Porcine circoviruses (PCVs) are widely distributed in swine herds. PCV2, the significant swine pathogen, causes infections characterized by growth and development disorders, skin lesions, and respiratory distress. PCV3 has been circulating worldwide and can be associated with various clinical signs and disease developments. Wild boars are the main reservoir of these pathogens in wildlife and can create an alarming threat to pig farming. In Russia, three PCV2 genotypes (PCV2a, PCV2b, and PCV2d) were identified in pig farms. Additionally, PCV3 was observed in pig herds during the monitoring studies in the country. However, data considering the circulation of PCVs in herds of wild boars in Russia is scant. For this purpose, we performed PCR assays of the samples from 30 wild boars hunted in the Moscow Region of Russia in 2021–2023. The ratios of wild boars positive for PCV2, PCV3, or coinfected were 50, 10, and 13.3%, respectively. Additionally, we sequenced 15 PCV2 and four PCV3 complete genomes and conducted phylogenetic analysis, which divided PCV2 isolates into two groups: PCV2d and PCV2b. The study showed a high infection rate of PCV2 among wild boars, with PCV2d dominance. Simultaneously, PCV3 also circulates among wild boars. The obtained results can provide a basis for the development of preventive measures to support infection transmission risks between farm and wild animals.

Rotaviruses are the major etiological agents of gastroenteritis and diarrheal outbreaks in plenty of mammalian species. The genus Rotavirus is highly diverse and currently comprises nine genetically distinct species, and four of them (A, B, C, and H) are common for humans and pigs. There is a strong necessity to comprehend phylogenetic relationships among rotaviruses from different host species to assess interspecies transmission, specifically between humans and livestock. To reveal the genetic origin of rotaviruses from Russian pig farms, nanopore-based metagenomic sequencing was performed on the PCR-positive specimens. Samples were selected among the cases submitted to routine diagnostic or monitoring studies to the Laboratory of Biochemistry and Molecular Biology of “Federal Scientific Center VIEV” (Moscow, Russia). The selected positive samples were genotyped using nanopore sequencing method. Five porcine RVA isolates were completely sequenced, and genotype analysis revealed various porcine G/P genogroups: G2, G3, G4, G5, G11 and P[6], P[7], P[13], P[23], P[27] with a typical backbone constellation I5-R1-C1-M1-A8-N1-T1/7-E1-H1. The RVB isolate was detected in combination with RVA in a rectal swab from a diseased pig in Krasnoyarsk Krai. It was characterized by the following genogroups: G15-P[X]-I11-R4-C4-M4-A8-N10-T4-E4-H7. The first complete porcine RVC genome from Russia was obtained with genomic constellation G6-P[5]-I14-R1-C1-M1-A7-N9-T6-E1-H1, and the phylogenetic analysis revealed putative novel genotype group for the VP6 gene-I14. Additionally, the first porcine kobuvirus isolate from Russia was phylogenetically characterized. The applied nanopore sequencing method successfully genotyped the RV isolates and additionally revealed co-circulated species. The study demonstrates high genetic variability of Russian RVA isolates in VP4/VP7 genes and phylogenetically describes local RVB and RVC. Complete characterization of genomic segments is a crucial methodology in tracing the rotavirus's evolution and evaluating interspecies transmissions.

Komina A, et al. J Vet Sci. 2022 Oct;23:e92. https://doi.org/10.4142/jvs.22182

Porcine parvovirus 5 (PPV5) is a novel virus frequently detected in pigs worldwide. However, its identification and prevalence in domestic pigs in Russia have not been described. In this study, retrospectively, 984 serum samples collected between 2020 and 2023 were tested by qPCR. All samples were obtained from 20 pig farms located in 10 regions of Russia. PPV5 circulation was confirmed in 11 pig farms with the overall detection rate at 8.9%. The highest detection rate was estimated in the farms of the Belgorod Region (17.1%), followed by the Sverdlovsk Region (15.9%), the Republic of Buryatia (14.7%), and the Moscow Region (14.0%). It has been confirmed that PPV5 has been circulating in the swine population since at least 2021. The phylogenetic analysis revealed a high nucleotide identity of Russian isolates with strains from the USA, Colombia, and China. The Moscow-4060 strain was isolated in primary porcine testicular cells (PPTCs), and its continuous replication was confirmed by qPCR. During microscopy, cytoplasmic vacuolization, pyknosis, and other alterations were observed. The results demonstrate the evidence of PPV5 circulation in domestic pigs in Russia and the first isolation of the virus ever described. These findings serve as a first step for studying PPV5 in vivo.

