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Johnston LH, Huang Y, Bermarija TD, Rafuse C, Zamlynny L, Bruce MR, Graham C, Comeau AM, Valadez-Cano C, Lawrence JE, Beach DG, Jamieson RC. Proliferation and anatoxin production of benthic cyanobacteria associated with canine mortalities along a stream-lake continuum. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 917:170476. [PMID: 38290679 DOI: 10.1016/j.scitotenv.2024.170476] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/16/2023] [Revised: 01/24/2024] [Accepted: 01/24/2024] [Indexed: 02/01/2024]
Abstract
Proliferations of benthic cyanobacteria are increasingly in the public eye, with rising animal deaths associated with benthic rather than planktonic blooms. In early June 2021, two dogs died after consuming material on the shore of Shubenacadie Grand Lake, Nova Scotia. Preliminary investigations indicated anatoxins produced by benthic cyanobacterial mats were responsible for the deaths. In this study, we monitored the growth of a toxic benthic cyanobacterial species (Microcoleus sp.) along a stream-lake continuum where the canine poisonings occurred. We found that the species was able to proliferate in both lentic and lotic environments, but temporal growth dynamics and the predominant sub-species were influenced by habitat type, and differed with hydrodynamic setting, nutrient and sunlight availability. Toxin concentration was greatest in cyanobacterial mats growing in the oligotrophic lakeshore environment (maximum measured total anatoxins (ATXs) >20 mg·kg-1 wet weight). This corresponded with a shift in the profile of ATX analogues, which also indicated changing sub-species dominance along the stream-lake transition.
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Affiliation(s)
- Lindsay H Johnston
- Centre for Water Resources Studies, Department of Civil & Resource Engineering, Dalhousie University, 1360 Barrington Street, Halifax, NS, Canada
| | - Yannan Huang
- Centre for Water Resources Studies, Department of Civil & Resource Engineering, Dalhousie University, 1360 Barrington Street, Halifax, NS, Canada
| | - Tessa D Bermarija
- Centre for Water Resources Studies, Department of Civil & Resource Engineering, Dalhousie University, 1360 Barrington Street, Halifax, NS, Canada
| | - Cheryl Rafuse
- Biotoxin Metrology, National Research Council Canada, 1411 Oxford St, Halifax, NS, Canada
| | - Lydia Zamlynny
- Biotoxin Metrology, National Research Council Canada, 1411 Oxford St, Halifax, NS, Canada
| | - Meghann R Bruce
- Canadian Rivers Institute, Department of Biology, University of New Brunswick, P.O. Box 4400, Fredericton, NB, Canada
| | - Catherine Graham
- Nova Scotia Department of Agriculture, Animal Health Laboratory, 65 River Rd, Bible Hill, NS, Canada
| | - André M Comeau
- Integrated Microbiome Resource (IMR), Dalhousie University, Halifax, Canada
| | - Cecilio Valadez-Cano
- Biology Department, University of New Brunswick, Fredericton, New Brunswick, Canada
| | - Janice E Lawrence
- Biology Department, University of New Brunswick, Fredericton, New Brunswick, Canada
| | - Daniel G Beach
- Centre for Water Resources Studies, Department of Civil & Resource Engineering, Dalhousie University, 1360 Barrington Street, Halifax, NS, Canada; Biotoxin Metrology, National Research Council Canada, 1411 Oxford St, Halifax, NS, Canada
| | - Rob C Jamieson
- Centre for Water Resources Studies, Department of Civil & Resource Engineering, Dalhousie University, 1360 Barrington Street, Halifax, NS, Canada.
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Miles CO, Strand DA, Rusch JC, Ballot A, Haande S, Løvberg KLE, Vrålstad T, Samdal IA. Microcystin profiles in European noble crayfish Astacus astacus and water in Lake Steinsfjorden, Norway. ENVIRONMENTAL RESEARCH 2024; 242:117623. [PMID: 37956753 DOI: 10.1016/j.envres.2023.117623] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2023] [Revised: 10/18/2023] [Accepted: 11/07/2023] [Indexed: 11/15/2023]
Abstract
Lake Steinsfjorden, an important noble crayfish (Astacus astacus) habitat, is often affected by blooms of Planktothrix spp. that produce microcystins (MCs). A poor correlation between MCs by ELISA in the water and in crayfish tissue in a study in 2015 prompted further investigation by LC-HRMS. LC-HRMS analyses of filters from water samples and on selected crayfish tissue extracts from the 2015 study revealed the presence of known and previously unreported MCs. Crayfish samples from May and June 2015 were dominated by MCs from the Planktothrix bloom, whereas in September novel MCs that appeared to be metabolites of MC-LR were dominant, even though neither these nor MC-LR were detected in the water in 2015. A water sample from October 2016 also showed MCs typical of Planktothrix (i.e., [d-Asp3]- and [d-Asp3,Dhb7]MC-RR and -LR), but low levels of MC-RR and MC-LR were detected in the lake water for the first time. In late summer and autumn, the MC profiles of crayfish were dominated by the homonorvaline (Hnv) variant MC-LHnv, a putative metabolite of MC-LR. Taken together, ELISA, LC-HRMS and previous PCR analyses showed that although Planktothrix was part of the crayfish diet, it was not the sole source of MCs in the crayfish. Possibly, crayfish in Lake Steinsfjorden may be ingesting MCs from benthic cyanobacteria or from contaminated prey. Therefore, information on the cyanobacterial or MC content in the water column cannot safely be used to make predictions about MC concentrations in the crayfish in Lake Steinsfjorden. Interestingly, the results also show that targeted LC-MS analysis of the crayfish would at times have underestimated their MC content by nearly an order of magnitude, even if all previously reported MC variants had been included in the analysis.
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Affiliation(s)
- Christopher O Miles
- Norwegian Veterinary Institute, Elizabeth Stephansens vei 1, 1433, Ås, Norway; National Research Council Canada, Halifax, Nova Scotia, B3H 3Z1, Canada
| | - David A Strand
- Norwegian Veterinary Institute, Elizabeth Stephansens vei 1, 1433, Ås, Norway
| | - Johannes C Rusch
- Norwegian Veterinary Institute, Elizabeth Stephansens vei 1, 1433, Ås, Norway
| | - Andreas Ballot
- Norwegian Institute for Water Research, Økernveien 94, 0579, Oslo, Norway
| | - Sigrid Haande
- Norwegian Institute for Water Research, Økernveien 94, 0579, Oslo, Norway
| | - Kjersti L E Løvberg
- Norwegian Veterinary Institute, Elizabeth Stephansens vei 1, 1433, Ås, Norway
| | - Trude Vrålstad
- Norwegian Veterinary Institute, Elizabeth Stephansens vei 1, 1433, Ås, Norway
| | - Ingunn A Samdal
- Norwegian Veterinary Institute, Elizabeth Stephansens vei 1, 1433, Ås, Norway.
