Background and Aim: The search and development of disinfectants is promising worldwide. However, there are currently no international regulations governing the testing and registration of germicidal agents. Moreover, the number of safety requirements for disinfectants for human, animal, and environmental health has increased. This research aimed to evaluate the prospects of using a collection of bacteriophages for disinfectant purposes. Materials and Methods: The objects of research were bacteriophages isolated from a total of 129 environmental samples obtained from seven sources in and around livestock buildings: (1) Feed residues from feeders and automatic drinkers; (2) washouts from floors, walls, and posts; (3) soil from underneath floors; (4) bedding; (5) sewage; (6) ponds; and (7) soil from paddocks. The corresponding strains were used as indicator test cultures for bacteriophages. The authors employed the following methods to work with bacteriophages: (a) Bacteriophage isolation methods, (b) the Appelman method (i.e., serial dilutions), (c) the Grazia method (i.e., agar layers), (d) phage titration on solid media, and (e) the bacterial phagotyping method. Results: The results of the analysis on the bacteria of the Enterobacteriaceae family isolated 11 bacteriophages; one bacteriophage is specific to Pseudomonas aeruginosa, and another one is specific to Brucella abortus. The results also indicate that all bacteriophage strains of the Enterobacteriaceae family demonstrate lysis at a pH of 7.0. In addition, this polyphage lyses all strains of sensitive bacterial cultures. The optimum temperature for the cultivation of bacteriophages is 35°C. While using electron microscopy to study the consortium of bacteriophages, clearly distinguishable virions of bacteriophages were found in the microscope field of view. Conclusion: The main parameters for the production of polyphages include the ratio of the bacteriophage and its corresponding bacteriophage-sensitive culture, the pH of the cultivation medium, and the cultivation time of the bacteriophage system as well as the sensitive bacterium. With regard to the aforementioned parameters, the results indicate that the average value for all bacteriophages is 1:2, and the average cultivation medium pH is 7.0 for all bacteriophages. The average cultivation time for all bacteriophages is 18-24 h.

Background/Objectives: Salmonella enterica is a major cause of foodborne infection globally, with poultry acting as an important reservoir. However, data from Central Asia remain limited. This study provides preliminary phenotypic and genomic characterization of S. enterica isolates recovered from poultry farms in southern Kazakhstan, focusing on antimicrobial resistance (AMR), serotypes/sequence types and phylogenetic relationships. Methods: In October 2024, 335 poultry and environmental samples were collected from three regions of southern Kazakhstan using a cross-sectional, detection-focused sampling strategy. Isolation of Salmonella enterica followed enrichment and selective culturing, with confirmation by biochemical assays, slide agglutination serology and real-time PCR. Antimicrobial susceptibility testing was performed using the Kirby-Bauer disk diffusion method and interpreted according to CLSI veterinary breakpoints (VET01/VET08) and CLSI M100 where veterinary criteria were unavailable. Whole-genome sequencing (Illumina) was used for in silico serotyping, MLST, AMR gene detection, plasmid replicon typing and SNP-based phylogenetic reconstruction. Results: Nine S. enterica isolates were confirmed (overall yield 2.7%; 9/335), comprising S. Enteritidis (ST11; n = 4), S. Infantis (ST32; n = 3) and ST68 (n = 2; Choleraesuis/Paratyphi C lineage). All isolates were resistant to ciprofloxacin, and most displayed resistance to ampicillin, gentamicin and trimethoprim-sulfamethoxazole. Plasmid-associated AMR determinants, including blaTEM-116, tet(A), sul1 and dfrA14, were frequently identified on IncF-type replicons. Phylogenetic analysis revealed that the isolates clustered with previously described Eurasian poultry-associated lineages. Conclusions: In this small, exploratory sample from poultry farms in southern Kazakhstan, all recovered S. enterica isolates were multidrug-resistant, with universal fluoroquinolone resistance and frequent plasmid-borne AMR genes. These preliminary findings provide baseline genomic evidence and highlight the need for broader, harmonized AMR surveillance in the regional poultry sector.

