Wang Yuyan, Ma Guanggang, Lu Chengping, Wen Hai
College of Veterinary Medicine, Nanjing Agric Univ, Nanjing, China.
Berl Munch Tierarztl Wochenschr. 2006 Jan-Feb;119(1-2):35-9.
An RT-nPCR assay was used for testing fecal samples of dogs, foxes, raccoon dogs and minks for the presence of canine coronavirus (CCV). The animals were raised in homes, dog schools or farms. Seventy out of 81 healthy dog feces from three cities and 21 out of 48 diarrhea feces from pet dogs were positive for type II CCV. From a total of 61 healthy fox feces, 43 were positive for type II and 29 for type I CCV, out of which 25 were simultaneously positive for the two different genotypes. Among 24 raccoon dogs samples, 22 were CCV type II-positive, and from those 16 were additionally type I positive. No CCVs was detected from healthy mink feces. Sequence analysis found that ten type II CCVs fragments of M gene shared a high similarity with reference strain CCV 1-71 (96.5-99.5%), and four type I CCVs shared a high similarity (96.7%-98.1%) with a reported FCV-like CCV strain. The sequence of one particular M gene fragment was found to cluster between the type I and type II CCV branches in phylogenetic analysis, suggesting the existence of a novel strain. Our study confirmed that type II CCVs infection is very common in domestic dog, fox, and raccoon dog populations in China. This is also the first report on the co-existence of two CCV genotypes in healthy foxes and raccoon dogs.
采用逆转录巢式聚合酶链反应(RT-nPCR)检测犬、狐、貉和水貂粪便样本中犬冠状病毒(CCV)的存在情况。这些动物饲养于家庭、犬类学校或农场。来自三个城市的81份健康犬粪便样本中有70份、48份宠物犬腹泻粪便样本中有21份检测出II型CCV呈阳性。在总共61份健康狐粪便样本中,43份检测出II型CCV呈阳性,29份检测出I型CCV呈阳性,其中25份同时对两种不同基因型呈阳性。在24份貉样本中,22份II型CCV呈阳性,其中16份还呈I型阳性。健康水貂粪便样本中未检测到CCV。序列分析发现,10个II型CCV的M基因片段与参考毒株CCV 1-71具有高度相似性(96.5%-99.5%),4个I型CCV与报道的类猫杯状病毒CCV毒株具有高度相似性(96.7%-98.1%)。在系统发育分析中,发现一个特定的M基因片段的序列聚集在I型和II型CCV分支之间,表明存在一种新型毒株。我们的研究证实,II型CCV感染在中国家犬、狐和貉种群中非常普遍。这也是关于健康狐和貉中两种CCV基因型共存的首次报道。