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1
Yusof, Tengku Nadiah, Mohd Rafatullah, Rohaslinda Mohamad, Norli Ismail, Zarina Zainuddin e Japareng Lalung. "Cyanobacteria Characteristics and Methods for Isolation and Accurate Identification of Cyanotoxins: A Review Article". Avicenna Journal of Environmental Health Engineering 4, n. 1 (30 giugno 2017): 10051. http://dx.doi.org/10.5812/ajehe.10051.
Testo completoAbstract (sommario):
Cyanobacteria are bacteria found in different ecosystems, such as lakes and rocks. These bacteria, capable of photosynthesis, are important sources of oxygen. However, some cyanobacterial strains can produce toxins, which are harmful to humans and animals. Therefore, collection of epidemiological and surveillance data on cyanobacterial toxins in the environment is vital to ensure a low risk of exposure to toxins in other organisms. For presentation of accurate data on environmental cyanobacterial toxins, it is essential to understand their characteristics, including taxonomy, toxin proteins, and genomic structures, and determine their environmental effects on bacterial populations and toxin production. Taxonomy, which is the scientific classification of organisms, is important in identifying species producing toxins. The structure of toxin proteins and their stability in the environment allow researchers to detect toxins with analytical methods and discuss their limitations. Onthe other hand, identifying toxins via molecular typing enables researchers to investigate toxic cyanobacteria by detecting toxin-encoding genes and toxin gene expression. Meanwhile, environmental factors, such as nutrient level, light intensity, and biotic factors, allow researchers to predict the suitable time and location for accurate sampling. In this review, these cyanobacterial features, which are important for accurate detection of cyanobacterial toxins, will be discussed.
2
Codd, Geoffrey A., Steven G. Bell e William P. Brooks. "Cyanobacterial Toxins in Water". Water Science and Technology 21, n. 3 (1 marzo 1989): 1–13. http://dx.doi.org/10.2166/wst.1989.0071.
Testo completoAbstract (sommario):
Cyanobacteria (blue-green algae) commonly occur in fresh- and brackish waters and may produce massive annual growths as a consequence of nutrient enrichment from natural waters, agricultural fertilizer run-off, or from domestic/industrial effluents. The cyanobacterial species which dominate these growths typically belong to the genera which produce toxins. Cyanobacterial toxins cause fatal poisonings of agricultural livestock, wild animals, birds and fish on a world-wide basis. The involvement of the toxins in human health problems has also been inferred in several countries and their presence in drinking water sources is of interest to the drinking water industry. The occurrence and properties of cyanobacterial toxins are discussed here. New methods are being developed for the purification of the toxins and for their recovery and quantification from waters. These include the use of chemical, cytotoxicity and immunological methods to complement the mouse bioassay which has hitherto been used in cyanobacterial toxin studies with laboratory cultures and water samples. Information on the regulation of cyanobacterial toxin production and on the possible biological significance of the toxins in aquatic environments is also presented. A greater awareness of cyanobacterial toxins in waters destined for human use is required.
3
Mohamad, Rohaslinda, Mohd Rafatullah, Tengku Yusof, Yi Sim, Norli Ismail e Japareng Lalung. "Detection of Microcystin (Mcye) Gene in Recreational Lakes in Miri, Sarawak, Malaysia". Current World Environment 11, n. 3 (25 dicembre 2016): 690–99. http://dx.doi.org/10.12944/cwe.11.3.02.
Testo completoAbstract (sommario):
Toxic cyanobacteria blooms became a worldwide problems as many countries encounter the presence of the blooms in most of water bodies. As part to develop monitoring of cyanobacterial toxins in Malaysia, samples taken in twelve points in five different lakes in Miri, Sarawak. Polymerase chain reaction (PCR) amplification of cyanobacterial 16S rRNA were carried out to detect the presence of cyanobacteria in the water samples. Cyanobacterial 16S rRNA were detected in all the samples collected. While molecular analysis for detection of cyanobacterial toxin encoding gene were done using specific primers. PCR amplification of cyanobacterial toxin-encoding gene were carried using the combination of forward primer; mcyE-F2 and reverse primer; mcyE-R4 to amplify generic microcystin (mcyE) gene in the samples. Out of twelve samples collected, microcystin (mcyE) producing gene was detected in one of the samples tested. Presence of microcystin encoding gene indicates the risk of cyanobacterial toxins in Miri, Sarawak.
4
Codd, G. A. "Cyanobacterial toxins: occurrence, properties and biological significance". Water Science and Technology 32, n. 4 (1 agosto 1995): 149–56. http://dx.doi.org/10.2166/wst.1995.0177.
Testo completoAbstract (sommario):
All of the most commonly encountered genera of cyanobacteria which form blooms and scums in fresh-brackish- and marine waters include members capable of producing potent toxins. Poisonings of vertebrate and invertebrate animals following the ingestion of cyanobacterial bloom/scum material have been widely reported for many years and recognition of the adverse effects of cyanobacterial blooms and their toxins is increasing. This review considers the occurrence of toxic cyanobacterial populations and properties of the toxins themselves, of which at least 60 are now recognised. When rightfully regarded as microbial secondary metabolites, a range of possible functions for cyanobacterial toxins is presented. Whether cyanobacterial toxins contribute to the ability of cyanobacteria to dominate many eutrophic waterbodies is unknown, although understanding of the occurrence of the toxins in aquatic environments and their actions at the molecular level and with whole organisms in laboratory studies indicates that this is possible.
5
Schwarzenberger, Anke. "Negative Effects of Cyanotoxins and Adaptative Responses of Daphnia". Toxins 14, n. 11 (7 novembre 2022): 770. http://dx.doi.org/10.3390/toxins14110770.
Testo completoAbstract (sommario):
The plethora of cyanobacterial toxins are an enormous threat to whole ecosystems and humans. Due to eutrophication and increases in lake temperatures from global warming, changes in the distribution of cyanobacterial toxins and selection of few highly toxic species/ strains are likely. Globally, one of the most important grazers that controls cyanobacterial blooms is Daphnia, a freshwater model organism in ecology and (eco)toxicology. Daphnia–cyanobacteria interactions have been studied extensively, often focusing on the interference of filamentous cyanobacteria with Daphnia’s filtering apparatus, or on different nutritional constraints (the lack of essential amino acids or lipids) and grazer toxicity. For a long time, this toxicity only referred to microcystins. Currently, the focus shifts toward other deleterious cyanotoxins. Still, less than 10% of the total scientific output deals with cyanotoxins that are not microcystins; although these other cyanotoxins can occur just as frequently and at similar concentrations as microcystins in surface water. This review discusses the effects of different cyanobacterial toxins (hepatotoxins, digestive inhibitors, neurotoxins, and cytotoxins) on Daphnia and provides an elaborate and up-to-date overview of specific responses and adaptations of Daphnia. Furthermore, scenarios of what we can expect for the future of Daphnia–cyanobacteria interactions are described by comprising anthropogenic threats that might further increase toxin stress in Daphnia.
6
Kormas, Konstantinos Ar, e Despoina S. Lymperopoulou. "Cyanobacterial Toxin Degrading Bacteria: Who Are They?" BioMed Research International 2013 (2013): 1–12. http://dx.doi.org/10.1155/2013/463894.
Testo completoAbstract (sommario):
Cyanobacteria are ubiquitous in nature and are both beneficial and detrimental to humans. Benefits include being food supplements and producing bioactive compounds, like antimicrobial and anticancer substances, while their detrimental effects are evident by toxin production, causing major ecological problems at the ecosystem level. To date, there are several ways to degrade or transform these toxins by chemical methods, while the biodegradation of these compounds is understudied. In this paper, we present a meta-analysis of the currently available 16S rRNA andmlrA(microcystinase) genes diversity of isolates known to degrade cyanobacterial toxins. The available data revealed that these bacteria belong primarily to the Proteobacteria, with several strains from the sphingomonads, and one from each of theMethylobacillusandPaucibactergenera. Other strains belonged to the generaArthrobacter, Bacillus, andLactobacillus. By combining the ecological knowledge on the distribution, abundance, and ecophysiology of the bacteria that cooccur with toxic cyanobacterial blooms and newly developed molecular approaches, it is possible not only to discover more strains with cyanobacterial toxin degradation abilities, but also to reveal the genes associated with the degradation of these toxins.
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Codd, Geoffrey A., James S. Metcalf, Clive J. Ward, Kenneth A. Beattie, Steven G. Bell, Kunimitsu Kaya e Grace K. Poon. "Analysis of Cyanobacterial Toxins by Physicochemical and Biochemical Methods". Journal of AOAC INTERNATIONAL 84, n. 5 (1 settembre 2001): 1626–35. http://dx.doi.org/10.1093/jaoac/84.5.1626.
