Temperature modulate disease susceptibility of the Pacific oyster Crassostrea gigas and virulence of the Ostreid herpesvirus type 1

Temperature triggers marine diseases by changing host susceptibility and pathogen virulence. Oyster mortalities associated with the Ostreid herpesvirus type 1 (OsHV-1) have occurred seasonally in Europe when the seawater temperature range reaches 16–24 °C. Here we assess how temperature modulates oyster susceptibility to OsHV-1 and pathogen virulence. Oysters were injected with OsHV-1 suspension incubated at 21 °C, … Continue reading Temperature modulate disease susceptibility of the Pacific oyster Crassostrea gigas and virulence of the Ostreid herpesvirus type 1

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Analysis of farm management strategies following herpesvirus (OsHV-1) disease outbreaks in Pacific oysters in Tasmania, Australia

The microvariant genotype of Ostreid herpesvirus 1 (OsHV-1 μVar) has severely disrupted oyster production in Europe, New Zealand, and Australia by causing repeated and seasonal outbreaks of mass mortality in Pacific oysters (Magallana gigas). The virus was first detected in Tasmania, Australia, in January 2016, and mortalities of up to 87% were reported (de Kantzow et … Continue reading Analysis of farm management strategies following herpesvirus (OsHV-1) disease outbreaks in Pacific oysters in Tasmania, Australia

Validation of housekeeping genes for quantitative mRNA expression analysis in OsHV-1 infected ark clam, Scapharca broughtonii

Highlights • Previous studies of housekeeping genes selection in mollusc species were reviewed. • Ten candidate housekeeping genes were assessed in ark shell under given conditions. • RL7 and EF-1a were the most stable genes across tissues in ark shells. • RL15 appeared more stable than others under a variety of given conditions. • 18s … Continue reading Validation of housekeeping genes for quantitative mRNA expression analysis in OsHV-1 infected ark clam, Scapharca broughtonii

Counting the dead to determine the source and transmission of the marine herpesvirus OsHV-1 in Crassostrea gigas

Marine herpesviruses are responsible for epizootics in economically, ecologically and culturally significant taxa. The recent emergence of microvariants of Ostreid herpesvirus 1 (OsHV-1) in Pacific oysters Crassostrea gigas has resulted in socioeconomic losses in Europe, New Zealand and Australia however, there is no information on their origin or mode of transmission. These factors need to … Continue reading Counting the dead to determine the source and transmission of the marine herpesvirus OsHV-1 in Crassostrea gigas

Histological alterations in Pacific oysters Crassostrea gigas that survived a summer mortality event in Baja California, Mexico

A mortality episode (>90%) of triploid and diploid Pacific oysters Crassostrea gigas cultured in Baja California Sur occurred during summer 2012, coinciding with a thermal anomaly, an algal bloom, and low oxygen values. To help explain the cause of the mortalities, histological analyses and molecular tests for specific pathogens (ostreid herpesvirus 1 [OsHV‐1] and Perkinsus … Continue reading Histological alterations in Pacific oysters Crassostrea gigas that survived a summer mortality event in Baja California, Mexico

A literature review as an aid to identify strategies for mitigating ostreid herpesvirus 1 in Crassostrea gigas hatchery and nursery systems

An understanding of husbandry strategies and any associated risk factors is important for designing management control measures that can reduce mortality in Pacific oysters, Crassostrea gigas, caused by ostreid herpesvirus 1 (OsHV‐1). The type of culture facility can be considered in relation to the potential pathways that could lead to the entry of a pathogen … Continue reading A literature review as an aid to identify strategies for mitigating ostreid herpesvirus 1 in Crassostrea gigas hatchery and nursery systems

Inefficient immune response is associated with microbial permissiveness in juvenile oysters affected by mass mortalities on field

Since 2008, juvenile Crassostrea gigas oysters have suffered from massive mortalities in European farming areas. This disease of complex etiology is still incompletely understood. Triggered by an elevated seawater temperature, it has been associated to infections by a herpes virus named OsHV-1 as well as pathogenic vibrios of the Splendidus clade. Ruling out the complexity … Continue reading Inefficient immune response is associated with microbial permissiveness in juvenile oysters affected by mass mortalities on field