title: Mortality occurrence and pathogen detection in Crassostrea gigas and Mytilus galloprovincialis close-growing in shallow waters (Goro lagoon, Italy).
abstract: The complex interactions occurring between farmed bivalves and their potential pathogens in the circumstances of global climate changes are current matter of study, owing to the recurrent production breakdowns reported in Europe and other regions of the world. In the frame of Project FP7-KBBE-2010-4 BIVALIFE, we investigated the occurrence of mortality and potential pathogens during the Spring-Summer transition in Crassostrea gigas and Mytilus galloprovincialis cohabiting in the shallow waters of one northern Italian lagoon (Sacca di Goro, Adriatic Sea) and regarded as susceptible and resistant species, respectively. In 2011, limited bivalve mortality was detected in the open-field trial performed with 6-12 month old spat whereas subsequent trials with 2-3 month old spat produced almost complete (2012) and considerable (2013) oyster mortality. Macroscopical examination and histology excluded the presence of notifiable pathogens but, in the sampling preceding the massive oyster spat mortality of 2012, a μdeleted variant of OsHV-1 DNA was found in wide-ranging amounts in all analyzed oysters in conjunction with substantial levels of Vibrio splendidus and Vibrio aestuarianus. The large oyster spat mortality with borderline OsHV-1 positivity recorded in 2013 supports the multi-factorial etiology of the syndrome. This is the first report of a OsHV-1 (under a form interpreted as the variant μVar) in the Goro lagoon. Transcriptional host footprints are under investigation to better understand the bivalve response to environmental factors, included viral and bacterial pathogens, in relation to the observed mortalities.
authors.affiliation: Department of Biology, University of Padova, Padova, Italy.
authors.forename: Stefania
authors.initials: S
authors.lastname: Domeneghetti
authors.affiliation: Department of Biology, University of Padova, Padova, Italy.
authors.forename: Laura
authors.initials: L
authors.lastname: Varotto
authors.affiliation: Istituto Zooprofilattico Sperimentale delle Venezie (IZSVe, also NRL for Mollusc Diseases), Adria, Italy.
authors.forename: Michele
authors.initials: M
authors.lastname: Civettini
authors.affiliation: Department of Biology, University of Padova, Padova, Italy.
authors.forename: Umberto
authors.initials: U
authors.lastname: Rosani
authors.affiliation: Department of Earth, Environmental and Life Sciences, University of Genova, Italy.
authors.forename: Monica
authors.initials: M
authors.lastname: Stauder
authors.affiliation: Istituto Zooprofilattico Sperimentale delle Venezie (IZSVe, also NRL for Mollusc Diseases), Adria, Italy.
authors.forename: Tobia
authors.initials: T
authors.lastname: Pretto
authors.affiliation: Department of Earth, Environmental and Life Sciences, University of Genova, Italy.
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Pezzati
authors.affiliation: Istituto Zooprofilattico Sperimentale delle Venezie (IZSVe, also NRL for Mollusc Diseases), Adria, Italy.
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Arcangeli
authors.affiliation: CRIM Laboratory - Delta Institute, Goro, Ferrara, Italy.
authors.forename: Edoardo
authors.initials: E
authors.lastname: Turolla
authors.affiliation: Department of Life Sciences, University of Trieste, Trieste, Italy.
authors.forename: Alberto
authors.initials: A
authors.lastname: Pallavicini
authors.affiliation: Department of Biology, University of Padova, Padova, Italy. Electronic address: paola.venier@unipd.it.
authors.forename: Paola
authors.initials: P
authors.lastname: Venier
mesh_terms: D000818:Animals; D017756:Aquaculture; D049872:Bivalvia / Q000276:immunology / Q000821:virology*; D004279:DNA, Viral / Q000737:chemistry / Q000235:genetics; D004196:Disease Outbreaks; D006564:Herpesviridae / Q000235:genetics / Q000302:isolation & purification*; D006566:Herpesviridae Infections / Q000276:immunology*; D006651:Histocytochemistry; D054884:Host-Pathogen Interactions; D007558:Italy; D016133:Polymerase Chain Reaction; D012621:Seasons; D014733:Vibrio / Q000235:genetics / Q000302:isolation & purification*; D014735:Vibrio Infections / Q000276:immunology*
chemical_list: D004279:DNA, Viral
keywords: Crassostrea gigas; Goro lagoon; Mytilus galloprovincialis; OsHV-1; Vibrio spp