Vashisht Kapil, Lichtensteiger Carol A, Miller Lou A, Gondim Luis F P, McAllister Milton M
Veterinary Diagnostic Laboratory, College of Veterinary Medicine, University of Illinois, 2001 S. Lincoln Avenue, Urbana, IL 61802, USA.
Vet Parasitol. 2005 Oct 10;133(1):19-25. doi: 10.1016/j.vetpar.2005.04.042.
Tissue stages similar to those of Sarcocystis neurona, the causative agent of equine protozoal myeloencephalitis, were identified in skeletal muscles of a dog. The dog, a 6-year-old Labrador retriever, was seropositive for Toxoplasma gondii infection and euthanized due to a history of polymyositis and progressive muscular atrophy. Histologically, 30, variably sized, microscopic, intracellular sarcocysts were observed in 60 sections of skeletal muscles taken from the neck, fore limbs and hind limbs. The cysts were only observed in inflamed skeletal muscles, but were mostly in myocytes at the periphery of areas infiltrated with leukocytes. Ultrastructurally, the cyst wall had villar protrusions consistent with sarcocysts. Immunohistochemistry with monoclonal S. neurona antibodies demonstrated positive labeling of zoites in merozoites or schizonts in the skeletal muscle interstitium, but no labeling of the sarcocysts. Initial PCR analysis with primers amplifying a genetic sequence encoding Apicomplexan 18s rRNA, and subsequent PCR analysis with differentiating primers indicated that the genetic sequences had 100% identity with sequences reported for S. neurona.
在一只犬的骨骼肌中发现了与马属动物原虫性脑脊髓炎病原体——刚地弓形虫相似的组织阶段。这只6岁的拉布拉多猎犬血清弓形虫感染呈阳性，因患有多肌炎和进行性肌肉萎缩病史而实施安乐死。组织学检查发现，从颈部、前肢和后肢采集的60个骨骼肌切片中观察到30个大小不一的微观细胞内肉孢子虫囊。这些囊肿仅在发炎的骨骼肌中观察到，但大多位于白细胞浸润区域周边的肌细胞中。超微结构上，囊肿壁有与肉孢子虫囊一致的绒毛状突起。用刚地弓形虫单克隆抗体进行免疫组织化学检测显示，骨骼肌间质中的裂殖子或裂殖体中的子孢子呈阳性标记，但肉孢子虫囊无标记。最初用扩增编码顶复门18s rRNA基因序列的引物进行PCR分析，随后用鉴别引物进行PCR分析，结果表明该基因序列与已报道的刚地弓形虫序列有100%的同一性。
