严重的Perkinsea感染(SPI)是一种新出现的青蛙疾病,可导致整个美国t的大量死亡。它是由属于Perkinsozoa门的原生动物引起的,它们形成了一个独特的群体,称为青蛙的致病性Perkinsea进化枝。在这项工作中,我们提供了178个自然感染的t的总体和组织学病变的详细描述,包括来自22个死亡事件的10个物种和来自不同地理区域的6个两栖动物健康监测研究。在外部检查中,我们观察到腹胀(10,5.6%),皮肤红斑和瘀点(3,1.7%),皮下水肿(3,1.7%),和白色皮肤变色区域(3,1.7%)。在内部器官的宏观检查中,我们发现肝肿大(68,38.2%),脾肿大(51,28.7%),肾肥大症(47,26.4%),腹水(15,8.4%),肠的节段性不规则增厚和白色变色(8,4.5%),胰腺肥大(4,2.2%),胰腺瘀斑(1,0.6%)。组织学上,超过60%的肝脏(148/165,89.7%),肾(113/147,76.9%),脾脏(96/97,99%),胰腺(46/68,67.6%)被无数的细胞内和细胞外Perkinsea催眠孢子样和滋养体样生物侵入。许多其他组织受到的影响程度较小。通常在未被淋巴粒细胞造血组织掩盖的感染区域观察到淋巴细胞或嗜酸性粒细胞较少的轻度组织细胞炎症。鉴于这些观察,我们提出了一个合乎逻辑的发病顺序。最后,我们为SPI提出了一个“病例定义”,以促进结果的标准化交流,并防止误诊为流行病学和病理重叠的疾病,例如肾病。
Severe Perkinsea infection (SPI) is an emerging disease of frogs responsible for mass mortalities of tadpoles across the United States. It is caused by protozoa belonging to the phylum Perkinsozoa that form a distinct group referred to as the Pathogenic Perkinsea Clade of frogs. In this work, we provide detailed description of gross and histologic lesions from 178 naturally infected tadpoles, including 10 species from 22 mortality events and 6
amphibian health monitoring studies from diverse geographic areas. On external examination, we observed abdominal distension (10, 5.6%), cutaneous erythema and petechia (3, 1.7%), subcutaneous edema (3, 1.7%), and areas of white skin discoloration (3, 1.7%). On macroscopic examination of internal organs, we found hepatomegaly (68, 38.2%), splenomegaly (51, 28.7%), nephromegaly (47, 26.4%), ascites (15, 8.4%), segmental irregular thickening and white discoloration of the intestine (8, 4.5%), pancreatomegaly (4, 2.2%), and pancreatic petechia (1, 0.6%). Histologically, over 60% of the liver (148/165, 89.7%), kidney (113/147, 76.9%), spleen (96/97, 99%), and pancreas (46/68, 67.6%) were invaded by myriad intracellular and extracellular Perkinsea hypnospore-like and trophozoite-like organisms. Numerous other tissues were affected to a lesser extent. Mild histiocytic inflammation with fewer lymphocytes or eosinophils was commonly observed in areas of infection that were not obscured by lympho-granulocytic hematopoietic tissue. In light of these observations, we suggest a logical pathogenesis sequence. Finally, we propose a \"
case definition\" for SPI to promote standardized communication of results and prevent misdiagnosis with epidemiological and pathologically overlapping diseases such as ranavirosis.