Infectious Diseases In Animals Research Articles

Bacteriophage Therapy in Companion and Farm Animals.

Bacteriophages, which are viruses with restricted tropism for bacteria, have been employed for over a century as antimicrobial agents; they have been largely abandoned in Western countries but are constantly used in Eastern European countries with the advent of antibiotics. In recent decades, the growing spread of multidrug-resistant bacteria, which pose a serious threat to worldwide public health, imposed an urgent demand for alternative therapeutic approaches to antibiotics in animal and human fields. Based on this requirement, numerous studies have been published on developing and testing bacteriophage-based therapy. Overall, the literature largely supports the potential of this perspective but also highlights the need for additional research as the current standards are inadequate to receive approval from regulatory authorities. This review aims to update and critically revise the current knowledge on the application of bacteriophages to treat bacterial-derived infectious diseases in animals in order to provide topical perspectives and innovative advances.

An optimized culture system for efficient derivation of porcine expanded potential stem cells from preimplantation embryos and by reprogramming somatic cells.

Pigs share anatomical and physiological traits with humans and can serve as a large-animal model for translational medicine. Bona fide porcine pluripotent stem cells (PSCs) could facilitate testing cell and drug therapies. Agriculture and biotechnology may benefit from the ability to produce immune cells for studying animal infectious diseases and to readily edit the porcine genome in stem cells. Isolating porcine PSCs from preimplantation embryos has been intensively attempted over the past decades. We previously reported the derivation of expanded potential stem cells (EPSCs) from preimplantation embryos and by reprogramming somatic cells of multiple mammalian species, including pigs. Porcine EPSCs (pEPSCs) self-renew indefinitely, differentiate into embryonic and extra-embryonic lineages, and permit precision genome editing. Here we present a highly reproducible experimental procedure and data of an optimized and robust porcine EPSC culture system and its use in deriving new pEPSC lines from preimplantation embryos and reprogrammed somatic cells. No particular expertise is required for the protocols, which take ~4-6 weeks to complete. Importantly, we successfully established pEPSC lines from both in vitro fertilized and somatic cell nuclear transfer-derived embryos. These new pEPSC lines proliferated robustly over long-term passaging and were amenable to both simple indels and precision genome editing, with up to 100% targeting efficiency. The pEPSCs differentiated into embryonic cell lineages in vitro and teratomas in vivo, and into porcine trophoblast stem cells in human trophoblast stem cell medium. We show here that pEPSCs have unique epigenetic features, particularly H3K27me3 levels substantially lower than fibroblasts.

Scientific justification of Mycobacterium avium survival in natural environment of Republic of Dagestan

Contamination of the environment with the infectious animal disease agents is still a pressing problem for the poultry farms. Mycobacterium avium can grow and replicate in organic wastes from the poultry farms for a long time thus contaminating vast adjacent areas and being the source of infection not only for wild and domestic animals but also for humans. The studies were aimed at the examination of the duration of Mycobacterium avium survival in the natural environment in two geographical regions of the Republic of Dagestan characterized by different soil and climate. Samples of Mycobacterium avium-contaminated feces and soil collected from pastures and farmyards (on the surface and from 5 cm depth) were tested. The experiments demonstrated that pathogenic for chickens mycobacteria survived for up to 30 days in the samples collected in the sub-mountainous areas in summertime, when the air temperature ranged from 15.1 to 30 °С, land surface temperature – from 17 to 38 °С, air humidity – from 44 to 94% and average monthly precipitation amounted to 1.5 mm. From September to May, with the air temperature ranging from –10.8 to +25 °C, land surface temperature from –14 to +30 °C, air humidity 26–100% and average precipitation 0.39 mm, the bacteria survived for up to 213 days on the soil surface on the pastures and farmyards, and for up to 243 days at the depth of 5 cm and in the feces. In the plain area, in the same time period in the slightly saline soil with high humus content and at air temperature from –11.9 to +27.3 °C, soil temperature from –13 to +45 °C, air humidity from 37 to 100% and average precipitation 20.4 mm, Mycobacterium avium survived just like in the sub-mountainous area, i.e. for 213 and 243 days, respectively. The post-mortem lesions in the internal organs of the poultry corresponded to the tuberculosis clinical signs in 86 of 171 birds (50.3%). The study results will allow for the development of the optimal algorithm for animal health and management measures aimed at tuberculosis eradication on the poultry farms.

