Oleksandr Kornieikov

The development and comprehensive study of disinfectants is still a relevant area of research in veterinary medicine. Along with studying the toxicity of new disinfectants and determining their biocidal spectrum in laboratory conditions, production tests must be conducted. The results of these tests form the basis for recommendations on introducing disinfectants into production. This study aimed to test nanocomposites D1 and D2 under production conditions. Disinfection and quality assessment were carried out in accordance with current regulatory documents. It was found that control swabs taken before disinfection revealed catalase-positive and oxidase-negative staphylococci, Escherichia coli, mono- and diplococci with a total contamination level of 60×103 CFU/100 cm2 (high level). At the same time, the above microorganisms were not detected in the test swabs taken after disinfection with nanocomposites D1 and D2. Molecular genetic studies have demonstrated that there is no genetic material present for the following pathogens: bovine infectious rhinotracheitis (Bovine herpesvirus I), bovine viral diarrhea (Bovine viral diarrhea virus), bovine coronavirus infection (Bovine coronavirus), chlamydiosis (Chlamydia spp.), mycoplasmosis (Mycoplasma spp.), salmonellosis (Salmonella spp.), brucellosis (Brucella spp.), pasteurellosis (Pasteurella multocida), and mycobacterial infections (Mycobacterium spp.). Nanocomposites D1 (binary nanoparticles Ag Zn, and Cu with a total NPMe concentration of 5.4 mmol/L, and by metals Ag, Zn2+, and Cu — 0.7, 2.2 and 2.5 mmol/L, respectively) and D2 (binary Ag Zn, and Cu Ag nanoparticles with a total NPMe content of 4.9 mmol/L and by metals Ag, Zn2+, and Cu — 1.7, 2.2, and 1.0 mmol/L, respectively) exhibit bactericidal properties against sanitary indicative microorganisms in production conditions. These nanocomposites can be used for preventive disinfection through wet treatment of premises and veterinary supervision facilities at a concentration of 5.0%, with an exposure time of one hour and a consumption rate of 200 cm³/m². Data on the use of metal nanoparticles in disinfectants under industrial conditions expands the range of innovative antimicrobial drugs for veterinary medicine

The article highlights the results of an analysis of literary sources, emphasizing the importance of studying naturally occurring infections, particularly dangerous ones, caused by pathogens belonging to the Flaviviridae family, in relation to human health and veterinary medicine. This family is divided into four genera: Flavivirus, Pestivirus, Hepacivirus, and Pegivirus. The Flavivirus genus (Orthoflavivirus), the most significant for humans, belongs to the arbovirus family, which is transmitted by arthropod vectors, such as mosquitoes and ticks. Vectors become infected when they feed on the blood of infected reservoir animals. Afterward, they are capable of transmitting the virus to humans. Transmission of pathogens through unprocessed milk and organ transplantation is also possible. The viruses of yellow fever, Japanese encephalitis, tick-borne encephalitis, Omsk hemorrhagic fever, dengue, Zika, West Nile, Murray Valley encephalitis, and Pyasanu encephalitis, as well as Kiasanur forest disease and Alhumra hemorrhagic fever, are of epidemiological significance

Given the ability of the bovine leukemia virus (BLV) to overcome the interspecies barrier under experimental conditions — leading to the development of an infectious process in pigs, monkeys, rats, capybaras, and other animal species — the study of the susceptibility of various animal species to the pathogen and the determination of their potential role in the epizootic process is relevant and requires further research. Therefore, the investigation of the possible use of laboratory animals, particularly rabbits, for studying the infectious process in leukemia is of scientific interest and may contribute fundamental knowledge about the ability of BLV to cross the species barrier. The possibility of infecting rabbits was studied by subcutaneous inoculation of stabilized blood, followed by assessment of hematological, serological, and molecular-genetic indicators in animals from both the experimental and control groups at distant time points after inoculation. Every 15 days, hematological parameters (ESR, hemoglobin level, and leukocyte differential count) were examined in both groups. Seroconversion in the infected animals was determined using the agar gel immunodiffusion test. At the same time, the presence of the virus’s genetic material was detected by polymerase chain reaction (PCR) using a specific primer pair. Analysis of hematological results from the experimental and control rabbit groups at later stages after infection revealed that 60 days after inoculation, there was an increase in leukocyte count due to a rise in band neutrophils and lymphocytes. Most hematological parameters (hemoglobin, neutrophils, basophils, ESR) in the experimental group returned to baseline levels, except for lymphocyte count. Seroconversion in the experimental group animals was observed starting from day 60 post-infection, with peak levels recorded between days 105–120. The presence of the leukemia virus in the animals during this period was confirmed by molecular-genetic studies, which correlated with the hematological findings, particularly the development of lymphocytosis starting on day 60, which is characteristic of the infectious process typical of BLV infection. Thus, the study experimentally confirmed the ability of the bovine leukemia virus to cross the species barrier and induce an infectious process in heterologous animal species, namely rabbits