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Beach DG, Zamlynny L, MacArthur M, Miles CO. Liquid chromatography-high-resolution tandem mass spectrometry of anatoxins, including new conjugates and reduction products. Anal Bioanal Chem 2023; 415:5281-5296. [PMID: 37507466 PMCID: PMC10444699 DOI: 10.1007/s00216-023-04836-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2023] [Revised: 06/27/2023] [Accepted: 06/30/2023] [Indexed: 07/30/2023]
Abstract
Anatoxins (ATXs) are a potent class of cyanobacterial neurotoxins for which only a handful of structural analogues have been well characterized. Here, we report the development of an LC-HRMS/MS method for the comprehensive detection of ATXs. Application of this method to samples of benthic cyanobacterial mats and laboratory cultures showed detection of several new ATXs. Many of these result from nucleophilic addition to the olefinic bond of the α,β-unsaturated ketone functional group of anatoxin-a (ATX) and homoanatoxin-a (hATX), analogous to the conjugation chemistry of microcystins, which contain similar α,β-unsaturated amide functionality. Conjugates with glutathione, γ-glutamylcysteine, methanethiol, ammonia, methanol and water were detected, as well as putative C-10 alcohol derivatives. Structural confirmation was obtained by simple and selective analytical-scale semisynthetic reactions starting from available ATX standards. Methanol, water and ammonia conjugates were found to result primarily from sample preparation. Reduction products were found to result from enzymatic reactions occurring primarily after cell lysis in laboratory cultures of Kamptonema formosum and Cuspidothrix issatschenkoi. The relative contributions of the identified analogues to the anatoxin profiles in a set of 22 benthic-cyanobacterial-mat field samples were estimated, showing conjugates to account for up to 15% of total ATX peak area and 10-hydroxyanatoxins up to 38%. The developed methodology, new analogues and insight into the chemical and enzymatic reactivity of ATXs will enable a more comprehensive study of the class than possible previously.
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Affiliation(s)
- Daniel G Beach
- Biotoxin Metrology, National Research Council Canada, 1411 Oxford St., Halifax, NS, Canada.
| | - Lydia Zamlynny
- Biotoxin Metrology, National Research Council Canada, 1411 Oxford St., Halifax, NS, Canada
| | - Melanie MacArthur
- Biotoxin Metrology, National Research Council Canada, 1411 Oxford St., Halifax, NS, Canada
| | - Christopher O Miles
- Biotoxin Metrology, National Research Council Canada, 1411 Oxford St., Halifax, NS, Canada
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McDonald K, DesRochers N, Renaud JB, Sumarah MW, McMullin DR. Metabolomics Reveals Strain-Specific Cyanopeptide Profiles and Their Production Dynamics in Microcystis aeruginosa and M. flos-aquae. Toxins (Basel) 2023; 15:254. [PMID: 37104192 PMCID: PMC10147050 DOI: 10.3390/toxins15040254] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Revised: 03/21/2023] [Accepted: 03/27/2023] [Indexed: 04/03/2023] Open
Abstract
Cyanobacterial blooms that release biologically active metabolites into the environment are increasing in frequency as a result of the degradation of freshwater ecosystems globally. The microcystins are one group of cyanopeptides that are extensively studied and included in water quality risk management frameworks. Common bloom-forming cyanobacteria produce incredibly diverse mixtures of other cyanopeptides; however, data on the abundance, distribution, and biological activities of non-microcystin cyanopeptides are limited. We used non-targeted LC-MS/MS metabolomics to study the cyanopeptide profiles of five Microcystis strains: four M. aeruginosa and one M. flos-aquae. Multivariate analysis and GNPS molecular networking demonstrated that each Microcystis strain produced a unique mixture of cyanopeptides. In total, 82 cyanopeptides from the cyanopeptolin (n = 23), microviridin (n = 18), microginin (n = 12), cyanobactin (n = 14), anabaenopeptin (n = 6), aeruginosin (n = 5), and microcystin (n = 4) classes were detected. Microcystin diversity was low compared with the other detected cyanopeptide classes. Based on surveys of the literature and spectral databases, most cyanopeptides represented new structures. To identify growth conditions yielding high amounts of multiple cyanopeptide groups, we next examined strain-specific cyanopeptide co-production dynamics for four of the studied Microcystis strains. When strains were cultivated in two common Microcystis growth media (BG-11 and MA), the qualitative cyanopeptides profiles remained unchanged throughout the growth cycle. For each of the cyanopeptide groups considered, the highest relative cyanopeptide amounts were observed in the mid-exponential growth phase. The outcomes of this study will guide the cultivation of strains producing common and abundant cyanopeptides contaminating freshwater ecosystems. The synchronous production of each cyanopeptide group by Microcystis highlights the need to make more cyanopeptide reference materials available to investigate their distributions and biological functions.
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Affiliation(s)
| | - Natasha DesRochers
- London Research and Development Center, Agriculture and Agri-Food Canada, London, ON N5V 4T3, Canada
| | - Justin B. Renaud
- London Research and Development Center, Agriculture and Agri-Food Canada, London, ON N5V 4T3, Canada
| | - Mark W. Sumarah
- London Research and Development Center, Agriculture and Agri-Food Canada, London, ON N5V 4T3, Canada
| | - David R. McMullin
- Department of Chemistry, Carleton University, Ottawa, ON K1S 5B6, Canada
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5
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Anatoxins from benthic cyanobacteria responsible for dog mortalities in New Brunswick, Canada. Toxicon 2023; 227:107086. [PMID: 36914100 DOI: 10.1016/j.toxicon.2023.107086] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Revised: 02/24/2023] [Accepted: 03/10/2023] [Indexed: 03/15/2023]
Abstract
In July 2018 three dogs died after visiting the Wolastoq (Saint John River) near Fredericton, New Brunswick, in Atlantic Canada. All showed signs of toxicosis, and necropsies revealed non-specific pulmonary edema and multiple microscopic brain hemorrhages. Liquid chromatography-high-resolution mass spectrometry (LC-HRMS) analysis of vomitus and stomach contents as well as water and biota from the mortality sites confirmed the presence of anatoxins (ATXs), a class of potent neurotoxic alkaloids. The highest levels were measured in a dried benthic cyanobacterial mat that two of the dogs had been eating before falling ill and in a vomitus sample collected from one of the dogs. Concentrations of 357 and 785 mg/kg for anatoxin-a and dihydroanatoxin-a, respectively, were measured in the vomitus. Known anatoxin-producing species of Microcoleus were tentatively identified using microscopy and confirmed by 16S rRNA gene sequencing. The ATX synthetase gene, anaC, was detected in the samples and isolates. The pathology and experimental results confirmed the role of ATXs in these dog mortalities. Further research is required to understand drivers for toxic cyanobacteria in the Wolastoq and to develop methodology for assessing occurrence.