Evaluation of a Combined Live Attenuated Vaccine against Lumpy Skin Disease, Contagious Bovine Pleuropneumonia and Rift Valley Fever.

The use of effective vaccines is among the most important strategies for the prevention and progressive control of transboundary infectious animal diseases. However, the use of vaccine is often impeded by the cost, a lack of cold chains and other factors. In resource-limited countries in Africa, one approach to improve coverage and reduce cost is to vaccinate against multiple diseases using combined vaccines. Therefore, the objective of this study was to evaluate a combined vaccine for the prevention and control of Lumpy Skin Disease (LSD), Contagious Bovine Pleuropneumonia (CBPP) and Rift Valley fever (RVF). The LSD and CBPP were formulated as a combined vaccine, and the RVF was formulated separately as live attenuated vaccines. These consisted of a Mycoplasma MmmSC T1/44 strain that was propagated in Hayflick-modified medium, RVF virus vaccine, C13T strain prepared in African green monkey cells (Vero), and the LSDV Neethling vaccine strain prepared in primary testis cells. The vaccines were tested for safety via the subcutaneous route in both young calves and pregnant heifers with no side effect, abortion or teratogenicity. The vaccination of calves induced seroconversions for all three vaccines starting from day 7 post-vaccination (PV), with rates of 50% for LSD, 70% for CBPP and 100% for RVF, or rates similar to those obtained with monovalent vaccines. The challenge of cattle vaccinated with the LSD/CBPP and the RVF vaccine afforded full protection against virulent strains of LSDV and RVFV. A satisfactory level of protection against a CBPP challenge was observed, with 50% of protection at 6 months and 81% at 13 months PV. A mass vaccination trial was performed in four regions of Burkina Faso that confirmed safety and specific antibody responses induced by the vaccines. The multivalent LSD/CBPP+RVF vaccine provides a novel and beneficial approach to the control of the three diseases through one intervention and, therefore, reduces the cost and improves vaccination coverage.

Effect of institutional antimicrobial stewardship guidelines on prescription of critically important antimicrobials for dogs and cats.

Veterinary hospital antimicrobial stewardship (AMS) guidelines might help combat antimicrobial resistance (AMR). Determine the conditions and types of infection for which antimicrobial drugs (AMDs) deemed critically important (CIA) by the World Health Organization (WHO) were prescribed and assess the effect of hospital AMS guidelines on adherence to International Society for Companion Animal Infectious Diseases published guidelines for the treatment of superficial bacterial folliculitis, respiratory tract disease and urinary tract infection in these cases. Dogs and cats managed at an academic veterinary hospital from 1/21 to 6/21 and 9/21 to 6/22. Prescriptions of cephalosporins (third or fourth generation), glycopeptides, macrolides/ketolides, polymyxins, and quinolones were identified. Data on culture and susceptibility (C/S) testing and previous AMD exposure were collected. Frequencies were compared between time periods using Fisher's exact test with Bonferroni corrections. In animals prescribed ≥1 WHO-CIA AMD, fluoroquinolones were the most frequently prescribed WHO-CIA class in dogs (567/1724, 32.9%) and cats (192/450, 42.7%). No animals were prescribed carbapenems, dihydrofolate reductase inhibitors/sulfonamides, or polymyxins. No cats were prescribed aminoglycosides or amphenicols. Institutional guidelines were followed in 57.8% (324/561) cases. The most frequent causes of nonadherence were failure to perform C/S testing 46.0% (109/237) and unnecessary use of a higher-tier AMD 43.0% (102/237). Bacterial C/S testing was more frequently performed after AMS guideline institution (59.7% vs. 46.8%, P = 0.0006). Adherence to published guidelines remained poor despite an increase in C/S testing. There were no changes in the frequencies of confirmed infections, positive cultures or AMD resistance between time periods.

