Laboratories of The Rockefeller Institute for Medical Research.
J Exp Med. 1925 Jul 31;42(2):253-74. doi: 10.1084/jem.42.2.253.
The evidence offered in the first of these studies indicative of a causative relationship between Rickettsia ruminantium and heartwater is supplemented by the following observations concerning the ticks which carry the disease. When larvae, which had taken no food since hatching, were allowed to feed upon cases of heartwater, they acquired Rickettsioe which appeared to be identical with those in the tissues of animals suffering from heartwater, whereas control larvae hatched from eggs deposited by the same female and fed on normal animals remained free of Rickettsioe. After larvae presumably infective had moulted, the resultant nymphae containing Rickettsioe in their alimentary tracts, when fed upon susceptible animals produced in them typical attacks of heartwater, which the control nymphae, devoid of Rickettsioe, failed to do. The tissues of animals thus infected were found upon histological examination to contain typical Rickettsioelig;.
这些研究中的第一项提供的证据表明，绵羊无浆体与心水病之间存在因果关系，以下关于携带这种疾病的蜱的观察结果对此加以补充。当幼虫自孵化以来从未进食过，被允许喂食心水病病例时，它们获得了与患心水病动物组织中相同的立克次体，而从同一雌蜱产下并喂食正常动物的对照幼虫仍然没有立克次体。在假定具有感染力的幼虫蜕皮后，含有立克次体的若虫在其消化道中，当喂食易感动物时，会在它们体内产生典型的心水病发作，而对照的若虫，没有立克次体，则不会这样做。在组织学检查中发现，被感染的动物组织中含有典型的立克次体。