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Turner AD, Beach DG, Foss A, Samdal IA, Løvberg KLE, Waack J, Edwards C, Lawton LA, Dean KJ, Maskrey BH, Lewis AM. A Feasibility Study into the Production of a Mussel Matrix Reference Material for the Cyanobacterial Toxins Microcystins and Nodularins. Toxins (Basel) 2022; 15:27. [PMID: 36668847 PMCID: PMC9867187 DOI: 10.3390/toxins15010027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Revised: 12/15/2022] [Accepted: 12/23/2022] [Indexed: 01/03/2023] Open
Abstract
Microcystins and nodularins, produced naturally by certain species of cyanobacteria, have been found to accumulate in aquatic foodstuffs such as fish and shellfish, resulting in a risk to the health of the seafood consumer. Monitoring of toxins in such organisms for risk management purposes requires the availability of certified matrix reference materials to aid method development, validation and routine quality assurance. This study consequently targeted the preparation of a mussel tissue reference material incurred with a range of microcystin analogues and nodularins. Nine targeted analogues were incorporated into the material as confirmed through liquid chromatography with tandem mass spectrometry (LC-MS/MS), with an additional 15 analogues detected using LC coupled to non-targeted high resolution mass spectrometry (LC-HRMS). Toxins in the reference material and additional source tissues were quantified using LC-MS/MS, two different enzyme-linked immunosorbent assay (ELISA) methods and with an oxidative-cleavage method quantifying 3-methoxy-2-methyl-4-phenylbutyric acid (MMPB). Correlations between the concentrations quantified using the different methods were variable, likely relating to differences in assay cross-reactivities and differences in the abilities of each method to detect bound toxins. A consensus concentration of total soluble toxins determined from the four independent test methods was 2425 ± 575 µg/kg wet weight. A mean 43 ± 9% of bound toxins were present in addition to the freely extractable soluble form (57 ± 9%). The reference material produced was homogenous and stable when stored in the freezer for six months without any post-production stabilization applied. Consequently, a cyanotoxin shellfish reference material has been produced which demonstrates the feasibility of developing certified seafood matrix reference materials for a large range of cyanotoxins and could provide a valuable future resource for cyanotoxin risk monitoring, management and mitigation.
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Affiliation(s)
- Andrew D. Turner
- Centre for Environment Fisheries and Aquaculture Science, Barrack Road, Weymouth DT4 8UB, UK
| | - Daniel G. Beach
- Biotoxin Metrology, National Research Council Canada, Halifax, NS B3H 3Z1, Canada
| | - Amanda Foss
- Greenwater Laboratories, 205 Zeagler Drive, Suite 302, Palatka, FL 32177, USA
| | | | | | - Julia Waack
- Centre for Environment Fisheries and Aquaculture Science, Barrack Road, Weymouth DT4 8UB, UK
- CyanoSol, School of Pharmacy and Life Sciences, Robert Gordon University, Aberdeen AB10 7GJ, UK
| | - Christine Edwards
- CyanoSol, School of Pharmacy and Life Sciences, Robert Gordon University, Aberdeen AB10 7GJ, UK
| | - Linda A. Lawton
- CyanoSol, School of Pharmacy and Life Sciences, Robert Gordon University, Aberdeen AB10 7GJ, UK
| | - Karl J. Dean
- Centre for Environment Fisheries and Aquaculture Science, Barrack Road, Weymouth DT4 8UB, UK
| | - Benjamin H. Maskrey
- Centre for Environment Fisheries and Aquaculture Science, Barrack Road, Weymouth DT4 8UB, UK
| | - Adam M. Lewis
- Centre for Environment Fisheries and Aquaculture Science, Barrack Road, Weymouth DT4 8UB, UK
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Hill D, Lang J, McCord J, Strynar M, Rosal C, Schmid J, Le TT, Chernoff N. Variability of Microcystin-LR Standards Available from Seven Commercial Vendors. Toxins (Basel) 2022; 14:toxins14100705. [PMID: 36287973 PMCID: PMC9611723 DOI: 10.3390/toxins14100705] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2022] [Revised: 10/07/2022] [Accepted: 10/10/2022] [Indexed: 12/05/2022] Open
Abstract
Microcystins (MCs) are a large group of heptapeptide cyanobacterial toxins commonly produced in harmful algal blooms (HABs) and associated with adverse health effects in wildlife, livestock, pets, and humans. MC chemical standards are extracted from cyanobacteria biomass rather than produced synthetically and are used in water assessment methods and toxicological studies. MC standards are generally supplied in less than 1 mg quantities, and verification of the mass can only be accomplished by analytical chemistry methods using a certified reference of the specific MC for comparison. Analytical quantification of MCs in environmental samples and toxicology studies using accurate doses of test chemicals administered to experimental animals rely on the availability and accuracy of chemical standards. To check the accuracy and purity of available standards, seven individual microcystin-LR (MCLR) standards were purchased from separate commercial vendors and analyzed to determine the actual mass supplied and identify the presence of potential contaminants. To determine the effect of varying toxin mass in toxicological studies, each MCLR standard was administered to CD-1 mice in doses based on mass purchased, by a single 40 µg/kg intraperitoneal injection. The measured mass purchased varied from the vendor label mass by more than 35% for two of the seven MCLR standards. Contaminants, including trifluoroacetic acid (TFA), were identified in four of the seven samples. Comparative in vivo hepatotoxicity between vendor samples closely reflected the actual amount of MCLR present in each standard and demonstrated the toxicological impact of varying cyanotoxin mass.
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Affiliation(s)
- Donna Hill
- Center for Public Health and Environmental Assessment, United States Environmental Protection Agency, Research Triangle Park, NC 27711, USA
- Correspondence:
| | - Johnsie Lang
- Arcadis (United States), 4204 Technology Dr, Durham, NC 27704, USA
| | - James McCord
- Center for Environmental Measurement and Modeling, United States Environmental Protection Agency, Research Triangle Park, NC 27711, USA
| | - Mark Strynar
- Center for Public Health and Environmental Assessment, United States Environmental Protection Agency, Research Triangle Park, NC 27711, USA
| | | | - Judith Schmid
- Center for Public Health and Environmental Assessment, United States Environmental Protection Agency, Research Triangle Park, NC 27711, USA
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Beach DG, Bruce M, Lawrence J, McCarron P. Rapid Quantitation of Anatoxins in Benthic Cyanobacterial Mats Using Direct Analysis in Real-Time-High-Resolution Tandem Mass Spectrometry. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:13837-13844. [PMID: 36125920 PMCID: PMC9535865 DOI: 10.1021/acs.est.2c05426] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Revised: 09/07/2022] [Accepted: 09/08/2022] [Indexed: 06/15/2023]
Abstract
Toxic benthic cyanobacterial mats are increasingly reported worldwide as being responsible for animal mortalities due to their production of the potent neurotoxin anatoxin-a (ATX) and its analogues. Improved analytical methods for anatoxins are needed to address public health and watershed management challenges arising from extremely high spatial and temporal variability within impacted systems. We present the development, validation, and application of a direct analysis in real-time-high-resolution tandem mass spectrometry (DART-HRMS/MS) method for analysis of anatoxins in cyanobacterial field samples, including a simplified sample preparation approach. The method showed excellent sensitivity and selectivity for ATX, homoanatoxin-a, and dihydroanatoxin-a. Isotopically labeled ATX was used as an internal standard for all three analogues and successfully corrected for the matrix effects observed (86 ± 16% suppression). The limit of detection and recovery for ATX was estimated as 5 ng/g and 88%, respectively, using spiked samples. The total analysis time was ∼2 min, and excellent agreement was observed with results from a liquid chromatography-HRMS reference method. Finally, the DART-HRMS/MS method was applied to a set of 45 Microcoleus-dominated benthic cyanobacterial mat samples from the Wolastoq near Fredericton, Canada, demonstrating its power and applicability in enabling broad-scale field studies of ATX distribution.
