Smith J H, Neill P J, Box E D
Department of Pathology, College of Medicine, Texas A&M University, College Station 77843-1114.
J Parasitol. 1989 Apr;75(2):270-87.
Forty-four budgerigars (Melopsittacus undulatus) were administered sporocysts of Sarcocystis falcatula orally and were examined at necropsy intervals from less than 12 hr to 168 days. Tissue were examined by touch preparations (of organ cut surfaces), light microscopy, and electron microscopy. Meront and cyst burdens were determined in various organs and correlated with duration of infection, inoculum, and the meront or cyst burdens of other organs. Host inflammatory tissue reactions were quantitated and correlated with meront and cyst burdens. Quantitation of meronts was more accurate in tissue sections than in touch preparations, but quantitation of merozoites was better in touch preparations. More than 97% of meronts were found in capillary, venular, and venous endothelial cells. Cysts were found only in cardiac and skeletal myocytes. Merogony began in the lamina propria of the small intestine less than 12 hr postinoculation (PI). Meronts were in liver and lung by the second day PI and in other organs by 3-7 days PI. Mean meront burdens were highest in lung (33 meronts/mm2), lower in liver and kidney (1-3 meronts/mm2), and infrequent in other organs (less than 0.9 meronts/mm2). Cysts were first seen in cardiac myocytes 7 days PI. They developed through the metrocyte stage and then degenerated, rarely reaching maturity. Cysts were first noted in skeletal muscle at 8 days PI. In leg, upper esophagus, and tongue, cysts matured between 44 and 77 days PI. In pectoral muscles, the majority of cysts degenerated during the late metrocyte and early intermediate stages (28-42 days PI). In addition to a previously reported and often fatal acute interstitial pneumonitis, S. falcatula-infected budgerigars also sustained a chronic active hepatitis, interstitial myocarditis, myositis, nephritis, splenitis, and encephalitis. These lesions weakly correlated with meront burdens in most sites during early infection (up to 50 days PI).
给44只虎皮鹦鹉（Melopsittacus undulatus）经口接种鸡住肉孢子虫（Sarcocystis falcatula）的孢子囊，并在剖检时进行检查，剖检间隔时间从不到12小时至168天不等。通过触摸标本（器官切面）、光学显微镜和电子显微镜对组织进行检查。测定不同器官中的裂殖体和包囊数量，并将其与感染持续时间、接种量以及其他器官的裂殖体或包囊数量进行关联分析。对宿主炎性组织反应进行定量分析，并将其与裂殖体和包囊数量进行关联分析。在组织切片中对裂殖体的定量分析比触摸标本更准确，但在触摸标本中对裂殖子的定量分析更好。超过97%的裂殖体见于毛细血管、小静脉和静脉内皮细胞。包囊仅见于心肌细胞和骨骼肌细胞。接种后不到12小时，裂体增殖在小肠固有层开始。接种后第2天，肝脏和肺中出现裂殖体，3 - 7天其他器官中出现裂殖体。平均裂殖体数量在肺中最高（33个裂殖体/mm²），在肝脏和肾脏中较低（1 - 3个裂殖体/mm²），在其他器官中较少见（不到0.9个裂殖体/mm²）。接种后7天，首次在心肌细胞中见到包囊。它们经过滋养母细胞阶段后退化，很少发育成熟。接种后8天，首次在骨骼肌中发现包囊。在腿部、食管上段和舌部，包囊在接种后44至77天成熟。在胸肌中，大多数包囊在滋养母细胞后期和早期中间阶段（接种后28 - 42天）退化。除了先前报道的且常为致命性的急性间质性肺炎外，感染鸡住肉孢子虫的虎皮鹦鹉还患有慢性活动性肝炎、间质性心肌炎、肌炎、肾炎、脾炎和脑炎。在早期感染（接种后50天内），这些病变在大多数部位与裂殖体数量的相关性较弱。
