Publications by authors named "Jose Leao-Martins"
The increasing occurrence of toxic freshwater cyanobacteria blooms in marine or brackish waters, coupled with elevated cyanotoxin concentrations in marine life, poses an emerging threat to human health. These events are often associated with temperature, salinity and the eutrophication of affected areas, however global changes causing extreme events can cause rapid shifts in their dynamics and subsequent propagation. This systematic review presents reports from 2010 to 2024 where the main objectives were to describe (i) worldwide occurrence of freshwater cyanobacteria toxins in transitional waters; (ii) global changes and shifts in cyanobacteria dynamics and (iii) patterns of the cyanotoxins microcystins, nodularins, saxitoxins, cylindrospermopsin and anatoxins in marine organisms.
View Article and Find Full Text PDFArticle Synopsis
- The Selvagens Islands, a marine protected area in Portugal, have been linked to fish containing harmful ciguatoxins (CTX) associated with ciguatera fish poisoning.
- A sampling campaign in September 2018 found high toxicity levels in fish, particularly intermediate species like zebra seabream and barred hogfish, reaching up to 0.75 µg CTX1B equivalent per kg.
- The research revealed that while C-CTX1 was the primary toxin, inconsistencies between cell-based assays and advanced mass spectrometry in top predator species indicate the presence of unknown metabolic products, highlighting the potential risks for fisheries and the need for better environmental management in the area.*
Article Synopsis
- Dinoflagellates from certain genera are known to produce toxic compounds like ciguatoxins and maitotoxins, with many species still poorly studied in areas like the western Mediterranean Sea.
- A strain from the Balearic Islands was previously analyzed and found to produce compounds such as 44-methyl gambierone and gambieric acids C and D but lacked the typical MTX1 found in Pacific strains.
- This study identified a new MTX analogue, MTX5, in the Mediterranean strain, demonstrating that it produces different toxins compared to Pacific strains and highlighting the challenges in identifying ciguatoxin precursors in this region.
Article Synopsis
- Recent research has advanced understanding of dinoflagellate taxonomy and distribution, particularly focusing on their bioactive compounds related to ciguatera poisoning (CP).
- Ciguatoxins and maitotoxins, notably maitotoxin-4, are highly toxic metabolites linked to CP and have been increasingly identified in various regions, including the Canary Islands and Madeira archipelago.
- This study emphasizes the importance of characterizing toxin profiles across different species and geographic areas, revealing that these profiles may vary significantly by species and location.
Ciguatera poisoning (CP) is a common seafood intoxication mainly caused by the consumption of fish contaminated by ciguatoxins. Recent studies showed that Caribbean ciguatoxin-1 (C-CTX1) is the main toxin causing CP through fish caught in the Northeast Atlantic, e.g.
View Article and Find Full Text PDFThe biodiversity of lactic acid bacteria in musts and wines of Albariño variety has been studied. The identification of species was addressed through a combination of biochemical and genetic methods (API 50 CHL test, 16S rDNA and gene sequences, Amplified Ribosomal DNA Restriction Analysis -ARDRA- and 16S-26S intergenic region analysis). The results grouped the isolates into six species predominating those of the genus and showing a typical biogeographical distribution.
View Article and Find Full Text PDFThis paper shows the results of an intralaboratory validation of a fast method for the determination of lipophilic shellfish toxins working under acidic conditions using ultra-high performance LC (UHPLC) with MS/MS. Fourteen lipophilic marine toxins and domoic acid were acquired with fast polarity switching. Whereas azaspiracids (AZAs), pecenotoxins, 13-desmethyl spirolide C (SPX1), and gymnodimine were analyzed in the positive mode, yessotoxins (YTXs) were measured in negative mode.
View Article and Find Full Text PDF