Detection and application of circular (concatemeric) DNA as an indicator of koi herpesvirus infection

Kawato, Yasuhiko; Yuasa, Kei; Shimahara, Yoshiko; Oseko, Norihisa

doi:10.3354/dao02785

Cited by 3 publications

(2 citation statements)

References 26 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The same method of seawater sampling was performed between June 2017 and June 2019 at another bay area (D), where fish surviving RSIVD in 2016 were transferred in April 2017. Heat-inactivated koi herpesvirus (KHV) NRIA0301 isolate ( 57 ) was added to the seawater samples between April 2018 and November 2019 as the external standard virus before the concentration process. Then, the seawater was concentrated using iron flocculation and eDNA was extracted, with minor modifications ( 16 ).…”

Section: Methodsmentioning

confidence: 99%

Application of Environmental DNA for Monitoring Red Sea Bream Iridovirus at a Fish Farm

Kawato¹,

Mekata²,

Inada³

et al. 2021

Microbiol Spectr

View full text Add to dashboard Cite

show abstract

Section: Methodsmentioning

confidence: 99%

Application of Environmental DNA for Monitoring Red Sea Bream Iridovirus at a Fish Farm

Kawato¹,

Mekata²,

Inada³

et al. 2021

Microbiol Spectr

View full text Add to dashboard Cite

show abstract

“…This process was performed at room temperature between 22°C and 26°C. First, approximately 10 3 copies in 50 µL of heat-inactivated KHV NRIA0301 isolate ( 48 ) were added to the seawater sample as an external standard virus for the internal control of eDNA before the iron flocculation process ( 32 ). The same volume of KHV in a 1.5-mL microtube was placed at room temperature during the iron flocculation process for each sampling batch as a control for copy number reduction during sample treatment.…”

Section: Methodsmentioning

confidence: 99%

Assessing the transmission risk of red sea bream iridovirus (RSIV) in environmental water: insights from fish farms and experimental settings

Kawato,

Takada,

Mizuno

et al. 2023

Microbiol Spectr

View full text Add to dashboard Cite

Aquatic animal viruses are considered to be transmitted via environmental water between fish farms. This study aimed to understand the actual transmission risk of red sea bream iridovirus (RSIV) through environmental water among fish farms. An environmental DNA (eDNA) method using iron-based flocculation coupled with large-pore filtration was used to monitor RSIV DNA copies in seawater from fish farms and from an experimental infection model. RSIV dispersion in seawater from a net pen where the disease outbreak occurred was visualized by the inverse distance weighting method using multiple-sampling data sets from a fish farm. The analysis demonstrated that the center of the net pen had a high viral load, and RSIV seemed to be quickly diluted by the tidal current. To evaluate the transmission risk of RSIV in environmental water, the red sea bream Pagrus major (approximately 10 g) was exposed to RSIV-contained seawater (10 3 , 10 4 , 10 5 , 10 6 , and 10 7 copies/L) for 3 days, which mimicked field exposure. A probit analysis of the challenge test indicated that the inferred infection rates of seawater containing 10 5.9 copies/L and 10 3.1 copies/L of RSIV were 50% and 0.0001%, respectively. In the surveillance for 3 years at 10 fixed points ( n = 306), there were only seven samples in which the viral load exceeded 10 4 copies/L in seawater. These results suggest that the transmission of RSIV among fish farms via seawater is highly associated with the distance between the net pens, and the environmental water is not always an infection source for the transmission of RSIV between fish farms. IMPORTANCE Our surveillance of viral loads for red sea bream iridovirus (RSIV) by monitoring environmental DNA in fish farms suggested that the viral loads in the seawater were low, except for the net pens where RSIV outbreaks occurred. Furthermore, our experimental infection model indicated that the infection risk of RSIV-contained seawater with less than 10 3 copies/L was extremely low. The limited risk of environmental water for transmission of RSIV gives an insight that RSIV could be partly transmitted between fish farms due to the movement of equipment and/or humans from the fish farm where the disease outbreaks. Since our data suggest that seawater can function as a potential wall to reduce the transmission of RSIV, biosecurity management, such as disinfection of equipment associated with fish farms could be effective, even in the semi-open system aquaculture that the environmental water can be freely transferred, to reduce the risk of RSIV outbreaks.

show abstract

Koi Herpesvirus Disease

Yuasa

2016

Fish Pathol.

View full text Add to dashboard Cite

Koi herpesvirus (KHV) disease caused by cyprinid herpesvirus 3 (CyHV-3) affects carp Cyprinus carpio and its varieties. The disease is listed by the OIE and is also designated as "Specific diseases" in a Japanese law. In Japan, the disease first occurred in 2003 and has quickly spread to all prefectures by distributing infected fish. This review describes basic information on KHV/KHV disease such as its pathogenicity, diagnostic methods, control measures and status of virus distribution in Japan.

show abstract

Detection and application of circular (concatemeric) DNA as an indicator of koi herpesvirus infection

Cited by 3 publications

References 26 publications

Application of Environmental DNA for Monitoring Red Sea Bream Iridovirus at a Fish Farm

Application of Environmental DNA for Monitoring Red Sea Bream Iridovirus at a Fish Farm

Assessing the transmission risk of red sea bream iridovirus (RSIV) in environmental water: insights from fish farms and experimental settings

Koi Herpesvirus Disease

Contact Info

Product

Resources

About