Treatment of infectious pancreatic necrosis virus (IPNV) disease using dimerized lysozyme (KLP-602)

Summary Following the successful treatment of infectious fish diseases using dimerized lysozyme (KLP‐602), its influence on the nonspecific cellular and humoral defence mechanisms and protection against viral diseases in rainbow trout (Oncorhynchus mykiss) was evaluated. KLP‐602 was applied in diets, at a dose of 10 μg kg‐1 body weight, for a period of 7 days. One week after feeding with the diets containing KLP‐602, the immunomodulatory effects on the suppressed cellular and humoral defence mechanisms were observed in fish naturally infected by infectious pancreatic necrosis virus (IPNV). All immunological parameters were significantly increased in comparison with untreated fish. Cumulative mortality was lower in fish fed the dietary treatment containing dimerized lysozyme (30%), compared with untreated fish (65%). The results showed that the lysozyme dimer (KLP‐602) modulated the cellular and humoral defence mechanisms after suppression induced by IPNV.