Academician I.N. Blokhina Nizhny Novgorod Scientific Research Institute of Epidemiology and Microbiology of the Federal Service for Supervision of Consumer Rights Protection and Human Welfare (Rospotrebnadzor).
Vopr Virusol. 2024 Sep 26;69(4):363-376. doi: 10.36233/0507-4088-254.
Rotavirus infection is the major cause of severe dehydrating diarrhea requiring hospitalization in young children worldwide. Due to their segmented genome, rotaviruses are capable of gene reassortment, which makes the emergence and spread of genetically novel strains possible. The purpose of this study was to search for unusual rotaviruses circulating in Nizhny Novgorod in 2021‒2023 and their molecular genetic characterization based on all genome segments.
Rotavirus-positive stool samples of children were examined by PCR genotyping and electrophoresis in PAAG. cDNA fragments of each of the 11 genes (, , , ), 570 to 850 nucleotide pairs in length were sequenced for the selected strains. The phylogenetic analysis was performed in the MEGA X program.
In the study period 2021‒2023, 11 G[P] combinations with a predominance of G3P[8] (59.5%) were identified. Six atypical (RVA) strains were identified: 2 strains of the G2P[4] genotype (G2-P[4]-I2-R2-C2-M2-A3-N2-T3-E2-H3, G2-P[4]-I2-R2-C2-M2-A3-N2-T3-E3-H2) and 4 G3P[9] strains (all strains had the genotype G3-P[9]-I2-R2-C2-M2-A3-N2-T3-E3-H3). Phylogenetic analysis based on all genes showed an evolutionary relationship between rotaviruses similar to rotaviruses of cats and dogs (BA222-like) and unusual strains of the G2P[4] genotype, for which a mixed combination of genotypes was identified and characterized for the first time.
The results obtained expand the understanding of the diversity of reassortant RVAs, as well as complement the data on the genotypic structure of the rotavirus population in Nizhny Novgorod.
The wide genetic diversity of reassortant RVA can help rotaviruses overcome the immunological pressure provided by natural and vaccine-induced immunity. In this regard, to control the emergence of new variants and assess changes in the virulence of rotaviruses after reassortment processes, continuous molecular monitoring for circulating RVA is necessary.
轮状病毒感染是导致全球幼儿严重脱水性腹泻并需要住院的主要原因。由于其基因组分段，轮状病毒能够发生基因重配，这使得新型遗传株的出现和传播成为可能。本研究的目的是在 2021 年至 2023 年期间，在下诺夫哥罗德寻找循环的异常轮状病毒，并基于所有基因组片段对其进行分子遗传学特征分析。
通过 PCR 基因分型和 PAAG 电泳检测轮状病毒阳性粪便样本。对选定的毒株，对每个长度为 570 至 850 个核苷酸的 11 个基因（、、、）的 cDNA 片段进行测序。在 MEGA X 程序中进行系统发育分析。
在 2021 年至 2023 年的研究期间，确定了以 G3P[8]（59.5%）为主的 11 种 G[P]组合。鉴定出 6 种异常 （RVA）株：2 株 G2P[4]基因型（G2-P[4]-I2-R2-C2-M2-A3-N2-T3-E2-H3，G2-P[4]-I2-R2-C2-M2-A3-N2-T3-E3-H2）和 4 株 G3P[9]株（所有菌株的基因型均为 G3-P[9]-I2-R2-C2-M2-A3-N2-T3-E3-H3）。基于所有基因的系统发育分析表明，轮状病毒与猫和狗的轮状病毒（BA222 样）之间存在进化关系，并且首次鉴定和表征了异常的 G2P[4]基因型。
研究结果扩展了对重组 RVAs 多样性的认识，并补充了下诺夫哥罗德轮状病毒群体的基因型结构数据。
重组 RVA 的广泛遗传多样性有助于轮状病毒克服自然和疫苗诱导免疫提供的免疫压力。在这方面，为了控制新变体的出现并评估重组后轮状病毒毒力的变化，有必要对循环 RVA 进行持续的分子监测。
