title: Geographical segregation of the neurotoxin-producing cyanobacterium Anabaena circinalis.
abstract: 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.
authors.affiliation: School of Microbiology and Immunology, The University of New South Wales, Sydney, New South Wales 2052, Australia.
authors.forename: E C
authors.initials: EC
authors.lastname: Beltran
authors.forename: B A
authors.initials: BA
authors.lastname: Neilan
mesh_terms: D017033:Anabaena / Q000145:classification* / Q000235:genetics / Q000502:physiology; D001315:Australia; D001427:Bacterial Toxins / Q000032:analysis*; D002170:Canada; D016384:Consensus Sequence; D000087522:Cyanobacteria Toxins; D017931:DNA Primers; D004275:DNA, Ribosomal / Q000235:genetics; D005843:Geography; D007564:Japan; D008387:Marine Toxins / Q000032:analysis*; D052998:Microcystins; D008969:Molecular Sequence Data; D009498:Neurotoxins / Q000032:analysis*; D010798:Phycocyanin / Q000235:genetics; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012758:Shellfish / Q000382:microbiology; D014326:Tropanes
chemical_list: D001427:Bacterial Toxins; D000087522:Cyanobacteria Toxins; D017931:DNA Primers; D004275:DNA, Ribosomal; D008387:Marine Toxins; D052998:Microcystins; D009498:Neurotoxins; D012336:RNA, Ribosomal, 16S; D014326:Tropanes; D010798:Phycocyanin; C509783:anatoxin a