Natalya A. Yarygina

Peste des petits ruminants (PPR) is a highly contagious disease caused by the PPR virus (PPRV), a Morbillivirus, that affects small domestic ruminants and a range of wild ruminants. The disease is associated with significant socioeconomic losses and poses conservation threats due to its impact on susceptible wild ungulates. Wild species do not typically serve as independent reservoirs of PPRV. However, spillover from infected livestock at the wildlife–livestock interface is well documented. Therefore, understanding the role of wildlife in PPR epidemiology is important for the global campaign to eradicate the disease. This is the first large-scale surveillance of wild ruminants conducted across the Russian Federation, which included many species that were not previously tested for PPRV. In total, 1709 samples were collected from 19 wild species over 7 years (2018–2024) across 54 regions. All samples were examined using the enzyme-linked immunosorbent assay (ELISA), real-time reverse transcription–polymerase chain reaction, and virus neutralization test (VNT). For the serological component of the study, an indirect ELISA was developed, based on recombinant nucleocapsid protein expressed in Escherichia coli, and was validated. The ELISA was validated against commercial competition ELISA and VNT. Results showed that the ELISA exhibited high performance with serum from multiple species, with a sensitivity of 97.5% and a specificity of 98% compared with the commercial kit, and with a sensitivity of 96.5% and a specificity of 99% versus VNT. All 1709 wildlife samples tested negative for PPRV antibodies and RNA, indicating no evidence of viral circulation in the surveyed populations. Although PPRV has been detected in goitered gazelle (Gazella subgutturosa), saiga (Saiga tatarica), and wild goat (Capra aegagrus) in neighboring countries, none of the Russian specimens—collected from several species, including Caspian red deer (Cervus elaphus maral) and Siberian musk deer (Moschus moschiferus)—tested positive. To the best of our knowledge, this is the first reported widescale PPR surveillance in wildlife species of its kind. This first comprehensive nationwide surveillance of PPRV in wild ruminants across Russia found no infection in the species or samples tested. The newly developed ELISA offers a rapid and reliable cost-effective alternative to VNT for large-scale screening. Our findings indicate that wild ruminants do not currently serve as a PPR reservoir in the surveyed regions and support the inclusion of wildlife monitoring in PPR control strategies for a better understanding of PPR epidemiology in wildlife.

Sheep- and goatpox are highly contagious, transboundary viral diseases caused by capripoxviruses (CaPV), severely impacting small ruminant production and resulting in significant economic losses. Our study aimed to analyze the spatiotemporal SGP distribution using the available genome sequence data and to evaluate the recombination occurrence. For this, the WAHIS, WOAH and FAO databases were utilized for the epidemiological analysis of SGP outbreaks. The cross-correlation was calculated to assess the impact of massive animal movements associated with the Islamic holiday of Eid al-Adha on the SGP epizootic situation, and phylodynamic and phylogeographic analysis, as well as a recombination analysis were performed. A total of 1629 SGP outbreaks were reported to WAHIS during 2010–2024, with the majority occurring in Mongolia, the Balkan countries, Russia and the Middle East. Over 60% of all SGP outbreaks were associated with croplands or grasslands, with the highest proportion corresponding to animal densities of 10–50 head/km². Statistically significant positive cross-correlation (p < 0.05) was identified between the month of the Eid al-Adha celebration and the number of SGP outbreaks in Russia, Mongolia, Bulgaria and Tajikistan, while in Greece and China no significant correlation was found. The inferred goat pox virus (GTPV) transmission pathways from China to Vietnam and from India to Bangladesh; for the sheeppox virus SPPV, the routes between Kazakhstan and Russia, Kazakhstan and India, as well as between Russia and China, had the strongest Bayes factor support. Intra-specific recombination events were not detected for the SSPV and GTPV datasets. However, inter-specific CaPV recombination analysis identified a single recombination event in GTPV. Therefore, the use of molecular epidemiological tools, along with the time-calibrated phylodynamic and phylogeographic analyses, has significant applications in the local and international surveillance of the occurrence of SGP outbreaks and for identification of potential recombination events.

Introduction. Transboundary and emerging infections of cattle and small ruminants, such as peste des petits ruminants, Schmallenberg virus infection, etc., pose a serious animal health and economic threat in the context of developing globalization. Given the current geopolitical situation, the need for modern domestically produced diagnostic systems is particularly acute. Such systems can be developed using genetic engineering methods. Objective. Analysis of domestic and foreign publications on the production of recombinant proteins of pathogens of transboundary and emerging infections of cattle and small ruminants. Creation of genetic constructs based on the processed data for further development of diagnostic tools, in particular ELISA test systems. Materials and methods. Using bioinformatics tools, codon composition of the sequences encoding the nucleocapsid proteins of peste des petits ruminants virus (PPRV) and Schmallenberg virus (SBV) was analyzed and optimized. The optimized gene fragments were synthesized de novo and cloned into the pET-32b(+) expression vector. Successful insertion of the target sequence into the vector was confirmed by polymerase chain reaction and restriction analysis. Results . Information on ELISA test systems developed on the basis of recombinant antigens for the diagnosis of peste des petits ruminants and Schmallenberg virus infection is presented. The main technological aspects of obtaining recombinant antigens for their further use in a diagnostic system factored in the biological features of a particular pathogen are highlighted. Our proprietary methodology for creating protein expression vectors for the pathogens of the diseases under review is additionally described. Conclusion. The most promising recombinant antigens for use in ELISA test systems designed to detect antibodies against PPRV and SBV are full-length and truncated virion nucleocapsid proteins. Furthermore, the biophysical properties and antigenic structure of these proteins enable their production in Escherichia coli. It should be noted that production of significant amounts of functional proteins in soluble form may require their expression as part of fusion proteins with tags enhancing solubility and facilitating correct folding.

Feed additives based on organic acids have a bactericidal and bacteriostatic effect that correlates with the input rate (dosage). The effect of the drugs is due to a cellular metabolic disorder of opportunistic bacteria and a change in the permeability of their cell membranes. The use of acid-based preparations helps to preserve the nutritional value of feed and prevent infection of animals and birds, which is an important aspect in maintaining the productivity of livestock. This article examines the effectiveness of the new feed additive “Vitasil 2 Plus” against micro-organisms of the species Salmonella Enteritidis, Escherichia coli, Pseudomonas aeruginosa by adding to water and various types of raw materials and feed.Epizootic strains isolated from pathological material from birds from poultry farms in the Russian Federation were used as test cultures. The effectiveness of the drug was studied at low and high input rates, depending on the type of substrate being studied. The following substrates were used: drinking water, granulated feed, powder, fish meal and soybean meal. Simple (meat peptone agar), selective (staphylococcal agar) and differential diagnostic (Endo medium, xyloselysine deoxycholate agar - XLD agar) nutrient media were used in the work.According to the results, it was found that the bactericidal and bacteriostatic effects of the feed additive, as a rule, correlate with high and low input rates. As a result, the effectiveness of the complex drug “Vitasil 2 Plus” has been proven against a number of microorganisms, thereby this feed additive can be used in the disinfection of feed and drinking water.