4 new publications related to VIVALDI activities released in 2017

In 2017 and early 2018, Italian and French researchers involved in VIVALDI have published 4 articles emphasising some first scientific results notably obtained thanks to our project.

Manuscript: Whole-genome enrichment provides deep insights into Vibrio cholerae metagenome from an African river. (Vezzulli L, Grande C, Tassistro G, Brettar I, Höfle MG, Pereira RPA, Mushi D, Pallavicini A, Vassallo P, Pruzzo C) 

Published in Microbial Ecology, 2017, doi: 10.1007/s00248-016-0902-x

VIVALDI partner involved: UNIGE (IT)

A novel whole genome enrichment technology for the bacteria Vibrio cholerae was developed and applied to contaminated river water so as to obtain 2000 times more pathogen DNA at the genome level. This protocol could be applied to other microbial pathogens with important application in outbreak epidemiology and microbial source tracking.

Manuscript: Comparative 16SrDNA gene-based microbiota profiles of the Pacific oyster (Crassostrea gigas) and the Mediterranean mussel (Mytilus galloprovincialis) from a shellfish farm (Ligurian Sea, Italy). (Vezzulli L, Stagnaro L, Grande C, Tassistro G, Canesi L, Pruzzo C)

Published in Microbial Ecology, 2018, doi: 10.1007/s00248-017-1051-6

VIVALDI Partner involved: UNIGE (IT)

Bacterial community (microbiota) associated to the pacific oyster Crassostrea gigas and the Mediterranean mussel Mytilus galloprovincialis were evaluated and compared before and after commercial depuration using last generation DNA sequencing technology. The study highlighted the ineffectiveness of commonly employed depuration practice in removing microbial pathogens naturally occurring in the aquatic environment (e.g. Vibrio species) from bivalve tissues.

Manuscript: Oyster RNA-seq Data Support the Development of Malacoherpesviridae Genomics. (Rosani U, Venier P)

Published in Front Microbiol, 2017 Aug, doi: 10.3389/fmicb.2017.01515

Viral infections caused by the Ostreid Herpesvirus type 1 (OsHV-1) are greatly challenging the oyster aquaculture sector. Molecular knowledge on the onset of productive infections is essential to outline mitigation and prevention strategies. Although belonging to the same group of several human and vertebrate viruses, mollusc viruses are far related to other members of the Herpesviridae family, and therefore more difficult to understand. This publication describes the molecular behaviour of the virus, identifies gene signatures possibly associated to different infection phases and to release a first interactive dataset of OsHV-1 gene expression values.

Manuscript: Haemocytes from Crassostrea gigas and OsHV-1: A promising in vitro system to study host/virus interactions. (Benjamin Morga, Nicole Faury, Stéphane Guesdon, Bruno Chollet, Tristan Renault)

Published in Journal of Invertebrate Pathology (2017) DOI:10.1016/j.jip.2017.09.007

The present study aimed at finding out if haemocytes (cell of the haemolymph of various invertebrates) can host the OsHV-1 virus in the Pacific oyster. To this end, haemocytes were collected from healthy Crassostrea gigas spat and exposed in vitro to a viral suspension. Results showed that the virus was detectable one hour after contact and the number of virus transcripts increased over time in association with an increase of viral DNA detection, which suggested that the virus was able to replicate rapidly inside haemocytes maintained in vitro. All the results suggested that the in vitro model using haemocytes can be valuable for providing new perspective on virus-oyster interactions.