【摘要】 为了比较经典兔出血症病毒（RHDV）与兔出血症病毒2型（RHDV2）对家兔的致病性与组织嗜性差异，试验将15只45～50日龄家兔随机分成3组，分别为经典RHDV攻毒组、RHDV2攻毒组和对照组，每组5只，经典RHDV攻毒组和RHDV2攻毒组每只家兔分别皮下注射含2×10⁸ copies/μL经典RHDV和RHDV2的病毒悬液1 mL,对照组每只家兔皮下注射PBS 1 mL,持续观察并记录每组的精神状态、体重变化、采食情况、运动状况和死亡情况，并于攻毒36 h后处死并剖检各组未死亡家兔。无菌采集各组肝脏、肺脏、脾脏、肾脏、心脏、脑、胃、肠、蚓突、圆小囊进行石蜡切片制作、H.E.染色和组织病变观察。各组无菌多点位采集等量心脏、肝脏、脾脏、肺脏、肾脏组织，提取病毒RNA反转录成cDNA后采用实时荧光定量PCR方法检测各组织中病毒载量。结果表明：攻毒后第6～10小时，经典RHDV攻毒组和RHDV2攻毒组均表现为精神沉郁、厌食、静卧、嗜睡、反应迟钝、体重下降等临床症状。经典RHDV攻毒组于攻毒后第24～25小时死亡3只，死亡率为60%（3/5）;RHDV2攻毒组于攻毒后第8～21小时全部死亡，死亡率达100%（5/5）;对照组5只家兔均存活且无异常表现。剖检可见经典RHDV攻毒组和RHDV2攻毒组气管环状出血，且RHDV2攻毒组气管中出现大量泡沫；经典RHDV攻毒组和RHDV2攻毒组肝脏质脆、肿大、出血，肺脏严重出血，心脏有明显出血点，脾脏明显肿大，经典RHDV攻毒组的组织匀浆中仅检出经典RHDV,RHDV2攻毒组的组织匀浆中仅检出RHDV2。经典RHDV攻毒组和RHDV2攻毒组的组织切片中可见多组织器官变性、坏死、扩张或淤血，其中RHDV2攻毒组肝脏和脾脏的损伤程度大于经典RHDV攻毒组；而蚓突、圆小囊和脑部未见明显病理变化；对照组所有组织器官均未见明显病变与异常。经典RHDV攻毒组内脏病毒载量从高到低依次为肝脏、脾脏、肾脏、肺脏和心脏；RHDV2攻毒组内脏病毒载量从高到低依次为肝脏、脾脏、肺脏、心脏和肾脏。RHDV2攻毒组肝脏、脾脏、肺脏病毒载量高于经典RHDV攻毒组，而心脏、肾脏病毒载量低于经典RHDV攻毒组。说明家兔感染经典RHDV或RHDV2后临床症状相似，相比经典RHDV,RHDV2的致病性更强；肝脏是经典RHDV或RHDV2侵染和定植的主要组织。更多还原

【Abstract】 In order to compare the differences in pathogenicity and histophilicity between classical Rabbit hemorrhagic disease virus(RHDV) and Rabbit hemorrhagic disease virus type 2(RHDV2) in rabbits, in the experiment, fifteen rabbits between 45 and 50 days of age were randomly divided into three groups: the classical RHDV group, the RHDV2 group and the control group with five rabbits in each group. In the classical RHDV and RHDV2 groups, each rabbit was injected subcutaneously with 1 mL of virus suspension containing 2×10~8 copies/μL of classical RHDV and RHDV2, respectively and in the control group, each rabbit was injected subcutaneously with 1 mL of PBS. The mental state, body weight change, feeding, exercise and death of each group were observed and recorded persistently; the rabbits that did not die in each group were executed for autopsy after 36 h of virus challenge. Liver, lung, spleen, kidney, heart, brain, stomach, intestines, earthworms, and round vesicles were aseptically collected from each group for paraffin section preparation, H.E. staining and histopathological observation. Equal amounts of heart, liver, spleen, lung, and kidney tissues were collected sterilely at multi-point locations in each group. After viral RNA was extracted and transcribed into cDNA, real-time PCR was used to detect the virus load in each tissue. The results showed that 6-10 h after the challenge, both the classical RHDV and RHDV2 challenge groups showed clinical symptoms such as depression, anorexia, lying down, lethargy, unresponsiveness and weight loss. Three rabbits in the classic RHDV group died within 24-25 h after the challenge, with a mortality rate of 60%(3/5); all rabbits in the RHDV2 group died within 8-21 h after the challenge, with a mortality rate of 100%(5/5); and the five rabbits in the control group survived without any abnormal behavior. At autopsy, both the classic RHDV-challenge group and the RHDV2-challenge group showed circumferential hemorrhage of the trachea, and a large amount of foam appeared in the trachea of the RHDV2-challenge group; the liver was brittle, swollen and bleeding; the lungs were severely bleeding; the heart was visibly bleeding, and the spleen was visibly swollen in both the classic RHDV-challenge group and the RHDV2-challenge group; only the classic RHDV was detected in the tissue homogenate of the classic RHDV-challenge group, and only the RHDV2 was detected in the tissue homogenate of the classic RHDV2-challenge group. The tissue sections of the classic RHDV and RHDV2 groups showed multiple tissue and organ degeneration, necrosis, dilatation or bruising; the degree of damage to the liver and spleen in the RHDV2 group was greater than that in the classic RHDV group, while no significant lesions were seen in the earthworm protuberance, rounded vesicles and brain. No obvious lesions and abnormalities were seen in all tissues and organs of the control group. The visceral viral load in the classical RHDV challenge group was liver, spleen, kidney, lung and heart from high to low; the visceral viral load in the RHDV2 challenge group was liver, spleen, lung, heart and kidney from high to low. The virus load of liver, spleen, lung in the RHDV2 challenge group were higher than those in the classical RHDV challenge group, while the virus load of heart and kidney in the RHDV2 challenge group was lower than that in the classical RHDV challenge group. The results indicated that the clinical symptoms of rabbits infected with classical RHDV or RHDV2 were similar. RHDV2 was more pathogenic than classical RHDV, and liver was the main tissue for RHDV or RHDV2 infection and colonization.更多还原