Zhao Yanbing, Lin Yan, Zeng Xujian, Lu Chengping, Hou Jiafa
College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China.
Virol J. 2013 Aug 29;10:272. doi: 10.1186/1743-422X-10-272.
Canine parvovirus (CPV) is an important pathogen that causes acute enteric disease in dogs. It has mutated and spread throughout the world in dog populations. We provide an update on the molecular characterization of CPV that circulated in Nanjing, a provincial capital in China between 2009 and 2012.
Seventy rectal swab samples were collected from the dogs diagnosed with CPV infection in 8 animal hospitals of Nanjing. Sequence analysis of VP2 genes of 31 samples revealed that 29 viral strains belonged to CPV-2a subtype, while other two strains were classified into CPV-2b. To investigate the pathogenicity of the prevalent virus, we isolated CPV-2a and performed the animal experiment. Nine beagles were inoculated with 105.86 of 50% tissue culture infectious doses (TCID50) of the virus. All the experimentally infected beagles exhibited mild to moderate mucoid or watery diarrhea on day 4 post-infection (p.i.). On day 9 p.i., characteristic histopathological lesions were clearly observed in multiple organs of infected dogs, including liver, spleen, kidney, brain and all segments of the small and large intestines, while viral DNA and antigen staining could be detected in the sampled tissues. It is notable that canine parvovirus was isolated in one from two brain samples processed.
Our results indicated that CPV-2a is the predominant subtype in Nanjing of China. And this virus caused extensive lesions in a variety of tissues, including the brain.
犬细小病毒（CPV）是引起犬急性肠道疾病的重要病原体。它已发生变异并在全球犬类种群中传播。我们提供了2009年至2012年间在中国省会南京流行的CPV分子特征的最新情况。
从南京8家动物医院诊断为CPV感染的犬只中采集了70份直肠拭子样本。对31份样本的VP2基因进行序列分析，结果显示29株病毒属于CPV-2a亚型，另外两株属于CPV-2b亚型。为研究流行病毒的致病性，我们分离了CPV-2a并进行了动物实验。9只比格犬接种了105.86的50%组织培养感染剂量（TCID50）的病毒。所有实验感染的比格犬在感染后第4天均出现轻度至中度的黏液样或水样腹泻。在感染后第9天，在感染犬的多个器官中明显观察到特征性的组织病理学损伤，包括肝脏、脾脏、肾脏、大脑以及小肠和大肠的所有节段，同时在采样组织中可检测到病毒DNA和抗原染色。值得注意的是，在处理的两份脑样本中有一份分离出了犬细小病毒。
我们的结果表明，CPV-2a是中国南京的主要亚型。并且这种病毒在包括大脑在内的多种组织中引起了广泛的损伤。