Testo completoAbstract (sommario):
Abstract Cyanobacteria (blue-green algae) produce a wide range of low molecular weight metabolites that include potent neurotoxins, hepatotoxins, and cytotoxins. The accumulation of such toxins in freshwaters, and in brackish and marine waters presents hazards to human and animal health by a range of exposure routes. A review is presented of developments in the detection and analysis of cyanobacterial toxins, other than bioassays, including application of physicochemical, immunoassays, and enzyme-based methods. Analytical requirements are considered with reference to recently derived guideline levels for the protection of health and to the availability, or otherwise, of purified, quantitative cyanobacterial toxin standards.
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Le, Kim Thien Nguyen, Eyerusalem Goitom, Hana Trigui, Sébastien Sauvé, Michèle Prévost e Sarah Dorner. "The Effects of Ferric Sulfate (Fe2(SO4)3) on the Removal of Cyanobacteria and Cyanotoxins: A Mesocosm Experiment". Toxins 13, n. 11 (23 ottobre 2021): 753. http://dx.doi.org/10.3390/toxins13110753.
Testo completoAbstract (sommario):
Cyanobacterial blooms are a global concern. Chemical coagulants are used in water treatment to remove contaminants from the water column and could potentially be used in lakes and reservoirs. The aims of this study was to: 1) assess the efficiency of ferric sulfate (Fe2(SO4)3) coagulant in removing harmful cyanobacterial cells from lake water with cyanobacterial blooms on a short time scale, 2) determine whether some species of cyanobacteria can be selectively removed, and 3) determine the differential impact of coagulants on intra- and extra-cellular toxins. Our main results are: (i) more than 96% and 51% of total cyanobacterial cells were removed in mesocosms with applied doses of 35 mgFe/L and 20 mgFe/L, respectively. Significant differences in removing total cyanobacterial cells and several dominant cyanobacteria species were observed between the two applied doses; (ii) twelve microcystins, anatotoxin-a (ANA-a), cylindrospermopsin (CYN), anabaenopeptin A (APA) and anabaenopeptin B (APB) were identified. Ferric sulfate effectively removed the total intracellular microcystins (greater than 97% for both applied doses). Significant removal of extracellular toxins was not observed after coagulation with both doses. Indeed, the occasional increase in extracellular toxin concentration may be related to cells lysis during the coagulation process. No significant differential impact of dosages on intra- and extra-cellular toxin removal was observed which could be relevant to source water applications where optimal dosing is difficult to achieve.
9
Omidi, Azam, Stephan Pflugmacher, Aaron Kaplan, Young Jun Kim e Maranda Esterhuizen. "Reviewing Interspecies Interactions as a Driving Force Affecting the Community Structure in Lakes via Cyanotoxins". Microorganisms 9, n. 8 (25 luglio 2021): 1583. http://dx.doi.org/10.3390/microorganisms9081583.
Testo completoAbstract (sommario):
The escalating occurrence of toxic cyanobacterial blooms worldwide is a matter of concern. Global warming and eutrophication play a major role in the regularity of cyanobacterial blooms, which has noticeably shifted towards the predomination of toxic populations. Therefore, understanding the effects of cyanobacterial toxins in aquatic ecosystems and their advantages to the producers are of growing interest. In this paper, the current literature is critically reviewed to provide further insights into the ecological contribution of cyanotoxins in the variation of the lake community diversity and structure through interspecies interplay. The most commonly detected and studied cyanobacterial toxins, namely the microcystins, anatoxins, saxitoxins, cylindrospermopsins and β-N-methylamino-L-alanine, and their ecotoxicity on various trophic levels are discussed. This work addresses the environmental characterization of pure toxins, toxin-containing crude extracts and filtrates of single and mixed cultures in interspecies interactions by inducing different physiological and metabolic responses. More data on these interactions under natural conditions and laboratory-based studies using direct co-cultivation approaches will provide more substantial information on the consequences of cyanotoxins in the natural ecosystem. This review is beneficial for understanding cyanotoxin-mediated interspecies interactions, developing bloom mitigation technologies and robustly assessing the hazards posed by toxin-producing cyanobacteria to humans and other organisms.
10
Sivonen, Kaarina. "Cyanobacterial toxins and toxin production". Phycologia 35, sup6 (novembre 1996): 12–24. http://dx.doi.org/10.2216/i0031-8884-35-6s-12.1.
Testo completo
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Subbiah, Seenivasan, Adcharee Karnjanapiboonwong, Jonathan D. Maul, Degeng Wang e Todd A. Anderson. "Monitoring cyanobacterial toxins in a large reservoir: relationships with water quality parameters". PeerJ 7 (16 luglio 2019): e7305. http://dx.doi.org/10.7717/peerj.7305.
Testo completoAbstract (sommario):
Cyanobacteria are widely distributed in fresh, brackish, and ocean water environments, as well as in soil and on moist surfaces. Changes in the population of cyanobacteria can be an important indicator of alterations in water quality. Metabolites produced by blooms of cyanobacteria can be harmful, so cell counts are frequently monitored to assess the potential risk from cyanobacterial toxins. A frequent uncertainty in these types of assessments is the lack of strong relationships between cell count numbers and algal toxin concentrations. In an effort to use ion concentrations and other water quality parameters to determine the existence of any relationships with cyanobacterial toxin concentrations, we monitored four cyanobacterial toxins and inorganic ions in monthly water samples from a large reservoir over a 2-year period. Toxin concentrations during the study period never exceeded safety limits. In addition, toxin concentrations at levels above the limit of quantitation were infrequent during the 2-year sampling period; non-detects were common. Microcystin-LA was the least frequently detected analyte (86 of 89 samples were ND), followed by the other microcystins (microcystin-RR, microcystin-LR). Cylindrospermopsin and saxitoxin were the most frequently detected analytes. Microcystin and anatoxin concentrations were inversely correlated with Cl−, SO${}_{4}^{-2}$, Na+, and NH${}_{4}^{+}$, and directly correlated with turbidity and total P. Cylindrospermopsin and saxitoxin concentrations in water samples were inversely correlated with Mg+2 and directly correlated with water temperature. Results of our study are expected to increase the understanding of potential relationships between human activities and water quality.
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Rajabpour, Nooshin, Bahareh Nowruzi e Maryam Ghobeh. "Investigation of the toxicity, antioxidant and antimicrobial activities of some cyanobacterial strains isolated from different habitats". Acta Biologica Slovenica 62, n. 2 (1 dicembre 2019): 4–12. http://dx.doi.org/10.14720/abs.62.2.15753.
Testo completoAbstract (sommario):
Cyanobacteria are known as a source of fine chemicals, renewable fuels, and toxic compounds. The present study aimed at evaluating the toxicity and antioxidant and antimicrobial activities of four cyanobacterial strains isolated from different habitats. Due to the lack of information regarding the relationship between toxicity and biological activity of the cyanobacteria in terrestrial and aquatic ecosystems of Iran, we decided to conduct a preliminary study on the cyanobacterial strains in order to identify the potentially toxic cyanobacteria strains. In this respect, biosynthesis genes related to cyanobacterial toxins, anatoxins (anaC gene), nodularins (ndaF gene) and microcystins (mcyG gene) were amplified. In addition, antioxidant, antimicrobial and biochemical properties of cyanobacterial strains have also been evaluated. The results of the molecular analysis demonstrated that only Fischerella sp. contained the microcystins (mcyG) gene. In fact, this strain encounters numerous predators in its habitat, therefore antibacterial and antioxidant metabolites found in this strain have thought to play an important role in defense mechanisms. This case is the documentation of toxicity and promotion of biological activities of a soil cyanobacterium regarding survival in competitive ecological niches.
13
Pham, Thanh Luu, Tran Thi Hoang Yen, Tran Thanh Thai e Ngo Xuan Quang. "Using quantitative real-time polymerase chain reaction (qRT-PCR) for detection microcystin producing cyanobacteria". Science and Technology Development Journal 24, n. 2 (12 maggio 2021): first. http://dx.doi.org/10.32508/stdj.v24i2.2523.
Testo completoAbstract (sommario):
Introduction: Cyanobacterial blooms (CBs) have become a growing concern worldwide. In the natural environment, potentially toxic (can produce toxins) and non-toxic (can not produce toxins) colonies often co-exist within a bloom.
Methods: The present study aimed to quantify toxic and non-toxic cells of cyanobacteria in the Tri An Reservoir (TAR) using a quantitative real-time polymerase chain reaction (qRT-PCR).
Results: Results showed that the Microcystis genus dominated the cyanobacterial communities in the TAR. Microcystis was also the primary microcystins (MC) producing cyanobacteria in the water. Total cyanobacteria and Microcystis cells ranged from 152103 to 27106 copy/L and from 105103 to 19106 copy/L, respectively. The cell number of potentially MC-producing cyanobacteria (corresponding to the Microcystis mcyD gene) varied from 27103 to 13106 copy/L. MC concentrations often present in raw water with a concentration of up to 4.8 mg/L. Our results showed that the MC concentration in raw water was positively correlated with the mcyD copy number, suggesting that Microcystis spp. are the main toxin producers in the TAR's surface water.
