Detection of Type 1 Ostreid Herpes variant (OsHV-1 micro Var) with no associated mortality in French-origin Pacific cupped oyster Crassostrea gigas farmed in Italy.

摘要

In April 2010, the sampling of juvenile Pacific cupped oysters originating from France was undertaken from a farm located off the coast of the Marche region in Italy. Samples were sent to the national reference laboratory for mollusc diseases for bacteriological, histological, electron microscopical and molecular analysis. Classical and Real-Time PCR indicated the presence of the microvariant (OsHV-1 micro var) of Type 1 Ostreid Herpes virus (OsHV-1) despite the absence of clinical and pathological signs normally associated with the presence of this variant. Further molecular and sequencing analysis revealed the presence of OsHV-1 micro var and OsHV-1 DNA in one oyster indicating that simultaneous detection of both viruses is possible. This is the first report of the presence of OsHV-1 micro var in Italy and also the first time that evidence of possible co-infection of OsHV-1 and OsHV-1 micro var has been provided.