Inter-Research > DAO > v133 > n1 > p7-17  

DAO 133:7-17 (2019)  -  DOI: https://doi.org/10.3354/dao03339

Prevalence of nervous necrosis virus (NNV) and Streptococcus species in wild marine fish and crustaceans from the Levantine Basin, Mediterranean Sea

Ran Berzak1, Aviad Scheinin1, Nadav Davidovich2, Yael Regev1, Rei Diga1, Dan Tchernov1, Danny Morick1,*

1Morris Kahn Marine Research Station, Department of Marine Biology, Leon H. Charney School of Marine Sciences, University of Haifa, 3498838, Israel
2Israeli Veterinary Services, Bet Dagan, 20250, Israel
*Corresponding author:

ABSTRACT: Infectious diseases in marine animals have ecological, socio-economic and environmental impacts. Nervous necrosis virus (NNV) and Streptococcus iniae have become major threats to marine aquaculture and have been detected in morbid marine organisms worldwide. However, despite their importance, there is a lack of knowledge regarding the prevalence of these pathogens in wild fish species. Here we sampled indigenous and Lessepsian species from different trophic levels and different biological niches in the eastern Mediterranean. A total of 174 fish and 32 crustaceans were tested for S. iniae and a total of 195 fish and 33 crustaceans were tested for NNV. We found an overall prevalence of 9.71% Streptococcus spp. and 21.49% NNV in selected marine fish and crustaceans by PCR and qPCR. In fish, the zoonotic agent S. iniae was detected at a higher prevalence in kidney compared to liver tissue. Co-infection by both pathogens was detected only in 5 specimens. We also examined gilthead sea bream Sparus aurata from an Israeli offshore marine farm during the grow-out period, in order to assess the possibility of horizontal pathogen transmission from wild to maricultured fish. Three out of 15 (20%) fish were found to be NNV positive after 120 d in the sea, suggesting spontaneous transmission from wild to farmed fish. Our findings suggest that more surveys should be conducted, especially in areas were mariculture farms are planned to be established.


KEY WORDS: Betanodavirus · Streptococcus iniae · Pathogens · Marine fish · Wild fish


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Cite this article as: Berzak R, Scheinin A, Davidovich N, Regev Y, Diga R, Tchernov D, Morick D (2019) Prevalence of nervous necrosis virus (NNV) and Streptococcus species in wild marine fish and crustaceans from the Levantine Basin, Mediterranean Sea. Dis Aquat Org 133:7-17. https://doi.org/10.3354/dao03339

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