Kiupel M, Stevenson G W, Mittal S K, Clark E G, Haines D M
Animal Disease Diagnostic Laboratory, Purdue University, West Lafayette, IN 47906-1175, USA.
Vet Pathol. 1998 Jul;35(4):303-7. doi: 10.1177/030098589803500411.
Inclusion bodies with staining affinity and ultrastructural characteristics typical of circoviruses that stained positive for porcine circovirus (PCV)-like virus were demonstrated in association with granulomatous lesions in multiple tissues of three clinically ill 10- to 12-week-old pigs. A syndrome of poor growth and wasting in 5-15% of weaned pigs was an intermittent problem on a 450-sow one-site farrow-to-finish swine farm in Indiana. Routine diagnostic testing did not demonstrate a cause. Gross examination of three representative weaned pigs from two farrowing groups over a 1-month period revealed generalized lymphadenopathy and interstitial pneumonia. A unique microscopic finding for all three pigs was granulomatous inflammation of lymphoid tissues associated with large numbers of multinucleate giant cells and characteristic viral inclusions in the cytoplasm of macrophages. These inclusions were round, homogeneous, and magenta to basophilic, varied in size (5-25 microm), and either were single or formed botryoid clusters. Ultrastructurally, these inclusions were composed of electron-dense paracrystalline arrays of small nonenveloped icosahedral viral particles that were approximately 17 nm in diameter. The sizes and shapes of the virus particles, the unique microscopic appearance of the inclusions, and the positive staining of the intracytoplasmic viral inclusions by the Feulgen technique are consistent with circoviruses. Immunohistochemistry for PCV-like virus demonstrated viral antigen in the cytoplasm of macrophages that were within inflammatory infiltrates in a variety of organs. The described inclusion bodies stained positively.
在3头10至12周龄临床患病猪的多个组织的肉芽肿性病变中，发现了具有圆环病毒典型染色亲和力和超微结构特征的包涵体，这些包涵体对猪圆环病毒（PCV）样病毒呈阳性染色。在印第安纳州一个拥有450头母猪的一体化分娩至育肥猪场中，5%至15%的断奶仔猪生长不良和消瘦综合征是一个间歇性问题。常规诊断检测未发现病因。在1个月的时间里，对来自两个分娩组的3头代表性断奶仔猪进行大体检查，发现全身淋巴结病和间质性肺炎。这3头猪的一个独特微观发现是淋巴组织的肉芽肿性炎症，伴有大量多核巨细胞以及巨噬细胞胞质内的特征性病毒包涵体。这些包涵体呈圆形、均匀一致，呈品红色至嗜碱性，大小不等（5至25微米），单个或形成葡萄状簇。超微结构上，这些包涵体由直径约17纳米的小的无包膜二十面体病毒颗粒的电子致密准晶体阵列组成。病毒颗粒的大小和形状、包涵体独特的微观外观以及Feulgen技术对胞质内病毒包涵体的阳性染色与圆环病毒一致。针对PCV样病毒的免疫组织化学显示，在各种器官炎症浸润内的巨噬细胞胞质中有病毒抗原。所述包涵体染色呈阳性。