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Affiliation(s)
- Daniel G. Beach
- Biotoxin
Metrology, National Research Council Canada, 1411 Oxford Street, Halifax, Nova Scotia B3H 3Z1, Canada
| | - Meghann Bruce
- Canadian
Rivers Institute, University of New Brunswick, P.O. Box 4400, Fredericton, New Brunswick E3B 5A3, Canada
| | - Janice Lawrence
- Department
of Biology, University of New Brunswick, 10 Bailey Drive, Fredericton, New Brunswick E3B 5A3, Canada
| | - Pearse McCarron
- Biotoxin
Metrology, National Research Council Canada, 1411 Oxford Street, Halifax, Nova Scotia B3H 3Z1, Canada
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Blahova L, Sehnal L, Lepsova-Skacelova O, Szmucova V, Babica P, Hilscherova K, Teikari J, Sivonen K, Blaha L. Occurrence of cylindrospermopsin, anatoxin-a and their homologs in the southern Czech Republic - Taxonomical, analytical, and molecular approaches. HARMFUL ALGAE 2021; 108:102101. [PMID: 34588122 DOI: 10.1016/j.hal.2021.102101] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Revised: 07/26/2021] [Accepted: 08/29/2021] [Indexed: 06/13/2023]
Abstract
Water bloom-forming cyanobacteria have a severe impact on freshwater quality. Although some cyanobacterial toxins such as microcystins have been studied extensively, other toxins like anatoxin-a (ATX) and their structural analogs - as well as cyanobacterial taxa producing these toxins remain to be explored in detail. The present study investigated levels of ATX, CYN and their homologs along with the occurrence of anaC and cyrJ genes in water blooms in 16 sites in the Czech Republic that were pre-selected concerning the presence of potential toxin producers. Besides, we also studied toxins and genes in a series of strains available in our laboratories. ATX and its congener HATX were detected in 5 natural biomass samples from the Czech Republic (maximum concentration 2.8 micrograms per gram d.w.). Interestingly, the anaC gene coding for ATX production was not detected in any of these toxin-positive biomass samples. The concentrations of ATX congeners in cyanobacterial laboratory strains were about 10-times higher than those of the original ATX, which calls for further research addressing levels and hazards of ATX analogs. Regarding the CYN and 7-deoxyCYN (other CYN congeners were not analyzed in this study) - these toxins were identified in a single small pond in the Czech Republic at concentrations 4.3 and 2.7 micrograms per gram of biomass d.w., respectively (corresponded to dissolved concentrations higher than 1 microgram per liter). The CYN-positive sample was dominated by CYN-producing taxa Raphidiopsis (basionym Cylindrospermopsis) and Cuspidothrix. We also confirmed the presence of a specific cyrJ gene in this natural bloom sample. To our knowledge, this is the first study pointing to Raphidiopsis (Cylindrospermopsis) and Cuspidothrix as producers of CYN in Europe. This observation calls for further research because of their increasing occurrence in (Central) Europe along with the global change. The present study demonstrates the importance of using combined (taxonomical, analytical, and molecular) approaches in the assessment of hazardous cyanobacteria and their toxins in freshwaters.
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Affiliation(s)
- Lucie Blahova
- RECETOX, Faculty of Science, Masaryk University, Kamenice 753/5, 625 00 Brno, Czech Republic
| | - Ludek Sehnal
- RECETOX, Faculty of Science, Masaryk University, Kamenice 753/5, 625 00 Brno, Czech Republic
| | - Olga Lepsova-Skacelova
- University of South Bohemia, Faculty of Science, Department of Botany, 370 05 Ceske Budejovice, Czech Republic
| | - Vendula Szmucova
- RECETOX, Faculty of Science, Masaryk University, Kamenice 753/5, 625 00 Brno, Czech Republic
| | - Pavel Babica
- RECETOX, Faculty of Science, Masaryk University, Kamenice 753/5, 625 00 Brno, Czech Republic
| | - Klara Hilscherova
- RECETOX, Faculty of Science, Masaryk University, Kamenice 753/5, 625 00 Brno, Czech Republic
| | - Jonna Teikari
- University of Helsinki, Department of Microbiology, P.O. Box 56, FI-00014 Helsinki, Finland
| | - Kaarina Sivonen
- University of Helsinki, Department of Microbiology, P.O. Box 56, FI-00014 Helsinki, Finland
| | - Ludek Blaha
- RECETOX, Faculty of Science, Masaryk University, Kamenice 753/5, 625 00 Brno, Czech Republic.
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10
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McDonald K, Renaud JB, Pick FR, Miller JD, Sumarah MW, McMullin DR. Diagnostic Fragmentation Filtering for Cyanopeptolin Detection. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2021; 40:1087-1097. [PMID: 33238037 DOI: 10.1002/etc.4941] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Revised: 10/25/2020] [Accepted: 11/20/2020] [Indexed: 06/11/2023]
Abstract
Cyanobacteria are ubiquitous photosynthetic prokaryotes that produce structurally diverse bioactive metabolites. Although microcystins are extensively studied, other cyanopeptides produced by common bloom-forming species have received little attention. Cyanopeptolins are a large cyanopeptide group that contain a characteristic 3-amino-6-hydroxy-2-piperidone (Ahp) moiety. In the present study we used diagnostic fragmentation filtering (DFF), a semitargeted liquid chromatography-tandem mass spectrometry (MS/MS) product ion filtering approach, to investigate cyanopeptolin diversity from 5 Microcystis strains and 4 bloom samples collected from lakes in Ontario and Quebec, Canada. Data processing by DFF was used to search MS/MS data sets for pairs of diagnostic product ions corresponding to cyanopeptolin partial sequences. For example, diagnostic product ions at m/z 150.0912 and 215.1183 identified cyanopeptolins with the NMe-Tyr-Phe-Ahp partial sequence. Forty-eight different cyanopeptolins, including 35 new variants, were detected from studied strains and bloom samples. Different cyanopeptolin profiles were identified from each sample. We detected a new compound, cyanopeptolin 1143, from a bloom and elucidated its planar structure from subsequent targeted MS/MS experiments. Diagnostic fragmentation filtering is a rapid, easy-to-perform postacquisition metabolomics strategy for inferring structural features and prioritizing new compounds for further study and dereplication. More work on cyanopeptolin occurrence and toxicity is needed because their concentrations in freshwater lakes after blooms can be similar to those of microcystins. Environ Toxicol Chem 2021;40:1087-1097. © 2020 SETAC.
