Biochemistry Division, North-West University, Private Bag X6001, Potchefstroom 2520, South Africa.
Infect Genet Evol. 2011 Dec;11(8):2072-82. doi: 10.1016/j.meegid.2011.09.023. Epub 2011 Oct 11.
Infection of a single host cell with two or more different rotavirus strains creates conditions favourable for evolutionary mechanisms like reassortment and recombination that can generate novel strains. Despite numerous reports describing mixed rotavirus infections, whole genome characterisation of rotavirus strains in a mixed infection case has not been reported. Double-stranded RNA, exhibiting a long electropherotype pattern only, was extracted from a single human stool specimen (RVA/Human-wt/ZAF/2371WC/2008/G9P[8]). Both short and long electropherotype profiles were however detected in the sequence-independent amplified cDNA derived from the dsRNA, suggesting infection with more than one rotavirus strain. 454® pyrosequencing of the amplified cDNA revealed co-infection of at least four strains. Both genotype 1 (Wa-like) and genotype 2 (DS-1-like) were assigned to the consensus sequences obtained from the nine genome segments encoding NSP1-NSP5, VP1-VP3 and VP6. Genotypes assigned to the genome segments encoding VP4 were P[4] (DS-1-like), P[6] (ST3-like) and P[8] (Wa-like) genotypes. Since four distinct genotypes [G2 (DS-1-like), G8, G9 (Wa-like) and G12] were assigned to the four consensus nucleotide sequences obtained for genome segment 9 (VP7), it was concluded that at least four distinct rotaviruses were present in the stool. Intergenotype genome recombination events were observed in genome segments encoding NSP2, NSP4 and VP6. The close similarities of some of the genome segments encoding NSP2, VP6 and VP7 to artiodactyl rotaviruses suggest that some of the infecting strains shared common ancestry with animal strains, or that interspecies transmission occurred previously. The sequence-independent genome amplification technology coupled with 454® pyrosequencing used in this study enabled the characterisation of the whole genomes of multiple rotavirus strains in a single stool specimen that was previously assigned single genotypes, i.e. G9P[8], by sequence-dependent RT-PCR.
单一宿主细胞感染两种或更多种不同的轮状病毒株会创造有利于进化机制的条件，如重组和重组，这些机制可以产生新的株系。尽管有许多报道描述了混合轮状病毒感染，但混合感染病例中轮状病毒株的全基因组特征尚未报道。从单一人类粪便标本中提取了双链 RNA（RVA/Human-wt/ZAF/2371WC/2008/G9P[8]），其仅表现出长电泳型模式。然而，在源自双链 RNA 的无序列依赖性扩增 cDNA 中检测到短和长电泳型谱，表明感染了不止一种轮状病毒株。对扩增 cDNA 的 454®焦磷酸测序显示至少有四种株系同时感染。基因型 1（Wa 样）和基因型 2（DS-1 样）均被分配给从编码 NSP1-NSP5、VP1-VP3 和 VP6 的九个基因组片段获得的共识序列。分配给编码 VP4 的基因组片段的基因型为 P[4]（DS-1 样）、P[6]（ST3 样）和 P[8]（Wa 样）基因型。由于从编码 VP7 的四个基因组片段获得了四个不同的基因型[G2（DS-1 样）、G8、G9（Wa 样）和 G12]，因此得出结论，粪便中至少存在四种不同的轮状病毒。在编码 NSP2、NSP4 和 VP6 的基因组片段中观察到不同基因型的基因组重组事件。编码 NSP2、VP6 和 VP7 的一些基因组片段与偶蹄动物轮状病毒的相似性表明，一些感染株与动物株系具有共同的祖先，或者以前发生过种间传播。本研究中使用的无序列依赖性基因组扩增技术与 454®焦磷酸测序相结合，能够对以前通过序列依赖性 RT-PCR 分配单一基因型（即 G9P[8]）的单个粪便标本中的多个轮状病毒株的全基因组进行特征描述。