Conclusion: Our study suggested that qRT-PCR techniques and traditional count are comparable and could be used to quantify cyanobacteria. In addition, the qRT-PCR techniques can determine the toxic cyanobacterial cells and could be used as a tool for early monitoring of toxic cyanobacteria in lakes and reservoirs.
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Esposito, Germana, Evgenia Glukhov, William H. Gerwick, Gabriele Medio, Roberta Teta, Massimiliano Lega e Valeria Costantino. "Lake Avernus Has Turned Red: Bioindicator Monitoring Unveils the Secrets of “Gates of Hades”". Toxins 15, n. 12 (13 dicembre 2023): 698. http://dx.doi.org/10.3390/toxins15120698.
Testo completoAbstract (sommario):
Lake Avernus is a volcanic lake located in southern Italy. Since ancient times, it has inspired numerous myths and legends due to the occurrence of singular phenomena, such as coloring events. Only recently has an explanation been found for them, i.e., the recurring color change over time is due to the alternation of cyanobacterial blooms that are a consequence of natural nutrient inputs as well as pollution resulting from human activities. This current report specifically describes the red coloring event that occurred on Lake Avernus in March 2022, the springtime season in this region of Italy. Our innovative multidisciplinary approach, the ‘Fast Detection Strategy’ (FDS), was devised to monitor cyanobacterial blooms and their toxins. It integrates remote sensing data from satellites and drones, on-site sampling, and analytical/bioinformatics analyses into a cohesive information flow. Thanks to FDS, we determined that the red color was attributable to a bloom of Planktothrix rubescens, a toxin-producing cyanobacterium. Here, we report the detection and identification of 14 anabenopeptins from this P. rubescens strain, seven of which are known and seven are newly reported herein. Moreover, we explored the mechanisms and causes behind this cyclic phenomenon, confirming cyanobacteria’s role as reliable indicators of environmental changes. This investigation further validates FDS’s effectiveness in detecting and characterizing cyanobacterial blooms and their associated toxins, expanding its potential applications.
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Sukenik, Assaf, Claudia Rosin, Ram Porat, Benjamin Teltsch, Roni Banker e Shmuel Carmeli. "TOXINS FROM CYANOBACTERIA AND THEIR POTENTIAL IMPACT ON WATER QUALITY OF LAKE KINNERET, ISRAEL". Israel Journal of Plant Sciences 46, n. 2 (13 maggio 1998): 109–15. http://dx.doi.org/10.1080/07929978.1998.10676717.
Testo completoAbstract (sommario):
A number of different species of cyanobacteria (blue-green algae) produce toxins of several different types. Cyanobacterial Wooms present a serious health concern when they occur in water bodies that supply potable water. Lake Kinneret, the major water source in Israel, was characterized for many years by relatively stable phytoplankton populations which fluctuated with the seasons in a quite predictable manner. An exceptional bloom of the filamentous cyanobacteriumAphanizomenon ovalisporum, which produces hepatotoxin, was observed for the first time in Lake Kinneret during the fall of 1994. Cylindrospermopsin, a toxin produced byA. ovalisporum, was purified and chemically characterized. The potential implications of cylindrospermopsin-producingA. ovalisporumbloom in Lake Kinneret on water quality is discussed, together with a general description of cyanobacterial toxins and their occurrence in natural waters.
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Ikehara, Tsuyoshi, Kyoko Kuniyoshi, Haruyo Yamaguchi, Yuuhiko Tanabe, Tomoharu Sano, Masahiro Yoshimoto, Naomasa Oshiro, Shihoko Nakashima e Mina Yasumoto-Hirose. "First Report of Microcystis Strains Producing MC-FR and -WR Toxins in Japan". Toxins 11, n. 9 (9 settembre 2019): 521. http://dx.doi.org/10.3390/toxins11090521.
Testo completoAbstract (sommario):
Microcystins (MCs) are a group of cyclic heptapeptide hepatotoxins produced by Microcystis and several other genera of cyanobacteria. Many structural variants have been characterized using various methods such as liquid chromatography–mass spectrometry (LC-MS) analysis, enzyme-linked immunosorbent assay (ELISA) and protein phosphatase 2A (PP2A) inhibition assay. The representative MC, MC-LR, and related cyanobacterial toxins strongly inhibit PP2A activity and can therefore be assayed by measuring the extent of PP2A inhibition. However, these methods require reference toxin standards for the quantification and identification of known MCs. To obtain various MC-producing cyanobacterial strains, we surveyed and collected MC-producing cyanobacteria from environmental sources of water in Okinawa, Japan. Using a dual assay (LC-MS analysis and PP2A inhibition assay), we identified and isolated Microcystis strains producing five MC variants (MC-LR, -RR, -LA, -FR and -WR). Approximately 4 mg of MC-WR and -FR toxins were purified from the laboratory culture of the Microcystis isolate NIES-4344. Pure MC-WR and -FR variants were prepared for future use as toxin standards in LC-MS analysis. Phylogenetic analysis based on ftsZ revealed that the NIES-4344 strain belongs to the identified groups in Microcystis aeruginosa. This is the first report of Microcystis strains producing mainly MC-WR and -FR toxins in Japan.
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Ballot, Andreas, Thida Swe, Marit Mjelde, Leonardo Cerasino, Vladyslava Hostyeva e Christopher O. Miles. "Cylindrospermopsin- and Deoxycylindrospermopsin-Producing Raphidiopsis raciborskii and Microcystin-Producing Microcystis spp. in Meiktila Lake, Myanmar". Toxins 12, n. 4 (7 aprile 2020): 232. http://dx.doi.org/10.3390/toxins12040232.
Testo completoAbstract (sommario):
Meiktila Lake is a shallow reservoir located close to Meiktila city in central Myanmar. Its water is used for irrigation, domestic purposes and drinking water. No detailed study of the presence of cyanobacteria and their potential toxin production has been conducted so far. To ascertain the cyanobacterial composition and presence of cyanobacterial toxins in Meiktila Lake, water samples were collected in March and November 2017 and investigated for physico-chemical and biological parameters. Phytoplankton composition and biomass determination revealed that most of the samples were dominated by the cyanobacterium Raphidiopsis raciborskii. In a polyphasic approach, seven isolated cyanobacterial strains were classified morphologically and phylogenetically as R. raciborskii, and Microcystis spp. and tested for microcystins (MCs), cylindrospermopsins (CYNs), saxitoxins and anatoxins by enzyme-linked immunosorbent assay (ELISA) and liquid chromatography–mass spectrometry (LC–MS). ELISA and LC–MS analyses confirmed CYNs in three of the five Raphidiopsis strains between 1.8 and 9.8 μg mg−1 fresh weight. Both Microcystis strains produced MCs, one strain 52 congeners and the other strain 20 congeners, including 22 previously unreported variants. Due to the presence of CYN- and MC-producing cyanobacteria, harmful effects on humans, domestic and wild animals cannot be excluded in Meiktila Lake.
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Ballot, Andreas, Morten Sandvik, Thomas Rundberget, Christo J. Botha e Christopher O. Miles. "Diversity of cyanobacteria and cyanotoxins in Hartbeespoort Dam, South Africa". Marine and Freshwater Research 65, n. 2 (2014): 175. http://dx.doi.org/10.1071/mf13153.
Testo completoAbstract (sommario):
The South African Hartbeespoort Dam is known for the occurrence of heavy Microcystis blooms. Although a few other cyanobacterial genera have been described, no detailed study on those cyanobacteria and their potential toxin production has been conducted. The diversity of cyanobacterial species and toxins is most probably underestimated. To ascertain the cyanobacterial composition and presence of cyanobacterial toxins in Hartbeespoort Dam, water samples were collected in April 2011. In a polyphasic approach, 27 isolated cyanobacterial strains were classified morphologically and phylogenetically and tested for microcystins (MCs), cylindrospermopsin (CYN), saxitoxins (STXs) and anatoxin-a (ATX) by liquid chromatography–tandem mass spectrometry (LC–MS/MS) and screened for toxin-encoding gene fragments. The isolated strains were identified as Sphaerospermopsis reniformis, Sphaerospermopsis aphanizomenoides, Cylindrospermopsis curvispora, Raphidiopsis curvata, Raphidiopsis mediterrranea and Microcystis aeruginosa. Only one of the Microcystis strains (AB2011/53) produced microcystins (35 variants). Forty-one microcystin variants were detected in the environmental sample from Hartbeespoort Dam, suggesting the existence of other microcystin producing strains in Hartbeespoort Dam. All investigated strains tested negative for CYN, STXs and ATX and their encoding genes. The mcyE gene of the microcystin gene cluster was found in the microcystin-producing Microcystis strain AB2011/53 and in eight non-microcystin-producing Microcystis strains, indicating that mcyE is not a good surrogate for microcystin production in environmental samples.
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Perri, Katherine A., Brent J. Bellinger, Matt P. Ashworth e Schonna R. Manning. "Environmental Factors Impacting the Development of Toxic Cyanobacterial Proliferations in a Central Texas Reservoir". Toxins 16, n. 2 (6 febbraio 2024): 91. http://dx.doi.org/10.3390/toxins16020091.
