Thao Phuong Huynh Ngo

Title : Tilapia lake virus (TiLV) from Vietnam is genetically distantly related to TiLV strains from other countries

Abstract:

Tilapia lake virus (TiLV) is reported as a threat to tilapia aquaculture in 16 countries from four continents with outbreaks causing up to 90% mortality. Our study is the first one working on TiLV from Vietnam. We propagated successfully a TiLV isolate HB196-VN-2020 from a diseased tilapia sample using an E-11 cell line and evaluated its virulence in different weights of red hybrid tilapia and three serial 10-fold diluted viral titers. Small fish (4.5 ± 1.98 g) were proved to be more susceptible to TiLV infection at the viral titer of 9.1 x 10⁵ TCID₅₀ fish^-1 than large fish (20.8 ± 7.5 g) with the mortalities of 92.5% and 12.5%, respectively. Phylogenetic analysis of the concatenated 10 segment coding regions placed two Vietnamese TiLVs (RIA2-VN-2019 and HB196-VN-2020) in a separate clade, distantly related to other reference 21 isolates. Reassortant detection analysis revealed seven potential reassortment events among 23 TiLV genomes, indicating the mixed infection of multiple TiLV isolates at the farms and the fish movement among different regions. However, additional sequences from various sampling locations and times are required to better understand the impacts of genetic diversity and ressortments on the evolution, migration and natural selection of TiLV in Vietnam and other countries.

Biography:

Dr Thao Phuong Huynh Ngo studied Biotechnology at Van Lang university, Vietnam for Engineering degree in 2000-2004 and gradated as Master of Science in Molecular Biology in 2006 from Northumbria university, Newcastle upon Tyne, United Kingdom. Then she joined the research group of Prof Sandra Adams at Stirling university, Scotland, United Kingdom. She received her PhD degree in 2017 at the same institution. She has had experience working at Biotechnology Center of Ho Chi Minh city, Vietnam since 2006 and worked as Head of Aquacultural Biotechnology Division since 2008. She is a molecular microbiologist with expertise in fish vaccine development and efficacy testing.