Oral administration of Fumagillin DCH protects chinook salmon Oncorhynchus tshawytscha from experimentally-induced proliferative kidney disease

Abstract

The antibiotic Fumagillin DCH was found to be effective in controlling experimental infections with PKX, the myxosporean that causes proliferative kidney disease (PKD) in salmonid fish. Following 6 or 7 wk of treatment, experimentally infected chinook salmon Oncorhynchus tshawytscha showed no evidence of PKX cells, or of the renal inflammation characteristic of PKD, on withdrawal of the treatment and tor up to 7 wk afterwards. In contrast, 90 to 100 % of fish (in 2 experiments) that were injected with PKX, but not glven the antibiotic, had numerous PKX cells in the kidney and developed clinical PKD. This is the first report of an effective orally administered drug for the control of a myxozoan infection in salmonid fish.

Efficacy of fumagillin against proliferative kidney disease and its toxic side effects in rainbow trout (Oncorhynchus mykiss) fingerlings.

“…A similar prophylactic effect was observed in experimentally-infected chinook salmon fed 1.0 to 0.5 g drug/kg feed (HEDRICK et al, 1988a).…”

“…The potential of the drug for treating microsporidian and myxosporean diseases of fish has also been reported (KANO et al, 1982;MOLNAR et al, 1987;HEDRICK et al, 1988a). The myxosporean PKX, is the cause of proliferative kidney disease (PKD), one of the most serious diseases of farm-reared salmonids in Europe and North America (CLIFTON HADLEY et al, 1984;HEDRICK et al, 1986 the control group fed unmedicated diet.…”

Trials with fumagillin DCH and malachite green to control ceratomyxosis in rainbow trout (Oncorhynchus mykiss).

“…These two treatments were examined because of recent successes in controlling certain myxosporean infections (MOLNAR et al, 1987, HEDRICK et al, 1988, WISHKOVSKY et al, 1990, ALDERMAN and CLIFTON -HADLEY, 1988, CLIFTON-HADLEY and ALDERMAN, 1987.…”

“…However, recent reports by ALDER MAN (1986), MOLNAR et al (1987), HEDRICK et al ( 1988) and CLIFTON-HADLEY and ALDERMAN (1987) have shown the efficacy of selected drug and chemical treatments for myxosporean infections. Proguanil and Clamoxyquin reduced the severity of the pathology and spore numbers among rainbow trout (Oncorhynchus mykiss) infected with Myxobolus (Myxosoma) cerebralis (ALDER MAN, 1986).…”

“…MOLNAR et al (1987) found that fumagillin DCH fed to common carp (Cyprinus carpio) fry could prevent experimental and reduce natural infections with Sphaerospora renicola. The similarities between the carp parasite and PKX, the causative agent of proliferative kidney disease (PKD) in salmonid fish, prompted HEDRICK et al (1988) to test fumagillin in chinook salmon (Oncorhynchus tshawytscha) as a potential therapeutic for PKD. Fumagillin was found to be very effective in preventing PKD infections when fed to chinook salmon at 0.5-1.0 g/kg of diet at approximately 1 % body weight per day.…”