Testo completoAbstract (sommario):
Cyanobacterial harmful algal proliferations (cyanoHAPs) are increasingly associated with dog and livestock deaths when benthic mats break free of their substrate and float to the surface. Fatalities have been linked to neurotoxicosis from anatoxins, potent alkaloids produced by certain genera of filamentous cyanobacteria. After numerous reports of dog illnesses and deaths at a popular recreation site on Lady Bird Lake, Austin, Texas in late summer 2019, water and floating mat samples were collected from several sites along the reservoir. Water quality parameters were measured and mat samples were maintained for algal isolation and DNA identification. Samples were also analyzed for cyanobacterial toxins using LC-MS. Dihydroanatoxin-a was detected in mat materials from two of the four sites (0.6–133 ng/g wet weight) while water samples remained toxin-free over the course of the sampling period; no other cyanobacterial toxins were detected. DNA sequencing analysis of cyanobacterial isolates yielded a total of 11 genera, including Geitlerinema, Tyconema, Pseudanabaena, and Phormidium/Microcoleus, taxa known to produce anatoxins, including dihydroanatoxin, among other cyanotoxins. Analyses indicate that low daily upriver dam discharge, higher TP and NO3 concentrations, and day of the year were the main parameters associated with the presence of toxic floating cyanobacterial mats.
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Dao, Thanh-Son, Jorge Nimptsch e Claudia Wiegand. "Dynamics of cyanobacteria and cyanobacterial toxins and their correlation with environmental parameters in Tri An Reservoir, Vietnam". Journal of Water and Health 14, n. 4 (11 marzo 2016): 699–712. http://dx.doi.org/10.2166/wh.2016.257.
Testo completoAbstract (sommario):
This study evaluates the water quality from Tri An Reservoir, a drinking water supply for several million people in southern Vietnam, in terms of cyanobacterial biomass and their potent toxins, microcystins (MCs). Cyanobacteria, their toxins and environmental parameters were monitored monthly for 1 year (April 2008–March 2009) at six stations covering a transect through the reservoir. Dynamics of cyanobacterial abundance in relation to cyanobacterial biomass, toxins and environmental factors were investigated. Environmental variables from Tri An Reservoir favored algal and cyanobacterial development. However, cyanobacterial biomass and proportion varied widely, influenced by physical conditions, available nutrients and nutrient competition among the phytoplankton groups. Cyanobacterial biomass correlated slightly positively to temperature, pH and biochemical oxygen demand (BOD5), but negatively to total inorganic nitrogen concentrations. During most of the sampling times, MC concentrations in the reservoir were quite low (≤0.07 μg L−1 MC-LR equivalent), and presented a slight positive correlation to BOD5, total nitrogen:total phosphorus ratio and cyanobacterial biomass. However, in cyanobacterial scum samples, which now and then occurred in the reservoir, MC concentrations reached up to 640 μg g−1 DW−1. The occurrence of MC in the reservoir poses a risk to local residents who use the water daily for domestic purposes.
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Andeden, Enver Ersoy, Sahlan Ozturk e Belma Aslim. "Antiproliferative, neurotoxic, genotoxic and mutagenic effects of toxic cyanobacterial extracts". Interdisciplinary Toxicology 11, n. 4 (1 dicembre 2018): 267–74. http://dx.doi.org/10.2478/intox-2018-0026.
Testo completoAbstract (sommario):
Abstract Cyanobacteria are the rich resource of various secondary metabolites including toxins with broad pharmaceutical significance. The aim of this work was to evaluate the antiproliferative, neurotoxic, genotoxic and mutagenic effects of cyanobacterial extracts containing Microcystin-LR (MCLR) in vitro. ELISA analysis results showed that MCLR contents of five cyanobacterial extracts were 2.07 ng/mL, 1.43 ng/mL, 1.41 ng/mL, 1.27 ng/mL, and 1.12 ng/mL for Leptolyngbya sp. SB1, Phormidium sp. SB4, Oscillatoria earlei SB5, Phormidium sp. SB2, Uncultured cyanobacterium, respectively. Phormidium sp. SB4 and Phormidium sp. SB2 extracts had the lowest neurotoxicity (86% and 79% cell viability, respectively) and Oscillatoria earlei SB5 extracts had the highest neurotoxicity (47% cell viability) on PC12 cell at 1000 µg/ml extract concentration. Leptolyngbya sp. SB1 and Phormidium sp. SB2 showed the highest antiproliferative effect (92% and 77% cell death) on HT29 cell. On the other hand, all concentrations of five toxic cyanobacterial extracts induced DNA damage between 3.0% and 1.3% of tail intensity and did not cause any direct mutagenic effect at the 1000 µg/plate cyanobacterial extracts. These results suggest that cyanobacteria-derived MCLR is a promising candidate for development of effective agents against colon cancer.
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Everson, Sally, Larelle Fabbro, Susan Kinnear, Geoff Eaglesham e Paul Wright. "Distribution of the cyanobacterial toxins cylindrospermopsin and deoxycylindrospermopsin in a stratified lake in north-eastern New South Wales, Australia". Marine and Freshwater Research 60, n. 1 (2009): 25. http://dx.doi.org/10.1071/mf08115.
Testo completoAbstract (sommario):
This paper describes the vertical water column distribution of the cyanobacterial toxins cylindrospermopsin and deoxycylindrospermopsin in a water body containing the cyanobacteria Aphanizomenon ovalisporum and Cylindrospermopsis raciborskii. The study site was Cobaki Village Lake, a small stratified anthropogenic lake in north-eastern New South Wales, Australia. Water quality analysis indicated that stratification and oxygenation of the water column were significant in both the distribution of the cyanobacterial populations and their associated toxin concentrations. Toxin was distributed throughout the entire water column, but the highest concentrations were recorded in the hypolimnion. Maximum toxin concentrations were detected in February 2007 (38.2 μg L–1 cylindrospermopsin (CYN) and 42.2 μg L–1 deoxy-CYN). The relative distribution of CYN and deoxy-CYN paralleled the distribution of NH3H and NOX within the water column, with oxygenated chemical species dominating above 15 m and de-oxygenated chemical species dominating below 15 m. Cyanobacterial cell concentrations were highest in the oxic, warm and low conductivity waters of the epilimnion and cyanobacterial species succession was associated with nutrient and trace-metal depletion in this surface layer. These research findings are directly relevant to the management of water supplies affected by toxic blue-green algal blooms, particularly with respect to the considered placement of off-take devices to avoid layers of cyanobacterial cell and toxin concentrations.
23
Srivastava, Ankita, Chi-Yong Ahn, Ravi Kumar Asthana, Hyung-Gwan Lee e Hee-Mock Oh. "Status, Alert System, and Prediction of Cyanobacterial Bloom in South Korea". BioMed Research International 2015 (2015): 1–8. http://dx.doi.org/10.1155/2015/584696.
Testo completoAbstract (sommario):
Bloom-forming freshwater cyanobacterial genera pose a major ecological problem due to their ability to produce toxins and other bioactive compounds, which can have important implications in illnesses of humans and livestock. Cyanobacteria such asMicrocystis, Anabaena, Oscillatoria, Phormidium, andAphanizomenonspecies producing microcystins and anatoxin-a have been predominantly documented from most South Korean lakes and reservoirs. With the increase in frequency of such blooms, various monitoring approaches, treatment processes, and prediction models have been developed in due course. In this paper we review the field studies and current knowledge on toxin producing cyanobacterial species and ecological variables that regulate toxin production and bloom formation in major rivers (Han, Geum, Nakdong, and Yeongsan) and reservoirs in South Korea. In addition, development of new, fast, and high-throughput techniques for effective monitoring is also discussed with cyanobacterial bloom advisory practices, current management strategies, and their implications in South Korean freshwater bodies.
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Aráoz, Rómulo, Jordi Molgó e Nicole Tandeau de Marsac. "Neurotoxic cyanobacterial toxins". Toxicon 56, n. 5 (ottobre 2010): 813–28. http://dx.doi.org/10.1016/j.toxicon.2009.07.036.
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Khomutovska, Nataliia, Małgorzata Sandzewicz, Łukasz Łach, Małgorzata Suska-Malawska, Monika Chmielewska, Hanna Mazur-Marzec, Marta Cegłowska et al. "Limited Microcystin, Anatoxin and Cylindrospermopsin Production by Cyanobacteria from Microbial Mats in Cold Deserts". Toxins 12, n. 4 (11 aprile 2020): 244. http://dx.doi.org/10.3390/toxins12040244.
