The Application Of Blood Indexs In The Diagnosis And Immune Response Evaluation Of The Giant Salamander Iridovirus Disease

In recent years, the viral hemorrhagic disease is widely spreading in the farming areas of the Chinese giant salamander and have caused huge economic loss. The giant salamander iridovirus (GSIV), which belongs to the genus of Ranavirus, the family of Iridoviridae, has been confirmed as the causative pathogen of the disease.By using the Wright-Giemsa staining method, in this study the morphology and the number of blood cells of Chinese giant salamander were identified and measured. The results indicate that:The red blood cells have various types and morphologies in development, including mature red blood cells, immature red blood cells, infantile red blood cells, red blood cells without nuclear, pear-shaped red blood cells and red blood cells on division stage. Mature red blood cells are long elliptical in shape, major axis is (45.17±3.46)μm, minor axis is (22.92±2.20)μm. White blood cells are irregular or approximate circular in shape, Neutrophil’s major axis is (33.36±4.93)μm and minor axis is (30.44±3.93)μm; Large lymphocyte’s major axis is (28.25±3.64)μm and minor axis is (25.49±2.39)μm; Small lymphocyte’s major axis is (21.08±2.61)μm and minor axis is (19.38±2.07)μm; Monocyte’s major axis is (37.32±7.46)μm and minor axis is (32.34±7.02)μm. Thrombocytes are small and fusiform or melon seed form in shape, they stay together usually or exist as single.The physiological and biochemical indexes in the bloods of the diseased Chinese giant salamander infected with GSIV and the healthy animals were analyzed comparatively in this study. The results indicate that, compared with healthy giant salamander, the number of white blood cells and the ratio of neutrophil are increased significantly (P<0.05) and the ratio of lymphocyte are decreased significantly (P＜0.05) in the diseased giant salamander. Meanwhile, in the diseased animal, ALT、AST are increase significantly (P<0.05), GLU, TP and TCHO are decreased significantly (P＜0.05), TG, AKP are no significant difference (P＞0.05), the activity of NOS and ACP are increase significantly (P＜0.05). The GSIV killed vaccine was used as an immunogen to immunize2-year-old healthy giant salamander. The blood samples were collected at day1,2,4,7,14,21,and day28post immunization, respectively, and then the blood cells counting, typing, the devour activity of phagocyte and serum antibody titers were determined. The results show that, the number of red blood cell and white blood cell, the classification of neutrophil percentage and the phagocytic percentage of phagocyte are all increase significantly (P＜0.05) within1weeks after immunization. The number of lymphocyte and the serum antibody titers reach the highest value on the day21post immunization.The challenge test of the immunized animal with live GSIV reveals that the relative percentage survival is about75%.