This review provides a data analysis of the test results for farm animal feeds. The analysis is based on the articles published from 1955 to 2020. It was found that the overall pooled prevalence estimates of Salmonella was 0.14: with a prevalence of 0.18 in raw feed components, 0.09 – in finished feed and 0.08 – in swabs from the surfaces of feed production equipment. The probability of contaminating raw animal feed components with Salmonella is 3.9 times higher than that for raw vegetable feeds. There is a tendency for Salmonella to be less detected in raw feed components; however, in finished feeds Salmonella detectability has remained unchanged for decades. The Salmonella prevalence in samples taken from environmental objects and surfaces of feed mill production equipment was 0.08. The risk of Salmonella detection at feed mills in the pre-heat treatment zone was 1.5 times higher than the risk of detection in the post-heat treatment zone. The analysis of Salmonella serovariants revealed that S. senftenberg, S. montevideo, S. typhimurium, S. anatum, S. havana, S. enteritidis, S. cerro are isolated everywhere. The S. salford serotype is found only on the African continent. A research into antimicrobial resistance of Salmonella isolates demonstrated resistance to such medicinalproducts as ceftriaxone, carbopenem and imipenem; and full genome sequencing showed at least one antibiotic resistance gene in 40% of Salmonella isolates detected at pig feed production plants.

Due to the great relevance of the problem of mastitis in cows, the diversity of udder microflora in the affected animals, as well as to develop therapeutic and preventive measures on farms, studies were conducted to identify similarities and differences in the species composition of microorganisms in animals with sub­clinical and clinical breast inflammation, their proportion, to establish the correlation between the secreted microflora and the type of mastitis, as well as to study and compare the enzymatic properties of Staphylococcus aureus isolated from animals with clinical and subclinical mastitis. It was found that on all the studied farms the number of cows and heifers with subclinical mastitis exceeded the number of animals with clinical udder inflammation. As a result of microbiological studies of 182 mammary gland secretion samples collected from cows with subclinical and clinical mastitis from 13 agricultural establishments of the Vologda, Yaroslavl and Kostroma regions, 70 cultures of pathogenic and opportunistic microflora were isolated. It was demonstrated that, in case of subclinical mastitis, the following cultures were most often isolated from milk: Staphylococcus aureus (17.9% of cases), pathogenic Streptococcus (9.8% of cases), of which the proportion of Streptococcus agalactiae and Streptococcus dysgalactiae was 6.5 and 3.3%, respectively. Opportunistic Staphylococcus (6.5%) and Enterobacteria (6.5%) were isolated in equal proportions. In case of cows with clinical mastitis, Staphylococcus aureus was isolated in 16.9% of cases, pathogenic Streptococcus – in 10.2% of cases, of which the proportion of Streptococcus agalactiae and Streptococcus dysgalactiae was 6.8 and 3.4%, respectively. Opportunistic Staphylococcus and Enterobacteria were found in equal amounts – 3.4% of cases each. No growth of Mycoplasma on special nutrient media was registered in both cases. It was established that similar pathogenic and opportunistic microorganisms are isolated from animals with subclinical and clinical mastitis. The main causative agent is Staphylococcus aureus, the incidence of which in case of latent mastitis is slightly higher (by 1.0%). It is followed by Streptococcus agalactiae and Streptococcus dysgalactiae, which are detected more often in case of clinical udder inflammation – by 0.2% on average. The frequency of isolation of opportunistic Staphy­lococcus is 1.9 times higher in case of subclinical mastitis. It is worth noting that with clinical udder inflammation, enterobacteria were detected only at one of the thirteen studied agricultural establishments.

Bacterial and fungal contamination of the semen collected in production environment largely depends on the sanitary conditions of its collection as well as on the bacteria carrier state in breeding bulls. Since antimicrobials contained in the diluent used during semen product cryopreservation do not allow an objective assessment of semen contamination, a microbiological testing of fresh undiluted bull semen was carried out at the AO «Krasnoyarskagroplem» breeding establishment to identify the contamination source. The isolated opportunistic microorganism cultures were tested for their susceptibility to antibiotics for the purpose of effective treatment of bacteria carriers. The experiment was performed at the Department for Epizootiology, Microbiology, Parasitology and Veterinary and Sanitary Expertise of the Institute of Applied Biotechnology and Veterinary Medicine of the FSBEI HE «Krasnoyarsk State Agrarian University» and at the Veterinary Laboratory of the AO «Krasnoyarskagroplem» in 2017 and 2018. Semen was collected in accordance with GOST 32222-2013 and tested for veterinary and sanitary parameters according to GOST 32198-2013. Isolated microorganism cultures were tested for their susceptibility to antibiotics with disc-diffusion method according to the Methodical Guidelines 4.2.1890-04 «Testing of microorganisms for their susceptibility to antimicrobials» using discs containing eight antimicrobials. Analysis of microbiological test results showed that semen was rejected for sanitary reasons at the breeding establishment due to isolation of the following opportunistic microorganisms: Pseudomonas aeruginosa (6.4% samples) and Proteus vulgaris (8.5% sample) in 2017 and Pseudomonas aeruginosa (2.4% samples) in 2018. Other test parameters (total microbial count, coliform count) were within admissible limits. № anaerobes and pathogenic fungi were detected. Four Pseudomonas aeruginosa isolates and three Proteus vulgaris isolates recovered during the test have demonstrated susceptibility to ciprofloxacin that can be used for etiotropic treatment of bulls identified as bacteria carriers.

