Oral Presentation Society of Environmental Toxicology and Chemistry Australasia 2023

Toxic traces: The use of DNA metabarcoding to investigate and monitor ciguatoxin-producing dinoflagellates along the coast of Queensland, Australia (#126)

Joseph C Perkins 1 , Jan M Strugnell 1 , Kyall R Zenger 1 , Yang Liu 1
  1. Centre for Sustainable Tropical Fisheries and Aquaculture, James Cook University, Townsville, QUEENSLAND, Australia

Aims

Ciguatera poisoning is a significant health and economic concern for coastal communities along the Queensland coast of Australia. To address this issue, we used DNA metabarcoding to create a comprehensive foundation to determine what species of ciguatoxin-producing dinoflagellates are present along the coast, and to map their distribution and prevalence.

Methods

Sand, water, and algae samples (n=105) were collected from Hervey Bay, Qld in May 2022, and January 2023, and from both Townsville and Gladstone Qld in November 2022 (all locations where past ciguatera cases have occurred). DNA extraction was applied using the Preserve, Precipitate, Lyse, Precipitate Purify (PPLPP) workflow. The 18S rDNA gene is predominantly used for primer choice, but the target region has been a topic of debate in previous research. Therefore, our research will also compare the efficiency of both the V4 and V8-V9 regions for assessing benthic toxic dinoflagellate communities along the Queensland coast. 180 samples including PCR replicates and control samples were sent to AGRF, a MiSeq paired-end library was constructed, and a two-step PCR was performed before sequencing was performed through Illumina MiSeq.

Results

The results of this research are expected to successfully identify ciguatoxin-producing dinoflagellates using metabarcoding along the Queensland coast in all locations. By detecting multiple species simultaneously, this approach provides greater depth in understanding ciguatoxin-producing dinoflagellate communities. Additionally, the results from this research will investigate the efficiency of two commonly used target regions of the 18S rDNA gene.

Conclusions

This study serves as a crucial baseline for future research and prevention of ciguatera outbreaks, which pose a significant risk to human health. By identifying the distribution and prevalence of these harmful dinoflagellates, we can develop effective strategies to mitigate the risk of ciguatera poisoning and safeguard the wellbeing of local communities.