Development of a time-resolved fluorescence immunoassay kit for detecting canine coronavirus and parvovirus through double labeling

ObjectiveCanine enteric coronavirus (CCV) and canine parvovirus type 2 (CPV-2) are the main pathogens responsible for acute gastroenteritis in dogs, and both single and mixed infections are common. This study aimed to establish a double-labeling time-resolved fluorescence immunoassay (TRFIA) to test and distinguish CCV and CPV-2 diseases.MethodsA sandwich double-labeling TRFIA method was established and optimized using europium(III) (Eu3+)/samarium(III) (Sm3+) chelates. CCV/CPV-2 antigens were first captured by the immobilized antibodies. Then, combined with Eu3+/Sm3+-labeled paired antibodies, the Eu3+/Sm3+ fluorescence values were detected after dissociation to calculate the CCV/CPV-2 ratios. The performance, clinical performance and methodology used for laboratory (sensitivity, specificity, accuracy and stability) testing were evaluated.ResultsA double-label TRFIA for CCV and CPV-2 detection was optimized and established. The sensitivity of this TRFIA kit was 0.51 ng/mL for CCV and 0.80 ng/mL for CPV-2, with high specificity for CCV and CPV-2. All the accuracy data were less than 10%, and the recovery ranged from 101.21 to 110.28%. The kits can be temporarily stored for 20 days at 4 °C and can be stored for 12 months at temperatures less than − 20 °C. Based on a methodology comparison of 137 clinically suspected patients, there was no statistically significant difference between the TRFIA kit and the PCR method. Additionally, for CCV detection, the clinical sensitivity was 95.74%, and the clinical specificity was 93.33%. For CPV-2 detection, the clinical sensitivity was 92.86%, and the clinical specificity was 96.97%.ConclusionIn this study, a double-label TRFIA kit was prepared for CCV and CPV-2 detection with high laboratory sensitivity, specificity, accuracy, stability, clinical sensitivity and specificity. This kit provides a new option for screening/distinguishing between CCV and CPV-2 and may help improve strategies to prevent and control animal infectious diseases in the future.

Prevalence of Borrelia burgdorferi and Anaplasma phagocytophilum in Ixodes ricinus collected from dogs in eastern Poland

Abstract Introduction Ixodes ricinus ticks are an important vector and reservoir of pathogenic microorganisms causing dangerous infectious diseases in humans and animals. The presence of ticks in urban greenery is a particularly important public health concern due to the potential for humans and companion animals to be exposed to tick-borne diseases there. The study assessed the prevalence of Borrelia burgdorferi and Anaplasma phagocytophilum infection in I. ricinus ticks feeding on dogs. Material and Methods The study consisted in analyses of I. ricinus ticks collected in 2018–2020 from owned and stray dogs in the north-eastern part of Lubelskie province (eastern Poland). An AmpliSens PCR kit was used for qualitative detection and differentiation of tick-borne infections. Results Infections of B. burgdorferi and A. phagocytophilum were detected in 10.9% and 12.9% of the examined ticks, respectively. One tick (0.7%) was co-infected by both pathogens. Infection with B. burgdorferi was significantly more highly prevalent in ticks collected from the owned dogs than from the strays (18.7% and 2.8%, respectively), whereas the prevalence of A. phagocytophilum was similar in both groups (12.0% and 13.9%, respectively). Conclusion The co-infection observed in the study suggests the possibility of simultaneous infection by both pathogens from a single tick bite. The presence of pathogens in ticks collected from dogs is a factor in assessing infection risk not only to companion animals but also to their owners, who are in close contact with their dogs and visit the same green areas recreationally.

Comparative evaluation of some commercial spray-applied insecticides as control method against Blatta orientalis

Cockroaches are globally distributed pests with high epidemic importance. Their role as spreaders of many infectious and parasitic diseases in animals and humans determines disinsection as the main antiepidemic measure. The present study compared the effectiveness of spray application of different commercial insecticides against a field population of oriental cockroaches (B. orientalis) under laboratory conditions. A very high efficiency of fipronil (100% mortality) was found as early as 37-48 hours after treatment and a high efficiency of synthetic pyrethroids - 95-97% mortality at 49-60 hours. With the organophosphate derivatives (Dichlorvos) low mortality (37%) and unsatisfactory efficiency was achieved. The obtained results confirm the insecticides from the phenylpyrazole group and the synthetic pyrethroids, in spray-applied forms, as an effective method of fighting the oriental cockroach.