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Affiliation(s)
| | - Justin B Renaud
- London Research and Development Center, Agriculture and Agri-Food Canada, London, Ontario, Canada
| | - Frances R Pick
- Department of Biology, University of Ottawa, Ottawa, Ontario, Canada
| | - J David Miller
- Department of Chemistry, Carleton University, Ottawa, Ontario, Canada
| | - Mark W Sumarah
- London Research and Development Center, Agriculture and Agri-Food Canada, London, Ontario, Canada
| | - David R McMullin
- Department of Chemistry, Carleton University, Ottawa, Ontario, Canada
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Beach DG, Rafuse C, Melanson JE, McCarron P. Rapid quantitative screening of cyanobacteria for production of anatoxins using direct analysis in real time high-resolution mass spectrometry. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2021; 35:e8940. [PMID: 32881159 DOI: 10.1002/rcm.8940] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Revised: 08/28/2020] [Accepted: 08/28/2020] [Indexed: 06/11/2023]
Abstract
RATIONALE Anatoxins (ATXs) are a potent class of cyanobacterial neurotoxins that are increasingly problematic in drinking water reservoirs and recreational water bodies worldwide. Because of their high polarity and low molecular weight, analysis of ATXs is challenging and they can be considered underreported compared with other classes of cyanobacterial toxins. Improved screening methods are therefore needed to effectively assess their occurrence and concentrations in the environment. METHODS A rapid screening method was developed for ATXs in cyanobacteria using direct analysis in real time combined with high-resolution mass spectrometry (DART-HRMS), requiring less than 2 min per sample for triplicate analysis. The developed method was evaluated for its quantitative capabilities, applied to the screening of 30 cyanobacterial culture samples for the presence of anatoxin-a, homoanatoxin-a and dihydroanatoxin-a, and compared with a more typical liquid chromatography (LC)/HRMS method. RESULTS Excellent linearity was observed in the analysis of a matrix-matched calibration curve using DART-HRMS, with ionization suppression of about 50% and relative standard deviations between replicate analyses of approximately 30%. Limits of detection for both anatoxin-a and homoanatoxin-a were estimated as 1 ng/mL. Excellent agreement was observed between DART-HRMS and LC/HRMS with all ATX-producing cultures correctly identified and only one false positive culture by DART-HRMS. CONCLUSIONS DART-HRMS shows excellent promise for the rapid, quantitative screening of ATXs in cyanobacteria and could be expanded in the future to include the analysis of field samples and drinking water, as well as additional ATX analogues.
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Affiliation(s)
- Daniel G Beach
- Biotoxin Metrology, National Research Council Canada, 1411 Oxford Street, Halifax, Nova Scotia, B3H 3Z1, Canada
| | - Cheryl Rafuse
- Biotoxin Metrology, National Research Council Canada, 1411 Oxford Street, Halifax, Nova Scotia, B3H 3Z1, Canada
| | - Jeremy E Melanson
- Organic Chemical Metrology, National Research Council Canada, 1200 Montreal Road, Ottawa, Ontario, K1A 0R6, Canada
| | - Pearse McCarron
- Biotoxin Metrology, National Research Council Canada, 1411 Oxford Street, Halifax, Nova Scotia, B3H 3Z1, Canada
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12
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Miller TR, Xiong A, Deeds JR, Stutts WL, Samdal IA, Løvberg KE, Miles CO. Microcystin Toxins at Potentially Hazardous Levels in Algal Dietary Supplements Revealed by a Combination of Bioassay, Immunoassay, and Mass Spectrometric Methods. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2020; 68:8016-8025. [PMID: 32597644 DOI: 10.1021/acs.jafc.0c02024] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Microcystins (MCs) are hepatotoxic heptapeptides produced by cyanobacteria and are potent inhibitors of protein phosphatases in eukaryotic cells. Algae for dietary supplements are harvested from outdoor environments and can be contaminated with MCs. Monitoring of MCs in these products is necessary but is complicated by their structural diversity (>250 congeners). We used a combination of protein phosphatase inhibition assay (PPIA), ELISA, LC-MS/MS, and nontargeted LC-high-resolution MS (LC-HRMS) with thiol derivatization to characterize the total MCs in 18 algal dietary supplements. LC-MS/MS revealed that some products contained >40 times the maximum acceptable concentration (MAC) of 1 μg/g MCs, but ELISA and PPIA showed up to 50-60 times the MAC. LC-HRMS identified all congeners targeted by LC-MS/MS plus MC-(H4)YR contributing up to 18% of total MCs, along with numerous minor MCs. Recommended dosages of the products greater than the MAC would result in 2.6-75 times the tolerable daily intake, presenting a risk to consumers. This study confirms the need for monitoring these products and presents strategies to fully describe the total MC pool in environmental samples and algal products.
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Affiliation(s)
- Todd R Miller
- Joseph J. Zilber School of Public Health, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin 53211, United States
| | - Ame Xiong
- Joseph J. Zilber School of Public Health, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin 53211, United States
| | - Jonathan R Deeds
- United States Food and Drug Administration, Center for Food Safety and Applied Nutrition, College Park, Maryland 20740-3835, United States
| | - Whitney L Stutts
- United States Food and Drug Administration, Center for Food Safety and Applied Nutrition, College Park, Maryland 20740-3835, United States
| | - Ingunn A Samdal
- Norwegian Veterinary Institute, P.O. Box 750 Sentrum, N-0106 Oslo, Norway
| | - Kjersti E Løvberg
- Norwegian Veterinary Institute, P.O. Box 750 Sentrum, N-0106 Oslo, Norway
| | - Christopher O Miles
- Biotoxin Metrology, National Research Council, 1411 Oxford Street, Halifax B3H 3Z1, NS, Canada
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13
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LeBlanc P, Merkley N, Thomas K, Lewis NI, Békri K, Renaud SL, Pick FR, McCarron P, Miles CO, Quilliam MA. Isolation and Characterization of [DLeu 1]microcystin-LY from Microcystis aeruginosa CPCC-464. Toxins (Basel) 2020; 12:toxins12020077. [PMID: 31979406 PMCID: PMC7076857 DOI: 10.3390/toxins12020077] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Revised: 01/15/2020] [Accepted: 01/20/2020] [Indexed: 01/29/2023] Open
Abstract
[D-Leu1]MC-LY (1) ([M + H]+m/z 1044.5673, Δ 2.0 ppm), a new microcystin, was isolated from Microcystis aeruginosa strain CPCC-464. The compound was characterized by 1H and 13C NMR spectroscopy, liquid chromatography–high resolution tandem mass spectrometry (LC–HRMS/MS) and UV spectroscopy. A calibration reference material was produced after quantitation by 1H NMR spectroscopy and LC with chemiluminescence nitrogen detection. The potency of 1 in a protein phosphatase 2A inhibition assay was essentially the same as for MC-LR (2). Related microcystins, [D-Leu1]MC-LR (3) ([M + H]+m/z 1037.6041, Δ 1.0 ppm), [D-Leu1]MC-M(O)R (6) ([M + H]+m/z 1071.5565, Δ 2.0 ppm) and [D-Leu1]MC-MR (7) ([M + H]+m/z 1055.5617, Δ 2.2 ppm), were also identified in culture extracts, along with traces of [D-Leu1]MC-M(O2)R (8) ([M + H]+m/z 1087.5510, Δ 1.6 ppm), by a combination of chemical derivatization and LC–HRMS/MS experiments. The relative abundances of 1, 3, 6, 7 and 8 in a freshly extracted culture in the positive ionization mode LC–HRMS were ca. 84, 100, 3.0, 11 and 0.05, respectively. These and other results indicate that [D-Leu1]-containing MCs may be more common in cyanobacterial blooms than is generally appreciated but are easily overlooked with standard targeted LC–MS/MS screening methods.
