猪7种腹泻相关病毒的临床检测及猪嵴病毒的遗传进化分析

Clinical detection of seven porcine diarrhea-associated viruses and evolution analysis of porcine kobuvirus

为了解引起猪腹泻疫病的病毒性病原种类及感染现状,本研究首先针对7种报道较少但可引起猪腹泻的病毒性病原建立了多重RT-PCR检测方法,包括猪捷申病毒(PTV)、猪萨佩罗病毒(PSV)、猪丁型冠状病毒(PDCo V)、猪嵴病毒(PKV)、猪札幌病毒(PSa V)、猪星状病毒(PAst V)和猪环曲病毒(PTo V)。利用该方法对419份临床腹泻粪便样品进行筛检,结果显示PKV检出率最高,阳性率达26.98%–45.79%;PKV和其他病原混合感染率达9.52%–18.54%。基于PKV的高检出率及其可能在猪腹泻疾病中发挥的作用,本试验进一步选取3个PKV阳性样品进行全基因组序列测定及遗传进化分析。结果表明,这3个阳性样品PKV均归属于猪嵴病毒属,且与其他动物嵴病毒遗传距离较远,分别标记为CM-PKV、JS-PKV和PD-PKV;它们的全基因组同源性为88.1%–89.1%;CM-PKV与2013年报道的中国株JS-02a-CHN/2013同源性最高,而JS-PKV和PD-PKV则与2008年报道的匈牙利株K-30-HUN/2008/HUN同源性最高。表明上海不同地区猪群中存在的PKV有明显的遗传差异,但毒株遗传特性的差异与其致病力的相关性需进一步研究。本研究为深入了解PKV的流行现状及探讨其在猪腹泻疫情中的作用提供了参考。

In order to analyze the epidemic situation of porcine viral diarrhea-associated diseases, a multiplex RT-PCR method was developed for detection of Seven diarrhea-associated viruses, including porcine teschovirus（PTV）, porcine sapelovirus（PSV）, porcine deltacoronavirus（PDCOV）, porcine kobuvirus（PKV）, porcine sapovirus（POSAV）, porcine astrovirus（PASTV） and porcine torovirus（PTOV）. A total of 419 samples were screened using the method, the results showed that PKV has the highest positive rate of 26.98%–45.79% and the mixed infection rate of PKV with others viruses were 9.52%–18.54%. On account of high positive rate of PKV and its potential important role in diarrhea disease, complete genome sequences of three PKV positive samples were further sequenced and genetic evolution were established. Sequences analysis indicated that three PKV-positive samples, designated as PD-PKV, JS-PKV and CM-PKV, respectively, were classified into the porcine kobuvirus genus. The genomic homologies of three viruses were 88.1%–89.1%. CM-PKV had the highest homology with a kobuvirus JS-02a-CHN/2013 reported in 2013, while JS-PKV and PD-PKV were most closed to a kobuvirusv K-30-HUN/2008/HUN reported in Hungary in 2008. This illustrated the significant genetic differences were existed among the PKV isolates in Shanghai. The relationship between the difference among the PKV isolates and the viral pathogenicity still needs to be explored. This research provides references for understanding the prevalence of PKV and its role in swine diarrhea disease.