Department of Veterinary Microbiology, Rajiv Gandhi College of Veterinary and Animal Sciences, Pondicherry, India.
Infect Genet Evol. 2010 Dec;10(8):1237-41. doi: 10.1016/j.meegid.2010.08.005. Epub 2010 Aug 17.
Canine parvovirus type 2 (CPV-2) causes acute haemorrhagic enteritis in dogs. Canine parvovirus is prone to genetic evolution and has undergone several mutations that produced different strains like CPV-2a, CPV-2b, New CPV-2a, New CPV-2b and CPV-2c in the past three decades. Mutations affecting the VP2 gene of CPV have been responsible for evolution of different antigenic variants. Sequence analysis of VP2 gene of the virus and subsequent characterization is important for molecular epidemiology. The present study was conducted to isolate and to characterize the virus by amplifying partial VP2 gene and further sequence analysis and also to estimate phylogenetic relationship of field virus with the reference strains. Out of 77 samples, 51 samples were found to be positive by PCR and all the 51 samples were subjected for virus isolation in CRFK cell line. Sixteen viruses could be isolated and 10 randomly selected isolates were subjected to sequence analysis along with four random clinical samples. All the 10 isolates and 4 clinical samples were characterized as New CPV-2a (CPV2a with 297-Ser→Ala). One of the field isolates was found to be phylogenetically closely related to New CPV-2a strains of Japan and India; another field isolates was found to share ancestral origins with New CPV-2a strains of Korea, USA, Italy, Brazil, Germany, Taiwan and Vietnam; rest other sequences had distinct lineage but shared molecular relationship with New CPV-2a reference strains.
犬细小病毒 2 型(CPV-2)可引起犬急性出血性肠炎。犬细小病毒易发生遗传进化,在过去三十年中经历了几次突变,产生了不同的毒株,如 CPV-2a、CPV-2b、新型 CPV-2a、新型 CPV-2b 和 CPV-2c。影响 CPV VP2 基因的突变导致了不同抗原变异体的进化。对病毒 VP2 基因的序列分析和后续特征分析对于分子流行病学非常重要。本研究旨在通过扩增部分 VP2 基因进行病毒分离和鉴定,并进一步进行序列分析,同时评估田间病毒与参考株的系统进化关系。在 77 个样本中,有 51 个样本通过 PCR 检测呈阳性,所有 51 个样本均在 CRFK 细胞系中进行病毒分离。共分离出 16 株病毒,随机选择 10 株分离株进行序列分析,并与 4 株随机临床样本一起进行序列分析。所有 10 个分离株和 4 个临床样本均被鉴定为新型 CPV-2a(CPV2a 297-Ser→Ala)。一个田间分离株与日本和印度的新型 CPV-2a 株系在系统进化上非常接近;另一个田间分离株与韩国、美国、意大利、巴西、德国、中国台湾和越南的新型 CPV-2a 株系具有共同的祖先起源;其余的序列具有不同的进化枝,但与新型 CPV-2a 参考株系具有分子关系。