Tran T N Hoa, Nakagomi Toyoko, Nakagomi Osamu
Department of Molecular Microbiology and Immunology, Graduate School of Biomedical Sciences, and The Global Center of Excellence, Nagasaki University, Nagasaki, Japan.
Trop Med Health. 2013 Mar;41(1):13-20. doi: 10.2149/tmh.2012-29. Epub 2013 Feb 7.
Rotavirus A causes severe diarrhoea in infants and young children worldwide. Many unusual combinations of G and P genotypes have been observed in rotaviruses circulating in developing countries. Mixed infection of a single individual with more than one strain is a mechanism by which genetic reassortants are formed with unusual G and P combinations. However, few studies have provided direct evidence for the formation of such unusual strains as a result of co-infection of co-circulating strains. Here, we used full-genome sequencing to re-analyze a G3P[4] strain (107E1B) and a G2P[4] strain (116E3D) detected in India in 1993 and showed that 107E1B had virtually an identical nucleotide sequence with 116E3D, except the VP7 gene. Phylogenetic analysis revealed that the 107E1B VP7 gene was of typical human rotavirus origin, with a 99.3% nucleotide sequence identity with another Indian G3 VP7 gene. Thus, this study provided robust evidence for the formation of the G3P[4] strain through genetic reassortment in which a G2P[4] strain with a typical DS-1 genogroup background acquired the VP7 gene from a co-circulating G3 human rotavirus strain. This study established a basis on which to facilitate full genome sequence analysis of an increasing number of G3P[4] strains in China and elsewhere in the world.
A组轮状病毒在全球范围内导致婴幼儿严重腹泻。在发展中国家流行的轮状病毒中，已观察到许多G和P基因型的异常组合。单个个体感染一种以上毒株的混合感染是形成具有异常G和P组合的基因重配体的一种机制。然而，很少有研究为共循环毒株的共同感染导致此类异常毒株的形成提供直接证据。在此，我们使用全基因组测序重新分析了1993年在印度检测到的一株G3P[4]毒株（107E1B）和一株G2P[4]毒株（116E3D），结果显示，除VP7基因外，107E1B与116E3D的核苷酸序列几乎相同。系统发育分析表明，107E1B的VP7基因起源于典型的人类轮状病毒，与另一个印度G3 VP7基因的核苷酸序列同一性为99.3%。因此，本研究为通过基因重配形成G3P[4]毒株提供了有力证据，即一株具有典型DS-1基因组背景的G2P[4]毒株从共循环的G3人类轮状病毒株获得了VP7基因。本研究为促进对中国及世界其他地区越来越多的G3P[4]毒株进行全基因组序列分析奠定了基础。
