探讨犬细小病毒2型(CPV-2)的流行概况和遗传多样性,在2020年至2021年期间,从中国河南省10个城市的疑似CPV-2感染的犬身上收集的111份临床样本进行了PCR筛选.结果显示CPV-2阳性率为88.29%(98/111)。对98株CPV-2菌株的近全长基因组进行测序和分析。CPV-2c株(91.84%,90/98)显著高于新的CPV-2a菌株(8.16%,8/98)在河南省未检测到其他CPV基因型,表明CPV-2c已成为河南省的优势基因型。NS1和VP2氨基酸的系统发育分析将本研究中的菌株与亚洲菌株进行了分组,聚集到一个相同的分支中。基于本研究中的CPV-2VP2序列,并可在NCBI数据库中获得,适应性分析表明,在CPV-2的VP2蛋白中鉴定出17个正选择位点和10个平行进化位点,其中3个位点(位点5,370和426)均处于正选择压力和平行进化.有趣的是,在本研究的82株CPV-2c株的VP2蛋白中也观察到两个氨基酸突变(A5G和Q370R),与中国较早的CPV-2c株(GU380303)不同。此外,在五个CPV-2c菌株的VP2蛋白中观察到一个独特的突变(I447M),最早在中国报道。这项研究为我们进一步了解CPV-2在中国的流行状况和演变提供了有力的见解。重要性CPV-2是在狗中鉴定的原始病毒株,导致狗的急性和致命疾病。随后,原始的CPV-2在世界各地被新的抗原变体取代(例如,CPV-2a,CPV-2b,新的CPV-2a,新的CPV-2b,和CPV-2c)。目前,中国河南省CPV-2的流行病学特征尚不清楚。在我们的研究中,共获得了98个CPV-2菌株的近全长基因组,以探索CPV-2在河南省的流行和遗传进化。此外,同时对CPV-2自发现以来在中国的流行病学和遗传进化进行了调查。这项研究的结果将为中国CPV-2菌株的进化提供有价值的信息。
To investigate the epidemic profile and genetic diversity of canine parvovirus type 2 (CPV-2), a total of 111 clinical samples collected from dogs suspected of CPV-2 infection in 10 cities of Henan province of
China during 2020 to 2021 were screened by PCR. The results showed a CPV-2-positive rate of 88.29% (98/111). Nearly full-length genomes of 98 CPV-2 strains were sequenced and analyzed. CPV-2c strains (91.84%, 90/98) were significantly higher than that of new CPV-2a strains (8.16%, 8/98) in Henan province without detecting other CPV genotypes, indicating that CPV-2c has become the dominant genotype in Henan province. A phylogenetic analysis of NS1 and VP2 amino acids grouped the strains in this study with Asian strains, which clustered into an identical branch. Based on the CPV-2 VP2 sequences in this study and available in the NCBI database, the adaptation analyses showed that 17 positive selection sites and 10 parallel evolution sites were identified in the VP2 protein of CPV-2, of which three sites (sites 5, 370, and 426) were both under positive selection pressure and parallel evolution. Interestingly, two amino acid mutations (A5G and Q370R) were also observed in the VP2 proteins of 82 CPV-2c strains in this study, which differed from the earlier CPV-2c strain (GU380303) in China. In addition, a unique mutation (I447M) was observed in the VP2 protein of five CPV-2c strains, which was first reported in
China. This study provides powerful insight to further our understanding of the epidemic status and evolution of CPV-2 in
China. IMPORTANCE CPV-2 was the original virus strain identified in dogs, which cause an acute and lethal disease in dogs. Subsequently, the original CPV-2 was replaced throughout the world by novel antigenic variants (e.g., CPV-2a, CPV-2b, new CPV-2a, new CPV-2b, and CPV-2c). Currently, the epidemiological characteristics of CPV-2 in Henan province of
China is still unclear. In our study, a total of 98 nearly full-length genomes of CPV-2 strains were obtained to explore prevalence and genetic evolution of CPV-2 in Henan Province. Moreover, the epidemiological and genetic evolution of CPV-2 in China since its discovery was also investigated. The results of this study will provide valuable information regarding the evolution of CPV-2 strains in
China.