Testo completoAbstract (sommario):
Toxic metabolites are produced by many cyanobacterial species. There are limited data on toxigenic benthic, mat-forming cyanobacteria, and information on toxic cyanobacteria from Central Asia is even more scarce. In the present study, we examined cyanobacterial diversity and community structure, the presence of genes involved in toxin production and the occurrence of cyanotoxins in cyanobacterial mats from small water bodies in a cold high-mountain desert of Eastern Pamir. Diversity was explored using amplicon-based sequencing targeting the V3-V4 region of the 16S rRNA gene, toxin potential using PCR-based methods (mcy, nda, ana, sxt), and toxins by enzyme-linked immunosorbent assays (ELISAs) and liquid chromatography-tandem mass spectrometry (LC-MS/MS). Molecular identification of cyanobacteria showed a high similarity of abundant taxa to Nostoc PCC-73102, Nostoc PCC-7524, Nodularia PCC-935 and Leptolyngbya CYN68. The PCRs revealed the presence of mcyE and/or ndaF genes in 11 samples and mcyD in six. The partial sequences of the mcyE gene showed high sequence similarity to Nostoc, Planktothrix and uncultured cyanobacteria. LC-MS/MS analysis identified six microcystin congeners in two samples and unknown peptides in one. These results suggest that, in this extreme environment, cyanobacteria do not commonly produce microcystins, anatoxins and cylindrospermopsins, despite the high diversity and widespread occurrence of potentially toxic taxa.
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Shaw, G., e P. K. S. Lam. "Health aspects of freshwater cyanobacterial toxins". Water Supply 7, n. 2 (1 luglio 2007): 193–203. http://dx.doi.org/10.2166/ws.2007.054.
Testo completoAbstract (sommario):
Cyanobacterial (blue-green algal) toxins are known to cause poisoning in humans, livestock and wild animals. Based on their toxic mechanisms, cyanobacterial toxins are generally categorized as neurotoxins, hepatotoxins or cytotoxins. The acute oral toxicities of these toxins vary substantially, with the saxitoxins being the most toxic having an LD50 of 60 μg/kg. By comparison, the acute oral LD50 for microcystin LR (the most toxic congener) and cylindrospermopsin are approximately 5,000 to 10,000 μg/kg and 6,000 μg/kg over 5 days, respectively. There are well known adverse health issues of cyanobacterial toxin poisonings. The most serious health consequences have occurred in Brazil with the reported deaths of people from gastrointestinal symptoms associated with exposure to microcystins and cylindrospermopsin. Increased number of symptoms has also been reported via exposure to cyanobacterial toxins through water-based recreational activities. Toxins may also be present in drinking water and thus guideline values are necessary to protect the health of the population. Guideline values are available for microcystins but not for saxitoxins, cylindrospermopsin or deoxycylindrospermopsin. Considerable research is being undertaken currently on more fully understanding the mechanisms of toxicity of cylindrospermopsin to enable relevant guidelines to be established.
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Moradinejad, Saber, Hana Trigui, Juan Francisco Guerra Maldonado, Jesse Shapiro, Yves Terrat, Arash Zamyadi, Sarah Dorner e Michèle Prévost. "Diversity Assessment of Toxic Cyanobacterial Blooms during Oxidation". Toxins 12, n. 11 (20 novembre 2020): 728. http://dx.doi.org/10.3390/toxins12110728.
Testo completoAbstract (sommario):
Fresh-water sources of drinking water are experiencing toxic cyanobacterial blooms more frequently. Chemical oxidation is a common approach to treat cyanobacteria and their toxins. This study systematically investigates the bacterial/cyanobacterial community following chemical oxidation (Cl2, KMnO4, O3, H2O2) using high throughput sequencing. Raw water results from high throughput sequencing show that Proteobacteria, Actinobacteria, Cyanobacteria and Bacteroidetes were the most abundant phyla. Dolichospermum, Synechococcus, Microcystis and Nostoc were the most dominant genera. In terms of species, Dolichospermum sp.90 and Microcystis aeruginosa were the most abundant species at the beginning and end of the sampling, respectively. A comparison between the results of high throughput sequencing and taxonomic cell counts highlighted the robustness of high throughput sequencing to thoroughly reveal a wide diversity of bacterial and cyanobacterial communities. Principal component analysis of the oxidation samples results showed a progressive shift in the composition of bacterial/cyanobacterial communities following soft-chlorination with increasing common exposure units (CTs) (0–3.8 mg·min/L). Close cyanobacterial community composition (Dolichospermum dominant genus) was observed following low chlorine and mid-KMnO4 (287.7 mg·min/L) exposure. Our results showed that some toxin producing species may persist after oxidation whether they were dominant species or not. Relative persistence of Dolichospermum sp.90 was observed following soft-chlorination (0.2–0.6 mg/L) and permanganate (5 mg/L) oxidation with increasing oxidant exposure. Pre-oxidation using H2O2 (10 mg/L and one day contact time) caused a clear decrease in the relative abundance of all the taxa and some species including the toxin producing taxa. These observations suggest selectivity of H2O2 to provide an efficient barrier against toxin producing cyanobacteria entering a water treatment plant.
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BITTENCOURT-OLIVEIRA, MARIA DO CARMO, VIVIANE PICCIN-SANTOS, ARIADNE N. MOURA, NÍSIA K. C. ARAGÃO-TAVARES e MICHELINE K. CORDEIRO-ARAÚJO. "Cyanobacteria, microcystins and cylindrospermopsin in public drinking supply reservoirs of Brazil". Anais da Academia Brasileira de Ciências 86, n. 1 (marzo 2014): 297–310. http://dx.doi.org/10.1590/0001-3765201302512.
Testo completoAbstract (sommario):
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.
29
Miller, M. J., e H. J. Fallowfield. "Degradation of cyanobacterial hepatotoxins in batch experiments". Water Science and Technology 43, n. 12 (1 giugno 2001): 229–32. http://dx.doi.org/10.2166/wst.2001.0745.
Testo completoAbstract (sommario):
Bank filtration offers a cost effective and low maintenance technique for the removal of cyanobacterial hepatotoxins from drinking water. For bank filtration to be effective, the toxins must be degraded. The broad aim of this research was to determine whether the hepatotoxins, nodularin and microcystin-LR, could be completely removed from the soil/water matrix of three soils by microbial degradation. The results indicated that complete toxin removal was possible within 10-16 d in 2/3 soils that were incubated in the dark at 20°C. The soils with the highest organic carbon content (2.9%) and the highest clay content (16.1%) were the most effective at removing the toxins in batch experiments. However, the sandy soil (98.5% sand) was incapable of degrading either toxin. The half-lives of toxin losses due to adsorption, desorption and degradation were calculated and for all soils. The degradation process had the highest half-life for both toxins. This suggested that degradation was likely to be the rate-limiting step of complete toxin removal. It was concluded that when a bank filtration site was being chosen, the degradation potential and the textural properties of the riverbank soil would be important when considering complete removal of cyanobacterial hepatotoxins.
30
Mantzouki, Evanthia, Miquel Lürling, Jutta Fastner, Lisette De Senerpont Domis, Elżbieta Wilk-Woźniak, Judita Koreivienė, Laura Seelen et al. "Temperature Effects Explain Continental Scale Distribution of Cyanobacterial Toxins". Toxins 10, n. 4 (13 aprile 2018): 156. http://dx.doi.org/10.3390/toxins10040156.
Testo completoAbstract (sommario):
Insight into how environmental change determines the production and distribution of cyanobacterial toxins is necessary for risk assessment. Management guidelines currently focus on hepatotoxins (microcystins). Increasing attention is given to other classes, such as neurotoxins (e.g., anatoxin-a) and cytotoxins (e.g., cylindrospermopsin) due to their potency. Most studies examine the relationship between individual toxin variants and environmental factors, such as nutrients, temperature and light. In summer 2015, we collected samples across Europe to investigate the effect of nutrient and temperature gradients on the variability of toxin production at a continental scale. Direct and indirect effects of temperature were the main drivers of the spatial distribution in the toxins produced by the cyanobacterial community, the toxin concentrations and toxin quota. Generalized linear models showed that a Toxin Diversity Index (TDI) increased with latitude, while it decreased with water stability. Increases in TDI were explained through a significant increase in toxin variants such as MC-YR, anatoxin and cylindrospermopsin, accompanied by a decreasing presence of MC-LR. While global warming continues, the direct and indirect effects of increased lake temperatures will drive changes in the distribution of cyanobacterial toxins in Europe, potentially promoting selection of a few highly toxic species or strains.
31
Thawabteh, Amin Mahmood, Hani A. Naseef, Donia Karaman, Sabino A. Bufo, Laura Scrano e Rafik Karaman. "Understanding the Risks of Diffusion of Cyanobacteria Toxins in Rivers, Lakes, and Potable Water". Toxins 15, n. 9 (20 settembre 2023): 582. http://dx.doi.org/10.3390/toxins15090582.
