Cyanotoxins Occurrence in Portugal: A New Report on Their Recent Multiplication

Abstract

Historical reports show that in Portugal, cyanotoxins reports were mainly in the Center (cylindrospermopsins) and South (cylindrospermopsins, saxitoxins) regions of the country apart from the well distributed microcystins. Therefore, in our study, seven freshwater ecosystems located in the North and Center Regions of Portugal were screened between April and September of 2017 for the main cyanotoxins (microcystins, cylindrospermopsins, anatoxin-a, and saxitoxins) by a two methods approach that combined the application of molecular (PCR) and immunological (ELISA) assays. Results from our survey reveal that both methods revealed the presence of all main cyanotoxins. ELISA results showed that 48% of the samples were above (1.6–18.8 μg/L) the guideline value established for microcystins (1 μg/L), while in the remaining cyanotoxins, 33% of the samples were above (1.1–6.8 μg/L) the guideline value established for anatoxin–a (1 μg/L). Further, for saxitoxins, only one sample gave a value above (4.3 μg/L) the guideline (3 μg/L) and this corresponded to a North Region ecosystem. In the cytotoxin cylindrospermopsins, none of the samples were above the guideline established value (1 μg/L). This study will improve the risk assessment strategy in Portugal, as well as advance water quality and water management.

Distribution of Toxic Cyanobacteria in Volcanic Lakes of the Azores Islands

“…Osswald et al [77], although without toxin identification in environmental samples, reported isolated strains from genus Anabaena, Aphanizomenon, Microcystis, and Oscillatoria as ATX-a producers. Moreira et al [28] identified ATX-a (ELISA: Enzyme-Linked Immunosorbent Assay) and the anaC gene in some environmental samples (freshwater).…”

“…In Lake Rasa da Serra Devassa, the presence of sxtA in the sample from February 2016 (Table S5) might be due to unknown STX producing strains of Dolichospermum (Table S4). In Portugal's mainland, STX has been reported, similarly to ATX-a, with an identification of a producing strain of Aphanizomenon flos-aquae [86] and identification of SXT through ELISA and identification of biosynthesis genes (sxtG and sxtI) in some environmental samples [28].…”

“…In recent years, molecular methods have been applied to identify toxigenic cyanobacteria strains, prior to toxin production [16,24,[26][27][28]. Mitigation actions that reduce the favorable conditions for cyanoHABs development and allow the identification of cyanotoxin production potential in water bodies are essential to avoid risks to public health [16,29].…”

High Levels of Anabaenopeptins Detected in a Cyanobacteria Bloom from N.E. Spanish Sau-Susqueda-El Pasteral Reservoirs System by LC–HRMS

“…Globally, the presence of cyanobacteria in the water bodies of many countries has been extensively studied [ 38 , 43 , 53 , 54 , 55 , 56 , 57 , 58 , 59 ]. At least eight countries have initiated national programs on water quality and cyanobacterial problems (Australia, Brazil, Canada, Finland, Great Britain, Japan, Portugal and the United States).…”

The 6th Iberian and 2nd Ibero-American Cyanotoxin Congress CIC2019

“…The scientific production related to cyanotoxins in countries like Portugal has been enormous in recent years. Moreira et al [ 10 ] presented an update of the current situation by focusing on the recent increase in both toxin events and the number of detected toxic compounds, and the importance of the methodologies followed.…”