Central Veterinary Research Laboratory (CVRL), POB 597, Dubai, United Arab Emirates.
Vet Microbiol. 2011 Apr 21;149(1-2):269-72. doi: 10.1016/j.vetmic.2010.09.037. Epub 2010 Oct 8.
Rhodococcus (R). equi, a recognized pathogen in horses, is emerging as a human opportunistic pathogen, especially in immunocompromized people. It affects also New World camelids, but there are no reports of R. equi infection in Old World camelids yet. Four cases of disseminated R. equi infection in adult breeding dromedaries occurred at one camel farm near Dubai within 16 months of each other. At necropsy the lungs were diffusely consolidated with large caseous areas. Histology revealed severe suppurative to necrotising pneumonia with multiple encapsulated abscesses. Immunohistochemistry enabled the detection of 15- to 17-kDa antigens (VapA) of R. equi in the lung sections. High numbers of R. equi were isolated from the lung lesions as well as from liver, spleen and mediastinal lymph nodes, indicative of septicaemia. The isolated strains were PCR-positive for the specific virulence plasmid (VapA-Gen) of R. equi, indicating virulent strains and containing an 85-kb type I plasmid. This is the first report of disseminated R. equi infection in Old World camelids. Since adult camels in general do not suffer from bacterial caused pneumonia (except tuberculosis), this is a new emerging disease for camels.
马分枝杆菌（R）。equi 是一种公认的马病原体，现在正成为人类机会性病原体，特别是在免疫功能低下的人群中。它还会影响新世界驼科动物，但尚未有旧世界驼科动物感染马分枝杆菌的报告。在迪拜附近的一个骆驼农场，在 16 个月的时间里，有 4 例成年单峰驼发生播散性马分枝杆菌感染。剖检时，肺部广泛实变伴大的干酪样区域。组织学显示严重化脓性至坏死性肺炎，伴有多个包裹性脓肿。免疫组织化学使肺组织切片中能够检测到马分枝杆菌的 15-17kDa 抗原（VapA）。从肺部病变以及肝脏、脾脏和纵隔淋巴结中分离出大量马分枝杆菌，提示败血症。分离株的 PCR 检测结果均为马分枝杆菌特异性毒力质粒（VapA-Gen）阳性，表明为毒力株，并含有 85kb 型 I 质粒。这是首例旧世界驼科动物播散性马分枝杆菌感染的报告。由于成年骆驼一般不会因细菌引起肺炎（除了肺结核），这对骆驼来说是一种新出现的疾病。
