Abstract:
Avian poxvirus infections typically manifest as 2 forms: cutaneous (\"dry\") pox, characterized by proliferative nodules on the skin, and diphtheritic (\"wet\") pox, characterized by plaques of caseous exudate in the oropharynx and upper respiratory and gastrointestinal tracts. Systemic spread of virus to visceral organs beyond the skin and mucous membranes is rarely reported. Out of 151 cases diagnosed with avian poxvirus over a 20-year period at a zoological institution, 22 were characterized as having systemic involvement based on histopathology and molecular findings. Gross lesions in systemic cases included soft white nodules scattered throughout the liver, spleen, and kidneys. Two histopathologic patterns emerged: (1) widespread histiocytic inflammation in visceral organs with intrahistiocytic viral inclusions and (2) severe, localized dry or wet pox lesions with poxvirus-like inclusions within dermal and subepithelial histiocytes. In situ hybridization targeting the core P4b protein gene confirmed the presence of poxvirus DNA within histiocytes in both patterns. Polymerase chain reaction was performed targeting the reticuloendothelial virus long terminal repeat (REV LTR) flanking region and the core P4b protein gene. Sequences of the REV LTR flanking region from all systemic pox cases were identical to a previously described condorpox virus isolated from an Andean condor with systemic pox. Sequences of the core P4b protein gene from all systemic pox cases grouped into cluster 2 of the B1 subclade of canarypox viruses. Systemic involvement of avian poxvirus likely occurs as a result of infection with certain strain variations in combination with various possible host and environmental factors.
摘要:
禽痘病毒感染通常表现为两种形式:皮肤(“干”)痘,以皮肤上的增生结节为特征,和白喉(“湿”)痘,以口咽和上呼吸道和胃肠道中的干酪样渗出物斑块为特征。很少报道病毒向皮肤和粘膜以外的内脏器官的系统性传播。在动物学机构20年期间诊断为禽类痘病毒的151例病例中,根据组织病理学和分子发现,22个被表征为具有全身受累。全身性病例中的大体病变包括散布在整个肝脏中的软白色结节,脾,脾还有肾脏.出现了两种组织病理学模式:(1)内脏器官中广泛的组织细胞炎症与组织细胞内病毒包涵体和(2)严重,皮肤和上皮下组织细胞内有痘病毒样包涵体。靶向核心P4b蛋白基因的原位杂交证实了在两种模式中组织细胞内痘病毒DNA的存在。针对网状内皮病毒长末端重复序列(REVLTR)侧翼区和核心P4b蛋白基因进行聚合酶链反应。来自所有全身性痘病毒病例的REVLTR侧翼区的序列与先前描述的从患有全身性痘病毒的安第斯秃鹰中分离的头痘病毒相同。来自所有系统性痘病毒病例的核心P4b蛋白基因序列,分为金丝雀痘病毒B1亚分化簇2。禽类痘病毒的系统性参与可能是由于某些毒株变异与各种可能的宿主和环境因素相结合而感染的结果。