Do Loan Phuong, Nakagomi Toyoko, Nakagomi Osamu
Department of Molecular Microbiology and Immunology, Graduate School of Biomedical Sciences, and Global Center of Excellence, Nagasaki University, Nagasaki, Japan.
Department of Molecular Microbiology and Immunology, Graduate School of Biomedical Sciences, and Global Center of Excellence, Nagasaki University, Nagasaki, Japan.
Infect Genet Evol. 2014 Jan;21:334-50. doi: 10.1016/j.meegid.2013.11.027. Epub 2013 Dec 6.
Rotavirus strains with a rearranged 11th genome segment may show super-short RNA electropherotypes. Examples from human strains were limited to seven strains, 69M, 57M, B37, Mc345, AU19, B4106 and BE2001, which have a variety of G and P genotypes. AU19 is a rare G1P[6] human rotavirus strain detected in a Japanese infant with severe acute gastroenteritis. This study was undertaken to better understand the origin of AU19 by determining the genotype constellation of AU19. Upon nearly-full genome sequencing, AU19 had a G1-P[6]-I5-R1-C1-M1-A8-N1-T1-E1-H2 genotype constellation. Possession of I5 and A8 genotypes is indicative of its porcine rotavirus origin, whereas possession of H2 genotype is indicative of its DS-1 like human rotavirus origin. At the phylogenetic lineage level for the genome segments that share the genotype between porcine and human rotaviruses, the VP1-4, VP7, NSP3-4 genes were most closely related to those of porcine rotaviruses, but the origin of the NSP2 gene was inconclusive. As to the NSP5 gene, the lineage containing AU19 and the other three super-short human strains, 69M, 57M and B37, carrying the H2 genotype (H2b) clustered with the lineage to which DS-1- like short strains belonged (H2a) albeit with an insignificant bootstrap support. Taken all these observations together, AU19 was likely to emerge as a consequence of interspecies transmission of a porcine rotavirus to a child coupled with the acquisition of a rare H2b genotype by genetic reassortment probably from a co-circulating human strain. The addition of the AU19 NSP5 sequence to much homogeneous H2b genotypes shared by previous super-short rotavirus strains made the genetic diversity of H2b genotypes as diverse as that of the H2a genotype, lending support to the hypothesis that super-short strains carrying H2b genotype have long been circulating unnoticed in the human population.
具有重排的第11个基因组片段的轮状病毒株可能呈现超短RNA电泳图谱型。人类毒株的例子仅限于7个毒株，即69M、57M、B37、Mc345、AU19、B4106和BE2001，它们具有多种G和P基因型。AU19是在一名患有严重急性胃肠炎的日本婴儿中检测到的一种罕见的G1P[6]人类轮状病毒株。本研究旨在通过确定AU19的基因型组合来更好地了解AU19的起源。经过近全基因组测序，AU19具有G1-P[6]-I5-R1-C1-M1-A8-N1-T1-E1-H2基因型组合。拥有I5和A8基因型表明其起源于猪轮状病毒，而拥有H2基因型表明其起源于类似DS-1的人类轮状病毒。在猪和人类轮状病毒之间共享基因型的基因组片段的系统发育谱系水平上，VP1-4、VP7、NSP3-4基因与猪轮状病毒的基因最为密切相关，但NSP2基因的起源尚无定论。至于NSP5基因，包含AU19和其他三个携带H2基因型（H2b）的超短人类毒株69M、57M和B37的谱系与类似DS-1的短毒株所属的谱系（H2a）聚类，尽管自展支持率不显著。综合所有这些观察结果，AU19可能是由于猪轮状病毒跨物种传播给一名儿童，并可能通过基因重配从同时流行的人类毒株获得罕见的H2b基因型而出现的。将AU19的NSP5序列添加到先前超短轮状病毒株共有的高度同源的H2b基因型中，使得H2b基因型的遗传多样性与H2a基因型一样多样，这支持了携带H2b基因型的超短毒株长期以来一直在人群中未被注意地传播的假设。
