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Introduction: Cytomegalovirus (CMV) is a DNA-containing virus that is widespread worldwide and is of great importance in infectious pathology of children and adults. The aim of this study is to evaluate the prevalence of CMV among children and immunocompromised patients in the Nizhny Novgorod region (central Russia) and to perform a phylogenetic analysis of the identified strains., Materials and Methods: DNA samples of CMV detected in frequently ill children and adult recipients of solid organs were studied. The genetic diversity of CMV was assessed for two variable genes: UL55 (gB) and UL7 3(gN), using NGS technology on the Illumina platform. Phylogenetic trees were constructed in the MEGA X program, the reliability of the cluster topology on the trees was confirmed using the rapid bootstrap method based on the generation of 500 pseudo-replicas., Results: Circulation of 5 CMV genotypes by gene UL55 (gB) and 5 genotypes by gene UL73 (gN) was established in the territory of the Nizhny Novgorod region. While genotypes gB1 and gB2 dominated both in children and in adults, genotype gB5 was detected only in children. The spectrum of gN genotypes was more diverse: genotypes gN4a and gN3b prevailed in children, and gN1 and gN4b genotypes were predominant in adults. The obtained results allowed us to establish the similarity of the landscape of CMV genotypes circulating in Russia (Nizhny Novgorod region), Brazil, China and the USA., Conclusion: The obtained data indicate the similarity of the landscape of CMV genotypes circulating in Russia (Nizhny Novgorod region), Brazil, China and the USA: in children, the predominant genotypes are gB1 (40.0%), gB2 (33.3%), gN4a (42.8%), and gN3b (28.6%), while in adults (recipients of solid organs) genotypes gB1 (37.5%), gB2 (37.5%), gN1 (26.3%), and gN4b (26.3%) are prevailed.

Introduction: 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., Materials and Methods: Rotavirus-positive stool samples of children were examined by PCR genotyping and electrophoresis in PAAG. cDNA fragments of each of the 11 genes ( VP1‒VP4 , VP6 , VP7 , NSP1‒NSP5 ), 570 to 850 nucleotide pairs in length were sequenced for the selected strains. The phylogenetic analysis was performed in the MEGA X program., Results: In the study period 2021‒2023, 11 G[P] combinations with a predominance of G3P[8] (59.5%) were identified. Six atypical Rotavirus (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.А (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., Discussion: 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., Conclusion: 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.

Reassortant DS-1-like rotavirus A strains have been shown to circulate widely in many countries around the world. In Russia, the prevalence of such strains remains unclear due to the preferred use of the traditional binary classification system. In this work, we obtained partial sequence data from all 11 genome segments and determined the full-genotype constellations of rare and reassortant rotaviruses circulating in Nizhny Novgorod in 2016-2019. DS-1-like G3P[8] and G8P[8] strains were found, reflecting the global trend. Most likely, these strains were introduced into the territory of Russia from other countries but subsequently underwent further evolutionary changes locally. G3P[8], G9P[8], and G12P[8] Wa-like strains of subgenotypic lineages that are unusual for the territory of Russia were also identified. Reassortant G2P[8], G4P[4], and G9P[4] strains with one Wa-like gene (VP4 or VP7) on a DS-1-like backbone were found, and these apparently had a local origin. Feline-like G3P[9] and G6P[9] strains were found to be phylogenetically close to BA222 isolated from a cat in Italy but carried some traces of reassortment with human strains from Russia and other countries. Thus, full-genotype determination of rotavirus A strains in Nizhny Novgorod has clarified some questions related to their origin and evolution., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Austria, part of Springer Nature.)

Currently, the full-genome-based classification is widely used to investigate rotavirus A (RVA) strains found in different countries around the world. However, the information on the full genotypes of rotaviruses circulating in Russia is limited. Using partial sequencing, this study determined the full genotype constellations of 15 RVA strains in total commonly detected in Nizhny Novgorod (European part of Russia) in 2017-2018, three from each of the following genotypes G1P[8], G4P[8], and G9P[8] and six from G2P[4]. There were two intergenogroup mono-reassortants possessing an identical genotype constellation of G4-P[8]-I1-R1-C1-M1-A1-N1-T1-E2-H1 with the DS-1-like NSP4 gene of probably local origin. A variety of subgenotype lineages and their combinations of Wa-like rotaviruses and genetic heterogeneity among G9P[8] and G1P[8] strains were shown on the basis of phylogenetic analysis of each gene. Moreover, two distinct co-circulating variants that differed in all 11 genome segments were found among DS-1-like rotaviruses., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Introduction: In recent years the presence of reassortant rotavirus strains is increasingly mentioned in the world due to the application of the full-genome based classification system. Information on the circulation of such strains in the territory of Russia is limited. The aim of this work was the development of the approach for determination of genotypes of segments encoding VP6 (I) and NSP4 (E) to reveal reassortant strains., Material and Methods: Rotavirus-positive samples were studied by means of nucleotide sequencing and multiplex PCR. Phylogenetic analysis was conducted using the Bayesian approach., Results: Three alleles of the VP6 gene (I1-1, I2-IV, I2-VII) and seven alleles of the NSP4 gene (E1-I, E1-III, E2-VI, E2-VII, E2-X, E2-XII, E3) were detected on the base of nucleotide sequences of Nizhny Novgorod rotaviruses. Taking into account these results, the oligonucleotide primers specific to genotypes I1, I2, I3 and E1, E2, E3 were designed. Optimal conditions for multiplex PCR were chosen. The method was tested using the strains collected in Nizhny Novgorod in 2018. The diversity of I and E genotypes was determined and various combinations with G and P genotypes were identified., Discussion: G9-P[8]-I1-E1 rotaviruses were predominant (32.7 %) and G2-P[4]-I2-E2 rotaviruses were in second place (29.1 %). Strains with genotypes G4-P[8]-I1-E2, G3-P[8]-I2-E2 and G2-P[4]-I2-E1 were detected sporadically. They had genes of two rotavirus genogroups, so can be considered to be reassortant., Conclusion: The proposed approach is a useful tool for the characterization of rotaviruses in the conditions of the beginning of vaccination against rotavirus infection in Russia., Competing Interests: The authors declare no conflict of interest.

A total of 5230 specimens from children with gastroenteritis collected in Nizhny Novgorod in 2006-2010 were screened for human parechoviruses (HPeV). HPeV were observed every year with mean frequency of 6.16%. The majority of HpeV (65.83%) was detected in children younger than 3 years. The typing of 71 detected HPeV with the use of partial sequencing of the VP3-VP1 region revealed the presence of HPeV1 (91.55%), HpeV6 (5.63%), HPeV3 (3.08%), HPeV4 (1.54%). HPeV1B was predominant among HPeV1, HPeV1A was identified rarely. Six stains of HPEV1 formed separate phylogenetic cluster, had sequence gomology with HPEV1A or HPeV1B not more than 88% and could be characterized as members of a separate genotype HPeV1.