Dr.Vanvimon has two research foci.: 1) RNA-based silencing technology (RNAi) for shrimp disease control; 2) Nucleic acid-based detection for shrimp infectious hypodermal and hematopoietic necrosis virus (IHHNV) and fish megalocytivirus with more accurate and high sensitivity.      

RNAi is highly effective for combating viral pathogens by using sequence

specific double-stranded (ds)RNA designed to knockdown key viral genes. Thus, it has potential for application in controlling shrimp viruses.  From 2008-2010, Vanvimon was supported by a grant for Young Researchers awarded by the Thailand Research Fund (TRF), with Professor Dr. Boonsirm Withyachumanarnkul as her mentor, that helped her start her early-career research in developing nucleic acid-based, antiviral technology for application in shrimp aquaculture.  With proof-of-concept outputs from the TRF project, she was able to develop these prototypes for full, large-scale and inexpensive production and testing of multi-target, double-stranded, antiviral RNA against white spot syndrome virus (WSSV), the most serious viral pathogen in Thailand (Thammasorn et al. 2015. BMC Biotechnology, 15:110, IF. 2.865, Cited 8). This project was financially sponsored by Gold Coin-Group Ltd. (Regional animal nutrition and feed milling company).  Her first international grant was from the International Foundation for Science (2010-2013; US$ 24,000) to work with the RNA interference-based antiviral technology against yellow head virus (YHV), the second most lethal shrimp virus in Thailand. The key challenge for RNAi application in the aquaculture industry is to develop production and oral delivery systems for dsRNA that are both safe and low-cost. Potential RNA delivery systems for farm application include bioencapsulation strategy, feed formulation, and injection of shrimp broodstock for producing viral-free offspring stock (Thammasorn et al., 2013. Antiviral Res.100:202-206 IF.4.271, Cited 10; Thammasorn et al., 2013, J of Biotechnology, 15:110,IF. 2.599, Cited 12; Saksmerprome V. et al., 2017. Virus Res. 235, 73-76, IF. 2.628). She has also worked with the Thai Shrimp Genetic Improvement Center in developing and testing a promising RNAi strategy for control and elimination of Laem-Singh virus, a component cause of serious stunting in cultivated, native black tiger shrimp (Penaeus monodon). The work developed practical and inexpensive dsRNA production and delivery systems for curing LSNV-associated slow growth syndrome in farmed shrimp and resulted in a prestigious research award to her group from National Research Council of Thailand 2017.

            Exploring possible alternatives to meet the challenge on biosafety of RNAi technology, Dr. Vanvimon considered ‘‘Generally Regarding As Safe (GRAS)’’ organisms by the US Food and Drug Administration such as probiotics and microalgae as a possible solution.  In her laboratory, work had already been initiated on engineering probiotics Lactobacillus plantarum and the microalga Chlamydomonas reinhardtii to produce oral RNA-based vaccines.  The engineered L. plantarum developed has dual defense functions in combating shrimp virus and pathogenic bacteria (Thammasorn et al. 2017, Aquaculture International 25, 1679-1692).  Currently, the attempt is to further engineer the strain for RNA production with higher yield. For alga research, Dr.Vanvimon and her team successfully bioengineered C. reinhardtii by nuclear transformation with a tailored expression vector and showed that it could successfully produce dsRNA targeting the shrimp virus YHV and showed that its oral application provided specific viral inhibition in shrimp (Somachai et al. 2016, Aquaculture Report, Cited 7).  However, this first experimental strain contained an antibiotic-resistant gene as a selective marker, making it unsuitable for field application, and it also produced a relatively low yield of dsRNA. For this reason, she initiated collaboration with the UK research team of Professor Colin Robinson (Head of School, School of Biosciences, University of Kent) and Professor Saul Purton (Institute of Structural and Molecular Biology, University College London) that had developed light-driven selection of engineered strains using a synthetic biology platform. Successful adaptation of this technology to the YHV-shrimp model would greatly simplify and accelerate the building and testing of constructs for antiviral dsRNA and would constitute a test of concept for applications to control other shrimp and fish pathogens using orally-delivered ds-RNA in an environmentally-friendly way.  Recently, Vanvimon and her team have co-written with Saul Purton (UCL) on a review entitled “Applications of microalgal biotechnology for disease control in aquaculture” (2018) the Special Issue Microalgal Biotechnology, Biology, 7, 2: 24.

2) Infectious hypodermal and hematopoietic necrosis virus (IHHNV) is also known as Penaeus stylirostris densovirus (PstDNV). Since it is listed as a reportable crustacean disease by the World Organization for Animal Health (OIE), many countries require testing for IHHNV in shrimp stocks imported for aquaculture, necessitating rapid and highly sensitive detection methods to guarantee and maintain absence of IHHNV in traded stocks. Dr.Vanvimon first started investigating an infectious type of IHHNV identified from farmed P. monodon in Australia in April 2008 by PCR amplification. Comparison of the maximum possible portion of this sequence with IHHNV isolates reported from Asia provided the results that are in agreement with the World Organization for Animal Health in July 2008 for the presence of infectious IHHNV in Australia (Saksmerprome et al 2010, Aquaculture 298:190-19, IF.2.57, Cited 21).   Consequently, Australian government removed requirement of IHHNV screening in imported shrimp P. monodon, and black tiger shrimp exporters from Thailand has gained benefits from this change in Australian regulation. In addition, non-infectious inserts of IHHNV genome into the shrimp genome have been found in captured P. monodon from East Africa and Australia. The occurrence of these inserts raised the question as to whether inserts of other IHHNV fragments also occurred in the P. monodon genome. The multiplex PCR assay using overlapping primer pairs to cover the whole IHHNV genome, developed from our abovementioned IHHNV sequence analysis, indicate that IHHNV inserts are common and variable in P. monodon from Thailand and that they may yield false-positive test results for infectious IHHNV using currently recommended methods.  The multiplex PCR developed herein proved optimal for convenient differentiation of shrimp specimens with real IHHNV infection and those with insert types (Saksmerprome et al., 2011 Virus Res. IF. 2.628, Cited 15; Molthathong et al., 2013 BMC Vet Res. 9:33, IF. 1.99, Cited 6).

Infectious spleen and kidney necrosis virus (ISKNV) has been classified in Megalocytivirus genus of the family Iridoviridae.  The disease outbreaks from this virus caused economic losses, due to mass mortality, in finfish industry of China, Japan and South-East Asia.  Infections of ISKNV have also been reported without causing clinical symptoms in various fish species at different age groups.  Dr.Vanvimon’s team has collaborated with Assistant Professor Dr. Triwit Rattanarojpong and Dr. Ha Thanh Dong (Department of Microbiology, Faculty of Science, King Mongkut's University of Technology Thonburi, Thailand), whose expertise is fish pathology, led to identification of multiple pathogens, including iridovirus, in tilapia from natural disease outbreak (Dong HT et al. 2015 Aquaculture, 448:427-435, IF. 2.57, Cited 21; Dong HT et al. 2017 Fish & Shellfish Immunology,68, 65-73;IF.3.148)