Genotoxic potential of the binary mixture of cyanotoxins microcystin- LR and cylindrospermopsin

From the abstract of a recent paper by Hercog et al. in Chemosphere:

“Increased eutrophication of water bodies promotes cyanobacterial blooming that is hazardous due to the production of various bioactive compounds. Microcystin-LR (MCLR) is among the most widespread cyanotoxins classified as possible human carcinogen, while cylindrospermopsin (CYN) has only recently been recognized as health concern. Both cyanotoxins are genotoxic; however, the mechanisms of their action differ. They are ubiquitously present in water environment and are often detected together. Therefore, we studied genotoxic potential of the binary mixture of these cyanotoxins. Human hepatoma cells (HepG2) were exposed to a single dose of MCLR (1 μg/mL), graded doses of CYN (0.01-0.5 μg/mL), and their combinations. Comet and Cytokinesis block micronucleus assays were used to detect induction of DNA strand breaks (sb) and genomic instability, respectively, along with the transcriptional analyses of the expression of selected genes involved in xenobiotic metabolism, immediate/early cell response and DNA-damage response. MCLR induced DNA sb that were only transiently present after 4 h exposure, whereas CYN, after 24 h exposure, induced DNA sb and genomic instability. The MCLR/CYN mixture induced DNA sb after 24 h exposure, but to lesser extent as CYN alone. On the other hand, induction of genomic instability by the MCLR/CYN mixture was comparable to that induced by CYN alone. In addition, patterns of changes in the expression of selected genes induced by the MCLR/CYN mixture were not significantly different from those induced by CYN alone. Our results indicate that CYN exerts higher genotoxic potential than MCLR and that genotoxic potential of the MCLR/CYN mixture is comparable to that of CYN alone.”

Reference:

Klara Hercog, Sara Maisanaba, Metka Filipič, Ángeles Jos, Ana M. Cameán, Bojana Žegura (2017). Genotoxic potential of the binary mixture of cyanotoxins microcystin-LR and cylindrospermopsin, Chemosphere, Volume 189, Pages 319-329, https://doi.org/10.1016/j.chemosphere.2017.09.075.

Distribution of Toxic Cyanobacteria and Cyanotoxins in Turkish Waterbodies

A recent paper by Latife Koker et al. (2017) presents results of the ‘SIYANOTOKS’ project that was carried out in Turkey by the Ministry of Forestry and Water Affairs, the General Directorate of Water Management in cooperation with the research group of Prof. Reyhan Akcaalan and Prof. Meric Albay, of Istanbul University, Faculty of Fisheries (now Faculty of Aquatic Sciences).
The project  monitored cyanobacteria and their toxins in 18 selected waterbodies in Turkey: 7 natural lakes, 8 reservoirs, 1 lagoon and 2 coastal and transitional waters
in Turkey. Potentially toxic cyanobacteria species were detected in 14 waterbodies and blooms were observed in 57% of them. A highest concentration of Microcystin-LR eq. was 29.7 μg/l and cylindrospermopsin was 9 μg/l. These results showed that cyanotoxin problems are very common in Turkish surface waters and regulation in drinking and
recreational waters should be implemented. The paper acknowledges CYANOCOST for networking and sharing of knowledge.

Reference: Koker et al. (2017), Journal of Environmental Protection and Ecology, 18(2), 425-432. Available on-line (open access). 

1st Announcement ! 11th International Conference on Toxic Cyanobacteria (ICTC11)- Krakow, Poland, 5-10 May 2019

Invitation from the Local Organizing Committee of ICTC11 (from ICTC11 website):

The International Conference on Toxic Cyanobacteria (ICTC) is a periodic summit of an international community focusing on the study of cyanotoxins and toxic cyanobacteria. Poland was chosen as the venue of the next ICTC11 by the participants of the conference in Wuhan in 2016. The five-day event includes interactive sessions and lively discussion panels which promote active scientific exchange and communication between scientists and students. This event will feature recent findings from leading academic experts in the field in the form of lectures and posters. Participants will have the opportunity to gain hands-on experience from the experts on the subject and to network with other enthusiasts.

The theme of this year’s ICTC 11 is: “Learning from the past to predict the future”

The event also includes excursions and off-site visits with the aim of giving the participants a wider insight about the heritage of Kraków and Małopolska region. The royal capital city of Kraków is the spiritual centre of Poland with rich heritage. Krakow’s Old Town, along with Wawel Castle and the city’s Kazimierz district found their place on the First World Heritage List, created by UNESCO in 1978. The city is home to Polish intellectual and artistic elites and is a magnet for the young. Students and young Polish professionals as well as a growing international community are drawn to the city.

