长沙地区奶牛无浆体动物感染试验及其传播途径调查

Investigation on Experimental Infection with Anaplasma from Cows and the Transmission Route of Pathogen in Changsha of Hunan

采集长沙地区某奶牛场疑似患病牛鲜血及牛舍周围吸血类昆虫(牛虻、厩蝇和蚊子等),分别作镜检观察,腹腔接种至试验小鼠体内(0.5 mL/只)进行培养和观察。为进一步证明其传播途径,将12只试验兔分别放置于牛舍不同方位饲养1周,进行临床感染试验。结果表明,病牛鲜血涂片染色后在血液红细胞内观察到呈圆点状或球状的无浆体虫体,绝大部分位于红细胞边缘,少数位于中央,染虫率达30%,患牛抗凝血在试验小鼠体内进行培养后,第4天开始在小鼠红细胞内查到虫体,第17天达到感染高峰;吸血类昆虫血液涂片、染色后,其中385片在血液红细胞内观察到虫体,虫体查出率达77%;吸血昆虫内容物在试验小鼠体内的培养情况大致与患牛抗凝血情况相同;在临床感染1周后的第6天,7只兔在血液红细胞中查到虫体,兔感染率达75%。

The blood of suspected infected cows and blood-sucking insects around the cowshed, which were collected from one dairy cow farm in Changsha, were examined by microscope or were cultivated and observed via intra-abdominal inoculation with the anticoagulated blood from infected cows（0. 5 mL/mouse） in laboratory, respectively. Moreover, to determine the route of transmission, 12 rabbits were examined in the clinical infection after cultivating for one week in the different aspects of the cowsheds. The results showed that punetiform and bulbiform Anaplasma could be observed in blood smears,and the most were at the edge,manipulus located in the centre. The infection rate was 30 %. Anaplasma were observed in mouse red blood cell（MRBC） at 4^th day and reached peak number in erythrocyte at 16^th day,after anticoagulated blood was cultivated in mice. Anaplasrna were observed in erythrocyte in 385pieces of blood smears of blood-sucking insects,the infection rate was 77%. The cultivating condition of the contents from bloodsucking insects was approximate as same as the anticoagulated blood of infected cows. And there had Anaplasma in blood erythrocytes of 7 rabbits at 6^th day after one week infection,the infection rate of rabbits was 75%.