Toxic cyanobacteria

Public concern about the abundance of algae, and of the toxic cyanobacteria in particular, was raised by events in the UK in the summer of 1989 which involved the deaths of dogs and sheep at Rutland Water, Leicestershire, and the acute... 

In this way, the near-linear chlorophyll-phosphorus relationship in lakes depends upon the outcome of a large number of interactive processes occurring in each one of the component systems in the model. One of the most intriguing aspects of those components is that the chlorophyll models do not need to take account of the species composition of the phytoplankton in which chlorophyll is a constituent. The development of blooms of potentially toxic cyanobacteria is associated with eutrophication and phosphorus concentration, yet it is not apparent that the yield of cyanobacterial biomass requires any more mass-specific contribution from phosphorus. The explanation for this paradox is not well understood, but it is extremely important to understand that it is a matter of dynamics. The bloom-forming cyanobacteria are among the slowest-growing and most light-sensitive members of the phytoplankton. ... 

S. -Z. Yu, in Toxic Cyanobacteria Current Status of Research and Management, proeeedings of an... 

In vitro cytotoxicity assays using isolated cells have been applied intermittently to cyanobacterial toxicity testing over several years." Cells investigated for suitability in cyanobacterial toxin assays include primary liver cells (hepatocytes) isolated from rodents and fish, established permanent mammalian cell lines, including hepatocytes, fibroblasts and cancerous cells, and erythrocytes. Earlier work suggested that extracts from toxic cyanobacteria disrupted cells of established lines and erythrocytes," but studies with purified microcystins revealed no alterations in structure or ion transport in fibroblasts or erythrocytes,... 

The ability to identify and quantify cyanobacterial toxins in animal and human clinical material following (suspected) intoxications or illnesses associated with contact with toxic cyanobacteria is an increasing requirement. The recoveries of anatoxin-a from animal stomach material and of microcystins from sheep rumen contents are relatively straightforward. However, the recovery of microcystin from liver and tissue samples cannot be expected to be complete without the application of proteolytic digestion and extraction procedures. This is likely because microcystins bind covalently to a cysteine residue in protein phosphatase. Unless an effective procedure is applied for the extraction of covalently bound microcystins (and nodiilarins), then a negative result in analysis cannot be taken to indicate the absence of toxins in clinical specimens. Furthermore, any positive result may be an underestimate of the true amount of microcystin in the material and would only represent free toxin, not bound to the protein phosphatases. Optimized procedures for the extraction of bound microcystins and nodiilarins from organ and tissue samples are needed. 

T. Kuiper-Goodman, S. Gupta, H. Combley and B. H. Thomas, in Toxic Cyanobacteria Current... 

In summary, it can be reported that toxic cyanobacteria can produce neurotoxic, hepatotoxic, and dermatotoxic compounds that are a direct threat to animal and human water supplies. This threat increases as water bodies become more eutrophic, thus supporting higher production of toxic and nontoxic cyanobacteria. Presence of these potent natural product toxins poses an increasing threat to the maintenance of quality water supplies for agriculture, municipal, and recreational use. 

Work with European toxic cyanobacteria was partially supported by a NATO collaborative research grant between W.W. Carmichael and G.A. Codd, University of Dundee, Scotland, and O.M. Skulberg, Norwegian Water Research Institute, Oslo, Norway. Toxin structure work on European and North American peptide toxins is supported in part by U.S. AMRDC contract DAMD17-87-C-7019 to W.W. Carmichael. Portions of the work represent part of the Ph.D. dissertation research of N.A. Mahmood and E.G. Hyde. Their work was supported in part by fellowship support from the Biomedical Ph.D. Program, Wright State University. 

Chorus, Ingrid, and Jamie Bartram, eds. Toxic Cyanobacteria in Water A Guide to Their Public Health Consequences, Monitoring and Management. London, England E FN Spon, 1999. 

Neurotoxins, such as saxitoxin and anatoxin-a, have been implicated in mediating competitive interactions between toxic cyanobacteria and other photoautotrophs, but few studies have explicitly examined the allelopathic effects of these compounds (e g., Kearns and Hunter 2001). Although it is reasonable to assume that these compounds bind to algal and cyanobacterial sodium channels in a similar fashion as in vertebrate neurons, support for this hypothesis is currently lacking. 

