Health Status of from Intensive Culture Areas in Chile Assessed by Molecular, Microbiological, and Histological Analyses.

Shellfish farming is a relevant economic activity in Chile, where the inner sea in Chiloé island concentrates 99% of the production of the mussel . This area is characterized by the presence of numerous human activities, which could harm the quality of seawater. Additionally, the presence of potentially pathogenic microorganisms can influence the health status of mussels, which must be constantly monitored. To have a clear viewpoint of the health status of and to study its potential as a host species for exotic diseases, microbiological, molecular, and histological analyses were performed. This study was carried out in October 2018, where gut were studied for: presence of food-borne bacteria (, , spp.), exotic bacteria (""), viruses (abalone and Ostreid herpes virus), and protozoa ( spp., spp. and spp.). Additionally, 18S rDNA metabarcoding and histology analyses were included to have a complete evaluation of the health status of Overall, despite the presence of risk factors, abnormal mortality rates were not reported during the monitoring period and the histological examination did not reveal significant lesions. Pathogens of mandatory notification to World Organization for Animal Health (OIE) and the Chilean National Fisheries and Aquaculture Service (SERNAPESCA) were not detected, which confirms that have a good health status, highlighting the importance of an integrated vision of different disciplines to ensure the sustainability of this important mussel industry in Chile.