Santos Norma, Volotão Eduardo M, Soares Caroline C, Albuquerque Maria Carolina M, da Silva Fabiano M, Chizhikov Vladimir, Hoshino Yasutaka
Departamento de Virologia, Instituto de Microbiologia, Universidade Federal do Rio de Janeiro, Cidade Universitária, CCS-Bl I, Ilha do Fundão, RJ 21 941-590, Rio de Janeiro, Brazil.
Virus Res. 2002 Dec;90(1-2):1-14. doi: 10.1016/s0168-1702(02)00106-5.
Rotaviruses are the single most important etiologic agents of severe diarrhea of infants and young children worldwide. Surveillance of rotavirus serotypes/genotypes (both VP7[G] and VP4[P]) is in progress globally in which polymerase chain reaction (PCR) has been the assay of choice. We investigated polymorphism of the VP7 gene of serotype G9 rotavirus strains and its impact on the determination of VP7 gene genotype by PCR assay. By VP7 gene sequence analysis, we and others have previously shown that the G9 rotavirus strains belong to one of three VP7 gene lineages. By PCR assay using three different sets of commonly used primers specific for G1-4, 8 and 9, 23 Brazilian G9 strains and 5 well-characterized prototype G9 strains which collectively represented all three VP7 gene lineages were typed as: (i). G3; (ii). G4; (iii). G9; (iv). G3 and G9; or (v). G9 and G4 depending on a primer pool employed. This phenomenon appeared to be due to: (i). a VP7 gene lineage-specific polymorphism, more specifically mutation(s) in the primer binding region of the VP7 gene of G9 strain; and (ii). the magnitude of difference in nucleotide homology at respective primer binding site between homotypic (G9) and heterotypic (G3 or G4) primers present in a primer pool employed.
轮状病毒是全球婴幼儿严重腹泻的最重要单一病因。全球正在开展轮状病毒血清型/基因型（VP7[G]和VP4[P]）监测，其中聚合酶链反应（PCR）是首选检测方法。我们研究了G9血清型轮状病毒株VP7基因的多态性及其对通过PCR检测确定VP7基因基因型的影响。通过VP7基因序列分析，我们和其他人之前已表明G9轮状病毒株属于三个VP7基因谱系之一。使用针对G1 - 4、8和9的三组不同常用引物进行PCR检测，23株巴西G9株和5株特征明确的原型G9株（共同代表所有三个VP7基因谱系）根据所使用的引物组合被分型为：（i）. G3；（ii）. G4；（iii）. G9；（iv）. G3和G9；或（v）. G9和G4。这种现象似乎是由于：（i）. VP7基因谱系特异性多态性，更具体地说是G9株VP7基因引物结合区域的突变；以及（ii）. 所用引物组合中同型（G9）和异型（G3或G4）引物在各自引物结合位点的核苷酸同源性差异程度。
