Nanoinjection as a tool to mimic vertical transmission of Flavobacterium psychrophilum in rainbow trout Oncorhynchus mykiss

Ekman, Elisabet; Åkerman, Gun; Balk, Lennart; Norrgren, Leif

doi:10.3354/dao055093

Cited by 15 publications

(16 citation statements)

References 30 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It might be possible that exposure to contaminants before the immune system has developed, has caused as yet unknown effects. The developing immune system in mammals has been shown to be highly sensitive to environmental contaminants (Ross et al 1997) and the same could be expected in fish.In an experimental infection with Flavobacterium psychrophilum using the nanoinjection method (Ekman et al 2003) the clinical signs of disease and pathological findings of dead and moribund fry are in accordance with those described in the present study. However, lesions on the yolk sac with vesicles, ulcerations and leakage of yolk were not noted in the previous study.…”

supporting

confidence: 65%

“…Yolk sac oedema has also been seen in association with experimental F. psychrophilum infection (Ekman et al 2003). Furthermore, F. psychrophilum has been suggested as being part of the aetiology of blue-sac disease, characterised by yolk sac oedema, in lake trout Salvelinus namaycush (Symula et al 1990).The mortality in the groups injected with 100 CFU bacteria was lower in this experiment compared to earlier results in a study by Ekman et al (2003). A passive transfer of immunity from the female to the offspring has been indicated (Mor & Avtalion 1990, Castillo et al 1993.…”

mentioning

confidence: 81%

“…Yolk sac oedema has previously been reported in connection with exposure to 2, 3, 7, 8-tetrachlorodibenzo-p-dioxin (TCDD) (Walker et al 1991) and PCB (Wilson & Tillitt 1996). Yolk sac oedema has also been seen in association with experimental F. psychrophilum infection (Ekman et al 2003). Furthermore, F. psychrophilum has been suggested as being part of the aetiology of blue-sac disease, characterised by yolk sac oedema, in lake trout Salvelinus namaycush (Symula et al 1990).…”

mentioning

confidence: 85%

“…Micro-and nanoinjection techniques into eggs or newly hatched fry have been used to mimic this maternal transfer of lipophilic contaminants (Walker et al 1996, Engwall et al 1994 as well as vertical transmission of bacteria, i.e. Renibacterium salmoninarum (Brown et al 1990) and Flavobacterium psychrophilum (Ekman et al 2003). The nanoinjection technique makes it possible to administer very small volumes into the newly fertilised egg without causing adverse effects.…”

Section: Introductionmentioning

confidence: 99%

“…A passive transfer of immunity from the female to the offspring has been indicated (Mor & Avtalion 1990, Castillo et al 1993. The eggs in this and the previous study by Ekman et al (2003) originated from 1 female each. It cannot be ruled out that the eggs in this study originated from a female that had been exposed to Flavobacterium psychrophilum previously during her life.…”

mentioning

confidence: 99%

See 4 more Smart Citations

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

Ekman

Åkerman²,

Balk³

et al. 2004

Dis. Aquat. Org.

Self Cite

View full text Add to dashboard Cite

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, and groups 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 the control 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 groups exposed 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 mean cumulative 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 indicates that maternal transfer of PCB might affect disease resistance to vertically transmitted F. psychrophilum. KEY WORDS: Flavobacterium psychrophilum · Rainbow trout fry syndrome · RTFS · Polychlorinated biphenyls · PCB · Disease resistance · Nanoinjection · Rainbow trout Resale or republication not permitted without written consent of the publisherDis Aquat Org 60: [31][32][33][34][35][36][37][38][39] 2004 unaltered susceptibility to infections have been observed (Snarski 1982, Mayer et al. 1985, Spitsbergen et al. 1988, Arkoosh et al. 2001, Powell et al. 2003.Infections with the bacterium Flavobacterium psychrophilum, the aetiological agent of rainbow trout fry syndrome (RTFS) and bacterial cold-water disease (BCWD), are a problem in salmonid aquaculture worldwide. RTFS is a septicaemic disease in rainbow trout (Oncorhynchus mykiss) fry that can cause mortalities up to 70% (Lorenzen et al. 1991, Bruno 1992. Disease outbreaks often occur during the first 2 mo of feeding (Lorenzen et al. 1991). Main pathological findings are an enlarged spleen, pale gills, liver and kidney, and a haemorrhagic protruding anus (Lorenzen et al. 1991). F. psychrophilum has been isolated from internal organs and sexual products of salmonid brood fish (Holt 1987, Rangdale et al. 1996, Brown et al. 1997, Ekman et al. 1999. The bacterium has also been isolated from the inside of fertilised eggs (Brown et al. 1997, Kumagai et al. 2000, strongly indicating that vertical transmission occurs.The developing fry can be exposed to lipophilic pollutants, like PCB, by transfer from the female to the egg before o...

show abstract

supporting

confidence: 65%