Pathomorphological changes in laboratory animals exposed to lethal doses of disinfec-tants

The use of disinfectants is a crucial aspect of preventive and health improvement measures for infectious diseases in farm and domestic animals. Regulatory documents require the determination of toxicity to macroorganisms, including the establishment of lethal doses and toxicity groups, during the development and registration of antimicrobial agents. This study aimed to investigate the histological changes in the internal organs of laboratory animals when determining lethal doses of innovative disinfectants. The experiments used domestic disinfectants containing glutaraldehyde as the active ingredient. Histological studies were conducted on the internal organs (kidney, liver, stomach, intestines, and spleen) of 75 laboratory animals using an Axioskop 40/40FL microscope (Carl Zeiss, Germany) with video microscopic photography. The methods used were under current standards. Hemodynamic disorders were observed in the renal tissue under the influence of lethal doses of aldehyde disinfectants. These disorders were characterized by capillary dilation and blood filling. Glomerular capillary dilation and overflow with blood cells were also detected. Additionally, stasis was observed in the lumen of the microcirculatory vessels throughout the entire length. The examination of histological sections from animal liver samples revealed a significant expansion of Dissé spaces, variations in the size of hepatocyte nuclei, beam decomposition and fragmentation, small acute perivascular hemorrhages, leukostasis in sinusoids, and hemodynamic disorders. The structure of the organ's beams was also disturbed, and a significant number of venous vessels were dilated and excessively filled with blood cells. Minor changes were detected in the stomach, including desquamation of the epithelial cells of the glands and their exfoliation into the gastric lumen, as well as circulatory disorders. Epithelial desquamation, blood vessel dilation, and signs of connective tissue edema were observed in the intestine. The kidneys exhibited signs of acute venous hemorrhage and stasis in vessels of various calibers, with the development of small acute parenchymal hemorrhages and localized lymphoid cell death in the white pulp. The prospect of further research is to investigate the histomorphological changes in the internal organs of laboratory animals when exposed to modern complex disinfectants with different active ingredients.

Anti-NMDA Receptor Encephalitis, Human Papillomavirus, and microRNA.

Anti-N-methyl-d-aspartate (Anti-NMDA) receptor encephalitis is a rare autoimmune disease, which is caused by antibodies attacking NMDA receptors in the brain. Previous studies revealed that this disorder might be induced by vaccination. Vaccination is the most useful strategy to prevent human or animal infectious diseases. Although vaccines can produce immunity against diseases, at low risk, they may trigger serious adverse events. Anti-NMDA receptor encephalitis has been studied to be related to the H1N1 (influenza A virus subtype H1N1), tetanus/diphtheria/ pertussis and polio vaccine, Japanese encephalitis, yellow fever, and coronavirus disease 2019 (COVID-19) vaccination. Several cases have been reported that anti-NMDA receptor encephalitis could also be triggered by the human papillomavirus (HPV) vaccine. However, there is a lack of studies to investigate the underlying mechanism. In this paper, the association between anti-NMDA receptor encephalitis and HPV vaccination is discussed in terms of their microRNA (miRNA) biomarkers. Phylogenetic tree and distance similarity analyses are used to explore the relationship between their miRNA biomarkers. The results show a higher degree of similarity between miRNA biomarkers associated with HPV and anti-NMDA receptor encephalitis or related vaccines when compared to the overall miRNAs. It indicates that while the risk of HPV triggering anti-NMDA receptor encephalitis is low, a connection between anti-NMDA receptor encephalitis and HPV vaccination cannot be ruled out. This finding suggests that in cases where individuals receiving HPV vaccination experience psychiatric or neurological symptoms, it should be considered to diagnose anti-NMDA receptor encephalitis, given the exclusion of other possible complications.

Lumpy skin disease virus ORF127 protein suppresses type I interferon responses by inhibiting K63-linked ubiquitination of tank binding kinase 1.

