Different Genotypes of Anatoxin-Producing Cyanobacteria Coexist in the Tarn River, France
Open Access
- 1 December 2007
- journal article
- Published by American Society for Microbiology in Applied and Environmental Microbiology
- Vol. 73 (23), 7605-7614
- https://doi.org/10.1128/aem.01225-07
Abstract
Repeated dog deaths occurred in 2002, 2003, and 2005 after the animals drank water from the shoreline of the Tarn River in southern France. Signs of intoxication indicated acute poisoning due to a neurotoxin. Floating scum and biofilms covering pebbles were collected in the summers of 2005 and 2006 from six different sites along 30 km from the border of this river. The cyanobacterial neurotoxic alkaloid anatoxin-a and/or its methyl homolog, homoanatoxin-a, was detected in the extracts of most samples examined by gas chromatography-mass spectrometry. Fifteen filamentous cyanobacteria of the order Oscillatoriales were isolated and displayed four distinct phenotypes based on morphological characteristics and pigmentation. Three of the phenotypes can be assigned to the genus Oscillatoria or Phormidium , depending on the taxonomic treatises (bacteriological/botanical) employed for identification. The fourth phenotype is typical of the genus Geitlerinema Anagnostidis 1989. Eight strains rendered axenic were analyzed for production of anatoxin-a and homoanatoxin-a, and all strains of Oscillatoria / Phormidium proved to be neurotoxic. The genetic relatedness of the new isolates was evaluated by comparison of the intergenic transcribed spacer sequences with those of six oscillatorian strains from the Pasteur Culture Collection of Cyanobacteria. These analyses showed that the neurotoxic representatives are composed of five different genotypes, three of which correspond to phenotypes isolated in this study. Our findings prove that neurotoxic oscillatorian cyanobacteria exist in the Tarn River and thus were most likely implicated in the reported dog poisonings. Furthermore, they reemphasize the importance of monitoring benthic cyanobacteria in aquatic environments to fully assess the health risks associated with these organisms.Keywords
This publication has 33 references indexed in Scilit:
- Neurotoxins in axenic oscillatorian cyanobacteria: coexistence of anatoxin-a and homoanatoxin-a determined by ligand-binding assay and GC/MSMicrobiology, 2005
- Anatoxin‐a toxin in the cyanobacterium Planktothrix rubescens from a fishing pond in northern ItalyEnvironmental Toxicology and Water Quality, 2004
- PHYLOGENY AND GENETIC VARIANCE IN TERRESTRIAL MICROCOLEUS (CYANOPHYCEAE) SPECIES BASED ON SEQUENCE ANALYSIS OF THE 16S rRNA GENE AND ASSOCIATED 16S–23S ITS REGION1Journal of Phycology, 2002
- REMARKABLE CONSERVATION OF INTERNALLY TRANSCRIBED SPACER SEQUENCES OF ARTHROSPIRA (“SPIRULINA” ) (CYANOPHYCEAE, CYANOBACTERIA) STRAINS FROM FOUR CONTINENTS AND OF RECENT AND 30‐YEAR‐OLD DRIED SAMPLES FROM AFRICA1Journal of Phycology, 2002
- A proposal for the unification of five species of the cyanobacterial genus Microcystis Kützing ex Lemmermann 1907 under the rules of the Bacteriological Code.International Journal of Systematic and Evolutionary Microbiology, 2001
- Phylogenetic relationships between toxic and non-toxic strains of the genusMicrocystisbased on 16S to 23S internal transcribed spacer sequenceFEMS Microbiology Letters, 1999
- Hepatotoxic microcystins and neurotoxic anatoxin-a in cyanobacterial blooms from Korean lakesEnvironmental Toxicology and Water Quality, 1998
- Biosynthesis of anatoxin-a in Anabaena flos-aquae and homoanatoxin-a in Oscillatoria formosaJournal of the Chemical Society, Chemical Communications, 1995
- Toxic cyanobacteria (blue-green algae) in Finnish fresh and coastal watersHydrobiologia, 1990
- Preliminary characterization of neurotoxic cyanobacteria blooms and strains from FinlandEnvironmental Toxicology and Water Quality, 1989