Testo completoAbstract (sommario):
Blue-green algae, or cyanobacteria, may be prevalent in our rivers and tap water. These minuscule bacteria can grow swiftly and form blooms in warm, nutrient-rich water. Toxins produced by cyanobacteria can pollute rivers and streams and harm the liver and nervous system in humans. This review highlights the properties of 25 toxin types produced by 12 different cyanobacteria genera. The review also covered strategies for reducing and controlling cyanobacteria issues. These include using physical or chemical treatments, cutting back on fertilizer input, algal lawn scrubbers, and antagonistic microorganisms for biocontrol. Micro-, nano- and ultrafiltration techniques could be used for the removal of internal and extracellular cyanotoxins, in addition to powdered or granular activated carbon, ozonation, sedimentation, ultraviolet radiation, potassium permanganate, free chlorine, and pre-treatment oxidation techniques. The efficiency of treatment techniques for removing intracellular and extracellular cyanotoxins is also demonstrated. These approaches aim to lessen the risks of cyanobacterial blooms and associated toxins. Effective management of cyanobacteria in water systems depends on early detection and quick action. Cyanobacteria cells and their toxins can be detected using microscopy, molecular methods, chromatography, and spectroscopy. Understanding the causes of blooms and the many ways for their detection and elimination will help the management of this crucial environmental issue.
32
Barney, Rachael E., Guohong Huang, Torrey L. Gallagher, Maeve Tischbein, John DeWitt, Rachel Martindale, Ethan M. P. LaRochelle, Gregory J. Tsongalis e Elijah W. Stommel. "Validation of a Droplet Digital PCR (ddPCR) Assay to Detect Cyanobacterial 16S rDNA in Human Lung Tissue". Toxics 11, n. 6 (14 giugno 2023): 531. http://dx.doi.org/10.3390/toxics11060531.
Testo completoAbstract (sommario):
Cyanobacteria produce a variety of secondary metabolites, including toxins that may contribute to the development of disease. Previous work was able to detect the presence of a cyanobacterial marker in human nasal and broncoalveolar lavage samples; however, it was not able to determine the quantification of the marker. To further research the relationship between cyanobacteria and human health, we validated a droplet digital polymerase chain reaction (ddPCR) assay to simultaneously detect the cyanobacterial 16S marker and a human housekeeping gene in human lung tissue samples. The ability to detect cyanobacteria in human samples will allow further research into the role cyanobacteria plays in human health and disease.
33
Berg, Katri A., Christina Lyra, R. Maarit Niemi, Benoit Heens, Kalle Hoppu, Kirsti Erkomaa, Kaarina Sivonen e Jarkko Rapala. "Virulence genes of Aeromonas isolates, bacterial endotoxins and cyanobacterial toxins from recreational water samples associated with human health symptoms". Journal of Water and Health 9, n. 4 (22 giugno 2011): 670–79. http://dx.doi.org/10.2166/wh.2011.206.
Testo completoAbstract (sommario):
Exposure to cyanobacterial water blooms has been associated with various kinds of adverse health effects. In addition to cyanobacteria and their toxins, the bacteria associated with cyanobacteria could also be the etiological agents. We isolated Aeromonas strains (n = 176) from water samples (n = 38) taken from sites where cyanobacteria were suspected to have caused human health symptoms, of which fever and gastrointestinal symptoms were the most common. The isolates were screened by PCR for six virulence gene types (12 genes). The majority (90%) of the strains contained at least one of the virulence genes. Most common amplification products were those of genes (act/aerA/hlyA) that encode cytotoxic enterotoxin and haemolytic products. The genes encoding cytotonic enterotoxins (ast and alt), phospholipase (lip/pla/lipH3/alp-1), elastase (ahyB) and flagellin subunits (flaA/flaB) were also present in 5–37% of the Aeromonas strains. Analysed toxins (cyanobacterial hepatotoxins and neurotoxins, and bacterial endotoxins) were not detectable or were present in only low concentrations in the majority of the samples. The results indicated that the toxins were unlikely to be the main cause of the reported adverse health effects, whereas more attention should be paid to bacteria associated with cyanobacteria as a source of health effects.
34
Florczyk, Maciej, Alicja Łakomiak, Maciej Woźny e Paweł Brzuzan. "Neurotoxicity of cyanobacterial toxins". Environmental Biotechnology 10, n. 1 (2014): 26–43. http://dx.doi.org/10.14799/ebms246.
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35
Mash, Deborah C. "CYANOBACTERIAL TOXINS IN NEURODEGENERATION". CONTINUUM: Lifelong Learning in Neurology 14 (ottobre 2008): 138–49. http://dx.doi.org/10.1212/01.con.0000337997.85667.1f.
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MOORE, R. E., I. OHTANI, B. S. MOORE, C. B. DE KONING, W. Y. YOSHIDA, M. T. C. RUNNEGAR e W. W. CARMICHAEL. "ChemInform Abstract: Cyanobacterial Toxins". ChemInform 24, n. 46 (20 agosto 2010): no. http://dx.doi.org/10.1002/chin.199346241.
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37
Matuszak, Piotr, Grzegorz Grodzicki, Tomasz Jankowski e Paweł Matlakiewicz. "Biomonitoring of Inland and Inshore Waters with Use of Dreissena Polymorpha Mussels". Polish Hyperbaric Research 52, n. 3 (1 settembre 2015): 49–53. http://dx.doi.org/10.1515/phr-2015-0016.
Testo completoAbstract (sommario):
Abstract The pollution of water that is used for consumption and in agricultural holdings contributes to an increased mortality rate, inhibition of growth and physiological functions, changes in the DNA (genotoxicity), changes within tissues (cytotoxicity) and organs of individuals who are exposed to chemical components. One of the most dangerous toxin classes which have effect on animals and humans who come into contact with contaminated water is the class of cyanobacterial toxins released by dying cyanobacteria. They contribute to very serious health conditions and also to fatalities. Toxins of this type are relatively difficult to detect on account of their seasonal changeability in blooming. One of the most effective methods of detecting water contamination automatically and continuously is biomonitoring with the use of Dreissena polymorpha mussels.
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Garamszegi, Susanna P., Daniel J. Brzostowicki, Thomas M. Coyne, Regina T. Vontell e David A. Davis. "TDP-43 and Alzheimer’s Disease Pathology in the Brain of a Harbor Porpoise Exposed to the Cyanobacterial Toxin BMAA". Toxins 16, n. 1 (12 gennaio 2024): 42. http://dx.doi.org/10.3390/toxins16010042.
Testo completoAbstract (sommario):
Cetaceans are well-regarded as sentinels for toxin exposure. Emerging studies suggest that cetaceans can also develop neuropathological changes associated with neurodegenerative disease. The occurrence of neuropathology makes cetaceans an ideal species for examining the impact of marine toxins on the brain across the lifespan. Here, we describe TAR DNA-binding protein 43 (TDP-43) proteinopathy and Alzheimer’s disease (AD) neuropathological changes in a beached harbor porpoise (Phocoena phocoena) that was exposed to a toxin produced by cyanobacteria called β-N-methylamino-L-alanine (BMAA). We found pathogenic TDP-43 cytoplasmic inclusions in neurons throughout the cerebral cortex, midbrain and brainstem. P62/sequestosome-1, responsible for the autophagy of misfolded proteins, was observed in the amygdala, hippocampus and frontal cortex. Genes implicated in AD and TDP-43 neuropathology such as APP and TARDBP were expressed in the brain. AD neuropathological changes such as amyloid-β plaques, neurofibrillary tangles, granulovacuolar degeneration and Hirano bodies were present in the hippocampus. These findings further support the development of progressive neurodegenerative disease in cetaceans and a potential causative link to cyanobacterial toxins. Climate change, nutrient pollution and industrial waste are increasing the frequency of harmful cyanobacterial blooms. Cyanotoxins like BMAA that are associated with neurodegenerative disease pose an increasing public health risk.
39
Rajkonwar, Jadab, Ajitabh Bora, Pichili Vijaya Bhaskar Reddy e Sanjai Kumar Dwivedi. "Occurrence of Toxigenic Microcystis spp in Major Water Bodies of North East India". Defence Life Science Journal 5, n. 2 (8 aprile 2020): 87–92. http://dx.doi.org/10.14429/dlsj.5.15596.
Testo completoAbstract (sommario):
Toxigenic cyanobacterial blooms in the water bodies represent a major ecological problem around the world. Some species produces a diverse range of toxins that have hepatotoxic, neurotoxic, cytotoxic and dermatoxic activity and hence have deleterious effect on humans, animals and fishes leading to death as well. Cultural eutrophication of water bodies leads to increased incidence of these harmful cyanobacterial blooms worldwide. North-East India being a biodiversity hotspot harbor many species of cyanobacteria. Few reports suggested presence of few toxigenic cyanobacteria in the water bodies of Assam, but no systematic studies have been undertaken to evaluate their toxicity. This work is being conducted to gather information on major toxigenic cyanobacteria, with special emphasis to microcystin (a cyclic heptapeptides with high acute and chronic toxicities to humans and animals) producing strains. Water samples have been collected from few water bodies of North-East and enriched in specific media. The toxin Microcystin was detected using specific ELISA kit and positive results have been obtained. Further, 16s rDNA sequencing was employed for molecular identification of the strains.
