猪瘟野毒混合毒实验室感染的研究

本研究以本所近年来所分离的高、中、低三株不同毒力（HeNXH3.98、JL1.94和FJFQ1.99）的猪瘟野毒混合毒对敏感猪进行实验室感染试验，利用HCFA、RT－PCR及序列测定进行检测和分析，结果2头试验猪均在感染后2周发病死亡，表现典型的猪瘟临床症状；序列测定及分析结果表明感染后1周及2周2头实验感染猪所分离的病毒E2基因主要抗原编码区序列完全一致，核苷酸及氨基酸同源性均为1005；与感染毒株序列比较，2头试验感染猪所分离的病毒E2基因主要抗原编码区序列与JL1.94株序列完全一致，核苷酸及 在酸同源性均为100％，且基因分群在同一群；而与HeNXH3.98和FJFQ1.99株序列则有一定的差异，且不在同一基因群或基因亚群，说明在多个猪瘟病毒存在的情况下，敏感猪存在对猪间病毒的优势选择。本试验的条件下3株不同和的猪瘟野毒混合感染以中等毒力毒株JL1.94为优势毒株。

Experimental Infection of the Mixed Field Isolated Strains of Hog Cholera Virus

Experimental infection on sensitive pigs was done with 3 mixed field isolated strains of Hog Cholera Virus(HeNXH3.98,JL 1.94 and FIFQ1.99),its toxicity was different and isolated by our institute in recent years.The method of analysis and examine were HCFA,RT_PCR and sequencing.The 2 infected pigs showed typical clinical symptoms of Hog Cholera and dead after infected 2 weeks.Analysis of sequence showed that the major antigen coding region sequences of E2 gene of isolated strains from 2 infected pigs were no difference after infected 1 and 2 weeks.The identity of nucleotide sequence and amino acid sequences was 100%.Compared with the infected strains,the major antigen coding region sequences of E2 gene of isolated strains from 2 infected pigs were identity with JL 1.94 strain.The identity of nucleotide sequence and amino acid sequences was 100%,and all belonged to the same gene group.But the major antigen coding region sequences of E2 gene of isolated strains from 2 infected pigs had little difference with the sequence of HeNXH3.98 and FJFQ1.99 strains,and they were not in the same gene group or gene subgroup.The results of this study illustrated that sensitive pigs have superior selection if there are many hog cholera viruses.In this experimental condition,the superior strain of infection of 3 different toxicity hog cholera field isolated strains was middle toxictiy strain of hog cholera field isolated strain.