Epidemiological Investigation Of Porcine Kobuvirus And Genome Sequence Analysis Of CH/HZ/2011Strain

Porcine kobuviruses are members of the large and growing familyPicornaviridae. Until now, two official, Aichi virus and Bovine kobuvirus,and one candidate kobuvirus species:porcine kobuvirus。Acute diarrhea is a leading cause of morbidity worldwide and animportant cause of death among pigs. The majority of acute diarrheathought to be caused by viruses, among which porcine epidemic diarrheavirus (PEDV), transmissible gastroenteritis virus rotaviruses (TGEV),porcine rotaviruses and so on. On the other hand, there are many newlydiscovered enteric viruses, which are potentially also associated with acutediarrhea including kobuvirus. Porcine kobuvirus was detected at highprevalence in stool samples from healthy pigs in Hungary, China, Japan, and Korea. Some studies have indicated that porcine kobuvirus infection iscertainly involved in diarrhea disease. To evaluate the prevalence ofporcine kobuvirus in China, a couple of primers was designed based on the3D gene conserved region of porcine kobuvirus and236specimen samplescollected from84farms in24provinces and cities were detected forantigen determination by RT-PCR method. The results indicated thatporcine kobuvirus the positive rate both in samples and pig farms whichwas25.00%(63/236) and40.48%(51/126) respectively. And to investigatethe variation in3D gene of porcine kobuvirus, a total of3D genes werecloned and sequenced from different pig farms in different provinces in2012, the analysis of gene sequences by bioinformatics software suggestedthat9of porcine kobuvirus3D gene belonged to the same branch.In order to understanding the phenotypic variation and evolutionarycharacteristics of PKoV strains in China, the complete nucleotide andamino acid sequences and genetic organization of porcine kobuvirus (Kobuvirus/swine/CH/HZ/2011, JX827598), were determined by usingSmarter rapid amplification of cDNA ends (RACE) kit. The8101-nucleotide (nt)-long RNA genome contains a large open readingframe (7377nt) encoding a potential polyprotein precursor of2459aminoacids (aa) that more closely related to strains HNXX-4, SH-W and XX.The complete genome sequence of CH/HZ has an18nt-deletion in5’endand a90nt-deletion in2B, respectively. A neighbor-joining tree indicated31porcine kobuvirus strains were divided into four clusters (Thai-Japanesegroup, Hungarian group, Chinese group Ⅰ and Ⅱ). The strain CH/HZ wasincluded in the Chinese group Ⅱ.