Pathogenic characterization of Aeromonas salmonicida subsp. masoucida turbot isolate from China.
J Fish Dis
; 43(10): 1145-1154, 2020 Oct.
Article
em En
| MEDLINE
| ID: mdl-32720397
ABSTRACT
Aeromonas salmonicida is a gram-negative bacterium that is the causative agent of furunculosis. An A. salmonicida strain was isolated from diseased turbot (Scophthalmus maximus) with the sign of furunculosis from North China. Based on vapA gene, the strain was further classified as A. salmonicida subsp. masoucida RZ6S-1. Culturing RZ6S-1 strain at high temperature (28°C) obtained the virulence attenuated strain RZ6S. Genome sequence comparison between the two strains revealed the loss of the type IV secretion system (T4SS) and type III secretion system (T3SS) from the native plasmid pAsmB-1 and pAsmC-1 of wild-type strain RZ6S-1, respectively. Further study demonstrated that the wild-type strain RZ6S-1, but not its derivative mutant RZ6S, can stimulate apoptosis. Elevated protein level of cleaved caspase-3 was detected from epithelioma papulosum cyprinid (EPC) cells infected with wild-type strain RZ6S-1 as compared with that infected with RZ6S strain. Meanwhile, the invasion of the mutant strain RZ6S was about 17-fold higher than the wild-type strain RZ6S-1, suggesting that some protein(s) from A. salmonicida subsp. masoucida RZ6S-1 suppress its invasion. The RZ6S mutant strain was attenuated, since its LD50 is over 10,000 times higher compared to the wild-type strain as revealed in the turbot infection model.
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Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Linguados
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Aeromonas
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Doenças dos Peixes
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Furunculose
Limite:
Animals
País como assunto:
Asia
Idioma:
En
Ano de publicação:
2020
Tipo de documento:
Article