四川地区猪细环病毒1型的流行病学调查和分子特征研究

Molecular Epidemiology and Molecular Characterization of TTSuV1 in Sichuan Province

为了解猪细环病毒1型(TTSuV1)在四川地区猪群中的流行情况及其遗传进化关系,采用PCR对四川省不同地区的5个规模化猪场采集的140份临床健康猪血清进行检测,并根据NCBI已发表的TTSuV1的全基因组序列,对TTSuV1中的2个亚型TTSuV1a和TTSuV1b进行全基因的扩增。结果显示,在140份临床健康猪血清样本中TTSuV1a和TTSuV1b的阳性检出率分别为49.29%(95%CI:40.7%~57.9%)和39.29%(95%CI:31.1%~47.9%)。通过克隆转化,序列测定后拼接获得TTSuV1a的近似全基因组长为2 497bp,TTSuV1b为2 693bp,对测得序列进行同源性和遗传进化分析。结果表明,扩增得到TTSuV1a的ORF1和ORF2序列,与国内外已发表的参考毒株间的核苷酸同源性分别为79.3%~97.5%和92.7%~98.2%,TTSuV1b的ORF1、ORF2序列与其他参考毒株间的核苷酸同源性分别为100%和97.1%~98.6%,分析表明其差异较小,亲缘关系较近。研究结果为四川省部分地区猪群中TTSuV1的流行情况提供数据参考,为进一步研究TTSuV的遗传进化提供一定的理论依据。

The objective of this study was to investigate the prevalence of porcine torque teno sus virus 1 （TTSuV1） in Sichuan province and to better study the genetic variation of TTSuV.In this study,a total of 140 clinical health pig sera were collected in 5 different intensive pig farms of Sichuan province.The preva- lence of TTSuV1 was detected by PCR.The genomes of TTSuVla and TTSuVlb were amplified according to the complete gene sequence of TTSuV1 published by NCBI.The results demonstrated that the TTSuVla and TTSuVlb infection rates were 49.29% （95%CI：40.7%-57.9%） and 39.29% （95%CI：31.1%-47.9%）, respectively.The near-full genome length of TTSuVla was 2 497 bp and 2 693 bp of TTSuVlb by cloning and sequencing.The nucleotide identities of ORF1 and ORF2 sequences of TTSuVla were 79.3-97.5 and 92.7%-98.2% to other strains in GenBank, respectively. The nucleotide identities of the ORF1 and ORF2 sequence of TTSuVlb were 100% and 97.1%-98.6%, with those of reference strains. The results may provide basic data on infection and prevalence of TTSuV1 virus in swine herds in Sichuan province, and provide a theoretical basis for further study of the genetic evolution of TTSuV virus.