First Report, Characterization and Pathogenicity of Isolated from Diseased Reared Larvae of Chilean Scallop, (Lamarck, 1819).

Two strains (VPAP36 and VPAP40) were isolated from moribund-settled larvae of the Chilean scallop during vibriosis outbreaks that occurred in two commercial scallop larvae hatcheries located in the Inglesa and Tongoy bays in Northern Chile. The strains were identified as using phenotypic characterization and whole genome sequence analysis. Both strains exhibited the phenotypic properties associated with virulence, gelatin hydrolysis and β-hemolysis, whereas only VPAP36 produced phospholipase and only VPAP40 produced caseinase.

Role of the Vibriolysin VemA Secreted by the Emergent Pathogen in the Colonization of Manila Clam Mucus.

is an emergent pathogen affecting clams, oysters and scallops produced in the most important countries for bivalve aquaculture. Studies concerning virulence factors involved in the virulence of are very scarce despite its global significance for aquaculture. Zinc-metalloproteases have been described as a major virulence factor in some spp.

Phage-host coevolution in natural populations.

Coevolution between bacteriophages (phages) and their bacterial hosts occurs through changes in resistance and counter-resistance mechanisms. To assess phage-host evolution in wild populations, we isolated 195 Vibrio crassostreae strains and 243 vibriophages during a 5-month time series from an oyster farm and combined these isolates with existing V. crassostreae and phage isolates.

Rapid evolutionary turnover of mobile genetic elements drives bacterial resistance to phages.

Although it is generally accepted that phages drive bacterial evolution, how these dynamics play out in the wild remains poorly understood. We found that susceptibility to viral killing in marine is mediated by large and highly diverse mobile genetic elements. These phage defense elements display exceedingly fast evolutionary turnover, resulting in differential phage susceptibility among clonal bacterial strains while phage receptors remain invariant.

First description outside Europe of the emergent pathogen Vibrio europaeus in shellfish aquaculture.

Vibrio europaeus is an emergent pathogen affecting the most important bivalve species reared in Spanish and French hatcheries. Using a genomic approach, we identified V. europaeus outside Europe for the first time from massive larval mortalities of scallop (Argopecten purpuratus) in Chile and from seawater near a shellfish hatchery in the US West Coast.