Lumpy skin disease (LSD) is a severe animal infectious disease caused by lumpy skin disease virus (LSDV), inducing extensive nodules on the cattle mucosa or the scarfskin. LSDV genome encodes multiple proteins to evade host innate immune response. However, the underlying molecular mechanisms are poorly understood. In this study, we found that LSDV could suppress the expression of IFN-β and interferon-stimulated genes (ISGs) in MDBK cells during the early stage of infection. Subsequently, an unbiased screen was performed to screen the LSDV genes with inhibitory effects on the type I interferon (IFN-I) production. ORF127 protein was identified as one of the strongest inhibitory effectors on the expression of IFN-β and ISGs, meanwhile, the 1-43 aa of N-terminal of ORF127 played a vital role in suppressing the expression of IFN-β. Overexpression of ORF127 could significantly promote LSDV replication through inhibiting the production of IFN-β and ISGs in MDBK cells. Mechanism study showed that ORF127 specifically interacted with TBK1 and decreased the K63-linked polyubiquitination of TBK1 which suppressed the phosphorylation of TBK1 and ultimately decreased the production of IFN-β. In addition, truncation mutation analysis indicated that the 1-43 aa of N-terminal of ORF127 protein was the key structural domain for its interaction with TBK1. In short, these results validated that ORF127 played a negative role in regulating IFN-β expression through cGAS-STING signaling pathway. Taken together, this study clarified the molecular mechanism of ORF127 gene antagonizing IFN-I-mediated antiviral, which will helpfully provide new strategies for the treatment and prevention of LSD.

Circulation of foot-and-mouth disease serotypes, risk factors, and their effect on hematological and biochemical profiles among cattle and buffalo in Quetta, Balochistan, Pakistan.

Foot-and-mouth disease (FMD) is an infectious disease of cloven-hoofed animals, including buffalo, cattle, sheep, goats, and pigs, causing major economic losses to the local farmers and, overall, to the national economy of the country. This study aimed to detect FMDV serotypes in year-round FMD outbreaks, hematological and biochemical changes, and oxidative stress in FMDV-infected cattle and buffaloes in the district of Quetta, Balochistan, Pakistan, and the socioeconomic impact of FMD outbreaks on farmers. We conducted a cross-sectional study in the district of Quetta, Balochistan, Pakistan, where FMD virus (FMDV) serotypes were detected by enzyme-linked immunosorbent assay (ELISA). Hematological, biochemical, and oxidative analyses were performed by analyzing the blood of FMDV-infected and non-infected animals. Information on the associated risk factors was obtained through a structured questionnaire by interviewing farmers in each FMD-affected farm. Thirty-four out of 38 farms (89%, 95% confidence interval [CI]: 75%-97%) were positive for FMD by ELISA. Higher FMD infection was detected in farms with a herd size of <50 animals (50%, 17/34), followed by >100 animals (32%, 11/34) and 51-100 animals (18%, 6/34). Fifty-seven percent (114/200, 95% CI: 50%-64%) of animals were positive for FMD. Of these, 61% (69/114) were cattle and 39% (45/114) were buffalo. FMD positivity was higher in females (86%, 98/114) than in males (14%, 16/114) and higher in animals older than 2 years of age (52%, 59/114). On average, farmers lose U.S. dollars 3000 annually due to FMD outbreaks. Animals infected with FMDV had significantly (p ≤ 0.05) white blood cell counts and significantly (p ≤ 0.05) lower hemoglobin and total protein concentrations in buffalo and cattle, whereas infected cattle showed significantly (p ≤ 0.05) lower albumin levels. Globulin levels were lower in buffaloes infected. Alanine aminotransferase levels were lower in infected cattle (p ≤ 0.05). Creatinine levels were higher in infected buffalo (p ≤ 0.05). Urea and phosphorus concentrations were higher in FMDV-infected cattle and buffalo (p ≤ 0.05). Calcium levels were lower in infected cattle and buffalo (p ≤ 0.05). Catalase enzyme activity in infected cattle and buffaloes was significantly lower (p < 0.05). Lipid peroxidation was significantly higher in FMDV-infected cattle and buffalo (p ≤ 0.05). This study confirmed serotype O circulation among cattle and buffalo in year-long FMD outbreaks in the Quetta District of Balochistan. Blood analysis identified a parameter deviated from the normal level due to FMDV infection. In addition, the outbreak of FMD has a significant negative economic impact on livestock farmers.

