Total genome sequencing of the Infectious Spleen and Kidney Necrosis Virus (ISKNV) obtained from tilapia (Oreochromis niloticus) farmed in the state of São Paulo/Brazil

• Grant number: 24/13226-1
• Support Opportunities: Scholarships abroad - Research Internship - Master's degree
• Start date: October 01, 2024
• End date: December 15, 2024
• Field of knowledge: Agronomical Sciences - Fishery Resources and Fishery Engineering - Aquaculture
• Principal Investigator: Cláudia Maris Ferreira Mostério
• Grantee: Guilherme Nunes Ferrez
• Supervisor: Thomas Barclay Waltzek
• Host Institution: Instituto de Pesca. Agência Paulista de Tecnologia dos Agronegócios (APTA). Secretaria de Agricultura e Abastecimento (São Paulo - Estado). São Paulo , SP, Brazil
• Institution abroad: Washington State University (WSU), United States
• Associated to the scholarship: 23/17337-0 - Detection and Characterization of Circulating Strains of ISKNV (Infectious Spleen and Kidney Necrosis Virus) in the State of São Paulo, BP.MS

Abstract

Aquaculture has grown significantly, with world fish production reaching 185 million tons by 2022. However, increased production in intensive systems has increased the spread of pathogens such as infectious spleen and kidney necrosis virus (ISKNV). This virus belongs to the Iridoviridae family and is associated with three genotypes: RSIV, TRBIV, and ISKNV. The main objective of this study is to sequence the complete genome of ISKNV strains in tilapia from fish farms in the state of São Paulo and determine the phylogenetic relationship with other strains described in the literature. To this end, samples of tilapia fry were collected from five fish farms in São Paulo between the fall of 2023 and the spring of 2024. Spleen and kidney samples were extracted, and DNA was isolated and amplified using conventional PCR. Positive samples were sequenced using the Sanger method. In order to understand the phylogeny and interrelationships of this virus, we intend to carry out whole genome sequencing using state-of-the-art techniques available at WSU. The sequences will be analyzed phylogenetically and compared with others described in the literature. The planned activities include improving qPCR techniques, viral isolation and next-generation sequencing, as well as training in evolutionary analysis and polymorphism studies. The importance of the study lies in the fact that viral genome sequencing is crucial to understanding the epidemiology of ISKNV, helping to identify genetic variants and strain diversity, which is fundamental to mitigating impacts on tilapia farming and natural ecosystems.