Raizman E A, Pogranichniy R, Lévy M, Negron M, Langohr I, Van Alstine W
Department of Comparative Pathobiology, School of Veterinary Medicine, Purdue University, West Lafayette, IN 47907, USA.
J Wildl Dis. 2009 Jul;45(3):653-60. doi: 10.7589/0090-3558-45.3.653.
The objective of the current study was to elucidate the within-host dynamics of bovine viral diarrhea virus (BVDV) type-1 infection to better understand how this virus could be maintained in white-tailed deer (Odocoileus virginianus, WTD) populations. The BVDV type-1 used in this study was originally isolated from a free-ranging WTD in Indiana. Four fawns were intranasally inoculated with 2 ml BVDV type-1 strain 544 WTD at a 10(6) tissue culture infectious dose (TCID(50))/ml. Two fawns were inoculated with sham inoculum (negative controls). Animals were bled on days -7, 0, 1, 7, and 14 postinoculation (PID) for a complete blood count, chemistry panel, buffy coat (BC), real-time RT-PCR, and virus neutralization (VN). On days 7 and 14 PID, nasal and rectal swabs were obtained for RT-PCR and two of the virus-inoculated fawns and one of the negative controls fawns were euthanized. At necropsy, multiple samples were obtained for histopathology and in situ hybridization (ISH). Quantitative RT-PCR was performed on serum, BC, nasal, and rectal swabs. All animals tested negative for BVDV type 1 neutralizing antibodies on day 0 and animals in the control group remained seronegative throughout the study. No gross lesions were observed at necropsy. BVDV was isolated from lung and pooled lymph nodes from all BVDV-inoculated fawns on days 7 and 14 PID. Infected deer had lymphoid depletion, apoptosis, and lymphoid necrosis in the Peyer's patches and mesenteric lymph nodes. BVDV was detected in lymphoid tissues of infected animals by ISH. No lesions or virus were identified in control fawns. On day 7 PID, samples from two virus-inoculated fawns were positive for BVDV by virus isolation and RT-PCR from BC and nasal swab samples. One fawn was also positive on a rectal swab. Nasal and rectal swabs from all animals were negative on day 14. Results indicate that infection of WTD with BVDV is possible, and leads to histologic lesions in variety of tissues. In addition, virus shedding into the environment through feces and other secretions is likely.
本研究的目的是阐明1型牛病毒性腹泻病毒（BVDV）在宿主体内的动态变化，以更好地了解该病毒如何在白尾鹿（Odocoileus virginianus，WTD）种群中持续存在。本研究中使用的1型BVDV最初是从印第安纳州的一只野生白尾鹿中分离出来的。四只小鹿经鼻接种2 ml 1型BVDV毒株544 WTD，接种剂量为10(6) 组织培养感染剂量（TCID(50)）/ml。两只小鹿接种假接种物（阴性对照）。在接种后（PID）第-7、0、1、7和14天对动物进行采血，用于全血细胞计数、生化指标检测、血沉棕黄层（BC）、实时RT-PCR和病毒中和（VN）检测。在PID第7天和第14天，采集鼻拭子和直肠拭子进行RT-PCR检测，并对两只接种病毒的小鹿和一只阴性对照小鹿实施安乐死。尸检时，采集多个样本用于组织病理学和原位杂交（ISH）检测。对血清、BC、鼻拭子和直肠拭子进行定量RT-PCR检测。所有动物在第0天检测1型BVDV中和抗体均为阴性，对照组动物在整个研究过程中均保持血清学阴性。尸检时未观察到明显病变。在PID第7天和第14天，从所有接种BVDV的小鹿的肺和汇集淋巴结中分离出BVDV。受感染的鹿在派伊尔氏结和肠系膜淋巴结中出现淋巴细胞耗竭、凋亡和淋巴细胞坏死。通过ISH在受感染动物的淋巴组织中检测到BVDV。在对照小鹿中未发现病变或病毒。在PID第7天，两只接种病毒的小鹿的样本通过病毒分离以及从BC和鼻拭子样本中进行RT-PCR检测，结果显示BVDV呈阳性。一只小鹿的直肠拭子检测结果也为阳性。在第14天，所有动物的鼻拭子和直肠拭子检测结果均为阴性。结果表明，白尾鹿感染BVDV是可能的，并会导致多种组织出现组织学病变。此外，病毒可能通过粪便和其他分泌物排放到环境中。
