Institute of Laboratory Animal Sciences, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100021, China.
Viruses. 2013 Oct 18;5(10):2548-60. doi: 10.3390/v5102548.
Kobuviruses comprise three species, the Aichivirus A, Aichivirus B, and Aichivirus C (porcine kobuvirus). Porcine kobuvirus is endemic to pig farms and is not restricted geographically but, rather, is distributed worldwide. The complete genomic sequences of four porcine kobuvirus strains isolated during a diarrhea outbreak in piglets in the Gansu province of China were determined. Two of these strains exhibited variations relative to the traditional strains. The potential 3C/3D cleavage sites of the variant strains were Q/C, which differed from the Q/S in the traditional porcine kobuvirus genome. A 90-nucleotide deletion in the 2B protein and a single nucleotide insertion in the 3'UTR were found in the variant strains. The VP1 regions of all four porcine kobuviruses in our study were highly variable (81%-86%). Ten common amino acid mutations were found specifically at certain positions within the VP1 region. Significant recombination sites were identified using SimPlot scans of whole genome sequences. Porcine kobuviruses were also detected in pig serum, indicating that the virus can escape the gastrointestinal tract and travel to the circulatory system. These findings suggest that mutations and recombination events may have contributed to the high level of genetic diversity of porcine kobuviruses and serve as a driving force in its evolution.
Kobuviruses 包括三个种，即 Aichivirus A、Aichivirus B 和 Aichivirus C（猪源博卡病毒）。猪源博卡病毒在猪场中普遍存在，没有明显的地理限制，而是分布于全球各地。本研究测定了 4 株在中国甘肃省仔猪腹泻暴发中分离的猪源博卡病毒的全基因组序列。其中 2 株与传统株存在差异。变异株的潜在 3C/3D 裂解位点为 Q/C，与传统猪源博卡病毒基因组中的 Q/S 不同。在变异株中发现 2B 蛋白中的 90 个核苷酸缺失和 3'UTR 中的单个核苷酸插入。我们研究的所有 4 株猪源博卡病毒的 VP1 区高度可变（81%-86%）。在 VP1 区的特定位置发现了 10 个共同的氨基酸突变。使用整个基因组序列的 SimPlot 扫描识别到了显著的重组位点。在猪血清中也检测到了猪源博卡病毒，表明该病毒可以逃避胃肠道并进入循环系统。这些发现表明，突变和重组事件可能导致了猪源博卡病毒高度的遗传多样性，并成为其进化的驱动力。
