Dhiraj Krisha
Email: gnc677@sund.ku.dk
Affiliation: Faroese Food and Veterinary Authority, The Faroe Islands.
Presentation: The inception of my interest in microbiology stemmed at an early stage from identifying specific fungal flora in my surroundings. Their complex and diverse nature and the ability to grow and adapt under extreme conditions piqued my scientific curiosity.
I began my studies with a professional bachelor’s degree in Fisheries Sciences from the College of Fisheries, KVAFSU, Mangalore. During my study, I was fortunate enough to take courses such as Pharmacology and Chemotherapeutics, Food and Aquatic microbiology, which laid the foundation for my interest in infectious diseases, host-pathogen interactions, and effective control methods. After graduation, I decided to transition from Fisheries Science to Clinical Sciences and obtained a master’s in Microbiology (Medical) from KMC, MAHE. The decision came from what I observed during my internship at a fish processing plant where utmost importance was given to the microbial quality of finished products with consumer safety in mind. Following my master’s study, I worked as a tutor to medical students and was in charge of the microbiology lab in a tertiary care hospital.
Studying infectious agents in aquatic and clinical samples has given me valuable insight into the complexity of which microbes interact with each other and their environment, which I plan to implement in my research career. Some topics of interest include antimicrobial resistance, focusing on MDR variants, phage biology and phage therapy, infection biology, and bioprospecting for novel therapeutic agents, emphasizing plant derivatives. I specialize in bacteriology and molecular diagnostics and would like to focus on using a multi-omics approach to address problems relevant to the current diagnostic approach to infectious diseases and develop novel treatment and control modalities.
Project description
ESR 9 – Biosecurity considerations in Atlantic salmon (Salmo salar) in RAS
With the goal of sustainable fish production, Recirculatory Aquaculture Systems (RAS) make it possible to produce healthier fish and reduce water consumption by filtering and reusing the water, providing a stable environment for optimal fish growth. Given the requirement of strict monitoring and control of parameters involved in RAS, any minor change can disturb the microbial balance making them vulnerable to the opportunistic pathogens present at low levels and also accumulation of pathogenic agents such as Infective Salmon Anemia Virus (ISAV) (Blancheton et al., 2013; Xue et al., 2017, Sommerset et al. 2021). These microorganisms can then establish themselves in biofilters and other areas that are difficult to disinfect, inducing high mortalities (Hjeltnes et al., 2019). Thus, a high level of Biosecurity is imperative to prevent the entry of pathogens into the system, ensuring fish health and welfare.
The Ph.D. project aims to identify significant pathogen entry points in salmon RAS and examine vital biosecurity issues in intensive RAS production, including the potential for virulence evolution and best management practices to control infections once they have entered the system, which will be studied under the following objectives.
- Identify major pathogen entry points by isolating and analyzing RNA/DNA from air and water using RT-qPCR and Next-Gen Sequencing (NGS) to identify the source of pathogens.
- Investigate transmission pathways of selected pathogens using a combination of data analysis and novel samplings at the RAS based on RT-qPCR and NGS to study the potential virulence evolution of two or more chosen pathogens (ISAV, SGPV, and Flavobacterium psychrophilum)
- Evaluate current approaches to control pathogens in salmon RAS using a longitudinal study at the RAS, conducting water and fish samplings evaluated based on RT-qPCR screenings and histopathological results on a subset of the samples.
4. Identify relevant pathogens in salmon freshwater RAS to include in a high-throughput fast monitoring platform (DNA-chip).