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

摘要:

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 (PDCoV)、猪嵴病毒 (PKV)、猪札幌病毒 (PSaV)、猪星状病毒 (PAstV)和猪环曲病毒 (PToV)。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的高检出率及其在腹泻病中扮演重要角色，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。测序结果表明，这3个阳性样品感染的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。这说明上海不同地区猪群中存在的PKV有明显的遗传差异，这种差异与病毒致病力的关系还有待深入研究。本研究为深入了解PKV的流行情况及探讨其在猪腹泻疫情中的作用提供了参考。

Abstract:

In this study, a multiplex RT-PCR method was developed for detection of seven diarrhea-associated porcine viruses, including porcine teschovirus (PTV), porcine sapovirus (PSV), porcine deltacornavirus (PDCoV), porcine kobuvirus (PKV), porcine sapovirus (PSaV), porcine astrovirus (PAstV) and porcine torovirus (PToV). A total of 419 samples were screened by this method and results showed that PKV had the highest positive rate of 26.98%?45.79% and its mixed infection rate reached 9.52%–18.54%. On account of high positive rate of PKV and its important role in diarrhea disease, complete genomic sequences of three PKV positive samples were further sequenced. Three PKV labeled as PD-PKV, JS-PKV and CM-PKV were classified into porcine kobuvirus genus and had far genetic distance with other kobuviruses. The complete genome homologies among them were 88.1%–89.1%. CM-PKV had the highest identity with the Chinese strain JS-02a-CHN/2013 reported in 2013 while JS-PKV and PD-PKV were most closed to the K-30-HUN/2008/HUN strain reported in Hungary in 2008. This illustrates the significant genetic differences of the different PKV isolates in Shanghai while its relationship with the viral pathogenicity still needs to be explored. This research provides references for further understanding the prevalence of PKV and its role in swine diarrhea.