Cyanobacteria, microcystins and cylindrospermopsin in public drinking supply reservoirs of Brazil

Abstract

Brazil has a history of blooms and contamination of freshwater systems by cyanobacterial toxins. The monitoring relevance of toxins from cyanobacteria in reservoirs for public supply is notorious given its high toxicity to mammals, included humans beings. The most recurrent toxins in Brazilian water bodies are microcystins (MC). However, the recent record of cylindrospermopsin (CyN) in northeastern Brazil, Pernambuco state, alerts us to the possibility that this could be escalating. This study reports occurrence of MC and CYN, quantified with ELISA, in 10 reservoirs, devoted to public drinking supply in northeastern Brazil. The composition and quantification of the cyanobacteria community associated with these water bodies is also presented. From 23 samples investigated for the presence of MC, and CyN, 22 and 8 out were positive, respectively. Considering the similarity of the cyanobacteria communities found in reservoirs from Pernambuco, including toxin-producing species associated to MC and CyN, we suggest that geographic spreading can be favored by these factors. These issues emphasize the need for increased monitoring of MC and CyN in drinking supply reservoirs in Brazil.

Cytotoxic and morphological effects of microcystin‐LR, cylindrospermopsin, and their combinations on the human hepatic cell line HepG2

“…Regarding to MC‐LR, there are several studies in the scientific literature in HepG2 cells but most of them used lower concentrations than in the present work as they were focused on the study of toxicity mechanisms and not in deriving EC 50 values (ie, Refs. ). Chong et al concluded that MC‐LR did not cause cytotoxic effects in HepG2 cells and other hepatic cell line in 48–96 h of exposure to concentrations up to 100 μg/mL.…”

“…The presence of two or more cyanobacterial species in water reservoirs is a common finding around the world . Among these cyanobacteria, many are capable to produce cyanotoxins, such as MC‐LR and CYN, which can cause harmful effects in animals, plants, and humans .…”

“…It has been described some cyanobacterial strains are able to produce different cyanotoxins or different congeners of a cyanotoxin . There are several studies concerning the co‐occurrence of MCs‐ and CYN‐producing cyanobacteria as well as the presence of combinations of both cyanotoxins at the same time . In this sense, Graham et al found that MCs are the most abundant cyanotoxins in blooms from USA, being present in all of them.…”

Cyanobacterial blooms in freshwaters bodies in a semiarid region, northeastern Brazil: A review

“…In Northeast Brazil, which is characterized by a semiarid climate, the cyanoHABs are more pronounced (e.g., Bittencourt-Oliveira et al, 2014;Lopes et al, 2015;Brasil et al, 2016;Lins et al, 2016) and favour water scarcity, high temperatures, elevated water residence time, and artificial eutrophication. The recurrence of cyanoHABs became a public health problem due to toxins produced by these organisms.…”

Current Techniques for Detecting and Monitoring Algal Toxins and Causative Harmful Algal Blooms

“…Even within the same water body, measured concentrations could be method dependent. Results from Bláhová et al [14][15][16][17][18][19][20][21][22][23][24] indicated that although concentrations determined by enzyme-linked immunosorbent assay (ELISA) and liquid chromatography-mass spectrometry (LC-MS) showed good quantitative agreement, concentrations determined by ELISA were systematically higher than concentrations determined by LC-MS, which was attributed to matrix effects (both in ELISA and LC-MS) and ELISA cross-reactivity with other unidentified derivatives of toxin CYL (Table 1). Table 1: Algal toxins and their environmentally relevant concentrations in selected waters of various regions; CYL = cylindrospermopsin; DA = domoic acid; GD = gymnodimine; MCs = microcystins; ND = Nodularin; OA = okadaic acid; PTX-2 = pectenotoxin-2-seco acid; STX = saxitoxin; ADDA-ELISA = ADDA ELISA Kit; LC-MS/MS = liquid chromatography-tandem mass spectrometry; cELISA = competitive enzymelinked immunosorbent assay; HPLC = high-performance liquid chromatography; HPLC-MS/MS = high-performance liquid chromatographytandem mass spectrometry; HPLC-ESI-MS = high performance liquid chromatography -electrospray ionization-mass spectrometry; LC-FD = liquid chromatography with fluorescence detection.…”