Summary of results for virus isolation, WNV RNA, and histopathology from mice sacrificed at various times p.i..

ND = not done.
1The number of mice with positive results from any of the eight tissues.
Adult, female B6 mice were inoculated s.c. in the left rear footpad with diluent alone (mock) or with 103 PFU of WNV. Mice were sacrificed at the indicated times p.i., and each time point included one mock-inoculated mouse. WNV infection was confirmed in all WNV-inoculated mice by seroconversion at 1 mo p.i.. Eight tissues (brain, spinal cord, skin–inoculation site, skin–distal sites, spleen, lymph nodes, kidney, and heart) per mouse were harvested for virus isolation and RT-PCR for WNV. Virus isolation was performed by co-culturing the homogenized tissues on Vero cell monolayers. All samples were passed at least two more times onto fresh monolayers, and tissue culture supernatants from the third passage were tested for the presence of WNV by RT-PCR. Brains were examined for histopathology. All tissues from mock-inoculated mice were negative for infectious virus, WNV RNA, and histologic lesions.

ND 意为未完成（not done）。
1. 任意8种组织中检测结果呈阳性的小鼠数量。
选取成年雌性B6小鼠，于左侧后足垫皮下（s.c.，subcutaneous）接种单纯稀释剂（空白对照，mock）或10³ PFU的西尼罗病毒（West Nile Virus, WNV）。于感染后（p.i.，post infection）的指定时间点处死小鼠，每个时间点均设置1只空白对照接种小鼠。所有接种西尼罗病毒的小鼠均在感染后1个月通过血清转换确认病毒感染。每只小鼠采集8种组织（脑、脊髓、接种部位皮肤、远端皮肤、脾脏、淋巴结、肾脏及心脏），用于西尼罗病毒的病毒分离与逆转录聚合酶链反应（Reverse Transcription-Polymerase Chain Reaction, RT-PCR）检测。病毒分离通过将组织匀浆与Vero细胞（Vero cell）单层共培养完成。所有样本至少再传代2次至新鲜细胞单层，取第3代细胞培养上清液，通过RT-PCR检测西尼罗病毒的存在。对脑组织开展组织病理学检查。所有空白对照接种小鼠的组织样本均未检出感染性病毒、西尼罗病毒RNA及组织病理学损伤。