Mohan K, Obwolo M J, Hill F W
Department of Paraclinical, University of Zimbabwe, Harare.
J Comp Pathol. 1992 Jul;107(1):73-9. doi: 10.1016/0021-9975(92)90097-e.
The prevalence of Mycoplasma ovipneumoniae (MO) in three Communal Lands flocks of goats on the outskirts of Harare is described. In a single sampling of nasal swabs from 172 randomly selected, apparently healthy goats, 112 animals were identified as carriers of MO. The three flocks had a history of occasional deaths, following chronic and subacute pneumonia associated with isolation of MO as the only identifiable pathogen. Attempts to induce clinical pneumonia in groups of 6 to 8-week-old kids and lambs with local isolates of MO were not successful. However, MO was consistently cultured from the trachea, lungs, lymph node and thymus of some test animals. Cuffing interstitial pneumonia was also observed in these animals. Infection of the thymus occurred; this has not previously been reported with any Mycoplasma sp. The animals did not produce detectable serum antibodies to MO nor were they reactive to MO antigen in a tuberculin-type hypersensitivity test. The possibility that a state of immunotolerance may have been responsible for failure to develop clinical pneumonia is discussed.
本文描述了哈拉雷市郊三个社区土地上的山羊群中绵羊肺炎支原体（MO）的流行情况。在对172只随机挑选的、看似健康的山羊进行鼻拭子单次采样中，有112只动物被鉴定为MO携带者。这三个羊群有偶尔出现死亡的病史，此前曾出现与MO作为唯一可识别病原体分离相关的慢性和亚急性肺炎。用当地分离的MO对6至8周龄的羔羊和幼羊进行分组诱导临床肺炎的尝试未成功。然而，在一些试验动物的气管、肺、淋巴结和胸腺中持续培养出MO。在这些动物中还观察到套袖状间质性肺炎。胸腺发生了感染；此前尚未有任何支原体属出现这种情况的报道。这些动物未产生可检测到的针对MO的血清抗体，在结核菌素型超敏反应试验中也未对MO抗原产生反应。本文讨论了免疫耐受状态可能是未能引发临床肺炎的原因这一可能性。