The object of this study is the high-power UV radiation at different pulses and its effect on Bacillus anthracis spores. The destruction of pathogenic microorganisms at environmental objects is the key to sustainable epizootological well-being. The results of the study show that the effect of powerful pulses on the destruction of pathogenic microorganisms is achieved during a short series and even single exposures. In this case, a pulsed UV sterilizer based on a magnetoplasma compressor with a pulsed ultraviolet flux power of 3.6 MW with a wavelength of 185‒320 nm of ultraviolet radiation was used. The prospects for pulsed sterilization technology have been shown. As a result of laboratory tests, it was established that the elimination degree of spores of the test microorganism Bacillus anthracis CTI, applied to wooden plates, is lg 2.5; applied to plastic plates – lg 3.2, while the degree of death of spores applied to metal plates is lg 4.0. Based on the results, wood and plastic require more attention when choosing disinfection methods due to their lower efficiency in this context. The high resistance of spore microorganisms requires the use of high dose loads to neutralize the anthrax pathogen. The proposed disinfection methodology is relevant and can be used by veterinary medicine laboratories, livestock farms of various forms of ownership, the scientific community, and industrial enterprises manufacturing technological equipment. Further research should be aimed at devising and improving methods for combating pathogenic microorganisms and ensuring sustainable epizootic well-being

Myotis alcathoe is one of the iconic species among cryptic European bats, described only 20 years ago. Despite research efforts, there is still limited knowledge about its distribution and ecology, leading to its Data Deficient status on the IUCN Red List. Ukraine lies on the eastern border of the species' range, with only a few known records. Here, we document a new genetically confirmed record of M. alcathoe from the Central-Western part of Ukraine (Rivne Region, in “Dermansko-Ostrozkyi” National Nature Park). Eight individuals were mist-netted in late April 2023 near a mine entrance, alongside a few Myotis nattereri and Myotis bechsteinii. This record extends the known range of M. alcathoe 30–40 km to the northeast, marking the second genetically confirmed record of this species in Ukraine. The woodlands of the National Park area, characterized by wet old-growth oak and hornbeam forests, seem to be suitable summer habitats for this species. Continued bat surveys during the breeding season are necessary in the area to better understand its habitat preferences and distribution.

One of the most relevant areas of scientific support in the field of veterinary medicine is the development and comprehensive evaluation of the effectiveness of antimicrobial agents under current requirements and taking into account the spread of antibiotic-resistant strains of pathogens. Today, among the promising ways to expand the range of disinfectants to ensure effective general veterinary and sanitary, and antiepizootic measures in livestock production is the use of modern chemical and biotechnologies, in particular those based on metal nanoparticles. The study aimed to investigate the spectrum of antimicrobial action of a mixture of binary nanoparticles of Ag, Zn, and Cu metals. The biocidal properties of the nanocomposite with a metal concentration of Ag — 367.2 mg/l, Zn — 287.76 mg/l, and Cu — 4.8 mg/l were studied on the model of cultures of enterobacteria Escherichia coli and Staphylococcus aureus, micromycetes Aspergillus flavus and larvae of helminths Toxocara canis using conventional methods. Microbiological studies have shown that the Ag-Zn-Cu nanocomposite exhibits bactericidal properties against the test cultures of S. aureus and E. coli and disinfects 100% of the test objects (tile, wood, cambric) contaminated by them at a concentration of 5% at an exposure time of 3 h and a concentration of 10.0% at an exposure time of 1 h. The Ag-Zn-Cu nanocomposite at a concentration of 5.0% with an exposure time of 1 h has a bacteriostatic effect on S. aureus and E. coli: on average, 98.2 and 99.4% of the cells were inactivated on tile, 95.3 and 97.5% on wood, and 98.4 and 99.1% on cambric, respectively. The nanocomposite at experimental concentrations (10.0–75.0% solution) at 20 ± 0.5 °C for 60, 120 and 180 min showed fungicidal properties against the test culture of A. flavus. In addition, a significant fungistatic effect against A. flavus was found with an 8.0% solution; a slight growth inhibition was observed with a 6.0% solution. The nanocomposite in 3.0 and 5.0% solutions showed neither fungicidal nor fungistatic properties under the above conditions. Treatment of the test culture with 5.0% and 10% solutions for 9, 12, 24, and 48 h affected the development of T. canis eggs and caused their death at the larval stage (larvae stopped moving and began to be destroyed). It was found that at an exposure time of 48 h and a concentration of 10.0%, the nanocomposite showed disinfestation activity, delaying the embryogenesis and invasive ability of larvae, and disinfected test objects contaminated with helminth eggs with high efficiency (up to 88.3–95.9%). The Ag-Zn-Cu nanocomposite exhibits bactericidal properties against the test cultures of enterobacteria S. aureus and E. coli and disinfects the test objects contaminated with them at a concentration of 5% at an exposure of 3 h and a concentration of 10.0% at an exposure of 1 h. The lowest concentration of the nanocomposite ensured complete inactivation of the A. flavus test culture at 20 ± 0.5 °C was 10%. The nanocomposite at a concentration of 10.0% for 24 and 48 h disinfects test objects contaminated with T. canis eggs and reduces the invasive ability of the larvae. Thus, the new data on the spectrum of biocidal action of metal nanoparticles make it possible to improve the development of innovative directions for controlling the level of pathogenic and opportunistic microorganisms in the environment

