Special Issue "Paralytic Shellfish Toxins: Analysis, New Analogs, Toxicology, Vectors, and Impacts in Wildlife"
A special issue of Toxins (ISSN 2072-6651). This special issue belongs to the section "Marine and Freshwater Toxins".
Deadline for manuscript submissions: 31 October 2021.
Special Issue Editors
Interests: marine biotoxin analysis; paralytic shellfish toxins; amnesic shellfish toxins; lipophillic toxins; emerging toxins; harmful algal blooms; non-traditional vectors; impacts in seabirds; toxicology; molecular detection tools
Interests: cell cycle; dinoflagellates; flow cytometry; life cycles; meiosis; microparasites; PSP regulation; resting cysts
Special Issue Information
Dear Colleagues,
Paralytic shellfish toxins (PSTs) are a group of natural neurotoxic alkaloids that can cause paralytic shellfish poisoning (PSP). PSP is characterized by neurological symptoms that vary from mild to severe and can even result in death. PSTs bioaccumulate in certain marine biota, are transferred throughout aquatic food webs, and can be vectored to humans. Therefore, it is essential to regularly monitor the production of phytoplankton and shellfish PST content in harvesting areas. PSTs can also seriously impact marine ecosystems, causing strandings and deaths in seabirds, seals, whales, etc. For years, fishery closures and PSP in humans were mainly attributed to filter-feeders (i.e., bivalve mollusks), although certain countries monitor other seafood as well. Recent studies report more frequent findings of PSTs in additional invertebrate vectors and fish. Therefore, it is essential to gather more data for the purpose of risk assessment and evaluation and to review monitoring strategies accordingly. Monitoring programs rely on intensive sampling and analysis that require rapid, sensitive, accurate, and precise testing methods. The accuracy of these methods is, among other factors, dependent on the availability of reference materials (standards and tissues), information on the congener’s toxicity, and the identification of new analogues.
This Special Issue is open to original research articles and reviews dealing with PSTs and the following subjects:
- new analytical methods (substantial modifications of internationally validated/well-established methods or their application to new matrixes);
- development of new reference materials;
- identification and characterization of new congeners;
- toxicological studies;
- the impact of PSTs on wildlife and new reports in non-traditional vectors;
- novel detection tools of PSTs production in marine environmental samples;
- biosynthetic pathways and gene regulation of PSTs; and
- toxinological studies leading to unveil environmental conditions or genetically determined factors responsible for differences in PSTs profiles between groups or strains from the same taxon.
Dr. Begoña Ben-Gigirey
Dr. Rosa Isabel Figueroa
Guest Editors
Manuscript Submission Information
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. All papers will be peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short 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 thoroughly refereed through a double-blind 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 2400 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.
Keywords
- paralytic shellfish toxins
- analytical methods
- reference materials
- molecular detection tools
- new congeners
- new vectors
- impacts in wildlife
- toxicology
Planned Papers
The below list represents only planned manuscripts. Some of these manuscripts have not been received by the Editorial Office yet. Papers submitted to MDPI journals are subject to peer-review.
Title: Looking For Landmarks of Sex in the Dinoflagellate Alexandrium Minutum and Its Consequences on Psp Toxin Inheritance
Authors: Dapena, C., Riobó, P., Escudeiro, A., Bravo, I., Díaz, P., Sixto, M., Figueroa, R.I.*
Abstract: It is a widely-accepted fact that sexuality is an important event in the life cycle of many dinoflagellates. However, there are not known external physiological features which could be used to mark the existence of its main process, meiosis, neither known which are the consequences of it, i.e. how recombination conditions the expression of dinoflagellate phenotypes. To elucidate both points: i) which physiological traits could be used to predict meiosis, and ii) evaluate the phenotypic effects of sex, we followed two different approximations. In the first, we studied by image flow cytometry (IFC) a sexual compatible cross of the toxic -Paralytic Shellfish Poisoning (PSP) producer- dinoflagellate, Alexandrium minutum. To identify and single out meiotic processes, three cell elements involved in gamete fusion and zygote development were labeled for the IFC analyses: the nucleus, the theca and the lipid content. Secondly, the inheritance of toxicity levels was studied in this cross through the analyses of 40 clones obtained after the germination of 40 different sexual resting cysts (F1 offspring). Parental strains of this cross were previously characterized as heterothallic (not resting cysts were produced within clones) and with outstanding differences regarding their toxin production. Our novel results are the following: 1) Zygote formation is achieved after the absorption of a naked gamete by a thecated gamete, 2) Triads and tetrads are formed as consequence of meiosis in A. minutum, 3) The inheritance of PST production in the F1 offspring follows a pattern consistent with the existence of multiple gene copies in tandem array. We additionally discuss about clonal stability in dinoflagellates and propose a model for the distribution and inheritance of PST gene copies in the Alexandrium minutum genome.
