猫细小病毒广西分离株FPV-GX01全基因的克隆及遗传进化分析

Cloning and phylogenetic analysis of FPV-GX01 gene of feline parvovirus isolated from Guangxi

为了解广西地区猫细小病毒（feline parvovirus,FPV）的生物学特性,阐明其基因组与遗传进化等特征。笔者采集经胶体金检测FPV阳性的粪便样品接种FK81细胞,进行病毒分离及理化特性鉴定,同时利用PCR分段扩增病毒基因组DNA,并与国内外分离株进行同源性及遗传进化比较分析。结果显示,分离株在FK81细胞上盲传3代后出现CPE,猪红细胞血凝价达1∶1 024,第5代病毒TCID50测定为10-5.2/0.1 m L,该毒株对热、酸、氯仿及乙醚有较强的抵抗力,将分离株命名为FPV-GX01。全基因测序结果表明,分离株基因组为4 901 bp,与2007年我国猫源细小病毒株FPV-XJ1同源性高达99.0%,属同一分支。氨基酸位点分析显示,FPV-GX01株VP2蛋白功能较少发生突变,与犬细小病毒（canine parvovirus,CPV）氨基酸位点存在宿主差异;FPV-GX01 NS1蛋白序列上没有VP2蛋白稳定,第619位异亮氨酸突变成苯丙氨酸。广西地区分离的猫细小病毒也在不断发生遗传变异进化,本研究对该地区猫细小病毒的进化特征提供了一定的参考。

To understand the biological characteristics of feline parvovirus（FPV）in Guangxi and to elucidate the genome and genetic evolution,fecal samples detected by colloidal gold to be FPV positive were inoculated with FK81 cells,followed by virus isolation and identification of physicochemical property,and at the same time DNA of the genome was amplified partially by PCR,the results of which were used to perform comparative analysis with domestic and foreign isolates in terms of homology and genetic evolution.The isolate showed CPE after blind passage for 3 generations on FK81 cells.Porcine erythrocytes hemagglutination titer was 1 ∶ 1 024.The TCID50 of the 5 th generation virus was determined to be 10-5.2/0.1 m L.The strain was strongly resistant to heat,acid,chloroform and ether.This isolate was named as FPV-GX01.The results of whole-genome sequencing showed that the isolate had a bp,sharing 99.0% homology with the feline parrot virus strain FPV-XJ1 identified in 2007,which proves that it belongs to the same branch.The analysis of amino acid sites showed that there was less mutation in the function of VP2 protein of the FPV-GX01 strain,but a few differences in amino acid sites with canine parvovirus（CPV） were showed.FPV-GX01 NS1 protein was discovered to be less stable than VP2 protein,and Leucine at position 619 mutated into phenylalanine.The feline parvovirus isolated in Guangxi displays continuous genetic variation.This study result is hoped to provide a reference of the evolutionary characteristics of feline parvovirus in this region.