Abstract：
Canine parvovirus (CPV) is the main cause of viral diarrhea in dogs. CPV became a global disease in 1978 and was endemic all over the world. CPV-2 was the first strain to be identified, but with genetic mutations, new genotypes such as CPV-2a/2b/2c/new-2a/new-2b have emerged. In this study, 128 fecal samples of stray dogs suspected of CPV-2 infection were collected from January to March 2021 in Shanghai, China. All samples were screened by PCR and further analyzed by VP2 gene. The positive rate of CPV-2 was 9.4% (12/128), of which 6 CPV-2 isolates were successfully isolated. Phylogenetic tree analysis showed that 4 isolates were CPV-2c genotype and 2 were new-CPV-2b genotype. VP-2 is a key protein that determines the antigenic properties, host range and receptor binding of cpv-2. The results of VP2 amino acid sequence analysis in this study showed that the CPV-2c isolated strain was the same as the previous strains reported in China, including F267Y, Y324I, Q370R and A5G mutations in addition to the typical N426E mutations. Similarly, in addition to the conventional N426D, S297A, F267Y and Y324I mutations, the new CPV-2b isolate also had a new mutation of T440A. This study further confirmed the prevalence of CPV-2c and new-CPV-2b in Shanghai, and also found a new mutation site of new-CPV-2c, which provided a theoretical basis for further enriching the epidemiological data of CPV-2 in Shanghai, as well as the development of vaccines and the prevention and control of the disease.
摘要：
犬细小病毒（CPV）是犬病毒性腹泻的主要病因。CPV在1978年成为一种全球性疾病，并在世界各地流行。CPV-2是第一个被鉴定的菌株,但是随着基因突变，出现了新的基因型，如CPV-2a/2b/2c/new-2a/new-2b。在这项研究中,2021年1月至3月，在上海收集了128只疑似CPV-2感染的流浪狗的粪便样本，中国。通过PCR筛选所有样品并通过VP2基因进一步分析。CPV-2阳性率为9.4%(12/128),其中成功分离出6株CPV-2。系统发育树分析表明，4株为CPV-2c基因型，2株为新CPV-2b基因型。VP-2是决定抗原特性的关键蛋白,cpv-2的宿主范围和受体结合。本研究VP2氨基酸序列分析结果表明,CPV-2c分离株与我国以前报道的菌株相同,包括F267Y，Y324I,除了典型的N426E突变外，还有Q370R和A5G突变。同样，除了传统的N426D，S297A,F267Y和Y324I突变，新的CPV-2b分离株也有一个新的T440A突变。这项研究进一步证实了CPV-2c和新CPV-2b在上海的流行。还发现了新的CPV-2c突变位点,为进一步丰富上海市CPV-2流行病学资料提供了理论依据,以及疫苗的开发和疾病的预防和控制。
