齐口裂腹鱼感染嗜水气单胞菌后血液生化指标与组织病理学研究

摘要

Schizothorax prenanti (S.prenanti) is an indigenous fish species and distributed in the upstream regions of the Yangtze River and its tributaries in China.S.prenanti has important commercial value in the southwest of China because of its fleshness and good flavor as food fish.Concurrently,the wild resources and populations of S.prenanti have rapidly declined because of water pollution and the construction of hydropower stations.In recent years,it has become one of the most important cold-water aquaculture species in China.However,overly dense stocking levels and rapid expansion of aquaculture has led to several problems affecting the sustainable development of the industry due to a frequent outbreak of infectious diseases.In order to study the effects of Aeromonas hydrophila (A.hydrophila) on blood biochemical indices,one hundred and eighty juveniles S.prenanti with an initial weight of (105±36) g were used and randomly divided into 6 groups (4,24,and 48h controlled groups;4,24,and 48h challenged groups) with three timepoints of 30 fish.Fish used in both the controlled and challenged groups were intraperitoneally injected with equal volumes (0.2 mL) of sterile physiological saline (0.65%) and a bacterial suspension (2.5×107 CFU/mL),respectively.From fish each group at 4,24 and 48 h timepoints post challenged,blood samples were collected to evaluate haematological biochemical indices and ion concentrations.The results showed that the activities of glutamic-pyruvic transaminase (ALT),albumin (ALB),total cholesterol (CHOL),blood glucose (GLU),lactic dehydrogenase (LDH),the concentration of potassium (K) ,sodium (Na),chlorine (Cl),calcium (Ca) and phosphorus (P) in infected groups was changed significantly.The activities of ALT increased significantly on 48 h after challenged,the concentration of ALB decreased significantly on 4 h after challenged,GLU decreased significantly on 48 h after challenged,the concentration of K increased significantly on 24 h after challenged,Na and Cl increased significantly on 4 h after challenged,Ca decreased significantly on 4 h and 24 h after challenged,P decreased significantly on 4 h,but increased significantly on 48 h after challenged.There were no significant differences in the level of aspartate aminotransferase (AST),alkaline phosphatase (ALP),total protein (TP),globulin (GLO),triglyceride (TG).Among the test indices,ALT,K,P was most affected by A.hydrophila,being able to the sensitive index of S.prenanti after infected.Histopathological examination showed hemorrhage,necrosis,edema and the inflammatory response in many organs,especially in liver,kidney,and muscle.In conclusion,A.hydrophila could influence the blood biochemical indices of S.prenanti,and destroy the liver,muscle,and kidney tissue of S.prenanti.%为了研究嗜水气单胞菌(Aeromonas hydrophila)对齐口裂腹鱼(Schizothorax prenanti)血液生理生化指标的影响,将180尾齐口裂腹鱼平均分成6组(4、24和48 h对照组;4、24和48 h感染组).对照组腹腔注射0.2 mL 0.65%的无菌生理盐水,感染组腹腔注射0.2 mL 2.5×107 CFU/mL的嗜水气单胞菌液.分别测定4、24和48 h对照组和感染组齐口裂腹鱼各项血液生理生化指标,并对肾脏、肝脏和肌肉组织进行病理学观察.结果显示:谷丙转氨酶、白蛋白、总胆固醇、葡萄糖、乳酸脱氢酶、钾、钠、氯、钙和磷含量均有显著变化.谷草转氨酶、碱性磷酸酶、总蛋白、球蛋白、甘油三酯则没有受到显著影响.由此可见,嗜水气单胞菌感染后对齐口裂腹鱼血液指标产生了显著的影响.对病鱼的病理学观察发现病鱼体表多处出现充血出血,溃疡和腹水,尤其是肝脏、肾脏和肌肉组织均出现不同程度的损伤,变性和局部坏死.