The genomic diversity and relative importance of distinct genotypes within natural bacterial populations have remained largely unknown. Here, we analyze the diversity and annual dynamics of a group of coastal bacterioplankton (greater than 99% 16S ribosomal RNA identity to Vibrio splendidus). We show that this group consists of at least a thousand distinct genotypes, each occurring at extremely...

Naturally occurring quinolone and quinolone-like compounds, such as quinine, 2-hydroxyquinoline, 4-hydroxyquinoline, and 2-heptyl-3-hydroxy-4(1H)-quinolone, increased expression of qnrS1 in Escherichia coli 2.3- to 11.2-fold, similar to the synthetic quinolone ciprofloxacin. In contrast, chromosomal qnrVS1 of Vibrio splendidus was not induced by these compounds. Molecules associated with quorum...

The cultivated Pacific oyster Crassostrea gigas has suffered for decades large scale summer mortality phenomenon resulting from the interaction between the environment parameters, the oyster physiological and/or genetic status and the presence of pathogenic microorganisms including Vibrio species. To obtain a general picture of the molecular mechanisms implicated in C. gigas immune responsivene...

18 Alginate lyases are enzymes that degrade alginate through β-elimination of the glycosidic bond 19 into smaller oligomers. We investigated the alginate lyases from Vibrio splendidus 12B01, a 20 marine bacterioplankton species that can grow on alginate as its sole carbon source. We 21 identified, purified, and characterized four polysaccharide lyase family 7 alginates lyases – 22 AlyA, AlyB, A...

Three strains (VPAP16, VPAP18 and VPAP23 strains) were isolated as the most predominant organisms from 3 different episodes of massive mortalities of larval cultures of the Chilean scallop Argopecten purpuratus occurred in different commercial hatcheries located in northern Chile. The main aims of this study were to identify the pathogenic strains and investigate their pathogenic activity. Base...

Five strains were isolated from moribund scallop (Pecten maximus) larvae over 5 years (1990-1995) during outbreaks of disease in a hatchery (Argenton, Brittany, France). Their pathogenic activity on scallop larvae was previously demonstrated by experimental exposure. The phenotypic and genotypic features of the strains were identical. The G + C content of the strains was in the range 39-41 mol%...

This study was conducted to evaluate the effects of Bacillus licheniformis and combined herbs extracts on physiological immune characteristics, intestinal microbiota, vibriosis resistance sea cucumber Apostichopus japonicus. The cucumbers were fed with basal diets supplemented B. (B group), (C or both (BC group). BC group exhibited better growth performance higher digestive enzyme activities, w...