Chang K O, Parwani A V, Saif L J
Department of Veterinary Preventive Medicine, Ohio Agricultural Research and Development Center, The Ohio State University, Wooster, USA.
Arch Virol. 2000;145(4):725-37. doi: 10.1007/s007050050666.
We previously reported the relatively high prevalence (15%) of bovine G6 subtypes (G6s) in the field using RT-PCR and restriction fragment length polymorphism (RFLP) analysis (Chang et al., Arch. Virol. 141: 1727-39). In the present study, we report the nucleotide and antigenic characterization of a G6s strain (C-8336). We also sequenced the VP7 genes of four additional bovine rotavirus (BRV) strains: another G6s (MC27), G6 (IND), G8 (C-8008) and G10 (2292B) and compared these with other bovine and human rotavirus strains. The C-8336 and MC27 strains were confirmed as P[11]G6s by RT-PCR and RFLP analysis. The VP7 genes of the C-8336 and MC27 strains showed high homology to each other (approximately 98%) and with other bovine G6s strains (greater than 95% homology in nucleotide and amino acid sequence with KN-4[P[11]G6s]) and also showed lower, but substantial sequence homology with human G6s strains and prototype G6 BRV (79-87% in nucleotide and 88-91% in amino acid). Serologic analysis of the cell culture adapted C-8336 strain showed that it was neutralized by a G6 monoclonal antibody (MAb IC3) to similar titers as the reference NCDV and IND G6 strains. In two-way cross-neutralization tests, strain C-8336 showed 4- to 16-fold differences in antibody titers with NCDV and IND G6 BRV. Moreover polyclonal antiserum against strain C-8336 neutralized the NCDV and IND strains weakly. Genetic variability was also observed among G8 and G10 bovine and human group A rotaviruses: the VP7 genes of the bovine C-8008 (P[5]G8) and 2292 B (P[11]G10) strains showed from 10 to 17% nucleotide divergence with those of Cody 1801 (P[1]G8, bovine), A5 (P[1]G8, bovine), 69M (P[10]G8, human) and Hal 1166 (P[14]G8, human), and I321(P[11]G10, human) and MC35 (P[14]G10, human) rotaviruses, respectively. The divergence of VP7 genes among bovine and human G6, G8 and G10 strains appears related to host species origin and their combination with VP4 (P type). The data presented in this report confirms the genetic variability among homotypic bovine and human strains and highlights the importance of continued monitoring of BRV G and P types circulating in the field for the future development and monitoring of effective vaccines.
我们之前曾报道，利用逆转录聚合酶链反应（RT-PCR）和限制性片段长度多态性（RFLP）分析发现，牛G6亚型（G6s）在野外的流行率相对较高（15%）（Chang等人，《病毒学档案》141: 1727 - 39）。在本研究中，我们报告了一株G6s毒株（C - 8336）的核苷酸和抗原特性。我们还对另外四株牛轮状病毒（BRV）毒株的VP7基因进行了测序：另一株G6s（MC27）、G6（IND）、G8（C - 8008）和G10（2292B），并将这些基因与其他牛和人轮状病毒毒株进行了比较。通过RT-PCR和RFLP分析，C - 8336和MC27毒株被确认为P[11]G6s。C - 8336和MC27毒株的VP7基因彼此之间显示出高度同源性（约98%），并且与其他牛G6s毒株也具有高度同源性（核苷酸和氨基酸序列与KN - 4[P[11]G6s]的同源性大于95%），同时与人类G6s毒株和原型G6 BRV也显示出较低但显著的序列同源性（核苷酸同源性为79 - 87%，氨基酸同源性为88 - 91%）。对适应细胞培养的C - 8336毒株的血清学分析表明，它被一种G6单克隆抗体（MAb IC3）中和，其效价与参考NCDV和IND G6毒株相似。在双向交叉中和试验中，C - 8336毒株与NCDV和IND G6 BRV的抗体效价显示出4至16倍的差异。此外，针对C - 8336毒株的多克隆抗血清对NCDV和IND毒株的中和作用较弱。在G8和G10牛和人A组轮状病毒中也观察到了遗传变异性：牛C - 8008（P[5]G8）和2292 B（P[11]G10）毒株的VP7基因与Cody