According to the results of the survey of cattle in 13 regions of Ukraine, it was found that 33.8% of them had circulating herpesvirus type 1 (BHV-1), which is the causative agent of infectious rhinotracheitis (IRT). The respiratory form of IRT was found in 41.7% of farms, genital and keratoconjunctivitis in 8.3%, and asymptomatic and polysymptomatic in 25.0% and 16.7%, respectively. A significant percentage of farms with asymptomatic cases is due to the almost total use of IRT vaccination. Of particular concern is the use of vaccines containing live attenuated strains of herpesvirus type 1 in the surveyed farms (66.7% of all cases), which further complicates the epizootic situation

In the article reviewed and discussed literature data on biological properties of nanomaterials. The biosafety of nanomaterials is a complex and multifaceted issue that demands a comprehensive, science-based approach. Modern environmental and economic factors should be considered in this regard. The EU’s nanotechnology policy is based on ‘an integrated, safe and responsible approach’ (Communication from the Commission to the European Parliament, the Council and the European Economic and Social Committee. Regulatory aspects of nanomaterials. SEC(2008) 2036 / COM(2008) 366 final). Based on the findings of toxicity and antimicrobial activity studies, metal nanoparticles appear to be a favorable choice as antibacterial agents in developing new disinfectants. However, further measures must be taken to ensure the safe and environmentally friendly use of metal nanoparticles (MeNPs). To achieve this, it is crucial to establish toxicity parameters for MeNPs of various compositions, sizes, and concentrations. These parameters must be compared and evaluated alongside the potential effects of MeNPs on laboratory and target animals (in vivo), as well as their antibacterial performance against microorganisms of different strains (in vitro). Thus, the investigation of possible hazards associated with the use of metal nanoparticles can be effectively achieved by analyzing the fundamental systemic characteristics of biological systems under both in vivo and in vitro conditions, taking into account various aspects such as physiological, biochemical, immunological, genetic and cytological responses that may be affected by toxic effects. The literary sources analysis and article publication were conducted under the National Research Foundation of Ukraine project No. 2021.01/0076 'Development of a novel, nanoparticle-based disinfectant for deactivation of pathogens causing emergent infectious diseases'

The article presents data on the effect of Aerosil A-300 on the growth of bacteria Lactobacillus plantarum No. 7-317, Bifidobacterium adolescentis No. 17-316, Streptococcus lactis No. 5. The results of studies have shown that the most optimal for the growth of bacteria content of Aerosil A-300 in the environment is 2.0%. It has been found that when Aerosil was added to nutrient media, bacteria grew and actively accumulated a significant number of viable cells: 3.8–4.5×107 CFU/cm3 (control 1.1–2.5×107 CFU/cm3) according to the average technological parameters pH 7.0 and the temperature of 37 ℃. Studies have shown that the relative increase in the number of cells, by which we assessed the effect of Aerosil on growth, was in Lactobacillus plantarum No. 7-317 (87.5 ± 12.0), which is 23% higher than control, in Bifidobacterium adolescentis No. 17-316 — (79.2 ± 11.9), which exceeded the control data by 14%

Isolation of the virus from biological material from a two-month-old calf with pathology of the respiratory system from a herd with a morbidity rate of 48% was performed. After detection the presence of IRT antigens in the lungs of the dead animal, the pathogen was isolated on a continuous culture of calf kidney cells, where a characteristic cytopathic effect was observed. The genetic material of the bovine herpesvirus type 1 (Bovine herpesvirus-1, BHV-1) was identified by polymerase chain reaction in the test sample. The virus isolate was adapted to continuous cell cultures of calf kidneys, sheep kidney, cow embryo lung and calf trachea, and the most suitable biological system was determined, where adsorption and reproductive properties of the virus were more pronounced. It was found that the highest titer of infectious activity of BHV-1 isolate (6.1 lg TCD50/cm3) was obtained on continuous culture of lung embryonic cells of a cow embryo after its reproduction during three consecutive passages (observation period)