猪捷申病毒4型的分离鉴定及VP1基因序列分析

Isolation and identification of Porcine teschovirus type 4 and sequence analysis of VP1 gene

为了对2021年7月份四川省某猪场送检的疑似感染猪捷申病毒(Poreine teschovirus,PTV)的猪腹泻粪便样品进行鉴定,试验将送检的病料接种ST细胞进行病毒分离,采用血凝试验、理化特性、RT-PCR进行鉴定,测序序列基于VP1基因构建系统发育树并进行同源性分析。结果表明:从疑似病料中分离出1株RNA病毒,ST细胞感染24 h后出现明显的细胞病变,该病毒不能凝集猪红细胞,耐酸,对氯仿及胰蛋白酶有一定的抵抗能力,对热敏感,二价阳离子(如Mg^(2+))可提高分离毒株对高温环境的抵抗力;结合RT-PCR和VP1基因比对分析可知该毒株为PTV,命名为Sichuan2021;经测定含量为1×10^(6.75)TCID_(50)/mL;分离毒株Sichuan2021与PTV-4毒株位于同一分支,且与参考毒株10BJ02(JQ975417)和SH1(KJ881010)的亲缘关系最近,核苷酸相似性分别为92.8%和92.5%。说明分离毒株Sichuan2021为PTV-4。

In order to identify pig diarrhea stool samples suspected of being infected with Porcine teschovirus(PTV)submitted for inspection by a pig farm in Sichuan Province in July 2021,in the experiment,the disease materials submitted for inspection were inoculated into ST cells for virus isolation,and the genotype was identified and determined by hemagglutination test,physicochemical properties and RT-PCR.A phylogenetic tree was constructed for the VP1 gene sequence and homology analysis was performed.The results showed that an RNA virus was isolated from the suspected disease material.24 hours after infection of ST cells,obvious cytopathic effect occured.The virus had no agglutination to porcine red blood cells,which was acid-resistant,resistant to chloroform and trypsin,and sensitive to heat.Divalent cations(such as Mg^(2+))could increase the resistance of isolated virus to high temperature environment.Combined with RT-PCR and VP1 gene comparison analysis,it could be seen that the strain was PTV,named Sichuan2021.The content was determined to be 1×10^(6.75)TCID_(50)/mL.The isolated strains Sichuan2021 and PTV-4 were located in the same branch,and were most closely related to reference strains 10 BJ02(JQ975417)and SH1(KJ881010),with nucleotide similarity of 92.8%and 92.5%,respectively.The results suggested that the isolated strain Sichuan2021 was PTV-4.