1.Cyanotoxin bioaccumulation in freshwater fish, Washington State, USA.
Hardy FJ1, Johnson A2, Hamel K2, Preece E3. Environ Monit Assess. 2015 Nov;187(11):667. doi: 10.1007/s10661-015-4875-x. Epub 2015 Oct 5.
Until recently, exposure pathways of concern for cyanotoxins have focused on recreational exposure, drinking water, and dermal contact. Exposure to cyanotoxins through fish consumption is a relatively new area of investigation. To address this concern, microcystins and other cyanotoxins were analyzed in fish collected from nine Washington lakes with recurrent toxic blooms using two types of enzyme-linked immunosorbent assays (ELISAs) and liquid chromatography/mass spectrometry/mass spectrometry (LC-MS/MS). Microcystins or microcystin-like compounds were elevated in fish liver relative to muscle and other tissues (liver>gut>muscle). Microcystin concentrations in fish fillet samples using anti-Adda ELISA (range 6.3-11 μg/kg wet weight) were consistently higher in all fish species than concentrations using anti-microcystin (MC)-leucine-arginine (LR) ELISA (range 0.25-2.4 μg/kg wet weight). MC-leucine-alanine (LA) was the only variant detected in fish (2.
2.Determination of BMAA and three alkaloid cyanotoxins in lake water using dansyl chloride derivatization and high-resolution mass spectrometry.
Roy-Lachapelle A1, Solliec M, Sauvé S. Anal Bioanal Chem. 2015 Jul;407(18):5487-501. doi: 10.1007/s00216-015-8722-2. Epub 2015 May 3.
A new analytical method was developed for the detection of alkaloid cyanotoxins in harmful algal blooms. The detection of the nonproteinogenic amino acid β-N-methylamino-L-alanine (BMAA) and two of its conformation isomers, 2,4-diaminobutyric acid (DAB) and N-(2-aminoethyl) glycine (AEG), as well as three alkaloid cyanotoxins, anatoxin-a (ANA-a), cylindrospermopsin (CYN), and saxitoxin (STX), is presented. The use of a chemical derivatization with dansyl chloride (DNS) allows easier separation with reversed phase liquid chromatography. Detection with high-resolution mass spectrometry (HRMS) with the Q-Exactive enables high selectivity with specific fragmentation as well as exact mass detection, reducing considerably the possibilities of isobaric interferences. Previous to analysis, a solid phase extraction (SPE) step is used for purification and preconcentration. After DNS derivatization, samples are submitted to ultra high-performance liquid chromatography coupled with heated electrospray ionisation and the Q-Exactive mass spectrometer (UHPLC-HESI-HRMS).
3.Feasibility study on production of a matrix reference material for cyanobacterial toxins.
Hollingdale C1, Thomas K, Lewis N, Békri K, McCarron P, Quilliam MA. Anal Bioanal Chem. 2015 Jul;407(18):5353-63. doi: 10.1007/s00216-015-8695-1. Epub 2015 May 1.
The worldwide increase in cyanobacterial contamination of freshwater lakes and rivers is of great concern as many cyanobacteria produce potent hepatotoxins and neurotoxins (cyanotoxins). Such toxins pose a threat to aquatic ecosystems, livestock, and drinking water supplies. In addition, dietary supplements prepared from cyanobacteria can pose a risk to consumers if they contain toxins. Analytical monitoring for toxins in the environment and in consumer products is essential for the protection of public health. Reference materials (RMs) are an essential tool for the development and validation of analytical methods and are necessary for ongoing quality control of monitoring operations. Since the availability of appropriate RMs for cyanotoxins has been very limited, the present study was undertaken to examine the feasibility of producing a cyanobacterial matrix RM containing various cyanotoxins. The first step was large-scale culturing of various cyanobacterial cultures that produce anatoxins, microcystins, and cylindrospermopsins.
4.Proteomic analysis of anatoxin-a acute toxicity in zebrafish reveals gender specific responses and additional mechanisms of cell stress.
Carneiro M1, Gutiérrez-Praena D2, Osório H3, Vasconcelos V4, Carvalho AP5, Campos A1. Ecotoxicol Environ Saf. 2015 Oct;120:93-101. doi: 10.1016/j.ecoenv.2015.05.031. Epub 2015 Jun 2.
Anatoxin-a is a potent neurotoxin produced by several genera of cyanobacteria. Deaths of wild and domestic animals due to anatoxin-a exposure have been reported following a toxic response that is driven by the inhibition of the acetylcholine receptors at neuromuscular junctions. The consequent neuron depolarization results in an overstimulation of the muscle cells. In order to unravel further molecular events implicated in the toxicity of anatoxin-a, a proteomic investigation was conducted. Applying two-dimensional gel electrophoresis (2DE) and MALDI-TOF mass spectrometry, we report early proteome changes in brain and muscle of zebrafish (Danio rerio) caused by acute exposure to anatoxin-a. In this regard, the test group of male and female zebrafish received an intraperitoneal (i.p.) injection of an anatoxin-a dose of 0.8µgg(-1) of fish body weight (bw) in phosphate buffered saline solution (PBS), while the control received an i.p. injection of PBS only.