Porcine parvoviruses (PPVs) are widespread worldwide in the swine population. PPV1 is a significant infectious agent in pig production, causing porcine reproductive failure. The pathogenic potential of novel PPVs has been poorly studied. Since wild boars are a reservoir for PPVs, the aim of this study was to investigate their prevalence and genetic diversity in the wild boar population. Tissue samples (spleen, lungs, and lymph nodes) collected from 108 wild boars from three regions of Russia during 2021–2024 were analyzed. PPV1–7 were found in wild boar populations in Russia, and the most abundant species were PPV7 (59.3%) and PPV3 (49.1%). The research did not reveal any significant relationship between the gender and age of the animals and the prevalence of PPVs. A comparison between the detection rates of PPVs and PCV2/PCV3 revealed the random nature of coinfections. For phylogenetic analysis, complete VP1/VP2 gene sequences of 17 PPV1 isolates were obtained. Most of them belonged to the 27a-like group. Two isolates were in the same cluster as the highly virulent Kresse strain. Isolate BelWB57 had amino acid substitutions that were specific to both the Kresse and 27a-like strains, but it was not classified in either group. Additionally, three sequences for PPV2, PPV3, and PPV7, and one sequence for PPV5 and PPV6 VP1/VP2 genes were obtained. PPV2, PPV3, and PPV7 isolates demonstrated distribution across various clusters with strains from domestic pigs and wild boars from different countries. PPV6 isolate was included in the same clade as the Russian isolate from a domestic pig, whereas PPV5 did not enter any clade with representatives from our country. This is the first work devoted to the study of the PPV1–7 prevalence, as well as the genetic characteristics of isolates circulating among wild boars in various regions of Russia. Our data showed that PPV1–7 is widespread in wild boar populations. Phylogenetic analysis of PPV1 demonstrates a significant prevalence of 27a-like isolates.

Introduction. Bovine coronaviruses (BCoVs) are causative agents of diarrhea, respiratory diseases in calves and winter cow dysentery. The study of genetic diversity of these viruses is topical issue. The purpose of the research is studying the genetic diversity of BCoV isolates circulating among dairy cattle in Siberia. Materials and methods. Specimens used in this study were collected from animals that died or was forcedly slaughtered before the start of the study. The target for amplification were nucleotide sequences of S and N gene regions. Results. Based on the results of RT-PCR testing, virus genome was present in 16.3% of samples from calves with diarrheal syndrome and in 9.9% with respiratory syndrome. The nucleotide sequences of S gene region were determined for 18 isolates, and N gene sequences - for 12 isolates. Based on S gene, isolates were divided into two clades each containing two subclades. First subclade of first clade (European line) included 11 isolates. Second one included classic strains Quebec and Mebus, strains from Europe, USA and Korea, but none of sequences from this study belonged to this subclade. 6 isolates belonged to first subclade of second clade (American-Asian line). Second subclade (mixed line) included one isolate. N gene sequences formed two clades, one of them included two subclades. First subclade included 3 isolates (American-Asian line), and second subclade (mixed) included one isolate. Second clade (mixed) included 8 sequences. No differences in phylogenetic grouping between intestinal and respiratory isolates, as well as according to their geographic origin were identified. Conclusion. The studied population of BCoV isolates is heterogeneous. Nucleotide sequence analysis is a useful tool for studying molecular epidemiology of BCoV. It can be beneficial for choice of vaccines to be used in a particular geographic region.