Structure-based virtual screening and molecular dynamics studies to explore potential natural inhibitors against 3C protease of foot-and-mouth disease virus.

Foot-and-mouth disease (FMD) is a highly infectious animal disease caused by foot-and-mouth disease virus (FMDV) and primarily infects cloven-hoofed animals such as cattle, sheep, goats, and pigs. It has become a significant health concern in global livestock industries because of diverse serotypes, high mutation rates, and contagious nature. There is no specific antiviral treatment available for FMD. Hence, based on the importance of 3C protease in FMDV viral replication and pathogenesis, we have employed a structure-based virtual screening method by targeting 3C protease with a natural compounds dataset (n = 69,040) from the InterBioScreen database. Virtual screening results identified five potential compounds, STOCK1N-62634, STOCK1N-96109, STOCK1N-94672, STOCK1N-89819, and STOCK1N-80570, with a binding affinity of -9.576 kcal/mol, -8.1 kcal/mol, -7.744 kcal/mol, -7.647 kcal/mol, and - 7.778 kcal/mol, respectively. The compounds were further validated through physiochemical properties and density functional theory (DFT). Subsequently, the comparative 300-ns MD simulation of all five complexes exhibited overall structural stability from various MD analyses such as root mean square deviation (RMSD), root mean square fluctuation (RMSF), radius of gyration (Rg), solvent accessible surface area (SASA), H-bonds, principal component analysis (PCA), and free energy landscape (FEL). Furthermore, MM-PBSA calculation suggests that all five compounds, particularly STOCK1N-62634, STOCK1N-96109, and STOCK1N-94672, can be considered as potential inhibitors because of their strong binding affinity toward 3C protease. Thus, we hope that these identified compounds can be studied extensively to develop natural therapeutics for the better management of FMD.

Novel fluorescence strategy based on G-quadruplex structure-switching aptamer for enrofloxacin detection in food and environmental samples

Enrofloxacin (ENR) is widely used in the prevention and treatment of animal infectious diseases, so it is necessary to strengthen the residue detection of this drug in animal-derived food and water environments. In this work, for the first time, we engineered assembly a split ENR aptamer into the G-quadruplex (G4) region to form a new aptamer (G4-ENRA) that provides a more sensitive signal-reporting function while retaining target-specific recognition ability of the aptamer. This rational design effectively overcomes the issue of difficulty in identification probe development. Under the optimized conditions, a response range of 0.05–20 µM and limit of detection of 26.7 nM were obtained by directly detecting fluorescence signals, displaying a comparative advantage over the previously reported methods. Moreover, this method demonstrated satisfactory performance for the ENR detection in various real food and environmental samples, with the detection recoveries ranging from 95.87 % to 104.36 %, illustrating promising applicability prospects.

Method of goat immunodiagnosis in arthritis-encephalitis

Currently, serological tests are used in the diagnosis of Caprine Arthritis Encephalitis (CAE), but a more accurate diagnosis of the disease requires the most reliable modern methods of immunodiagnosis. This is important for timely diagnosis and prevention of this disease, especially in commercial production of goat milk. At the present stage, the practice of infectious diseases immunodiagnosis in animals includes the determination of cytokines 6 and 10. The discovered cytokines allow for a different view on the infectious disease pathogenesis, while the previously used diagnostic methods are not excluded from the veterinary practice. At present, during the restoration and renewal of the goat population, new breeds purchased in foreign countries have appeared, and with them have come new diseases not previously prevalent in the Russian Federation. Therefore, practicing veterinarians need to develop the most effective immunodiagnostic tests for these diseases and work out effective control and prevention methods, as well as to be able to assess the risks of new infections or mixt infections. Immunophenotyping is performed in various infectious animal diseases, and immunological monitoring is also possible.

