Impact of PCB on resistance to Flavobacterium psychrophilum after experimental infection of rainbow trout Oncorhynchus mykiss eggs by nanoinjection

Diseases of Aquatic Organisms

Elisabet Ekman¹  Leif Norrgren¹  Gun Åkerman¹  Lennart Balk¹ 

关键词: Flavobacterium psychrophilum;    Rainbow trout fry syndrome;    RTFS;    Polychlorinated biphenyls;    PCB;    Disease resistance;    Nanoinjection;    Rainbow trout;   

DOI  :  10.3354/dao060031

学科分类：生物科学（综合）

来源: Inter-Research

【 摘 要 】

ABSTRACT: The effects of sublethal exposure of a commercial blend of polychlorinated biphenyls (PCB), i.e. Clophen A50, on disease resistance to the aetiological agent of rainbow trout fry syndrome, Flavobacterium psychrophilum, were investigated.Newly fertilised rainbow trout Oncorhynchus mykiss eggs were nanoinjected with 2 doses of Clophen A50 (0.4 or 2 µg egg^-1) and/or 100 colony forming units of F. psychrophilum. The mean cumulative mortality in control groups, andgroups exposed to the lower dose of Clophen A50 (0.4 µg egg^-1) was below 5.0%. The mean cumulative mortality in groups exposed to the higher dose of Clophen A50 (2.0 µg egg^-1) was 5.8%, which was not significantly different from thecontrol groups. In all groups infected with F. psychrophilum, with or without exposure to Clophen A50, significantly higher cumulative mortalities compared with control groups were recorded. No differences in mortality were recorded between groupsexposed to bacteria alone or bacteria in combination with the higher dose of Clophen A50 (21.6 and 20.4%, respectively). Decreased disease resistance was recorded in groups exposed to F. psychrophilum and the lower dose of Clophen A50, with a meancumulative mortality of 56.0%. These results could be due to non dose-dependent effects on the immune system, or toxic effects of PCB or their metabolites on the bacteria in groups exposed to the higher dose of Clophen A50. The present study indicatesthat maternal transfer of PCB might affect disease resistance to vertically transmitted F. psychrophilum.

【 授权许可】

Unknown