Retrospective descriptive epizootological study was conducted in the Amur Oblast (Russian Far East), where a rabies outbreak was reported in 2018. The aim of the study was to analyze probable routes of rabies introduction and features of its spatial and temporal spread in the territory that remained free from this infection from 1972 to 2018. In 2018–2021, altogether 1,416 animals were examined for the infection with the rabies virus. Forty-seven animal rabies cases were confirmed; the proportion of wild animals (Vulpes vulpes, Nyctereutes procyonoides, Canis lupus) amounted to 66%. The first cases were detected within 30 km from the state border with China. Nucleotide sequences of the nucleoprotein gene of three rabies virus isolates were determined and their belonging to the Arctic-like-2 genetic lineage was established. Genetically closest rabies virus isolates have been found in Heilongjiang Province (China, 2011, 2018) and Jewish Autonomous Oblast (Russia, 1980). GIS and open Earth remote sensing data were used to map the rabies cases. After 2018, the epizootic spread within the forest-steppe landscapes of the Zeya-Bureya Plain, where human and animal rabies cases had been earlier reported (until 1972). The front of the epizootic spread in a north-eastern direction at an average speed of 59 (16–302) km during one epizootic cycle. The introduction of the rabies virus was most likely along the Amur River valley from downstream regions of Russia and China that are rabies infected.

The paper presents the results of the study of the epizootiological characteristics of echinococcosis in dogs, sheep and goats in the Caspian Sea region of Russia where Echinococcus occurrence varies from 30 to 80%, as well as the results of tests of the complex product Prazibars (at different doses) for its effectiveness against this parasitosis. The extensity of Echinococcus invasion in sheep and goats in the Caspian Depression is 38.6%; it is expansive and affects more and more areas. Some researchers report that Echinococcus granulosus occurrence in sheep in the Caspian Sea region of Russia increases by 0.2–0.3% annually and averages 32.8%. It is demonstrated that Echinococcus granulosus invasion intensity and extensity in sheep dogs in the natural altitudinal zones of the region average 3,136.7 ± 343.0 par­asites/animal and 30.1%, respectively. In the zones covered by the study, Echinococcus species are detected in adult pasture-raised sheep throughout the year, the invasion intensity and extensity average 22.3 ± 2.1 parasites/animal and 23.0%, respectively. It was found that echinococcosis was reported in adult sheep and goats in all the Caspian Sea region areas covered by the study. Complete helminthological necropsy revealed the presence of fertile larva cysts in 1 mL of echinococcal fluid in sheep and goats of all age groups, except for animals under 1 year of age; their number averaged 23.02 ± 1.28 larval cysts/animal. It is shown that echinococcosis is widely spread in carnivores and livestock across all altitudinal zones of the Caspian Sea region of Russia, including Dagestan, and this suggests the necessity of continuous epizootiological control and monitoring of the situation with respect to cestodes of the family Taeniidae, in particular Echinococcus granulosus. Since echinococcosis in dogs and other carnivores constitutes a large-scale social problem and is a helminthiasis that is dangerous for humans, seeking state-of-the-art ways and means to combat this parasitic disease of carnivores is an urgent challenge. Based on the results of the tests performed, the complex product Prazibars administered individually one time at a dose of 15.0 mg/kg of live weight in admixture with minced meat demonstrated high effectiveness against spontaneous echinococcosis in dogs and other carnivorous animals.