40
Larsen, Megan L., Helen M. Baulch, Sherry L. Schiff, Dana F. Simon, Sébastien Sauvé e Jason J. Venkiteswaran. "Extreme rainfall drives early onset cyanobacterial bloom". FACETS 5, n. 1 (1 gennaio 2020): 899–920. http://dx.doi.org/10.1139/facets-2020-0022.
Testo completoAbstract (sommario):
The increasing prevalence of cyanobacteria-dominated harmful algal blooms is strongly associated with nutrient loading and changing climatic patterns. Changes to precipitation frequency and intensity, as predicted by current climate models, are likely to affect bloom development and composition through changes in nutrient fluxes and water column mixing. However, few studies have directly documented the effects of extreme precipitation events on cyanobacterial composition, biomass, and toxin production. We tracked changes in a eutrophic reservoir following an extreme precipitation event, describing an atypically early toxin-producing cyanobacterial bloom and successional progression of the phytoplankton community, toxins, and geochemistry. An increase in bioavailable phosphorus by more than 27-fold in surface waters preceded notable increases in Aphanizomenon flos-aquae throughout the reservoir approximately 2 weeks postevent and ∼5 weeks before blooms typically occur. Anabaenopeptin-A and three microcystin congeners (microcystin-LR, -YR, and -RR) were detected at varying levels across sites during the bloom period, which lasted between 3 and 5 weeks. These findings suggest extreme rainfall can trigger early cyanobacterial bloom initiation, effectively elongating the bloom season period of potential toxicity. However, effects will vary depending on factors including the timing of rainfall and reservoir physical structure.
41
Nugumanova, Galina, Eugene D. Ponomarev, Sholpan Askarova, Elizaveta Fasler-Kan e Natasha S. Barteneva. "Freshwater Cyanobacterial Toxins, Cyanopeptides and Neurodegenerative Diseases". Toxins 15, n. 3 (21 marzo 2023): 233. http://dx.doi.org/10.3390/toxins15030233.
Testo completoAbstract (sommario):
Cyanobacteria produce a wide range of structurally diverse cyanotoxins and bioactive cyanopeptides in freshwater, marine, and terrestrial ecosystems. The health significance of these metabolites, which include genotoxic- and neurotoxic agents, is confirmed by continued associations between the occurrence of animal and human acute toxic events and, in the long term, by associations between cyanobacteria and neurodegenerative diseases. Major mechanisms related to the neurotoxicity of cyanobacteria compounds include (1) blocking of key proteins and channels; (2) inhibition of essential enzymes in mammalian cells such as protein phosphatases and phosphoprotein phosphatases as well as new molecular targets such as toll-like receptors 4 and 8. One of the widely discussed implicated mechanisms includes a misincorporation of cyanobacterial non-proteogenic amino acids. Recent research provides evidence that non-proteinogenic amino acid BMAA produced by cyanobacteria have multiple effects on translation process and bypasses the proof-reading ability of the aminoacyl-tRNA-synthetase. Aberrant proteins generated by non-canonical translation may be a factor in neuronal death and neurodegeneration. We hypothesize that the production of cyanopeptides and non-canonical amino acids is a more general mechanism, leading to mistranslation, affecting protein homeostasis, and targeting mitochondria in eukaryotic cells. It can be evolutionarily ancient and initially developed to control phytoplankton communities during algal blooms. Outcompeting gut symbiotic microorganisms may lead to dysbiosis, increased gut permeability, a shift in blood-brain-barrier functionality, and eventually, mitochondrial dysfunction in high-energy demanding neurons. A better understanding of the interaction between cyanopeptides metabolism and the nervous system will be crucial to target or to prevent neurodegenerative diseases.
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Pomati, Francesco, Carlo Rossetti, Gianluca Manarolla, Brendan P. Burns e Brett A. Neilan. "Interactions between intracellular Na+ levels and saxitoxin production in Cylindrospermopsis raciborskii T3". Microbiology 150, n. 2 (1 febbraio 2004): 455–61. http://dx.doi.org/10.1099/mic.0.26350-0.
Testo completoAbstract (sommario):
Saxitoxin (STX) is the most potent representative among the paralytic shellfish poisoning (PSP) toxins, which are highly selective Na+ channel-blocking alkaloids. This study investigated, in cultures of the cyanobacterium Cylindrospermopsis raciborskii T3, the effects of pH, salt, amiloride and lidocaine hydrochloride on total cellular levels of Na+ and K+ ions and STX accumulation. Both Na+ levels and intracellular STX concentrations increased exponentially in response to rising alkalinity. NaCl inhibited cyanobacterial growth at a concentration of 10 mM. In comparison with osmotically stressed controls, however, NaCl promoted STX accumulation in a dose-dependent manner. A correlation was seen in the time-course of both total cellular Na+ levels and intracellular STX for NaCl, amiloride and lidocaine exposure. The increase in cellular Na+ induced by NaCl at 10 mM was coupled with a proportional accumulation of STX. The two Na+ channel-blocking agents amiloride and lidocaine had opposing effects on both cellular Na+ levels and STX accumulation. Amiloride at 1 mM reduced ion and toxin concentrations, while lidocaine at 1 μM increased the total cellular Na+ and STX levels. The effects of the channel-blockers were antagonistic and dependent on an alkaline pH. The results presented suggest that, in C. raciborskii T3, STX is responsive to cellular Na+ levels. This may indicate that either STX metabolism or the toxin itself could be linked to the maintenance of cyanobacterial homeostasis. The results also enhance the understanding of STX production and the ecology of PSP toxin-producing cyanobacteria.
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Kleinteich, J., F. Hildebrand, S. A. Wood, S. Ciŕs, R. Agha, A. Quesada, D. A. Pearce, P. Convey, F. C. K̈pper e D. R. Dietrich. "Diversity of toxin and non-toxin containing cyanobacterial mats of meltwater ponds on the Antarctic Peninsula: a pyrosequencing approach". Antarctic Science 26, n. 5 (14 maggio 2014): 521–32. http://dx.doi.org/10.1017/s0954102014000145.
Testo completoAbstract (sommario):
AbstractDespite their pivotal role as primary producers, there is little information as to the diversity and physiology of cyanobacteria in the meltwater ecosystems of polar regions. Thirty cyanobacterial mats from Adelaide Island, Antarctica were investigated using 16S rRNA gene pyrosequencing and automated ribosomal intergenic spacer analysis, and screened for cyanobacterial toxins using molecular and chemical approaches. A total of 274 operational taxonomic units (OTUs) were detected. The richness ranged between 8 and 33 cyanobacterial OTUs per sample, reflecting a high mat diversity. Leptolyngbya and Phormidium (c. 55% and 37% of the OTUs per mat) were dominant. Cyanobacterial community composition was similar between mats, particularly those obtained from closely adjacent locations. The cyanotoxin microcystin was detected in 26 of 27 mats (10–300 ng g-1 organic mass), while cylindrospermopsin, detected for the first time in Antarctica, was present in 21 of 30 mats (2–156 ng g-1 organic mass). The latter was confirmed via liquid chromatography-mass spectrometry and by the presence of the cyrAB and cyrJ genes. This study demonstrates the usefulness of pyrosequencing for characterizing diverse cyanobacterial communities, and confirms that cyanobacteria from extreme environments produce a similar range of cyanotoxins as their temperate counterparts.
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Thuduhena, Anjana Chamilka. "The HARMFUL CYANOBACTERIAL BLOOMS AND DEVELOPED CYANOPHAGES AS A BIOLOGICAL SOLUTION". Bacterial Empire 2, n. 1 (14 gennaio 2019): 6. http://dx.doi.org/10.36547/be.2019.2.1.6-9.
Testo completoAbstract (sommario):
Abstract
Cyanobacterial Harmful Algal blooms (CHABs) cause devastating impacts to fisheries, tourism, public health and ecosystem around the world, and have increased in frequency. Cyanobacterial blooms occur in fresh water and marine environments, producing a variety of toxins, and poisoning risks to humans and animals. Chemicals can be used to kill cyanobacteria. Unfortunately, many of these chemicals are toxic to other forms of life, including fish and organisms they eat. The use of chemicals in natural lakes could create more problems than they solve, is not permitted. Cyanophage is a double-stranded DNA virus that infects cyanobacteria and is detected in both freshwater and marine environments as a biological solution developed Cyanophages can use for long term treatment options.
Key words: Cyanobacterial Harmful Algal blooms, Cyanophage, DNA Viruses
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Metcalf, James S., Maeve Tischbein, Paul Alan Cox e Elijah W. Stommel. "Cyanotoxins and the Nervous System". Toxins 13, n. 9 (16 settembre 2021): 660. http://dx.doi.org/10.3390/toxins13090660.