DeMott WR, Moxter F (1991) Foraging on cyanobacteria by copepods responses to chemical defenses and resource abundance. Ecology 72 1820-1834 DeMott WR, Zhang Q, Carmichael WW (1991) Effects of toxic cyanobacteria and purified toxins on the survival and feeding of a copepod and three species of Daphnia. Limnol Oceanogr 36 1346-1357... 

Sheath RG (2003) Red Algae. In Wehr JD, Sheath RG (eds) Freshwater algae of North America ecology and classification. Academic, San Diego, CA, pp 197-224 Sivonen K, Jones G (1999) Cyanobacterial toxins. In Chorus I, Bartram J (eds) Toxic cyanobacteria in water a guide to their public health consequences, monitoring and management. WHO, E FN Spon, London, pp 41-111... 

Cyanobacterial toxins (both marine and freshwater) are functionally and chemically a diverse group of secondary chemicals. They show structure and function similarities to higher plant and algal toxins. Of particular importance to this publication is the production of toxins which appear to be identical with saxitoxin and neosaxitoxin. Since these are the primary toxins involved in cases of paralytic shellfish poisons, these aphantoxins could be a source of PSP standards and the study of their production by Aphanizomenon can provide information on the biosynthesis of PSP s. The cyanobacteria toxins have not received extensive attention since they have fewer vectors by which they come in contact with humans. As freshwater supplies become more eutrophicated and as cyanobacteria are increasingly used as a source of single cell protein toxic cyanobacteria will have increased importance (39). The study of these cyanobacterial toxins can contribute to a better understanding of seafood poisons. 

Bartram J, Carmichael WW, Chorus I, Jones G, Skulberg OV (1999) Introduction. In Bartram J, Choms I (eds) Toxic Cyanobacteria in Water. E FN Spon, London, p 1... 

Chorus I, Bartram J. 1999. Toxic cyanobacteria in water. A guide to their public health consequences, monitoring and management. London (UK) E and FN Spon. 

Historically, inquiries have been prompted by toxic cyanobacteria events, and the first section of this chapter will describe compounds discovered through such... 

The synthetic aspects of anatoxin-a (AN) and analogues are discussed in a separate chapter of this text, and the analytical methods for anatoxins are the subject of a separate review to be published elsewhere. A number of reviews have demonstrated the importance of understanding toxic cyanobacteria as potential environmental and health hazards as well as a resource of bioactive molecules (Harada 1999 Skulberg 2000 Briand et al. 2003). AN was one of the first cyanobacterial toxins to be chemically and functionally characterized and its high neurotoxicity has attracted extensive research activity. 

Briand, J.F., Jacquet, S., Bemar4 C., and Humbert, J.F. 2003. Health hazards for terrestrial vertebrates from toxic cyanobacteria in surface water ecosystems. Vet Res 34, 361—377. 

Carmichael, W.W., and Yuan, M.C.F. 2004. Human mortality from accidental ingestion of toxic cyanobacteria - A case re-examined. In Sixth international conference on toxic cyanobacteria, p. 61 (abstract), Bergen, Norway. 

Claska, M.E., and Gilbert, J. J. 1998. The effect of temperature on the response of Daphnia to toxic cyanobacteria. Freshwat Biol 39, 221-232. 

Harada, K. 1999. Recent advances of toxic cyanobacteria researches. J Health Sci 45, 150-165. 

Sivonen, K., Niemela, S., Niemi, R., Lepisto, L., Luoma, H., and Rasanen, L. 1990. Toxic cyanobacteria (blue-green algae) in Finnish fresh and coastal waters. Hydrobiologia 190, 267-275. 

Bateman, K.P, Thibault, P, Douglas, D.J., and White, R.L. 1995. Mass spectral analyses of microcystins from toxic cyanobacteria using on-line chromatographic and electrophoretic separations. Journal of Chromatography A 712 253-268. 

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