A novel divergent group of Ostreid herpesvirus 1 µVar variants associated with a mortality event in Pacific oyster spat in Normandy (France) in 2016.
J Fish Dis
; 41(11): 1759-1769, 2018 Nov.
Article
em En
| MEDLINE
| ID: mdl-30151980
ABSTRACT
The acute course of disease in young oysters infected by OsHV-1 and the rapid tissue degradation often preclude histological examination of specimens collected during outbreaks in field. Herein, live spat originated from two geographical areas were sampled just at the onset of a mortality event that occurred in Normandy (France) in June 2016. The lesions, associated with high OsHV-1 DNA quantities, were characterized by severe and diffuse haemocytosis mainly involving blast-like cells, myocyte degeneration and large, irregularly shaped degenerate eosinophilic cells in the connective tissue. The herpesvirus was identified by negative staining TEM and real-time PCR. Sequencing of the C region and ORFs 42/43 confirmed that the variants met the definition of OsHV-1 µVar. We sequenced 30 other ORFs in twenty OsHV-1-positive individuals and compared them to the µVar specimens isolated between 2009 and 2011. The ORFs encoding putative membrane proteins showed the highest number of variations. Seven different genotypes were identified, confirming the presence of relevant genetic diversity. Phylogenetic analysis provided evidence for a well-separated µVar new group, with an evolutionary divergence estimated at 0.0013 from the other µVar variants. The geographical distribution of these newly described variants and their effective virulence should be investigated in future.
Palavras-chave
Texto completo:
1
Bases de dados:
MEDLINE
Assunto principal:
Vírus de DNA
/
Crassostrea
Tipo de estudo:
Risk_factors_studies
Limite:
Animals
País/Região como assunto:
Europa
Idioma:
En
Revista:
J Fish Dis
Assunto da revista:
BIOLOGIA
/
MEDICINA VETERINARIA
Ano de publicação:
2018
Tipo de documento:
Article
País de afiliação:
Itália