An important factor affecting the performance of cattle is the satisfaction of animal needs in nutrients, macro- and microelements. High-yielding dairy cows with intense metabolism are especially sensitive to errors in feeding practices, because even minor nutritional or mineral deficiencies cause metabolic disorders leading to immunodeficiency conditions, reduced resistance to infectious agents and raised sensitivity to infections with pathogenic and opportunistic microorganisms. Besides some infections, for example acute respiratory diseases, also result in metabolic disorders, immunosuppression, decrease in the overall resistance of the organism and ultimately in mixed infections. All this is the reason for low efficacy of vaccination against major infectious diseases. The paper presents the results of testing of plant tissue product «Vidoral», developed by the FSBEI HE Ural SAU for prevention of immunodeficiency conditions in cattle, caused by different factors. The product was injected subcutaneously at a dose of 0.025 ml/kg of live weight to cows in late gestation and calves showing mild anemia, low red blood cells counts, leukocytosis, high lymphocyte and monocyte counts and elevated erythrocyte sedimentation rate, which suggest inflammatory processes in the animal body. Fourteen days post injection blood was collected for hematological and biochemical testing. It was demonstrated that the product restores the animal metabolism, improves hematopoiesis and reduces inflammation. It was established that injection of «Vidoral» in combination with vaccination against infectious rhinotracheitis, viral diarrhea, infection with respiratory syncytial virus and parainfluenza-3 virus induced generation of specific antibodies against the abovementioned infections.

Mycoplasmas are bacteria that are extremely unstable in vitro as they lack a rigid cell wall. They are most often detected in association with other pathogens, including those that can become L-forms if treated with antibiotics. Mycoplasma colonies, as well as colonies of L-form bacteria, have a typical «fried egg» appearance, therefore it is necessary to differentiate them for the accurate diagnosis and choice of treatment. The paper presents data on mycoplasma infection diagnosis in cattle and results of differentiation of isolated mycoplasma and L-form bacteria colonies using multiple passaging and real-time polymerase chain reaction. For that, 177 samples were collected from animals with mycoplasmosis clinical signs, 45 of them were tested using molecular genetic method, 132 samples were subjected to bacteriological testing. Mycoplasma DNA was detected in 71.1% of samples, and specific colonies were detected in 3.8% of samples. Such biochemical tests of mycoplasma species identification as arginine hydrolysis, blood serum liquefaction, film and grain formation, inoculation into Tween-80-containing medium, hemadsorption and hemolysis of erythrocytes do not allow an objective assessment of the species belonging to mycoplasmas, but, according to the results obtained, the isolated species most likely belongs to Mycoplasma dispar, which is pathogenic for cattle. Real-time polymerase chain reaction is undoubtedly the most accurate and rapid diagnostic method for mycoplasmosis, but a preliminary diagnosis can also be established bacteriologically within 2–7 days. In addition, during microbiological testing, it is possible to assess the antibiotic resistance of mycoplasma isolates, thereby developing an optimal and high-quality scheme of the disease treatment and prevention.

Senecavirus, previously known as Seneca valley virus, is an emerging virus belonging to Senecavirus genus, Picornaviridae family, that can cause idiopathic vesicular disease clinically indistinguishable from foot-and-mouth disease, vesicular stomatitis and swine vesicular disease and thereby posing a great threat for pig holdings. Recently, evidence of Senecavirus A occurrence in pig herds in such countries as Brazil, the USA, Colombia, China and Thailand has been provided in foreign literature. Accurate diagnosis is crucial for of Senecavirus infection control. Results of studying the disease situation with genodiagnostic methods in the Russian Federation are presented in the paper. Primers and probe for real-time RT-PCR described by V. L. Fowler et al. in 2017 were used but the reaction conditions were optimized. Analysis of the method for its sensitivity showed absence of cross-reactivity with other tested viruses. The developed method for virus RNA detection was used to investigate senecavirus occurrence in pig holdings in the Russian Federation. A total of 1,577 samples of biological materials collected form pigs of different ages in 112 holdings located in 37 regions of the country were tested during 2018–2020. Senecavirus was detected in one holding located in the Urals Federal Okrug. It was supposed that the infectious agent had entered the said pig holding at the time of putting of the said holding into operation in 2015 and introduction of young breeding animals imported from Canada. This is the first report on Senecavirus detection in the Russian Federation. The threat of the pathogen introduction from other countries requires further Senecavirus infection investigation and control. The developed method can be used as a potential sensitive method for the said infectious disease diagnosis.

It is necessary to continue the analysis of the situation and molecular and biological properties of the current African swine fever virus isolates, recovered in the Russian border territories to cover the following tasks: eradication of African swine fever; development of effective disease surveillance and control programs; search for promising genome markers for the vaccine development; implementation of the differentiation strategy between vaccinated and non-vaccinated animals; and clustering of the isolates. The post-hoc analysis of some ASF epidemiological data and comparative genetic analysis of isolates circulating in the Far East Federal District suggested the agent introduction and spread routes, as well as the seasonality of the infection occurrence in the Primorsky Krai. It was established, that two ASFV subgenotypes (IGR-I и IGR-II), differentiated by intergenic region I73R/I329L, circulated in the region under study during the first months post infection. Analysis of biological properties of ASFV/Primorsky 19/WB-6723 isolate recovered from the long bone of a dead wild boar in the Primorsky Krai suggested that the isolate is highly virulent, able to cause peracute to subacute disease and up to 100% mortality among infected animals. The incubation period and duration of the disease course in experimentally infected pigs were 4–6 and 3–5 days post infection, respectively. The ASFV genome was detected in blood samples collected from infected pigs on 5–8 days post infection by real-time polymerase chain reaction. Specific antibodies in blood samples were not detected. The need in further research of molecular and biological properties of current ASFV isolates was reaffirmed. To prevent the continuation of the epizooty and deterioration of the current situation the approaches to the disease surveillance and control need to be modified.

