Ultraviolet irradiation inactivates the waterborne infective stages of Myxobolus cerebralis: a treatment for hatchery water supplies

摘要: The effects of ultraviolet (UV) irradiation on the viability waterborne triactino- myxon stages Myxobolus cerebralis were evaluated by vital staining and infectivity for juve- nile rainbow trout Oncorhynchus mykiss. A dose 1300 mWs cm -2 was required to inactivate 100% triactinomyxons held under a static collimated beam UV as determined staining. Juvenile protected from infections with M. when exposed 14 000 or 1400 triactinomyxon spores per fish that had been treated collimating apparatus (1300 ). Among all receiving UV-treated triactinomyxons, none clinical signs whirling disease, evidence microscopic lesions after 5 mo at water temperatures 15°C. In contrast, higher untreated myxons developed disease both infection detected in high low expo- sures. Two additional trials Cryptosporidium Inactivation Device (CID) its ability treat flow-through 15°C well which added over 2 wk period. CID treatments cumulative exceeding 64 juvenile rain- bow cerebralis. Rainbow controls same number cranial spore concentrations up 10 4.6 1 ⁄2 head, although no observed. (126 mW s , apparatus) also effective killing Flavobacterium psychrophilum, agent causing salmonid bacterial coldwater demonstrated inability cells grow artificial media following treatment.