On behalf of the Local Organizing Committee, we cordially invite you to attend the 11th International Conference on Toxic Cyanobacteria to be held in Kraków, Poland from 5 to 10 May, 2019.

Chairman,
Dr. Dariusz Dziga
On behalf of the Local Organizing Committee

Breaking news ! Publication of “Molecular Tools for the Detection and Identification of Toxigenic Cyanobacteria” from CYANOCOST-Wiley

This book (link to Wiley) is designed as a handbook describing the molecular monitoring of toxigenicity and diversity of cyanobacteria in surface waters including lakes, rivers, drinking water reservoirs but also in food supplements. This handbook, edited by Rainer Kurmayer, Kaarina Sivonen, Annick Wilmotte and Nico Salmaso is the first one of its type providing up-to-date overviews plus the necessary scientific basis for the subsequent use of molecular tools, qualitative and quantitative analyses and the interpretation of the results.

Although genetic methods are only able to indicate the potential of toxin synthesis it is possible that molecular detection tools will also support risk assessment in the future. On the other hand if the cyanobacteria do not have genes for toxin production they are not able to produce a specific toxin. The use of molecular tools in monitoring comprises (i) Early warning (i.e. waterbodies bearing a risk in toxic bloom formation could be identified early on in the growing season possibly assisting in an economically more efficient application of cyanotoxin detection techniques), (ii) Understanding environmental drivers (i.e. early identification of toxigenic genotype occurrence may lead to a more detailed recording of environmental factors potentially influencing the abundance of toxigenic genotypes), (iii) Identifying toxigenic cyanobacteria (i.e. by sequencing of PCR amplified DNA fragments indicative of cyanotoxin synthesis).

44 standardized operational protocols (SOPs) written by 37 scientists participating in the CYANOCOST network describe the steps of water (food supplement) sampling (six protocols), cyanobacterial strain isolation and purification (six protocols) and taxonomic assignment (two protocols), nucleic acid extraction (eight protocols) and downstream analysis including conventional PCR (nine protocols) as well as qPCR (eight protocols) but also diagnostic and transcriptomic microarray (two protocols), genotyping (one protocol) and community characterization by Next Generation Sequencing techniques (two protocols). A list of toxic strains containing the respective target genes and which are available through international culture collections has been compiled and will serve as reference materials and control measures to make sure that a specific molecular method works. Finally the application of molecular tools is reviewed with regard to environmental samples but also with regard to quality control in microalga biomass production.

The handbook is intended to be used by trained professionals analyzing cyanobacterial toxigenicity and diversity in water samples in the laboratory in both academic and governmental institutions, as well as technical offices and agencies which are in charge of water body surveillance and monitoring. Students will learn important methods’ standards of essential protocols including steps from sampling until results evaluation.

Download a flyer of the two published CYANOCOST books here.

Special Issue “Toxic Cyanobacteria and Toxic Dinoflagellates”in the open-access journal Microorganisms. Call for papers.

Please visit the journal website for more information and to submit your papers.

From the Microorganisms website:

The occurrence of toxic phytoplankton in freshwater and marine environments is a worldwide phenomenon that causes a number of hygienic and ecological problems. Two major phytoplankton groups of concern are toxic cyanobacteria and toxic dinoflagellates, which are the topic of this Special Issue.

The Special Issue wants to emphasize interdisciplinary contributions that combine chemical, biological, and toxicological knowledge, and bring professionals from various disciplines together. While all publishable papers must fulfill strict scientific criteria the editors encourage open-minded and innovative discussion. Some relevant topics are the following: Classical and modern taxonomical work on toxic cyanobacteria and toxic dinoflagellates, research on the genetic basis of toxicity and toxin synthesis pathways, elucidation of factors influencing toxin composition and production, toxinology, work on toxic effects on individual organisms and ecosystems, descriptions of biological and ecological functions of the toxins, work on invasive toxic species, and research on methods to combat and manage toxic phytoplankton.

Eligible research on toxic cyanobacteria is not limited to the aquatic environment but papers describing terrestrial toxic cyanobacteria are also welcome. The focus of the Special Issue is not on purely analytical papers dealing with techniques of toxin detection. However, analytical work with a clear coupling to biological phenomena is eligible.

Both original and review papers can be considered but potential review paper authors are encouraged to contact the Guest Editors in advance.

PS Please feel free to redistribute this call to your colleagues and PhD students.

Dr. Jussi Meriluoto
Dr. Anke Kremp
Guest Editors