Duck virus hepatitis, a highly contagious disease occurring in ducklings, is currently reported in all countries with duck breeding industry. This infection is included in the list of notifiable diseases of the World Organization for Animal Health, restrictive measures are established and the regionalization of the country’s territory is carried out in case of its occurrence. Timely vaccination of parent flocks in order to obtain immune offspring takes a priority place in the system of anti-epidemic measures. Due to active development of duck breeding industry and increasing number of backyard farms, the need for high-quality and effective prevention tools for this infectious disease is growing. To date, one domestic native vaccine produced by FGBI «ARRIAH» and registered in the Russian Federation is available in native form and is intended for parenteral use. In order to extend the vaccine’s shelf life and for storage and transportation convenience, a live freeze-dried vaccine against duck virus hepatitis is being developed. The paper presents results of studying the pathogenesis of duck virus hepatitis and evaluating the efficacy and safety of the vaccine under development. Pathomorphological studies carried out post experimental infection indicate that duck hepatitis virus induces pathogenic effect not only in birds’ digestive organs (the liver, in particular) but also causes degenerative changes in central and peripheral immune organs: in cloacal bursa, thymus and third eyelid gland, that may be manifested as deficiency of B- and T-cell immunity and requires further studies. It has been shown that in case of immunization of 3-day-old ducklings, the experimental vaccine induces antibody-mediated immune response, no harmful effect is produced on poultry if a tenfold dose is admin­istered which indicates its safety, and the vaccine ensures protection against infection with a control virulent strain of hepatitis virus.

Antigen of H5N1 low pathogenic avian influenza virus Yamal strain included in the inactivated emulsion vaccine is able to induce strong immunity against highly pathogenic avian influenza in chickens. Inactivated emulsion vaccines based on antigen of H5N1 low pathogenic avian influenza virus Yamal strain and antigen of H5N1 highly pathogenic avian influenza virus А/chicken/Primorsky/85/08 strain are capable of inducing dose-dependent cross immunity against current Н5N1 and H5N8 highly pathogenic avian influenza viruses. Thus, inoculation dose of H5N1 low pathogenic avian influenza virus Yamal strain antigen required for pro­tection of 95% of chickens against H5N1 highly pathogenic avian influenza virus А/chicken/Primorsky/85/08 strain and against H5N8 highly pathogenic avian influenza virus A/duck/KChR/1590-20/20 in the vaccine inoculation volume shall be at least 609 HAU and 255 HAU, respectively. The inoculation dose of H5N1 highly pathogenic avian influenza virus А/chicken/Primorsky/85/08 strain antigen for protection from H5N8 highly pathogenic avian influenza virus A/duck/KChR/1590-20/20 strain shall be at least 294 HAU. Protective effect of the tested inactivated vaccines was associated with humoral immunity level in poultry. Predicted titre of antibodies to homologous virus antigens conferring expected 95% protection of vaccinated poultry was 1:538 or 9.1 log2. Inactivated vaccine based on H5N1 low pathogenic avian influenza virus Yamal strain antigen demonstrates its high immunogenicity in chickens infected with Н5N1 and Н5N8 highly pathogenic avian influenza influenza virus.

Cancer is one of the major causes of death in pet animals and humans worldwide. The contraindications and side effects associated with conventional cancer therapies heighten the importance of research aimed at finding new ways to combat cancer. One of the promising methods for the treatment of oncological diseases is the use of components of bacterial toxins, in particular the toxins of Bacillus anthracis, the causative agent of anthrax. Lethal factor is the main virulence factor of the anthrax pathogen, which is a zinc-dependent metalloprotease, the substrate for which is intracellular MAPK signaling pathways widely present in cancer cells. This review focuses on discussing the experience of foreign researchers in the application of Bacillus anthracis lethal factor in cancer therapy. The paper presents data from the studies that characterize the structure and functions of the lethal factor, reflect the results of its application on cancer cells both as a part of anthrax toxin and as a separate unit, reveal its therapeutic potential. The analysis of literature demonstrated good prospects for the potential use of the lethal factor to combat such types of cancer as liver, lung, colon, breast, pancreatic, ovarian, prostate, stomach and nervous system cancers. However, despite the impressive results, further in-depth research is needed in this area concerning selection of optimum doses of the lethal factor, determination of sensitivity of different types of cancer to it, investigation of its effects on other body tissues and interaction with the immune system during therapy.