3株脑心肌炎病毒河南分离株VP1基因的序列测定与遗传进化分析

Sequencing and Phylogenetic Analysis of VP1 Gene of Three EMCV Isolates in Henan Provine

为研究野猪家养在猪场脑心肌炎（EMC）发生发展过程中可能扮演的角色和鼠在不同猪源脑心肌炎病毒（EMCV）交叉感染中的作用，应用 RT-PCR和测序技术，对分离自河南省同一发病猪场的良种猪源、家养野猪源和鼠源EMCV 等3株病毒的VP1基因进行序列比较和遗传进化分析，发现 EMCV可分为G1、G2和G33个群。3株分离病毒的遗传距离较近，核苷酸序列同源性高达99．6％～99．8％，并与国内猪源EMCV亲缘关系最近，同属于G1群，而与欧美毒株的亲缘关系较远，存在较大的地域差异。研究结果证实，野猪家养可传播EMCV并引起良种猪感染发病，鼠在不同猪源 EMCV的交叉感染、传播与流行中起到重要媒介作用；分离自同一猪场的良种猪源EMCV和家养野猪源 EMCV应是同一株病毒对不同猪种的感染，因而需要在野生动物家养活动中充分考虑自然疫源性疾病传播的生态学因素。

In order to study the role of EMCV occurrence and development in wild boars fed in pig farms and the impact of mice in the cross-infection of EMCV among different species of pigs,the sequence comparison and analy-sis of VP1 gene of the three strains isolated from pigs,domesticated boars and mice in a same farm isolated from Henan provine were conducted by RT-PCR.The results showed that EMCV was divided into G1,G2 and G3 three groups.The genetic distance of the three isolates was close,and nucleotide sequence identity was 9 9 .6%-9 9 .8%. They have close relationship with the domestic strains,belonging to group G1 ,and distant relationship with for-eign strains,existing lager regional divergence.Our results confirmed that domesticated wild boar can spread EM-CV and caused infection in pigs;mice play an important role in cross infection,transmission and prevalence of EM-CV disease between pigs and domesticated wild boars.Therefore,the attention should take into full consideration in the ecology of natural epidemic disease spread in the wild animal breeding activities.