奶牛无浆体人工感染实验动物及其传播途径的研究

Study on artificial infection of experimental animals with Anaplasma from cattle and the transmission route of pathogen

采用地塞米松注射液长期抑制试验动物的免疫力,通过小鼠腹腔、皮下接种含有无浆体病原的奶牛血液、阳性厩蝇内容物、脏器悬液,并进行阳性小鼠接触感染和兔子临床同层感染等试验,研究奶牛无浆体的感染和传播及在试验动物体内的消长规律,建立起无浆体人工感染模型,调查临床中病原体的实际传播途径。结果表明,无浆体在小鼠和兔子体内呈现一定的规律性。无浆体在感染后第6d和第8d分别在小鼠和兔子血液中可以检测到;感染后第16d～19d和第17d～20d在两者体内达到感染高峰;感染后第20d和第25d均逐渐消失。因此,可用小鼠或兔子在免疫抑制情况下建立无浆体人工感染动物模型。实验证明无浆体的感染方式有以下几种:腹腔、皮下接种、接触感染以及通过厩蝇等非蜱类吸血昆虫机械性传播。

To establish anaplasma artificial infection model in experimental animals which treated with dexamethasone to investigate the transmission route of the pathogen, mice were infected via intra-abdominal and subcutaneous inoculation with the blood from infected cattle, the homogenate of infected gadflies and viscera of infected mice, contacting infected mice, respectively, while rabbits were infected through co-feeding with affected cattle. Results indicated that the anaplasma could be observed by microscope in erythrocyte of experimental animals at 6th to 8th day, and the anaplasma reached peak number in erythrocyte at 16th to 20th day, disappearing at 25th day after infection. Artificial anaplasma infection model was established in experimental animals under immune suppression conditions by means of infection via contact, intra-abdominal and subcutaneous inoculation. It was suggested that anaplasma could be transmitted naturally by gadfly biting or contacting blood-contaminated fomites.