Title: Proposal for improvements the UHPLC-MS/MS for the determination of Paralytic Shellfish Toxins and Tetrodotoxin in bivalves
Authors: Araceli E. Rossignoli *, Carmen Mariño, Helena Martín, and Juan Blanco
Abstract: The search of analytical methods to substitute the mousse bioassay (MBA) has been one of the main goals of recent years in the field of marine toxins detection. In Europe from January 1, 2019, biological methodology was replaced as the EU reference method for determination of paralytic shellfish poisoning toxins (PSTs) by a chemical detection using pre-column oxidation LC–fluorescence detection (FLD), as described by AOAC INTERNATIONAL Official Method of Analysis (OMA) 2005.06. Since then, this method has been incorporated in some countries into the official control monitoring programs for the bivalve’s production areas. However and despite the fact that the method provide a good level of protection, some complexities, including the requirement for multiple cleanup steps and analyses, has caused that the method to have numerous detractors. Recently in 2020, a new ultrahigh-performance hydrophilic interaction liquid chromatography with tandem mass spectrometry method (UHPLC-MS/MS) for paralytic shellfish toxins (PSTs) and tetrodotoxins (TTXs) has been developed successfully through a collaborative study (Turner et al. 2020). This method seems to be a good candidate as an official alternative method of analysis for regulatory control of PSTs and TTXs. In this study we present several modifications of this UHPLC-MS/MS method which are related with the mobile phases (acidic and basic) and the type of chromatographic column used. These modifications improve the analysis both in terms of reduction of the toxins retention times (and therefore, the duration of the analysis), and also to increase the durability of the chromatographic columns (working with column fillings of larger particle size). In addition, based on these same UHPLC-MS/MS methods, several options are also presented for the analysis of TTXs, whose importance at a global level has increased due to its greater incidence in recent years. The methods allow to analyze the TTXs in runs of less than 4 minutes with a good recoveries and a very reasonable limits of detection (LOD) and quantitation (LOQ).
Title: Latitudinal variation in toxicity and sexual compatibility of Alexandrium catenella strains from southern Chile
Authors: Camilo Rodríguez-Villegas, Patricio A. Díaz, Pilar Riobó, Araceli E. Rossignoli, Francisco Rodríguez, Patricia Loures, Ángela Baldrich, Daniel Varela, Alondra Sandoval, and Rosa I. Figueroa
Abstract: Harmful algal blooms of the toxic dinoflagellate Alexandrium catenella are the main responsible for Paralytic Shellfish Poisoning (PSP) in Southern Chile (39.5-55°S). This area has been affected by intense PSP outbreaks (world record in toxicity levels) since their first detection 50 years ago. Considering Alexandrium catenella complex life history, that involves the formation of benthic sexual cysts, we studied a potential link between latitude, toxicity and sexual compatibility. Thus, we selected nine clones isolated from the three southernmost regions and conducted self and out-crosses in all possible combinations (n=45). The latitude effect was assessed in i) toxin profiles; ii) reproductive suc-cess indexes, and iii) resting cysts production. The toxin profiles were similar for all strains, characterized by C1, C2, GTX4, GTX1, GTX3, and NeoSTX. Nonetheless, both the analogs proportion (%) and the cell content (pg cell-1) presented a latitudinal gradient, being more toxic strains located at the north ~40.6°S. The reproductive success also showed a latitudinal tendency, with lower values at the north. Neither self-crosses yielded resting cysts. Compatible pairings dis-tanced between 1000-1650 km displayed the highest resting cysts production. Our results contribute to the understand-ing of the intensity of PSP outbreaks in the region, enhance the importance of the resting cysts to fuel new HAB events and give insights into the risk of introduction of strains from neighboring regions.
Title: Modelling the spatial and temporal dynamics of paralytic shellfish toxins (PST) at different scales: implica-tions for research and management
Authors: Patricio A. Díaz, Carlos Molinet, Miriam Seguel, Manuel Díaz, Gonzalo Álvarez, Edwin Niklitschek, Juan Blanco, Iván Pérez-Santos, Daniel Varela, Camilo Rodríguez-Villegas, Leonardo Guzmán, Rosa I. Figueroa
Abstract: Harmful Algal Blooms, in particular recurrent blooms of Alexandrium catenella, associated to Par-alytic Shellfish Poisoning (PSP), pose a serious socio-economical problem worldwide. Although most affected resources are characterized by very patchy and spatially heterogeneous distribu-tions, few research and monitoring programs have considered the analysis of scale effects and spatially-explicit trends in PSP toxicity. Our objective was to study the spa-tial and temporal dy-namic of PSP toxicity in specific patches located within two clam beds (Venus antiqua), affected by an intense toxic bloom of A. catenella (up to 1.1x106 cells L-1), during summer 2009, in Southern Chile. Generalized linear models (GLMs) were used to identify the influence of different envi-ronmental variables upon PSP concentrations along 12 months. In order to obtain quantitative descriptors for accumulation and detoxification dynamic of PSP on clam’s patches, we used a simplified one-box model, defined by two parameters: a proportionality constant between A. catenella and PSP toxicity and an instantaneous PSP decay rate. Results showed significant varia-bility on the spatial and temporal dynamics of PSP toxicity, within and between patches and beds. Our observations support the relevance of considering different spatial scales (patch/bed/oceanographic area) to enhance understanding about PSP accumula-tion and detoxifi-cation dynamics and to improve the efficacy of fisheries management actions after toxic events.