福建省猪流行性腹泻病毒检测与S基因遗传变异分析

Clinical Detection and Variation Analysis on S Genes of Porcine Epidemic Diarrhea Viruses in Fujian

为了解猪流行性腹泻（PED） 在福建省的流行和流行毒株S基因的变异情况,对2011-2014 年采自117个规模猪场的295份疑似PED 的病料进行检测,对14株具有代表性的PEDV 毒株进行S基因序列分析.结果显示,2011-2014年病料阳性率分别为87.30%、75.00%、40.91% 和34.15%,总阳性率为69.49%,虽然PED 阳性率在福建省有下降趋势,但仍较高.基因序列分析表明福建省14株PEDV 分离株S基因核苷酸之间的同源性分别为98.5%～100.0%,与国内其他毒株之间的同源性为93.3%～99.5%,其中与国内2009年以前流行的PEDV 毒株的同源性较低;与2008年泰国NPPED2008_2 株的同源性分别为95.8% ～96.1%;与CV777标准株的同源性为93.8%～94.1%.分离毒株的S基因片段氨基酸存在多个位点突变、插入和缺失现象.遗传进化树表明14 株PEDV 分离株与2008 年泰国NPPED2008 _2 毒株和2009 年韩国毒株亲缘关系较近, 与attenuatedDR13弱毒株及CV777标准株亲缘关系比较远.14株PEDV 的S基因序列已登陆Genbank.

The intensity and widespread of the porcine epidemic diarrhea (PED) have continuously been on the climb in Fujian since the end of 2010. The infectious disease caused high mortalities in suckling piglets ,and has become one of the most serious concerns for the pig farms in the area .To deter the epidemic and understand the genetic variations of S genes of PED viruses ,295 clinical samples from 117 sizable pig farms were collected during 2011 -2014 for RT‐PCR analysis .Overall ,205 out of 295 samples (69.49% ) were tested positive .Annually ,the infection rate declined from 87.3% ,75.00% ,40.91% to 34.15% during the year of 2011 to 2014. Nonetheless ,it remained a serious problem for the industry .The study on nucleotide sequence revealed that the S genes of the 14 isolated PED strains shared 98.5% -100.0% homogeneity among themselves ,and 93.3% -99.5% in comparison with other strains in China ,93.8% -94.1% with CV777 ,and 95.8% - 96.1% with NPPED2008 _ 2. Variants , insertions and deletions of amino acids on the genes were found .The phylogenetic analysis on the 14 PED viruses showed a close relationship with the Thailand and Korean strains ,and a remote one with the attenuated DR13 and CV777. The S gene sequence obtained from this study has been filed with Genbank .