Widders P R, Paisley L G, Gogolewski R P, Evermann J F, Smith J W, Corbeil L B
Infect Immun. 1986 Nov;54(2):555-60. doi: 10.1128/iai.54.2.555-560.1986.
"Haemophilus somnus" has been identified in the etiology of bovine abortion on the basis of the isolation of the organism from aborted fetal and placental tissues. To investigate the role of hematogenous dissemination of "H. somnus" in the pathogenesis of abortion and to monitor the humoral immune response to infection, 19 pregnant cows (gestation ages, 1.4 to 7 months) were challenged intravenously (11 cows) or intrabronchially (8 cows). Five cows challenged intravenously aborted, and one cow challenged intrabronchially resorbed her fetus. "H. somnus" was isolated in large numbers from aborted tissues, and placental lesions were similar to those reported in a field case of "H. somnus" abortion. Antibody titers in serum were measured by the microagglutination test (MAT) and by enzyme-linked immunosorbent assay (ELISA). A response to challenge was measured by MAT; it was also measured by ELISA within the immunoglobulin G1 (IgG1), IgG2, and IgM isotypes. On comparison of pre- and postchallenge antibody titers, the greatest and most persistent response was detected within the IgG2 isotype. Prechallenge antibody titers (measured by MAT and by IgG2 ELISA) were lower in animals that aborted than in normal calving animals, indicating that IgG2 antibody may have a role in limiting hematogenous dissemination of "H. somnus."
基于从流产胎儿和胎盘组织中分离出该病原体，已确定“睡眠嗜血杆菌”是牛流产的病因。为了研究“睡眠嗜血杆菌”的血行播散在流产发病机制中的作用，并监测对感染的体液免疫反应，对19头怀孕母牛（妊娠年龄为1.4至7个月）进行了静脉注射（11头母牛）或支气管内注射（8头母牛）攻击。静脉注射攻击的5头母牛流产，支气管内注射攻击的1头母牛吸收了胎儿。从流产组织中大量分离出“睡眠嗜血杆菌”，胎盘病变与“睡眠嗜血杆菌”流产的田间病例报告相似。通过微量凝集试验（MAT）和酶联免疫吸附测定（ELISA）测量血清中的抗体滴度。通过MAT测量对攻击的反应；还通过ELISA在免疫球蛋白G1（IgG1）、IgG2和IgM同种型内测量。比较攻击前后的抗体滴度，在IgG2同种型内检测到最大且最持久的反应。流产动物的攻击前抗体滴度（通过MAT和IgG2 ELISA测量）低于正常产犊动物，这表明IgG2抗体可能在限制“睡眠嗜血杆菌”的血行播散中起作用。
