also more amenable to a larger scale of multiplexing. The diversity of such efforts and the multitude of formats under investigation suggest that multiple solutions will be found to satisfy the need for multiplexed toxin detection.


Assuntos
Técnicas Biossensoriais/métodos , Micotoxinas/análise , Técnicas Biossensoriais/instrumentação , Cromatografia de Afinidade/métodos , Ensaio de Imunoadsorção Enzimática/instrumentação , Ensaio de Imunoadsorção Enzimática/métodos , Citometria de Fluxo/métodos , Microbiologia de Alimentos , Ressonância de Plasmônio de Superfície/métodos
18.
Toxins (Basel) ; 7(10): 3903-15, 2015 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-26426046

RESUMO

Paxilline (PAX) is a tremorgenic mycotoxin that has been found in perennial ryegrass infected with Acremonium lolii. To facilitate screening for this toxin, four murine monoclonal antibodies (mAbs) were developed. In competitive indirect enzyme-linked immunosorbent assays (CI-ELISAs) the concentrations of PAX required to inhibit signal development by 50% (IC50s) ranged from 1.2 to 2.5 ng/mL. One mAb (2-9) was applied to the detection of PAX in maize silage. The assay was sensitive to the effects of solvents, with 5% acetonitrile or 20% methanol causing a two-fold or greater increase in IC50. For analysis of silage samples, extracts were cleaned up by adsorbing potential matrix interferences onto a solid phase extraction column. The non-retained extract was then diluted with buffer to reduce solvent content prior to assay. Using this method, the limit of detection for PAX in dried silage was 15 µg/kg and the limit of quantification was 90 µg/kg. Recovery from samples spiked over the range of 100 to 1000 µg/kg averaged 106% ± 18%. The assay was applied to 86 maize silage samples, with many having detectable, but none having quantifiable, levels of PAX. The results suggest the CI-ELISA can be applied as a sensitive technique for the screening of PAX in maize silage.


Assuntos
Anticorpos Monoclonais Murinos , Técnicas Biossensoriais/métodos , Ensaio de Imunoadsorção Enzimática/métodos , Indóis/análise , Micotoxinas/análise , Animais , Calibragem , Indóis/imunologia , Limite de Detecção , Camundongos , Micotoxinas/imunologia , Padrões de Referência , Zea mays/microbiologia
19.
Artigo em Inglês | MEDLINE | ID: mdl-25832782

RESUMO

Patulin is a mycotoxin commonly found in certain fruit and fruit products. For this reason many countries have established regulatory limits pertaining to, in particular, apple juice and apple products. Fruit leathers are produced by dehydrating fruit puree, leaving a sweet product that has a leathery texture. A recent report in the literature described the detection of patulin at substantial levels in fruit leathers. To investigate this further, an ultra-high-performance liquid chromatography-photodiode array (UPLC-PDA) method was developed for the sensitive detection of patulin in fruit leathers. Investigations were also made of the suitability of direct analysis in real time-mass spectrometry (DART-MS) for detection of patulin from the surface of fruit leathers. Results indicated DART-MS was insufficiently sensitive for quantification from the surface of home-style apple leathers, although patulin spiked onto the surface of leather or peel could be detected. The UPLC-PDA method was used to determine the fate of patulin during the preparation of home-made fruit leathers. Interestingly, when a home-style process was used, the patulin was not destroyed, but rather increased in concentration as the puree was dehydrated. The UPLC-PDA method was also used to screen for patulin in commercial fruit leathers. Of the 36 products tested, 14 were above the limit of detection (3.5 µg kg(-1)) and nine were above the limit of quantification (12 µg kg(-1)). Positive samples were confirmed by UPLC-MS/MS. Only one sample was found above the US regulatory limit for single-strength apple juice products (50 µg kg(-1)). These results suggest patulin can be concentrated during preparation and can be found in fruit leathers. The limited survey suggests that patulin is fairly prevalent in such commercial products, but that the levels are usually low.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Análise de Alimentos/métodos , Contaminação de Alimentos/análise , Frutas/química , Patulina/análise , Espectrometria de Massas em Tandem/métodos , Malus , Estrutura Molecular
20.
J Agric Food Chem ; 63(2): 731-8, 2015 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-25520274

RESUMO

T-2 toxin is a trichothecene mycotoxin produced when Fusarium fungi infect grains, especially oats and wheat. Ingestion of T-2 toxin contaminated grain can cause diarrhea, hemorrhaging, and feed refusal in livestock. Cereal crops infected with mycotoxin-producing fungi form toxin glycosides, sometimes called masked mycotoxins, which are a potential food safety concern because they are not detectable by standard approaches and may be converted back to the parent toxin during digestion or food processing. The work reported here addresses four aspects of T-2 toxin-glucosides: phytotoxicity, stability after ingestion, antibody detection, and the anomericity of the naturally occurring T-2 toxin-glucoside found in cereal plants. T-2 toxin-ß-glucoside was chemically synthesized and compared to T-2 toxin-α-glucoside prepared with Blastobotrys muscicola cultures and the T-2 toxin-glucoside found in naturally contaminated oats and wheat. The anomeric forms were separated chromatographically and differ in both NMR and mass spectrometry. Both anomers were significantly degraded to T-2 toxin and HT-2 toxin under conditions that mimic human digestion, but with different kinetics and metabolic end products. The naturally occurring T-2 toxin-glucoside from plants was found to be identical to T-2 toxin-α-glucoside prepared with B. muscicola. An antibody test for the detection of T-2 toxin was not effective for the detection of T-2 toxin-α-glucoside. This anomer was produced in sufficient quantity to assess its animal toxicity.


Assuntos
Avena/química , Glucosídeos/química , Micotoxinas/química , Toxina T-2/análogos & derivados , Triticum/química , Avena/metabolismo , Digestão , Contaminação de Alimentos/análise , Glucosídeos/metabolismo , Humanos , Isomerismo , Cinética , Modelos Biológicos , Estrutura Molecular , Micotoxinas/metabolismo , Toxina T-2/química , Toxina T-2/metabolismo , Triticum/metabolismo
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