Department of Animal Production, Faculty of Veterinary Medicine, University of Nairobi, P.O Box 29053, Nairobi, 00625, Kenya,
Arch Virol. 2014 Jun;159(6):1313-9. doi: 10.1007/s00705-013-1942-x. Epub 2013 Dec 11.
In this study, swine fecal specimens (n = 251) collected from nursing and weaned piglets raised under smallholder production systems were screened for the presence of kobuviruses by RT-PCR. Porcine kobuviruses were detected in 13.1 % (33/251) of the samples. We demonstrated that porcine kobuvirus infections exist in indigenous pigs in Kenya and Uganda and that the prevalence was higher in young piglets than older pigs: nursing piglets (15 %), post-weaning (3-month-old) pigs (17 %), 4-month-old pigs (10 %). Genetic analysis of the partial RNA-dependent RNA polymerase (RdRp) region (690 nt) revealed that kobuviruses circulating in East Africa are diverse, sharing nucleotide sequence identities ranging from 89.7 to 99.1 % and 88 to 92.3 % among them and with known porcine kobuviruses, respectively. The nucleotide sequence identities between our kobuvirus strains and those of human, bovine and canine kobuviruses were 69.4-70.7 %, 73.1-74.4 % and 67-70.7 %, respectively. Additionally, upon sequencing selected samples that showed consistent 720-bp RT-PCR bands while using the same primer set, we detected porcine astroviruses in our samples belonging to type 2 and type 3 mamastroviruses. To our knowledge, this study reports the first detection and molecular analysis of both porcine kobuviruses and astroviruses in an African region. Further studies are required to determine the role of these viruses in gastrointestinal infections of pigs in this region and to determine the genetic diversity of the circulating strains to develop accurate diagnostic tools and implement appropriate control strategies.
在这项研究中，通过 RT-PCR 对从小型生产者系统中饲养的哺乳期和断奶仔猪的粪便标本（n = 251）进行了筛查，以检测是否存在科布病毒。在 13.1%（33/251）的样本中检测到了猪科布病毒。我们证明，肯尼亚和乌干达的本地猪中存在猪科布病毒感染，并且幼猪的感染率高于成年猪：哺乳期仔猪（15%）、断奶后（3 月龄）仔猪（17%）、4 月龄仔猪（10%）。对部分 RNA 依赖性 RNA 聚合酶（RdRp）区域（690nt）的遗传分析表明，东非流行的科布病毒具有多样性，与已知的猪科布病毒相比，它们之间的核苷酸序列同一性范围为 89.7%至 99.1%，分别为 88%至 92.3%。我们的科布病毒株与人类、牛和犬科布病毒株的核苷酸序列同一性分别为 69.4-70.7%、73.1-74.4%和 67-70.7%。此外，在用相同的引物组对显示出一致的 720bp RT-PCR 条带的选定样本进行测序后，我们在样本中检测到了属于 2 型和 3 型哺乳动物科布病毒的猪星状病毒。据我们所知，这项研究首次在非洲地区报告了猪科布病毒和星状病毒的检测和分子分析。需要进一步研究这些病毒在该地区猪的胃肠道感染中的作用，并确定循环株的遗传多样性，以开发准确的诊断工具并实施适当的控制策略。
