Development of a Piscirickettsia salmonis immersion challenge model to investigate the comparative susceptibility of three salmon species.
J Fish Dis
; 44(1): 1-9, 2021 Jan.
Article
en En
| MEDLINE
| ID: mdl-33067883
ABSTRACT
Piscirickettsia salmonis, the aetiological agent of salmonid rickettsial septicaemia (SRS), is a global pathogen of wild and cultured marine salmonids. Here, we describe the development and application of a reproducible, standardized immersion challenge model to induce clinical SRS in juvenile pink (Oncorhynchus gorbuscha), Atlantic (Salmo salar) and sockeye salmon (O. nerka). Following a 1-hr immersion in 105 colony-forming units/ml, cumulative mortality in Atlantic salmon was 63.2% while mortality in sockeye salmon was 10%. Prevalence and levels of the bacterium in kidney prior to onset of mortality were lower in sockeye compared with Atlantic or pink salmon. The timing and magnitude of bacterial shedding were estimated from water samples collected during the exposure trials. Shedding was estimated to be 82-fold higher in Atlantic salmon as compared to sockeye salmon and peaked in the Atlantic salmon trial at 36 d post-immersion. These data suggest sockeye salmon are less susceptible to P. salmonis than Atlantic or pink salmon. Finally, skin lesions were observed on infected fish during all trials, often in the absence of detectable infection in kidney. As a result, we hypothesize that skin is the primary point of entry for P. salmonis during the immersion challenge.
Palabras clave
Texto completo:
1
Banco de datos:
MEDLINE
Asunto principal:
Oncorhynchus
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Salmo salar
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Infecciones por Piscirickettsiaceae
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Susceptibilidad a Enfermedades
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Piscirickettsia
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Enfermedades de los Peces
Tipo de estudio:
Risk_factors_studies
Límite:
Animals
Idioma:
En
Año:
2021
Tipo del documento:
Article