RT Journal Article T1 An Outbreak of Aeromonas salmonicida in Juvenile Siberian Sturgeons (Acipenser baerii) A1 Vázquez Fernández, Esther A1 Chinchilla Rodríguez, Blanca A1 Rebollada Merino, Agustín Miguel A1 Domínguez Rodríguez, Lucas José A1 Rodríguez Bertos, Antonio Manuel AB Aeromonas salmonicida is one of the major threats to world aquaculture, causing fish furunculosis and high mortality rates in cultured fish, particularly salmonids. Although Aeromonas spp. is a thoroughly studied pathogen, little is known regarding aeromoniasis in sturgeons. After a mortality outbreak, four juvenile sturgeons (Acipenser baerii) were submitted for autopsy and tissue samples were collected for histopathological and microbiological studies. The external examination revealed size heterogenicity, skin hyperpigmentation and reduced body condition of sturgeons. Within the abdominal cavity, mild hepatomegaly and splenomegaly were observed, as well as generalized organic congestion. Histology revealed severe multifocal haemorrhagic and ulcerative dermatitis, mainly localized in the dorsal and latero-ventral areas of fish. The histological study also showed moderate to severe inflammation of gills and organic lesions compatible with septicaemia. Bacterial isolates were identified as Aeromonas salmonicida subsp. salmonicida using MALDI-TOF MS and PCR. Overall, the lesions first described here are consistent with those previously reported in other cultured fish species and contribute to a better understanding of the pathogenesis of Aeromonas salmonicida subsp. salmonicida in the Siberian sturgeon, aside from providing new diagnostic tools for bacterial diseases impacting the fast-growing industry of caviar. PB MDPI SN 2076-2615 YR 2023 FD 2023-08-23 LK https://hdl.handle.net/20.500.14352/103650 UL https://hdl.handle.net/20.500.14352/103650 LA eng NO Vázquez-Fernández, E., Chinchilla, B., Rebollada-Merino, A., Domínguez, L., & Rodríguez-Bertos, A. (2023). An Outbreak of Aeromonas salmonicida in Juvenile Siberian Sturgeons (Acipenser baerii). Animals : an open access journal from MDPI, 13(17), 2697. https://doi.org/10.3390/ani13172697 NO Author Contributions: Conceptualization, A.R.-B. and B.C.; methodology, A.R.-B.; software, E.V.-F.; validation, B.C., A.R.-M., L.D. and A.R.-B.; formal analysis, E.V.-F., B.C. and A.R.-M.; investigation, E.V.-F. and B.C.; resources, L.D. and A.R.-B.; data curation, E.V.-F., B.C. and A.R.-M.; writing—original draft preparation, E.V.-F. and B.C.; writing—review and editing A.R.-M., L.D. and A.R.-B.; supervision, L.D. and A.R.-B. All authors have read and agreed to the published version of the manuscript. NO European Commission NO Ministerio de Ciencia e Innovación (España) DS Docta Complutense RD 28 jul 2024