Understanding the role of Francisella halioticida in mussel mortalities in France: an integrative approach.

Since 2014, mass mortalities of mussels Mytilus spp. have occurred in production areas on the Atlantic coast of France. The aetiology of these outbreaks remained unknown until the bacterium Francisella halioticida was detected in some mussel mortality cases.

Development of a semi-quantitative PCR assay for the detection of Francisella halioticida and its application to field samples.

The current study describes the development and application of a TaqMan real-time PCR assay for the detection of the bacterium Francisella halioticida. Previously, detection of F. halioticida is relied on bacterial culture and conventional PCR; however, the real-time PCR provides many advantages because it is faster, less labour-intensive and reduces the risk of cross-contamination.

First detection of Francisella halioticida in mussels Mytilus spp. experiencing mortalities in France.

This note describes the first detection of the bacteria Francisella halioticida in mussels Mytilus spp. from locations in Normandy and northern Brittany (France) experiencing high mussel mortalities, while it was not detected in the Bay of St Brieuc (northern Brittany), an area which was not affected by abnormal mussel mortality. The distribution of the bacteria in mussels seems to be restricted to inflammatory granulomas as observed in Yesso scallops Mizuhopecten yessoensis from Canada and Japan.

High mortality of mussels in northern Brittany - Evaluation of the involvement of pathogens, pathological conditions and pollutants.

In 2014, a high and unusual mass mortality of mussels occurred in several important production areas along the French coasts of the Atlantic and English Channel. In the first quarter of 2016, mass mortalities hit farms on the west coast of the country once again. These heterogeneous mortality events elicited a multi-parametric study conducted during the 2017 mussel season in three sites in northern Brittany (Brest, Lannion and St.

Experimental infection of Mytilus edulis by two Vibrio splendidus-related strains: Determination of pathogenicity level of strains and influence of the origin and annual cycle of mussels on their sensitivity.

This study aimed at assessing the pathogenicity of two Vibrio splendidus-related species and evaluating the influence of the origin and annual life cycle of mussels on their sensitivity during a bacterial challenge. Thus, in vivo infection assays were made with Vibrio crassostreae 7T4_12 and Vibrio splendidus 3G1_6, over, respectively, thirteen and 9 months, on adult blue mussels from five recruitment areas in France. Two bacterial concentrations were tested: one consistent with the loads of Vibrio spp.