Identification and toxigenic potential of a cyanobacterial strain (Stigomena sp.)

Cyanobacteria are well known for their production of a multitude of highly toxic substances. The genus Stigomena is regarded as good candidates for producing biologically active secondary metabolites, which are highly toxic to humans and other animals. The carcass of a dog was found at the shore of Lake Ali-Abad, Iran. Biomass from the discovery site appeared to be of cyanobacterial nature. We identified the strain as freshwater bloom-forming representative of the Stigomena genus on the basis of its 16S rRNA sequence. It carried the mcyE gene, as well as a potential cryptic hassallidin gene cluster. These results suggest that microcystin-induced liver damage may have significantly ontributed to the death of the dog. This case is thus the first reported incident of potential microcystin intoxication in a dog in Iran