| Abstract | Since early autumn 2016, Mass Mortality Events (MME) have drastically impacted the population of the fan mussel Pinna nobilis in the Mediterranean Sea. Haplosporidium pinnae, a newly described Haplosporidian species, has been considered the causative agent of the mortality outbreaks in association to opportunistic bacterial pathogens. In the present study, we first reported a cytological description of H. pinnae in moribund specimens of P. nobilis which were collected in the Gulf of Taranto (Ionian Sea, Italy) during summer 2018. Different life-cycle stages of the parasite, including uni- and binucleate cells, small plasmodia, big multinucleate plasmodia and sporocysts with spores, were detected in all the examined animals and most of the parasite cells were present in gills, mantle and digestive gland, while the spores were found only in the latter organ. Histology and molecular biology were also performed, confirming the nature of the infectious agent, as already reported in the area. Additionally, molecular study revealed the presence of bacteria from the Mycobacterium ulcerans - M. marinum complex but no evident macroscopical or microscopical lesions, just as no bacteria referred to Mycobacterium were observed by histology. In conclusion, the present study aimed to provide further contributions to the un- derstanding of the mortality of P. nobilis, pointing to the role of the cytological method of investigation both for diagnostic and epidemiological purposes, and discussing the current epidemic situation in the Adriatic sea. |
| Text | 465871 2022 10.1016/j.jip.2022.107735 Pinna nobilis Haplosporidium pinnae Cytology Mycobacterium Hemocytes New insights about Haplosporidium pinnae and the pen shell Pinna nobilis mass mortality events Pietro Giorgio Tiscar Fernando Rubino Barbara Paoletti Cristina Di Francesco Francesco Mosca Leonardo Della Salda Jasmine Hattab Camilla Smoglica Simone Morelli Giovanni Fanelli Faculty of Veterinary Medicine, University of Teramo, Piano D Accio, Teramo, Italy CNR Water Research Institute, Taranto, Italy Faculty of Veterinary Medicine, University of Teramo, Piano D Accio, Teramo, Italy Faculty of Veterinary Medicine, University of Teramo, Piano D Accio, Teramo, Italy Faculty of Veterinary Medicine, University of Teramo, Piano D Accio, Teramo, Italy Faculty of Veterinary Medicine, University of Teramo, Piano D Accio, Teramo, Italy Faculty of Veterinary Medicine, University of Teramo, Piano D Accio, Teramo, Italy Faculty of Veterinary Medicine, University of Teramo, Piano D Accio, Teramo, Italy Faculty of Veterinary Medicine, University of Teramo, Piano D Accio, Teramo, Italy CNR Water Research Institute, Taranto, Italy Since early autumn 2016, Mass Mortality Events MME have drastically impacted the population of the fan mussel Pinna nobilis in the Mediterranean Sea. Haplosporidium pinnae, a newly described Haplosporidian species, has been considered the causative agent of the mortality outbreaks in association to opportunistic bacterial pathogens. In the present study, we first reported a cytological description of H. pinnae in moribund specimens of P. nobilis which were collected in the Gulf of Taranto Ionian Sea, Italy during summer 2018. Different life cycle stages of the parasite, including uni and binucleate cells, small plasmodia, big multinucleate plasmodia and sporocysts with spores, were detected in all the examined animals and most of the parasite cells were present in gills, mantle and digestive gland, while the spores were found only in the latter organ. Histology and molecular biology were also performed, confirming the nature of the infectious agent, as already reported in the area. Additionally, molecular study revealed the presence of bacteria from the Mycobacterium ulcerans M. marinum complex but no evident macroscopical or microscopical lesions, just as no bacteria referred to Mycobacterium were observed by histology. In conclusion, the present study aimed to provide further contributions to the un derstanding of the mortality of P. nobilis, pointing to the role of the cytological method of investigation both for diagnostic and epidemiological purposes, and discussing the current epidemic situation in the Adriatic sea. 190 Published version https //doi.org/10.1016/j.jip.2022.107735 Articolo in rivista Academic Press, 0022 2011 Journal of invertebrate pathology Print Journal of invertebrate pathology Print J. invertebr. pathol. Print Journal of invertebrate pathology. Print giovanni.fanelli FANELLI GIOVANNI fernando.rubino RUBINO FERNANDO |