Testo completoAbstract (sommario):
Cyanobacteria are capable of producing a wide range of bioactive compounds with many considered to be toxins. Although there are a number of toxicological outcomes with respect to cyanobacterial exposure, this review aims to examine those which affect the central nervous system (CNS) or have neurotoxicological properties. Such exposures can be acute or chronic, and we detail issues concerning CNS entry, detection and remediation. Exposure can occur through a variety of media but, increasingly, exposure through air via inhalation may have greater significance and requires further investigation. Even though cyanobacterial toxins have traditionally been classified based on their primary mode of toxicity, increasing evidence suggests that some also possess neurotoxic properties and include known cyanotoxins and unknown compounds. Furthermore, chronic long-term exposure to these compounds is increasingly being identified as adversely affecting human health.
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Young, Ian, J. Johanna Sanchez, Fatih Sekerciouglu, Binyam N. Desta, Claire Holeton, Dylan Lyng, Victoria Peczulis, Shane Renwick, Teresa Brooks e Jordan Tustin. "Burden of recreational water illness due to exposure to cyanobacteria and their toxins in freshwater beaches in Canada: protocol of a prospective cohort study". BMJ Open 14, n. 6 (giugno 2024): e085406. http://dx.doi.org/10.1136/bmjopen-2024-085406.
Testo completoAbstract (sommario):
IntroductionCyanobacterial blooms are increasingly common in freshwater sources used for swimming and other recreational water contact activities in Canada. Many species of cyanobacteria can produce toxins that affect human and animal health, but there are limited data on the risk of illness associated with water contact at impacted beaches.Methods and analysisThis study will investigate the incidence of recreational water illness due to exposure to cyanobacterial blooms and their toxins in four targeted and popular freshwater beaches in Ontario, Manitoba and Nova Scotia, Canada. A prospective cohort design and One Health approach will be used. On-site recruitment of recreational water users will be conducted at two beaches per year during the summers of 2024 and 2025. The population of interest includes recreational water users of any age and their pet dogs. After enrolment, an in-person survey will determine beach exposures and confounding factors, and a 3-day follow-up survey will ascertain any acute illness outcomes experienced by participants or their dogs. The target sample size is 2500 recreational water users. Water samples will be taken each recruitment day and analysed for cyanobacterial indicators (pigments), cell counts and toxin levels. Bayesian regression analysis will be conducted to estimate the association with water contact, cyanobacterial levels and risks of different acute illness outcomes.Ethics and disseminationThis study has been approved by the Toronto Metropolitan University Research Ethics Board (REB 2023-461). Study results will be published in a peer-reviewed journal and as infographics on a project website.
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Rhoades, Jonathan, Stamatia Fotiadou, Georgia Paschalidou, Theodoti Papadimitriou, Avelino Álvarez Ordóñez, Konstantinos Kormas, Elisabeth Vardaka e Eleni Likotrafiti. "Microbiota and Cyanotoxin Content of Retail Spirulina Supplements and Spirulina Supplemented Foods". Microorganisms 11, n. 5 (30 aprile 2023): 1175. http://dx.doi.org/10.3390/microorganisms11051175.
Testo completoAbstract (sommario):
Cyanobacterial biomass such as spirulina (Arthrospira spp.) is widely available as a food supplement and can also be added to foods as a nutritionally beneficial ingredient. Spirulina is often produced in open ponds, which are vulnerable to contamination by various microorganisms, including some toxin-producing cyanobacteria. This study examined the microbial population of commercially available spirulina products including for the presence of cyanobacterial toxins. Five products (two supplements, three foods) were examined. The microbial populations were determined by culture methods, followed by identification of isolates using matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF), and by 16S rRNA amplicon sequencing of the products themselves and of the total growth on the enumeration plates. Toxin analysis was carried out by enzyme-linked immunosorbent assay (ELISA). Several potentially pathogenic bacteria were detected in the products, including Bacillus cereus and Klebsiella pneumoniae. Microcystin toxins were detected in all the products at levels that could lead to consumers exceeding their recommended daily limits. Substantial differences were observed in the identifications obtained using amplicon sequencing and MALDI-TOF, particularly between closely related Bacillus spp. The study showed that there are microbiological safety issues associated with commercial spirulina products that should be addressed, and these are most likely associated with the normal means of production in open ponds.
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Spoof, Lisa, Sauli Jaakkola, Tamara Važić, Kerstin Häggqvist, Terhi Kirkkala, Anne-Mari Ventelä, Teija Kirkkala, Zorica Svirčev e Jussi Meriluoto. "Elimination of cyanobacteria and microcystins in irrigation water—effects of hydrogen peroxide treatment". Environmental Science and Pollution Research 27, n. 8 (6 gennaio 2020): 8638–52. http://dx.doi.org/10.1007/s11356-019-07476-x.
Testo completoAbstract (sommario):
AbstractCyanobacterial blooms pose a risk to wild and domestic animals as well as humans due to the toxins they may produce. Humans may be subjected to cyanobacterial toxins through many routes, e.g., by consuming contaminated drinking water, fish, and crop plants or through recreational activities. In earlier studies, cyanobacterial cells have been shown to accumulate on leafy plants after spray irrigation with cyanobacteria-containing water, and microcystin (MC) has been detected in the plant root system after irrigation with MC-containing water. This paper reports a series of experiments where lysis of cyanobacteria in abstracted lake water was induced by the use of hydrogen peroxide and the fate of released MCs was followed. The hydrogen peroxide–treated water was then used for spray irrigation of cultivated spinach and possible toxin accumulation in the plants was monitored. The water abstracted from Lake Köyliönjärvi, SW Finland, contained fairly low concentrations of intracellular MC prior to the hydrogen peroxide treatment (0.04 μg L−1 in July to 2.4 μg L−1 in September 2014). Hydrogen peroxide at sufficient doses was able to lyse cyanobacteria efficiently but released MCs were still present even after the application of the highest hydrogen peroxide dose of 20 mg L−1. No traces of MC were detected in the spinach leaves. The viability of moving phytoplankton and zooplankton was also monitored after the application of hydrogen peroxide. Hydrogen peroxide at 10 mg L−1 or higher had a detrimental effect on the moving phytoplankton and zooplankton.
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Vilar, Mauro C. P., Thiago F. C. P. Rodrigues, Luan O. Silva, Ana Beatriz F. Pacheco, Aloysio S. Ferrão-Filho e Sandra M. F. O. Azevedo. "Ecophysiological Aspects and sxt Genes Expression Underlying Induced Chemical Defense in STX-Producing Raphidiopsis raciborskii (Cyanobacteria) against the Zooplankter Daphnia gessneri". Toxins 13, n. 6 (8 giugno 2021): 406. http://dx.doi.org/10.3390/toxins13060406.
Testo completoAbstract (sommario):
Cyanobacteria stand out among phytoplankton when they form massive blooms and produce toxins. Because cyanotoxin genes date to the origin of metazoans, the hypothesis that cyanotoxins function as a defense against herbivory is still debated. Although their primary cellular function might vary, these metabolites could have evolved as an anti-predator response. Here we evaluated the physiological and molecular responses of a saxitoxin-producing Raphidiopsis raciborskii to infochemicals released by the grazer Daphnia gessneri. Induced chemical defenses were evidenced in R. raciborskii as a significant increase in the transcription level of sxt genes, followed by an increase in saxitoxin content when exposed to predator cues. Moreover, cyanobacterial growth decreased, and no significant effects on photosynthesis or morphology were observed. Overall, the induced defense response was accompanied by a trade-off between toxin production and growth. These results shed light on the mechanisms underlying zooplankton–cyanobacteria interactions in aquatic food webs. The widespread occurrence of the cyanobacterium R. raciborskii in freshwater bodies has been attributed to its phenotypic plasticity. Assessing the potential of this species to thrive over interaction filters such as zooplankton grazing pressure can enhance our understanding of its adaptive success.
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Wilk-Woźniak, Elżbieta. "An introduction to the 'micronet' of cyanobacterial harmful algal blooms (CyanoHABs): cyanobacteria, zooplankton and microorganisms: a review". Marine and Freshwater Research 71, n. 5 (2020): 636. http://dx.doi.org/10.1071/mf18378.
Testo completoAbstract (sommario):
Cyanobacterial harmful algal blooms are known all around the world. Climate change (temperature increase) and human activity (eutrophication) are factors that promote the proliferation of cyanobacteria, leading to the development of blooms and the release of toxins. Abiotic and biotic factors are responsible for the development of blooms and how long they last. Although the abiotic factors controlling blooms are well known, knowledge of biotic factors and their interactions is still lacking. This paper reviews five levels of biotic interactions, namely cyanobacteria–zooplankton, cyanobacteria–ciliates, cyanobacteria–bacteria, cyanobacteria–viruses and cyanobacteria–fungi, showing a more complex food web network than was previously thought. New findings published recently, such as the relationships between cyanobacteria and viruses or cyanobacteria and fungi, indicate that cyanobacterial blooms are not the end of the cycle of events taking place in water habitats, but rather the middle of them. As such, a new approach needs to consider mutual connections, genetic response, horizontal gene transfer and non-linear flow of carbon.