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Affiliation(s)
- Patricia LeBlanc
- Biotoxin Metrology, National Research Council, 1411 Oxford Street, Halifax, NS B3H 3Z1, Canada; (P.L.); (N.M.); (K.T.); (N.I.L.); (K.B.); (P.M.); (C.O.M.)
| | - Nadine Merkley
- Biotoxin Metrology, National Research Council, 1411 Oxford Street, Halifax, NS B3H 3Z1, Canada; (P.L.); (N.M.); (K.T.); (N.I.L.); (K.B.); (P.M.); (C.O.M.)
| | - Krista Thomas
- Biotoxin Metrology, National Research Council, 1411 Oxford Street, Halifax, NS B3H 3Z1, Canada; (P.L.); (N.M.); (K.T.); (N.I.L.); (K.B.); (P.M.); (C.O.M.)
| | - Nancy I. Lewis
- Biotoxin Metrology, National Research Council, 1411 Oxford Street, Halifax, NS B3H 3Z1, Canada; (P.L.); (N.M.); (K.T.); (N.I.L.); (K.B.); (P.M.); (C.O.M.)
| | - Khalida Békri
- Biotoxin Metrology, National Research Council, 1411 Oxford Street, Halifax, NS B3H 3Z1, Canada; (P.L.); (N.M.); (K.T.); (N.I.L.); (K.B.); (P.M.); (C.O.M.)
| | - Susan LeBlanc Renaud
- Department of Biology, University of Ottawa, Ottawa, ON K1N 6N5, Canada; (S.L.R.); (F.R.P.)
| | - Frances R. Pick
- Department of Biology, University of Ottawa, Ottawa, ON K1N 6N5, Canada; (S.L.R.); (F.R.P.)
| | - Pearse McCarron
- Biotoxin Metrology, National Research Council, 1411 Oxford Street, Halifax, NS B3H 3Z1, Canada; (P.L.); (N.M.); (K.T.); (N.I.L.); (K.B.); (P.M.); (C.O.M.)
| | - Christopher O. Miles
- Biotoxin Metrology, National Research Council, 1411 Oxford Street, Halifax, NS B3H 3Z1, Canada; (P.L.); (N.M.); (K.T.); (N.I.L.); (K.B.); (P.M.); (C.O.M.)
| | - Michael A. Quilliam
- Biotoxin Metrology, National Research Council, 1411 Oxford Street, Halifax, NS B3H 3Z1, Canada; (P.L.); (N.M.); (K.T.); (N.I.L.); (K.B.); (P.M.); (C.O.M.)
- Correspondence:
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14
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Bouaïcha N, Miles CO, Beach DG, Labidi Z, Djabri A, Benayache NY, Nguyen-Quang T. Structural Diversity, Characterization and Toxicology of Microcystins. Toxins (Basel) 2019; 11:E714. [PMID: 31817927 PMCID: PMC6950048 DOI: 10.3390/toxins11120714] [Citation(s) in RCA: 206] [Impact Index Per Article: 41.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2019] [Revised: 12/02/2019] [Accepted: 12/04/2019] [Indexed: 11/22/2022] Open
Abstract
Hepatotoxic microcystins (MCs) are the most widespread class of cyanotoxins and the one that has most often been implicated in cyanobacterial toxicosis. One of the main challenges in studying and monitoring MCs is the great structural diversity within the class. The full chemical structure of the first MC was elucidated in the early 1980s and since then, the number of reported structural analogues has grown steadily and continues to do so, thanks largely to advances in analytical methodology. The structures of some of these analogues have been definitively elucidated after chemical isolation using a combination of techniques including nuclear magnetic resonance, amino acid analysis, and tandem mass spectrometry (MS/MS). Others have only been tentatively identified using liquid chromatography-MS/MS without chemical isolation. An understanding of the structural diversity of MCs, the genetic and environmental controls for this diversity and the impact of structure on toxicity are all essential to the ongoing study of MCs across several scientific disciplines. However, because of the diversity of MCs and the range of approaches that have been taken for characterizing them, comprehensive information on the state of knowledge in each of these areas can be challenging to gather. We have conducted an in-depth review of the literature surrounding the identification and toxicity of known MCs and present here a concise review of these topics. At present, at least 279 MCs have been reported and are tabulated here. Among these, about 20% (55 of 279) appear to be the result of chemical or biochemical transformations of MCs that can occur in the environment or during sample handling and extraction of cyanobacteria, including oxidation products, methyl esters, or post-biosynthetic metabolites. The toxicity of many MCs has also been studied using a range of different approaches and a great deal of variability can be observed between reported toxicities, even for the same congener. This review will help clarify the current state of knowledge on the structural diversity of MCs as a class and the impacts of structure on toxicity, as well as to identify gaps in knowledge that should be addressed in future research.
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Affiliation(s)
- Noureddine Bouaïcha
- Écologie, Systématique et Évolution, Univ. Paris-Sud, CNRS, AgroParisTech, Université Paris-Saclay, 91405 Orsay, France; (A.D.); (N.Y.B.)
| | - Christopher O. Miles
- Biotoxin Metrology, National Research Council Canada, 1411 Oxford St, Halifax, NS B3H 3Z1, Canada; (C.O.M.); (D.G.B.)
| | - Daniel G. Beach
- Biotoxin Metrology, National Research Council Canada, 1411 Oxford St, Halifax, NS B3H 3Z1, Canada; (C.O.M.); (D.G.B.)
| | - Zineb Labidi
- Laboratoire Biodiversité et Pollution des Écosystèmes, Faculté des Sciences de la Nature et de la Vie, Université Chadli Bendjedid d’El Taref, 36000 El Taref, Algeria;
| | - Amina Djabri
- Écologie, Systématique et Évolution, Univ. Paris-Sud, CNRS, AgroParisTech, Université Paris-Saclay, 91405 Orsay, France; (A.D.); (N.Y.B.)
