Affiliations 

  • 1 Bachok Marine Research Station, Institute of Ocean and Earth Sciences, University of Malaya, 16310, Bachok, Kelantan, Malaysia
  • 2 Third Institute of Oceanography, Ministry of Natural Resources, Xiamen, 361005, China
  • 3 Bachok Marine Research Station, Institute of Ocean and Earth Sciences, University of Malaya, 16310, Bachok, Kelantan, Malaysia. Electronic address: ptlim@um.edu.my
  • 4 Bachok Marine Research Station, Institute of Ocean and Earth Sciences, University of Malaya, 16310, Bachok, Kelantan, Malaysia. Electronic address: cpleaw@um.edu.my
Mar Environ Res, 2024 Jul;199:106593.
PMID: 38852495 DOI: 10.1016/j.marenvres.2024.106593

Abstract

The marine dinophyte Alexandrium tamiyavanichii is a toxigenic species that produces a group of neurotoxins that is responsible for paralytic shellfish poisoning in humans. Early detection of the species is essential for efficient monitoring. Harmful microalgal monitoring systems have evolved over the years with the advent of environmental DNA (eDNA)-based species detection techniques. In this study, eDNA samples were collected from a large-scale sampling covering the southern South China Sea. The sensitivity and specificity of metabarcoding of the V4 and V9 18S ribosomal DNA barcodes by high-throughput sequencing (HTS) were compared to the species-specific real-time qPCR targeting the A. tamiyavanichii ITS2 region. Environmental samples were screened for A. tamiyavanichii by qPCR (n = 43) and analyzed with metabarcoding (n = 30). Our results revealed a high occupancy profile across samples for both methods; 88% by qPCR, and 80-83% by HTS. When comparing the consistency between the two approaches, only two samples out of 30 were discordant. The V4 and V9 molecular units detected in each sample were positively correlated with the qPCR ITS2 gene copies (V4, rs = 0.67, p 

* Title and MeSH Headings from MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.