Background and Aim: Bovine tuberculosis (bTB), caused by Mycobacterium bovis, remains a significant zoonotic and eco­nomic threat globally. Despite the long-standing use of the Bacillus Calmette-Guérin (BCG) vaccine, its inconsistent efficacy and interference with surveillance tests underscore the need for alternative approaches. This study evaluated the safety, immunogenicity, and protective efficacy of a novel influenza vector-based vaccine expressing M. bovis antigens ESAT-6 and TB10.4, formulated with or without an adjuvant. Materials and Methods: Recombinant influenza A viruses expressing ESAT-6 and TB10.4 were constructed using reverse genetics and incorporated into vaccine formulations. Guinea pigs and calves were immunized with adjuvanted and non-adjuvanted formulations, followed by challenge with a virulent M. bovis strain. Safety was assessed through clinical observation and histopathology. Immune responses were monitored using interferon-gamma (IFNγ) enzyme-linked immu­nosorbent assay, and protection was evaluated through organ damage indices, bacterial load, and survival rates over a 12-month period. Results: Both formulations were safe and well-tolerated in guinea pigs and calves, with no adverse clinical signs. The non-adjuvanted vaccine induced the highest and most sustained IFNγ response, peaking between 2 and 5 months post-vac­cination. In guinea pigs, the protection index reached +0.60 lg in the non-adjuvanted group versus +0.2 lg in the adjuvanted group. In calves, lung bacterial load was reduced to 1.83–1.93 lg colony-forming unit (CFU) in vaccinated animals compared with 5.8 lg CFU in unvaccinated controls. Histopathological examination confirmed minimal tissue damage in the vaccinated groups. Both vaccine formulations demonstrated protective efficacy equivalent to or better than BCG, with the non-adju­vanted version showing superior performance. Conclusion: This novel influenza vector-based vaccine expressing ESAT-6 and TB10.4 antigens elicits strong, long-lasting cellular immunity and provides significant protection against M. bovis infection in guinea pigs and calves. The adjuvant-free formulation demonstrated higher immunogenicity, simplified production, and minimal adverse reactions, positioning it as a promising alternative to BCG for bTB control in livestock. Keywords: Bovine tuberculosis, calves, ESAT-6, guinea pigs, interferon-gamma, influenza vector, Mycobacterium bovis, protective efficacy, TB10.4, vaccine.

This article presented the results of a study on the impact of physicochemical factors on the biological activity of the SARS-CoV-2 coronavirus isolated from a dog in the Republic of Kazakhstan. The results indicated that storing the virus at a temperature of -70°C led to a decrease in viral activity, similar to the effect observed when stored at room temperature. Storage at +40°C resulted in complete inactivation of the virus. The study on the effect of various concentrations of ionic and non-ionic detergents revealed that exposure to the ionic detergent DOC at concentrations of 0.1% and 0.5% caused a decrease in viral activity, while no change was observed at a concentration of 0.01%. The detergent SDS, at concentrations of 0.01%, 0.1%, and 0.5%, reduced the biological activity of the virus from the initial titer (5.25 lg TCID50/cm³) to 4.00 lg TCID50/cm³. Similarly, the use of non-ionic detergents, Triton X-100 and Tween-20, led to a reduction in viral activity from the initial titer to 4.50 lg TCID50/cm³. The effect of pH in acidic, neutral, and alkaline environments on the biological activity of the virus was also studied. A decrease in viral activity was observed at acidic and alkaline pH levels, whereas a neutral pH environment had no impact on viral activity.

This article presents the results of studies on biological samples collected from 640 swabs taken from dogs and cats across various regions of the Republic of Kazakhstan. These samples were part of a monitoring study on the spread of coronavirus among domestic animals. Total RNAs were isolated using the magnetic sorption method with the ALPREP kit and subsequently analyzed with the ALSENSE-SARS-CoV-2 RT-qPCR kit. Real-time RT-PCR analysis revealed that 104 samples tested positive within 22–37 amplification cycles. These positive samples were then cultured in Vero cell lines to confirm the presence of the virus. The biological activity of the resulting virus-containing suspension was determined using the Reed-Muench method. During cultivation, one viral isolate with a biological activity of 5.83±0.08 lg TCID50/ml was obtained. A microphotograph of the virus was taken using an electron microscope to determine its size, shape, and structure, which confirmed its morphology corresponding to the Coronaviridae family. The data obtained further indicate that domestic animals can suffer from and carry coronavirus. It is becoming increasingly evident that the virus can infect and replicate in the organs of various farm and domestic animals.

When testing anti-brucellosis vaccines, an important role is played by studying the infecting dose of control strains. To restore the virulent properties of the control strains Brucella melitensis 16 M and Brucella abortus 544, it is necessary to carry out multiple successive passages in different doses (starting from 1,000,000 colony-forming units, CFU/cm3 to 5 CFU/cm3), through the body of sensitive laboratory animals. In this case, for experimental work, we took 54 heads of guinea pigs (males) weighing 350-380 g, from which we created 9 groups of 6 heads each. The article reflects the progress and results of research into determining the minimum fixing infectious dose of the control reference strains Brucella melitensis 16 M and Brucella abortus 544.Based on the results of the studies, the minimum infectious dose (5 CFU) of Brucella after the ninth passage, which causes the generalized form of brucellosis, was determined. Spent virulent fixing doses (5 CFU/cm3) strains of Brucella melitensis 16 M and Brucella abortus 544 can be used for control infection when setting up various experiments to determine and evaluate the immunogenicity of anti-brucellosis vaccines and chemoprophylaxis.