Special Issue "Advances in Toxin Detection"

Guest Editor
Dr. Xiaohua He
Research Molecular Biologist, USDA, ARS, WRRC, 800 Buchanan Street, Albany, CA94710, USA
Website: http://www.ars.usda.gov/pandp/people/people.htm?personid=39023
E-Mail: xiaohua.he@ars.usda.gov
Phone: +1 510 559 5823
Fax: +1 510 559 5768
Interests: molecular tools and technologies for rapid; accurate; and sensitive detection and quantification of zoonotic pathogens and toxins in food; mechanisms of interactions between bacterial toxins and host cells; binding between antigen and antibody or receptors

Dear Colleagues,

Toxins are produced by many prokaryotes, plants, and animals.  They are poisonous substances and capable of causing diseases or even death when introduced into the body tissues of living organisms. When toxins are released into agricultural products and environment, timely detection is crucial for planning an effective response. However, the detection of toxins is often difficult due to the combination of the complex sample matrix effect and the low dose of toxins needed to cause the illness. This special issue highlights detection of toxins in food, biological and environmental samples using methods ranging from classic cell culture to cutting edge molecular approaches.

Dr. Xiaohua He
Guest Editor

Submission

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. Papers will be published continuously (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are refereed through a peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Toxins is an international peer-reviewed Open Access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 800 CHF (Swiss Francs) for well prepared manuscripts submitted before 1 July 2013. The APC for manuscripts submitted from 1 July 2013 onwards are 1000 CHF per accepted paper.

• animal toxin
• cell-based assay
• enzymatic activity
• immunoassay
• mass spectrometry
• microbial toxin
• mycotoxin
• plant toxin
• receptor binding

Feature papers

Type of Paper: Article
Title: Enzyme-Amplified Colorimetric Detection of Shiga Toxins with an Antibody Microarray Platform
Authors: Pina Fratamico and Andrew G. Gehring
Affiliation: USDA-ARS, 600 East Mermaid Lane, Wyndmoor, PA 19038, USA; E-Mail: Pina.Fratamico@ARS.USDA.GOV (P.F.); Tel.: 1-215-233-6491
Abstract: Shiga toxins (Stx-1 and Stx-2) from Shiga toxin producing E. coli (STEC) bacteria were simultaneously detected with an antibody microarray platform. The proteinaceous toxins were immobilized and sandwiched between biorecognition elements (antibodies) and avidin-conjugated horseradish peroxidase (HRP). Following reaction of HRP with precipitating chromogenic substrate (3,3-diaminobenzidine tetrahydrochloride or DAB), formation of colored product was quantitatively measured with an inexpensive flatbed page scanner. Detection of
Stx-1 and Stx-2 was linear over a dynamic range of at least 3 orders of magnitude. The Shiga toxins and their variants, produced by various strains of STECs, were also detected following treatment of cultured cells with Ofloxacin (a toxin stimulatory reagent) and B-PER (a cell bacterial protein extraction reagent). Detection of released Shiga toxins was also demonstrated to be linear with relative cell concentration.

Type of Paper: Article
Title: ELISA Methodology for ribosome-Inactivating Protein Detection in Food Matrices
Author: David Brandon
Affiliation: USDA-ARS, 800 Buchanan St., Albany, CA94710, USA; E-Mail: David.Brandon@ARS.USDA.GOV
Abstract: This paper will focus on 2 ribosome-inactivating protein (RIP) toxins, ricin and Shiga toxin 2, with emphasis on the former. Enzyme-linked immunosorbent assay (ELISA) has been applied to all areas of biomedical and food-related research, based on structural recognition by the immune system. The ability of ELISA to discriminate between active and inactive toxins depends on judicious choices of antibodies and assay formats. Naturally occurring and synthetic antibody variants offer additional possibilities for improved toxin detection. For example, chicken IgY contains an extra domain compared to IgG and has a more rigid hinge region. The paper will present the characterization of mouse and chicken antibodies for detection of RIPs in food matrices by ELISA and present data on matrix interference with signal generation and on strategies to overcome these effects.

Type of paper: Article
Title: Faces of a Changing Climate: Semi-Quantitative Multi-Mycotoxin Analysis of Grain Grown in Exceptional Climatic Conditions in Norway
Authors: Silvio Uhlig ¹, Gunnar Sundstøl Eriksen ¹, Ingerd Skov Hofgaard ², Rudolf Krska ³, Eduardo Beltrán ⁴ and Michael Sulyok ³
Affiliations: 1 Section for Chemistry and Toxicology, Norwegian Veterinary Institute, Ullevålsveien 68, N-0454 Oslo, Norway; E-Mails: silvio.uhlig@vetinst.no (S.U.); gunnar.eriksen@vetinst.no (G.S.E.) 2 Bioforsk Plant Health and Plant Protection, Høgskoleveien 7, N-1432 Ås, Norway 3 Center for Analytical Chemistry, Department IFA-Tulln, University of Natural Resources and Applied Life Sciences (BOKU), Vienna, Konrad Lorenz Str. 20, A-3430 Tulln, Austria; E-Mail: michael.sulyok@boku.ac.at (M.S.) 4 Research Institute for Pesticides and Water, University Jaume I., E-12071 Castellón de la Plana, Spain
Abstract: Recent climatological research predicts a significantly wetter climate in Southern Norway as a result of global warming. The country has already experienced unusually wet summer seasons in the last three years (2010–2012). This has resulted in increasing contamination of cereal grain with trichothecenes, especially of the B-type. Type-B trichothecenes are important mycotoxins related to infection with Fusarium graminearum and F. culmorum, and are commonly monitored in survey programmes. In order to get an impression of the contamination with a wide range of fungal metabolites the aim of this pilot study was to apply an existing multi-analyte LC-MS/MS method for the semiquantitative determination of 320 fungal metabolites in grain samples from the 2011 growing season. The method includes all regulated and well-known mycotoxins such as aflatoxins, trichothecenes, fumonisins and zearalenone, and in addition a wide range of less studied compounds, e.g. Alternaria toxins, ergot alkaloids and other metabolites related to fungal species within Fusarium, Penicillium and Aspergillus. A total of 46 fungal metabolites were detected in the 76 barley, oats and wheat samples. The analyses confirmed the high prevalence and in part high concentrations of type-A and -B trichothecenes (e.g., deoxynivalenol up to 7,230 µg/kg, HT-2 toxin up to 333 µg/kg). Zearalenone was likewise among the major mycotoxins detected (maximum concentration 1,670 µg/kg). Several other Fusarium metabolites such as culmorin, 2-AOD-3-ol and avenacein Y were co-occurring. The most prevalent Alternaria toxin was alternariol with a maximum concentration of 449 µg/kg. A number of Penicillium/Aspergillus metabolites were likewise detected in the samples, e.g. sterigmatocystin in concentrations up to 20 µg/kg. This pilot study will form the basis for new national survey programs and toxicological investigations.