Ndung'u L W, Aguirre C, Rurangirwa F R, McElwain T F, McGuire T C, Knowles D P, Palmer G H
Veterinary Research Center, Kenya Agricultural Research Institute, Kabete.
J Clin Microbiol. 1995 Mar;33(3):675-9. doi: 10.1128/jcm.33.3.675-679.1995.
A competitive inhibition enzyme-linked immunosorbent assay (ELISA) based on a major surface protein 5 (MSP5) B-cell epitope conserved among Anaplasma species was used to detect goats infected with Anaplasma ovis. We examined strains of A. ovis isolated from goats in Kenya and demonstrated that MSP5 and the target B-cell epitope, bound by monoclonal antibody ANAF16C1, were conserved. Sera from 149 goats in four regions of Kenya and from 302 goats in six U.S. states were tested for the presence of epitope-specific antibodies with the MSP5 competitive inhibition ELISA. Evidence that the assay can be used to detect A. ovis-infected goats includes the following: (i) 53 goats raised in confinement with arthropod control were all seronegative; (ii) six goats experimentally infected with A. ovis seroconverted at the same time that they developed detectable rickettsemia; (iii) seroconverted goats remained seropositive, consistent with the persistence of A. ovis in goats and the presence of anti-MSP5 antibody in cattle persistently infected with Anaplasma marginale; and (iv) 119 of 127 known A. ovis-infected goats in Kenya were seropositive. A. ovis infection, as determined serologically and by demonstration of infected erythrocytes, in goats from the four regions in Kenya was highly prevalent. In contrast, despite the presence of A. ovis and competent arthropod vectors in the United States, the prevalence of infection appeared to be very low. The high prevalence in Kenya and the occurrence of anemia in persistently infected goats may be impediments to current efforts to increase milk yields on small farms.
基于无形体属物种间保守的主要表面蛋白5（MSP5）B细胞表位的竞争性抑制酶联免疫吸附测定（ELISA），被用于检测感染绵羊无形体的山羊。我们检测了从肯尼亚山羊分离出的绵羊无形体菌株，并证明MSP5以及被单克隆抗体ANAF16C1识别的目标B细胞表位是保守的。使用MSP5竞争性抑制ELISA检测了来自肯尼亚四个地区的149只山羊以及美国六个州的302只山羊血清中表位特异性抗体的存在情况。该检测方法可用于检测感染绵羊无形体山羊的证据如下：（i）在有节肢动物控制的圈养环境中饲养的53只山羊均为血清阴性；（ii）6只经实验感染绵羊无形体的山羊在出现可检测到的立克次体血症的同时发生了血清转化；（iii）血清转化的山羊保持血清阳性，这与绵羊无形体在山羊体内的持续存在以及持续感染边缘无形体的牛体内存在抗MSP5抗体一致；（iv）肯尼亚127只已知感染绵羊无形体的山羊中有119只为血清阳性。通过血清学检测和感染红细胞的鉴定，肯尼亚四个地区山羊的绵羊无形体感染非常普遍。相比之下，尽管美国存在绵羊无形体和有效的节肢动物传播媒介，但感染率似乎非常低。肯尼亚的高感染率以及持续感染山羊中出现的贫血症，可能会阻碍目前在小农场提高牛奶产量的努力。
