Atypical porcine pestivirus (APPV) was first identified in 2015 in North America by high-throughput sequencing. APPV is associated with congenital tremor A-II and is widely distributed worldwide. In this study, a total of 2630 samples of domestic pigs obtained from 14 regions of Russia from 2020 to 2024 were screened for APPV presence by qRT-PCR. APPV was detected in 12 farms located in eight regions. The overall positive rate was 8.8%. It has been established that APPV has been circulating in Russian swine herds since at least 2020. The phylogenetic analysis demonstrated that the Russian isolates are variable and assigned into three clusters. The isolates from the Krasnoyarsk Krai, Belgorod, Tomsk, and Kursk regions and the Republic of Buryatia share a high nucleotide identity (94.3–98.8%) with the Hungarian strains, while the isolates from the Moscow and Pskov regions share a nucleotide identity (89.2–94.3%) with strains from the USA. The isolate from the Republic of Mordovia has a high nucleotide identity (97.1%) with the South Korean strain. In vitro studies of the Russian isolates revealed the replication of the Belgorod 151 strain in SPEV cells. Thus, this is the first large-scale study that confirms the circulation of APPV in swine herds in Russia and describes its isolation in cell culture.

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.

ATYPICAL PORCINE PESTIVIRUS (Pestivirus K) — A NEW CHALLENGE FOR PIG FARMING (review) A.M. Anoyatbekova, A.G. Yuzhakov, M. Anoyatbekov, T.I. Aliper, A.M. Gulyukin

Introduction. African swine fever virus (ASF) is a large, enveloped virus with an icosahedral capsid morphology and a double-stranded DNA genome ranging in size from 170 to 190 kb. The replication cycle proceeds in two phases, the early phase lasting 46 hours and the late 820 hours after infection. The adaptation of the ASF virus to growth in continuous cell lines makes efficient and reliable genetic analysis and more accurate interpretation of its results. Objective. Adaptation of a new isolate of the ASF virus to growth in a continuous cell line by the method of accelerated passages and preliminary genetic analysis of the resulting strain. Materials and methods. For virus isolation and passaging of the ASF virus, a porcine leukocyte cell culture (PL) and continuous cell cultures of porcine origin (ST, PK, PPK-66b) were used with Eagle MEM and HLA essential media with 10% porcine or fetal serum. Results. The article presents data on the isolation and analysis of the changes in the reproductive properties of a new African swine fever (ASF) virus isolate in the process of adaptation to growth in a continuous piglet kidney cell culture clone b (PPK-66b). The current state of the problem of cultivation of the ASF virus, the features of its reproduction, and the basis of the genetic differentiation of its isolates are described in detail. Understanding the uniqueness of the nature of the ASF virus determined the approaches to the processes of its cultivation and adaptation. In this regard, the results of studies of cultural properties, and analysis of the nucleotide sequence of 6 genes of the new isolate, as well as phylogenetic analysis of these genes with already known strains and isolates of the ASF virus are presented. Conclusion. A new strain obtained in the process of cell adaptation of ASVF/Znaury/PPK-23 ASF virus by the accelerated passaging method reaches a high level of reproduction in 72 hours with an accumulation titer of 7.07 lg HAdE50/cm3. Primary genetic analysis allowed to establish the main phylogenetic relationships of the newly isolated strain with previously known variants of the current ASF panzootic.

The efficacy of measures against peste des petits ruminants in Tajikistan possibly reduced through spreading of other viral infectious diseases. Pestiviruses are among these infections. Information on pestiviruses distribution in sheep and goats farms in Tajikistan is extremely limited. The obtained results of our studies showed that the border disease virus (Pestivirus D) is participating in the infectious pathology of small ruminants’ herds in Tajikistan. Pestivirus D was detected by serology, virological and molecular-genetic methods. In addition, the contamination of a series of peste des petits ruminants virus vaccine with Hobi-like pestivirus (Pestivirus H) was established. We hope that the findings of our research will improve the implementation of the International Program for the control and eradication of peste des petits ruminants.