Dr Aden Ip1, Dr Chen Jing1, Chee Wai Lee1, Adrian Tan1, Dr Zi Yan Brian Tan1, Mr Hor Yee Collin Tong2, Ms Clara Lau1, Ms Li Ying Tan1, Dr Karenne Tun2, Dr Charlene Judith Fernandez1, Dr Siow Foong Chang3, Dr Him Hoo Yap3, Mr Kenneth B. H. Er3
1Centre for Animal and Veterinary Sciences, National Parks Board, , Singapore, 2National Biodiversity Centre, National Parks Board, , Singapore, 3National Parks Board, , Singapore
Sea turtle fibropapillomatosis (FP) is a lethal disease caused by the chelonian-specific alpha herpes virus (ChHV5). Over the last two years, infection cases have increased by at least 35% worldwide, while three sea turtle carcasses with FP have recently been observed in Singapore. Juvenile sea turtles, which are seed stock and critical for population recovery progress, are most susceptible to this virus. This increased susceptibility impacts sea turtle conservation efforts and therefore sparks urgency in devising effective management strategies to monitor the spread of the virus within the local sea turtle population. We present the application of environmental DNA (eDNA) methods as an efficient and alternative biosurveillance tool for detecting ChHV5 from environmental samples since existing sampling methods are invasive and may involve sacrificing the infected animal. A total of four seawater and 12 sediment samples were collected from an aquarium housing infected green turtles and four hawksbill turtle nests, respectively. Real-time PCR (qPCR) was used for preliminary ChHV5 detection in the eDNA from seawater and sediment samples. The qPCR results were confirmed with sequencing using the Oxford Nanopore’s MinION. We detected ChHV5 in the seawater but not from the nest sediment samples. Assembly of the ChHV5 genome from environmental samples is ongoing. The extension of this eDNA biosurveillance application is also underway, such as the analyses of RNA and host immune response signals from the environment, which can enhance the utility of eDNA tools for pathogen diagnostics and detection of OIE-listed aquatic animal diseases.
Biography:
Aden Ip is a scientist at the Centre for Animal and Veterinary Sciences, National Parks Board Singapore. He earned his Ph.D. from the National University of Singapore in 2021, and his primary expertise is in the development and application of environmental DNA for the biomonitoring of marine species. Aden has an interest in molecular field applications and high-throughput sequencing. He is currently working on virus phylogenomics, as well as establishing eDNA protocols to safeguard Singapore’s biosecurity through pathogen biosurveillance from aquatic, sediment, and air samples.