Development and evaluation of a PCR based assay for detection of the toxic dinoflagellate, Gymnodinium catenatum (Graham) in ballast water and environmental samples
Patil, JG and Gunasekera, RM and Deagle, BE and Bax, NJ and Blackburn, SI, Development and evaluation of a PCR based assay for detection of the toxic dinoflagellate, Gymnodinium catenatum (Graham) in ballast water and environmental samples, Biological Invasions, 7 pp. 983-994. ISSN 1387-3547 (2005) [Refereed Article]
Gymnodinium catenatum is a bloom forming dinoﬂagellate that has been known to cause paralytic shell-ﬁsh poisoning (PSP) in humans. It is being reported with increased frequency around the world, with ballast water transport implicated as a primary vector that may have contributed to its global spread. Major limitations to monitoring and management of its spread are the inability for early, rapid, and accurate detection of G. catenatum in plankton samples. This study explored the
feasibility of developing a PCR-based method for speciﬁc detection of G. catenatum in cultures and heterogeneous ballast water and environmental samples. Sequence comparison of the large sub unit (LSU) ribosomal DNA locus of several strains and species of dinoﬂagellates allowed the design of G. catenatum speciﬁc PCR primers that are ﬂanked by conserved regions. Assay speciﬁcity was validated through screening a range of dino- ﬂagellate cultures, including the morphologically similar and taxonomically closely related species G. nolleri. ampliﬁcation of the diagnostic PCR product from all the strains of G. catenatum but not from other species of dinoﬂagellates tested imply the species speciﬁcity of the assay. Sensitivity of the assay to detect cysts in ballast water samples was established by simulated spiked experiments. The assay could detect G. catenatum in all ‘blank’ plankton samples that were spiked with ﬁve or more cysts. The assay was used to test environmental samples collected from the Derwent river estuary, Tasmania. Based on the results we conclude that the assay may be utilized in large scale screening of environmental and ballast water samples.