- Laboratoire Biodiversité et Pollution des Écosystèmes, Faculté des Sciences de la Nature et de la Vie, Université Chadli Bendjedid d’El Taref, 36000 El Taref, Algeria;
| | - Naila Yasmine Benayache
- Écologie, Systématique et Évolution, Univ. Paris-Sud, CNRS, AgroParisTech, Université Paris-Saclay, 91405 Orsay, France; (A.D.); (N.Y.B.)
| | - Tri Nguyen-Quang
- Biofluids and Biosystems Modeling (BBML), Faculty of Agriculture, Dalhousie University, 39 Cox Road, Truro, B2N 5E3 Nova Scotia, Canada;
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15
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Haddad SP, Bobbitt JM, Taylor RB, Lovin LM, Conkle JL, Chambliss CK, Brooks BW. Determination of microcystins, nodularin, anatoxin-a, cylindrospermopsin, and saxitoxin in water and fish tissue using isotope dilution liquid chromatography tandem mass spectrometry. J Chromatogr A 2019; 1599:66-74. [PMID: 30961962 DOI: 10.1016/j.chroma.2019.03.066] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2018] [Revised: 02/09/2019] [Accepted: 03/29/2019] [Indexed: 12/25/2022]
Abstract
Cyanobacteria can form dense blooms under specific environmental conditions, and some species produce secondary metabolites known as cyanotoxins, which present significant risks to public health and the environment. Identifying toxins produced by cyanobacteria present in surface water and fish is critical to ensuring high quality food and water for consumption, and protectionn of recreational uses. Current analytical screening methods typically focus on one class of cyanotoxins in a single matrix and rarely include saxitoxin. Thus, a cross-class screening method for microcystins, nodularin, anatoxin-a, cylindrospermopsin, and saxitoxin was developed to examine target analytes in environmental water and fish tissue. This was done, due to the broad range of cyanotoxin physicochemical properties, by pairing two extraction and separation techniques to improve isolation and detection. For the first time a zwitterionic hydrophilic interaction liquid chromatography column was evaluated to separate anatoxin-a, cylindrospermopsin, and saxitoxin, demonstrating greater sensitivity for all three compounds over previous techniques. Further, the method for microcystins, nodularin, anatoxin-a, and cylindrospermopsin were validated using isotopically labeled internal standards, again for the first time, resulting in improved compensation for recovery bias and matrix suppression. Optimized extractions for water and fish tissue can be extended to other congeners in the future. These improved separation and isotope dilution techniques are a launching point for more complex, non-targeted analyses, with preliminary targeted screening.
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Affiliation(s)
- Samuel P Haddad
- Department of Environmental Science, Center for Reservoir and Aquatic Systems Research, Baylor University, Waco, TX, 76798, USA
| | - Jonathan M Bobbitt
- Department of Chemistry and Biochemistry, Baylor University, Waco, TX, 76798, USA
| | - Raegyn B Taylor
- Department of Chemistry and Biochemistry, Baylor University, Waco, TX, 76798, USA
| | - Lea M Lovin
- Department of Environmental Science, Center for Reservoir and Aquatic Systems Research, Baylor University, Waco, TX, 76798, USA
| | - Jeremy L Conkle
- Department of Physical and Environmental Sciences, Texas A&M University, Corpus Christi, TX, 78412, USA
| | - C Kevin Chambliss
- Department of Environmental Science, Center for Reservoir and Aquatic Systems Research, Baylor University, Waco, TX, 76798, USA; Department of Chemistry and Biochemistry, Baylor University, Waco, TX, 76798, USA
| | - Bryan W Brooks
- Department of Environmental Science, Center for Reservoir and Aquatic Systems Research, Baylor University, Waco, TX, 76798, USA; Institute of Biomedical Studies, Baylor University, Waco, TX, 76798, USA.
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16
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Beach DG, Kerrin ES, Giddings SD, Quilliam MA, McCarron P. Differential Mobility-Mass Spectrometry Double Spike Isotope Dilution Study of Release of β-Methylaminoalanine and Proteinogenic Amino Acids during Biological Sample Hydrolysis. Sci Rep 2018; 8:117. [PMID: 29311581 PMCID: PMC5758758 DOI: 10.1038/s41598-017-18392-w] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2017] [Accepted: 11/16/2017] [Indexed: 12/12/2022] Open
Abstract
The non-protein amino acid β-methylamino-L-alanine (BMAA) has been linked to neurodegenerative disease and reported throughout the environment. Proposed mechanisms of bioaccumulation, trophic transfer and chronic toxicity of BMAA rely on the hypothesis of protein misincorporation. Poorly selective methods for BMAA analysis have led to controversy. Here, a recently reported highly selective method for BMAA quantitation using hydrophilic interaction liquid chromatography-differential mobility spectrometry-tandem mass spectrometry (HILIC-DMS-MS/MS) is expanded to include proteinogenic amino acids from hydrolyzed biological samples. For BMAA quantitation, we present a double spiking isotope dilution approach using D3-BMAA and 13C15N2-BMAA. These methods were applied to study release of BMAA during acid hydrolysis under a variety of conditions, revealing that the majority of BMAA can be extracted along with only a small proportion of protein. A time course hydrolysis of BMAA from mussel tissue was carried out to assess the recovery of BMAA during sample preparation. The majority of BMAA measured by typical methods was released before a significant proportion of protein was hydrolyzed. Little change was observed in protein hydrolysis beyond typical hydrolysis times but the concentration of BMAA increased linearly. These findings demonstrate protein misincorporation is not the predominant form of BMAA in cycad and shellfish.
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Affiliation(s)
- Daniel G Beach
- Measurement Science and Standards, National Research Council Canada, 1411 Oxford St., Halifax, NS, B3H 3Z1, Canada.
| | - Elliott S Kerrin
- Measurement Science and Standards, National Research Council Canada, 1411 Oxford St., Halifax, NS, B3H 3Z1, Canada
| | - Sabrina D Giddings
- Measurement Science and Standards, National Research Council Canada, 1411 Oxford St., Halifax, NS, B3H 3Z1, Canada
| | - Michael A Quilliam
- Measurement Science and Standards, National Research Council Canada, 1411 Oxford St., Halifax, NS, B3H 3Z1, Canada
| | - Pearse McCarron
- Measurement Science and Standards, National Research Council Canada, 1411 Oxford St., Halifax, NS, B3H 3Z1, Canada
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17
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Ortiz X, Korenkova E, Jobst KJ, MacPherson KA, Reiner EJ. A high throughput targeted and non-targeted method for the analysis of microcystins and anatoxin-A using on-line solid phase extraction coupled to liquid chromatography-quadrupole time-of-flight high resolution mass spectrometry. Anal Bioanal Chem 2017. [PMID: 28634756 DOI: 10.1007/s00216-017-0437-0] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Microcystins are cyclic heptapeptide hepatotoxins produced by cyanobacteria in freshwater. Sample preparation for the analysis of these cyanotoxins in water from algal blooms can take up to several days due to the matrix complexity and the low detection limits required to comply with current legislation. Moreover, there is a large number of unknown microcystins that could potentially exist in the environment resulting from different amino acid substitutions into the microcystin skeletal structure. To tackle these problems, the present study involved the development of a high throughput method based on on-line solid phase extraction coupled to liquid chromatography that could provide quantitative results for 12 microcystin variants (LR, YR, RR, HtyR, HilR, WR, LW, LA, LF, LY, Dha7-LR, and Dha7-RR) and anatoxin-A in less than 3 h with detection limits between 0.004 and 0.01 μg L-1 and expanded uncertainty between 4 and 14%. Data-dependent acquisition was employed for the non-targeted analysis of these cyanotoxins. Filtering the data based on structure diagnostic fragments, two unknown microcystin variants not previously reported in the literature were detected. The structures Leu1-microcystin-Met(O)R and Leu1-microcystin-LY were fully characterized by accurate mass measurement, collision-induced dissociation, and fragmentation prediction software.
