Cyanotoxins are not implicated in the etiology of coral black band disease outbreaks on Pelorus Island, Great Barrier Reef

• Published in: FEMS microbiology ecology Vol. 73; no. 1; pp. 43 - 54
• Main Authors: Glas, Martin S, Motti, Cherie A, Negri, Andrew P, Sato, Yui, Froscio, Suzanne, Humpage, Andrew R, Krock, Bernd, Cembella, Allan, Bourne, David G
• Format: Journal Article
• Language: English
• Published: Oxford, UK Oxford, UK : Blackwell Publishing Ltd 01.07.2010; Blackwell Publishing Ltd; Blackwell; Oxford University Press
• Subjects: Animal, plant and microbial ecology; Animals; Anthozoa - microbiology; Australia; Bacterial Infections - microbiology; Bacterial Toxins - adverse effects; Bacterial Toxins - genetics; Bacterial Toxins - isolation & purification; Bacteriology; Biological and medical sciences; black band disease; coral disease; cultivation; Cyanobacteria; Cyanobacteria - genetics; Cyanobacteria - isolation & purification; Cyanobacteria - pathogenicity; cyanotoxin; Cylindrospermopsin; DNA, Bacterial - genetics; Ecology; Epidemics; Etiology; Fundamental and applied biological sciences. Psychology; Gene sequencing; High-performance liquid chromatography; Lesions; Liquid chromatography; Marine; Microbial ecology; Microbiology; microcystin; Microcystins; Microcystins - adverse effects; Microcystins - genetics; Microcystins - isolation & purification; Microorganisms; Miscellaneous; Morphology; Operons; Organic chemistry; Outbreaks; Pathogenicity; Pathogens; Phylogeny; RNA, Ribosomal, 16S - genetics; rRNA 16S; Saxitoxin; Species; Toxins; Australia; Oceania; Great Barrier Reef; ISEW, Australia, Queensland, Great Barrier Reef; cyanotoxin; black band disease; cultivation; cyanobacteria; coral disease; microcystin; Disease; Cyanotoxin; Island; Toxin; Outbreak; Etiology; Cyanobacteria; Bacteria; Great Barrier Reef
• ISSN: 0168-6496; 1574-6941
• DOI: 10.1111/j.1574-6941.2010.00874.x

Cyanobacterial toxins (i.e. microcystins) produced within the microbial mat of coral black band disease (BBD) have been implicated in disease pathogenicity. This study investigated the presence of toxins within BBD lesions and other cyanobacterial patch (CP) lesions, which, in some instances (~19%), facilitated the onset of BBD, from an outbreak site at Pelorus Island on the inshore, central Great Barrier Reef (GBR). Cyanobacterial species that dominated the biomass of CP and BBD lesions were cultivated and identified, based on morphology and 16S rRNA gene sequences, as Blennothrix- and Oscillatoria-affiliated species, respectively, and identical to cyanobacterial sequences retrieved from previous molecular studies from this site. The presence of the cyanotoxins microcystin, cylindrospermopsin, saxitoxin, nodularin and anatoxin and their respective gene operons in field samples of CP and BBD lesions and their respective culture isolations was tested using genetic (PCR-based screenings), chemical (HPLC-UV, FTICR-MS and LC/MSn) and biochemical (PP2A) methods. Cyanotoxins and cyanotoxin synthetase genes were not detected in any of the samples. Cyanobacterial species dominant within CP and BBD lesions were phylogenetically distinct from species previously shown to produce cyanotoxins and isolated from BBD lesions. The results from this study demonstrate that cyanobacterial toxins appear to play no role in the pathogenicity of CP and BBD at this site on the GBR.