AUTHOR=Carella Francesca , Antuofermo Elisabetta , Farina Simone , Salati Fulvio , Mandas Daniela , Prado Patricia , Panarese Rossella , Marino Fabio , Fiocchi Eleonora , Pretto Tobia , De Vico Gionata 

TITLE=In the Wake of the Ongoing Mass Mortality Events: Co-occurrence of Mycobacterium, Haplosporidium and Other Pathogens in Pinna nobilis Collected in Italy and Spain (Mediterranean Sea)

JOURNAL=Frontiers in Marine Science

VOLUME=7

YEAR=2020

URL=https://www.frontiersin.org/journals/marine-science/articles/10.3389/fmars.2020.00048

DOI=10.3389/fmars.2020.00048

ISSN=2296-7745

ABSTRACT=<p>Following the Mass Mortality Events (MMEs) of the pen shell <italic>P. nobilis</italic> in Campania region and Sicily, a survey of moribund <italic>P. nobilis</italic> specimens was also conducted in other Italian regions (Campania, Tuscany, Sardinia, and Apulia) and Spain (Catalunya). Histopathological and molecular examination of 27 specimens of <italic>P. nobils</italic> revealed different types of pathogens associated with tissue lesions, morbidity and mortality. Presence of Mycobacterium, <italic>Vibrio</italic> species, <italic>Haplosporidium pinnae</italic> and <italic>Perkinsus</italic> sp. were detected, differently distributed into the areas. The <italic>Mycobacterium</italic> sp., previously reported in Campania and Sicily samples, was observed in all the analyzed areas and individuals, associated to systemic inflammatory lesions. In Spain, <italic>H. pinnae</italic> was observed in 36% of cases, always associated to the <italic>Mycobacterium</italic> sp. Molecular study using <italic>hsp65</italic> genes and Internal Transcriber Spacer <italic>ITS</italic> support that a new species of Mycobacteria is infecting <italic>P. nobilis</italic>, close to <italic>M. triplex</italic> and belonging to the group of <italic>M. simiae complex</italic> with <italic>M. sherrisi</italic>. Presence of <italic>Perkinsus</italic> spp. resembling <italic>P. mediterraneus</italic> was observed in 2 out of 13 Italian individuals whose presence should be addressed as potential risk for shellfish aquaculture of the area. <italic>Vibrio</italic> spp. were also detected in some case. The preliminary results of this study suggest that <italic>Mycobacterium</italic> sp., <italic>Vibrio</italic> spp., <italic>H. pinnae</italic> and <italic>Perkinsus</italic> sp. cooperate to disease pathogenesis, being <italic>Mycobacterium</italic> and <italic>Haplosporidium</italic> most of the time involved. Vigilant inspection of those areas where MME is now starting, along with continuous systematic surveys, are crucial to define the spatiotemporal progress of mortality and the role of every single pathogen in the disease outcome.</p>