Send to

Choose Destination
Appl Environ Microbiol. 2000 Oct;66(10):4468-74.

Geographical segregation of the neurotoxin-producing cyanobacterium Anabaena circinalis.

Author information

School of Microbiology and Immunology, The University of New South Wales, Sydney, New South Wales 2052, Australia.


Blooms of the cyanobacterium Anabaena circinalis are a major worldwide problem due to their production of a range of toxins, in particular the neurotoxins anatoxin-a and paralytic shellfish poisons (PSPs). Although there is a worldwide distribution of A. circinalis, there is a geographical segregation of neurotoxin production. American and European isolates of A. circinalis produce only anatoxin-a, while Australian isolates exclusively produce PSPs. The reason for this geographical segregation of neurotoxin production by A. circinalis is unknown. The phylogenetic structure of A. circinalis was determined by analyzing 16S rRNA gene sequences. A. circinalis was found to form a monophyletic group of international distribution. However, the PSP- and non-PSP-producing A. circinalis formed two distinct 16S rRNA gene clusters. A molecular probe was designed, allowing the identification of A. circinalis from cultured and uncultured environmental samples. In addition, probes targeting the predominantly PSP-producing or non-PSP-producing clusters were designed for the characterization of A. circinalis isolates as potential PSP producers.

[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for HighWire Icon for PubMed Central
Loading ...
Support Center