Some Hematological and Non-Specific Immune Responses of Rosehip (Rosa canina) - Fed Russian Sturgeon (Acipenser gueldenstaedtii Brandt & Ratzeburg, 1833) to Mycobacterium salmoniphilum

ABSTRACT In the study, the immunostimulant effects of rosehip (Rosa canina) on the health indicator hematological and non-specific immune parameters of Mycobacterium salmoniphilum-infected sturgeon were investigated. The rosehip was applied in the ratios of R5 (5%), R10 (10%), and R15 (15%) in three repetitions. After a 35-day feeding period, the fish were infected with M. salmoniphilum and analyzed after day 7, when symptoms were observed at elevated levels. Erythrocyte, erythrocyte indices, hemoglobin, hematocrit, leukocyte levels and the non-specific immune parameters including lymphocyte, monocyte, eosinophil, neutrophil, cytokines, phagocytic activity levels were comparatively examined using positive and negative control groups. The evaluations revealed that the RBC, Hb, Hct and WBC counts in the R15 group were significantly higher than those of the C+ group. Moreover, depending on the level of the immune response of the fish, among the immune parameters, significant increases in the lymphocyte, monocyte, cytokine, and phagocytic activity levels were observed in the R15 group. The results showed that the hematological and immune response to M. salmoniphilum infection was stimulated significantly in the 15% rosehip-fed fish. Hence, the effective dose of rosehip in fish was determined to be 15% and rosehip is suggested as an alternative to currently recommended immunostimulants.

Characterization of Mycobacterium salmoniphilum as causal agent of mycobacteriosis in Atlantic salmon, Salmo salar L., from a freshwater recirculation system.

Thirty Atlantic salmon, Salmo salar L., with low corporal condition relative to other fish present in the culture system, were sampled from a freshwater recirculation pisciculture located in Chile. The most characteristic signs and lesions were cachexia and presence of multiple greyish-white granulomas within internal organs. The external and internal lesions, along with the microscopic, histologic and biochemical findings, were consistent with mycobacteriosis. The identification of Mycobacterium salmoniphilum as the causal agent of the lesions was possible through the use of molecular analyses. This study represents the first report of Mycobacterium salmoniphilum in a freshwater recirculation system and the first case of fish mycobacteriosis described in Chile.