Implementing an environmental DNA/RNA-based approach to non-invasively investigate disease caused by Ichthyophthirius multifiliis

Infectious diseases impose a substantial burden on aquaculture, acting as a significant constraint on production yields, entailing considerable management costs. White spot disease, which is caused by the protozoan fish parasite, Ichthyophthirius multifiliis (Ich), is a good example of a disease whi...

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Main Authors: Yajiao Duan, Moonika Haahr Marana, Hannah Malene Jensen, Cyril Henard, Louise von Gersdorff Jørgensen
Format: Article
Language:English
Published: Elsevier 2025-03-01
Series:Aquaculture Reports
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Online Access:http://www.sciencedirect.com/science/article/pii/S2352513424006501
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author Yajiao Duan
Moonika Haahr Marana
Hannah Malene Jensen
Cyril Henard
Louise von Gersdorff Jørgensen
author_facet Yajiao Duan
Moonika Haahr Marana
Hannah Malene Jensen
Cyril Henard
Louise von Gersdorff Jørgensen
author_sort Yajiao Duan
collection DOAJ
description Infectious diseases impose a substantial burden on aquaculture, acting as a significant constraint on production yields, entailing considerable management costs. White spot disease, which is caused by the protozoan fish parasite, Ichthyophthirius multifiliis (Ich), is a good example of a disease which continuously cause major challenge for the aquaculture worldwide. Utilization of environmental DNA/RNA (eNA) extracted from fish water for pathogen detection and quantification offers a potentially non-invasive and routine strategy for monitoring diseases in aquaculture systems. In this experimental study, rainbow trout (Oncorhynchus mykiss) were challenged with Ich in two concentrations. The eNA was extracted from the tank water and was used to detect the parasite throughout the course of the disease targeting a gene encoding an Ich immobilization antigen (Iag52a). Simultaneously, the parasite burden and immune-relevant gene expression in both water and fish gills were investigated. The results showed that the level of Ich eNA exhibited a peak at the onset of mortality at 10 days post challenge (dpc), decreasing at 12 dpc. Most immune relevant genes expressed in the gills were downregulated at 2 dpc and upregulated at 8 dpc. The gene expression of two acute phase proteins from the host, Serum amyloid A (SAA) and Hepcidin, were investigated both in the gills and in the water. The two genes were downregulated in water at 10 dpc, coinciding with the peak mortality time point and the highest parasite eNA load in the water. This study provides an insight into the pathogen eNA dynamics where a Ct value of 18–25 of iag52a indicated critical disease outbreak.
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spelling doaj-art-7095c87758d54e8ab6beb7c7173777112025-02-06T05:12:08ZengElsevierAquaculture Reports2352-51342025-03-0140102562Implementing an environmental DNA/RNA-based approach to non-invasively investigate disease caused by Ichthyophthirius multifiliisYajiao Duan0Moonika Haahr Marana1Hannah Malene Jensen2Cyril Henard3Louise von Gersdorff Jørgensen4Corresponding author.; Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg C, DenmarkDepartment of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg C, DenmarkDepartment of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg C, DenmarkDepartment of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg C, DenmarkDepartment of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Frederiksberg C, DenmarkInfectious diseases impose a substantial burden on aquaculture, acting as a significant constraint on production yields, entailing considerable management costs. White spot disease, which is caused by the protozoan fish parasite, Ichthyophthirius multifiliis (Ich), is a good example of a disease which continuously cause major challenge for the aquaculture worldwide. Utilization of environmental DNA/RNA (eNA) extracted from fish water for pathogen detection and quantification offers a potentially non-invasive and routine strategy for monitoring diseases in aquaculture systems. In this experimental study, rainbow trout (Oncorhynchus mykiss) were challenged with Ich in two concentrations. The eNA was extracted from the tank water and was used to detect the parasite throughout the course of the disease targeting a gene encoding an Ich immobilization antigen (Iag52a). Simultaneously, the parasite burden and immune-relevant gene expression in both water and fish gills were investigated. The results showed that the level of Ich eNA exhibited a peak at the onset of mortality at 10 days post challenge (dpc), decreasing at 12 dpc. Most immune relevant genes expressed in the gills were downregulated at 2 dpc and upregulated at 8 dpc. The gene expression of two acute phase proteins from the host, Serum amyloid A (SAA) and Hepcidin, were investigated both in the gills and in the water. The two genes were downregulated in water at 10 dpc, coinciding with the peak mortality time point and the highest parasite eNA load in the water. This study provides an insight into the pathogen eNA dynamics where a Ct value of 18–25 of iag52a indicated critical disease outbreak.http://www.sciencedirect.com/science/article/pii/S2352513424006501Immune responseeNAIchthyophthirius multifiliisFish diseaseDisease surveillance
spellingShingle Yajiao Duan
Moonika Haahr Marana
Hannah Malene Jensen
Cyril Henard
Louise von Gersdorff Jørgensen
Implementing an environmental DNA/RNA-based approach to non-invasively investigate disease caused by Ichthyophthirius multifiliis
Aquaculture Reports
Immune response
eNA
Ichthyophthirius multifiliis
Fish disease
Disease surveillance
title Implementing an environmental DNA/RNA-based approach to non-invasively investigate disease caused by Ichthyophthirius multifiliis
title_full Implementing an environmental DNA/RNA-based approach to non-invasively investigate disease caused by Ichthyophthirius multifiliis
title_fullStr Implementing an environmental DNA/RNA-based approach to non-invasively investigate disease caused by Ichthyophthirius multifiliis
title_full_unstemmed Implementing an environmental DNA/RNA-based approach to non-invasively investigate disease caused by Ichthyophthirius multifiliis
title_short Implementing an environmental DNA/RNA-based approach to non-invasively investigate disease caused by Ichthyophthirius multifiliis
title_sort implementing an environmental dna rna based approach to non invasively investigate disease caused by ichthyophthirius multifiliis
topic Immune response
eNA
Ichthyophthirius multifiliis
Fish disease
Disease surveillance
url http://www.sciencedirect.com/science/article/pii/S2352513424006501
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