Smith S I, West D M, Wilson P R, de Lisle G W, Collett M G, Heuer C, Chambers J P
Institute of Veterinary, Animal and Biomedical Sciences, Massey University, Private Bag 11222, Palmerston North 4442 , New Zealand.
N Z Vet J. 2011 Sep;59(5):240-3. doi: 10.1080/00480169.2011.596257.
To determine whether viable Mycobacterium avium subsp. paratuberculosis (Map) is present in skeletal muscle and blood in ewes with and without Johne's disease confirmed histologically.
A total of 51 mixed-aged ewes in poor body condition from a farm with a history of clinical Johne's disease were culled and examined at necropsy. BACTEC radiometric culture was performed on samples of skeletal muscle from the biceps femoris, mononuclear cells in peripheral blood (hereafter referred to as blood), and ileum. Histological sections and Ziehl-Neelsen (ZN)-stained impression smears of terminal ileum and mesenteric lymph nodes were examined. Ewes were defined as having confirmed Johne's disease if there was histopathological evidence typical of the disease within the ileum and adjacent lymph nodes.
Eighteen of 21 (86%) ewes with confirmed clinical Johne's disease were culture-positive for Map from sites peripheral to the alimentary tract, comprising 15 from skeletal muscle and 13 from blood. Five of 30 (17%) ewes that did not have Johne's disease were culture-positive, with four from skeletal muscle and one from blood. The likelihood that ewes with confirmed Johne's disease had systemic Map infection compared with ewes without was determined as OR=30 (95% CI=6.3-142.0; p<0.001).
The prevalence of Map infection of skeletal muscle and blood in ewes with confirmed Johne's disease was 71% and 62% respectively, and in unaffected ewes was 13% for muscle and 3% for blood.
Skeletal muscle and blood are potential sources of exposure of humans to Map, and the risk appears higher from sheep with Johne's disease.
确定组织学确诊或未确诊约翰氏病的母羊骨骼肌和血液中是否存在活的副结核分枝杆菌（Map）。
从一个有临床约翰氏病病史的农场挑选了51只体况不佳、年龄各异的母羊，进行屠宰并尸检。对股二头肌的骨骼肌样本、外周血单核细胞（以下简称血液）和回肠进行BACTEC放射测量培养。检查回肠末端和肠系膜淋巴结的组织切片以及齐-尼（ZN）染色压片。如果回肠和相邻淋巴结有该疾病典型的组织病理学证据，则母羊被定义为确诊患有约翰氏病。
21只确诊临床约翰氏病的母羊中，有18只（86%）在消化道外周部位的Map培养呈阳性，其中15只来自骨骼肌，13只来自血液。30只未患约翰氏病的母羊中有5只（17%）培养呈阳性，4只来自骨骼肌，1只来自血液。确诊约翰氏病的母羊发生全身性Map感染的可能性与未患病母羊相比，经测定比值比（OR）=30（95%可信区间=6.3 - 142.0；p<0.001）。
确诊约翰氏病的母羊骨骼肌和血液中Map感染率分别为71%和62%，未受影响的母羊骨骼肌感染率为13%，血液感染率为3%。
骨骼肌和血液是人类接触Map的潜在来源，来自患约翰氏病绵羊的风险似乎更高。