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Affiliation(s)
- Xavier Ortiz
- Ontario Ministry of the Environment and Climate Change, 125 Resources Road, Toronto, ON, M9P 3V6, Canada.
| | - Eva Korenkova
- Ontario Ministry of the Environment and Climate Change, 125 Resources Road, Toronto, ON, M9P 3V6, Canada
| | - Karl J Jobst
- Ontario Ministry of the Environment and Climate Change, 125 Resources Road, Toronto, ON, M9P 3V6, Canada
| | - Karen A MacPherson
- Ontario Ministry of the Environment and Climate Change, 125 Resources Road, Toronto, ON, M9P 3V6, Canada
| | - Eric J Reiner
- Ontario Ministry of the Environment and Climate Change, 125 Resources Road, Toronto, ON, M9P 3V6, Canada
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18
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Quantitative determination of the neurotoxin β-N-methylamino-L-alanine (BMAA) by capillary electrophoresis-tandem mass spectrometry. Anal Bioanal Chem 2016; 409:1481-1491. [PMID: 27909777 DOI: 10.1007/s00216-016-0091-y] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2016] [Revised: 10/31/2016] [Accepted: 11/09/2016] [Indexed: 12/28/2022]
Abstract
Recent reports of the widespread occurrence of the neurotoxin β-N-methylamino-L-alanine (BMAA) in cyanobacteria and particularly seafood have raised concerns for public health. LC-MS/MS is currently the analytical method of choice for BMAA determinations but incomplete separation of isomeric and isobaric compounds, matrix suppression and conjugated forms are plausible limitations. In this study, capillary electrophoresis (CE) coupled with MS/MS has been developed as an alternative method for the quantitative determination of free BMAA. Using a bare fused silica capillary, a phosphate buffer (250 mM, pH 3.0) and UV detection, it was possible to separate BMAA from four isomers, but the limit of detection (LOD) of 0.25 μg mL-1 proved insufficient for analysis of typical samples. Coupling the CE to a triple quadrupole MS was accomplished using a custom sheath-flow interface. The best separation was achieved with a 5 M formic acid in water/acetonitrile (9:1) background electrolyte. Strong acid hydrolysis of lyophilized samples was used to release BMAA from conjugated forms. Field-amplified stacking after injection was achieved by lowering sample ionic strength with a cation-exchange cleanup procedure. Quantitation was accomplished using isotope dilution with deuterium-labelled BMAA as internal standard. An LOD for BMAA in solution of 0.8 ng mL-1 was attained, which was equivalent to 16 ng g-1 dry mass in samples using the specified extraction procedure. This was comparable with LC-MS/MS methods. The method displayed excellent resolution of amino acid isomers and had no interference from matrix components. The presence of BMAA in cycad, mussel and lobster samples was confirmed by CE-MS/MS, but not in an in-house cyanobacterial reference material, with quantitative results agreeing with those from LC-MS/MS. Graphical Abstract CE-MS separation and detection of BMAA, its isomers and the internal standard BMAA-d3.
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19
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Beach DG, Kerrin ES, Quilliam MA. Selective quantitation of the neurotoxin BMAA by use of hydrophilic-interaction liquid chromatography-differential mobility spectrometry-tandem mass spectrometry (HILIC-DMS-MS/MS). Anal Bioanal Chem 2015; 407:8397-409. [PMID: 26396078 DOI: 10.1007/s00216-015-9012-8] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2015] [Revised: 08/19/2015] [Accepted: 08/26/2015] [Indexed: 12/22/2022]
Abstract
The neurotoxin β-N-methylamino-L-alanine (BMAA) has been reported in cyanobacteria and shellfish, raising concerns about widespread human exposure. However, inconsistent results for BMAA analysis have led to controversy. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) is the most appropriate method for analysis of BMAA, but the risk of interference from isomers, other sample components, and the electrospray background is still present. We have investigated differential mobility spectrometry (DMS) as an ion filter to improve selectivity in the hydrophilic interaction liquid chromatographic (HILIC)-MS/MS determination of BMAA. We obtained standards for two BMAA isomers not previously analyzed by HILIC-MS, β-amino-N-methylalanine and 3,4-diaminobutanoic acid, and the typically used 2,4-diaminobutanoic acid and N-(2-aminoethyl)glycine. DMS separation of BMAA from these isomers was achieved and optimized conditions were used to develop a sensitive and highly selective multidimensional HILIC-DMS-MS/MS method. This work revealed current technical limitations of DMS for trace quantitation, and practical solutions were implemented. Accurate control of low levels of DMS carrier gas modifier was essential, but required external metering. The linearity of our optimized method was excellent from 0.01 to 6 μmol L(-1). The instrumental LOD was 0.4 pg BMAA injected on-column and the estimated method LOD was 20 ng g(-1) dry weight for BMAA in sample matrix. The method was used to analyze cycad plant tissue, a cyanobacterial reference material, and mussel tissues, by use of isotope-dilution quantitation with deuterated BMAA. This confirmed the presence of BMAA and several of its isomers in cycad and mussel tissues, including commercially available mussel tissue reference materials certified for other biotoxins. Graphical Abstract Differential Mobility Spectrometry is used to increases the selectivity of BMAA analysis by HILIC-MS/MS.
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Affiliation(s)
- Daniel G Beach
- Measurement Science and Standards, National Research Council Canada, 1411 Oxford Street, Halifax, NS, B3H 3Z1, Canada.
| | - Elliott S Kerrin
- Measurement Science and Standards, National Research Council Canada, 1411 Oxford Street, Halifax, NS, B3H 3Z1, Canada.,Department of Chemistry, Dalhousie University, 6274 Coburg Road, Halifax, NS, B3H 4R2, Canada
| | - Michael A Quilliam
- Measurement Science and Standards, National Research Council Canada, 1411 Oxford Street, Halifax, NS, B3H 3Z1, Canada.,Department of Chemistry, Dalhousie University, 6274 Coburg Road, Halifax, NS, B3H 4R2, Canada
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