Dangerous bacterial infections of farm animals in Russia and the Tyumen region

In the 21st century, there is a clear trend of growth in quantitative and qualitative indicators of Russian animal husbandry. The Tyumen region is distinguished by the sustainable development of the agro-industrial complex. In conditions of intensive development of animal husbandry in Russia and the Tyumen region, it is of particular importance to preserve the health of livestock at enterprises and in private subsidiary farms. The article examines particularly dangerous bacterial infectious diseases of farm animals. Such diseases include anthrax, tuberculosis, brucellosis and leptospirosis. The main epidemic characteristics in dynamics over the past five years, including the incidence of animals and the spread of infections in Russia and the Tyumen region, have been analyzed, peaks in morbidity and main trends have been identified. Brief characteristics of diseases are presented, the main preventive measures and measures provided for by legislation are analyzed.

Aleutian disease: Risk factors and ImmunAD strategy for genetic improvement of tolerance in American mink (Neogale vison).

Aleutian disease (AD) is a devastating infectious disease in American mink (Neogale vison) industry caused by Aleutian mink disease virus (AMDV). Two crucial steps toward controlling infectious diseases in farm animals are: (i) assessment of the infection risk factors to minimize the likelihood of infection and (ii) selection of animals with superior immune responses against pathogens to build tolerant farms. This study aimed to investigate AD risk factors and evaluate a novel "ImmunAD" approach for genetic improvement of AD tolerance. Phenotypic records and pedigree information of 1,366 and 24,633 animals were included in this study. The risk of animal's age, sex, color type, and year of sampling on AMDV infection was assessed using a logistic regression model and counter immune-electrophoresis (CIEP) test results. ImmunAD phenotype was calculated based on AMDVG enzyme-linked immunosorbent assay (ELISA) and CIEP test results, and breeding values for ImmunAD were estimated using an animal model. Animals were classified into high-coordinated (HCIR), average-coordinated (ACIR), and low-coordinated immune responders (LCIR) using ImmunAD's breeding values, and the impact of selection of HCIR on live grade of pelt quality (PQ), harvest weight (HW), and harvest length (HL) breeding values were evaluated. Age of > 1 year, male sex, and year of sampling were identified as significant risk factors of AD (p < 0.05). A moderate-to-high heritability (0.55±0.07) was estimated for ImmunAD, while a higher heritability was observed among the CIEP-positive animals (0.76±0.06). Significantly higher breeding values were observed for PQ and HL among HCIR than those for LCIR and ACIR (p < 0.05). Our findings indicate the critical role of male breeders in AD distribution within mink farms. Regular screening of AD in male breeders before pairing them with females during breeding seasons can help disease control. ImmunAD strategy can be applied to genetic improvement of AD tolerance, with favorable impacts on some growth and production traits. Higher genetic gains can be achieved in populations with higher AD seroprevalences.

Występowanie i zwalczanie wysoce zjadliwej grypy ptaków w krajach Unii Europejskiej, w tym w Polsce w sezonie 2020/2021

Highly pathogenic avian influenza is one of the most contagious and dangerous infectious animal diseases of the twenty first century. Its recurring outbreaks in recent years have been increasing in scope and have resulted in previously unrecorded losses in poultry production, related to both its high mortality rate and the need to kill poultry in outbreaks, as well as economic losses related to trade restrictions imposed on affected countries and regions. An increase in the average duration of the so-called „flu season” was also observed. This is related to the shift in the phenological calendar observed in nature, which was created based on the analysis of climatic factors, weather and the impact on animal behavior. Currently, in the countries of the European Union, the direct legal basis for the control of highly pathogenic avian influenza in the EU, is provided by the provisions of Regulation (EU) 2016/429 of the European Parliament and of the Council (EU) (Animal Health Law, AHL), while the detailed manner and mode of control of this disease is defined in the Commission Delegated Regulation (EU) 2020/687 of December 17, 2019.

Potential Antibacterial Effects of Ethanol Extract and Essential Oil of Origanum vulgare on Klebsiella pneumonia and Staphylococcus aureus

Klebsiella pneumonia (K. pneumonia) and Staphylococcus aureus (S. aureus) are pathogenic bacteria causing various infectious diseases in humans and animals. Currently, herbal ingredients are widely used as antibacterial agents to combat bacterial infections due to their lower side effects, compared to chemical drugs. One such plant with medicinal promise as an antibacterial agent is the oregano plant (Oregano vulgare). It contains substances, such as tannin, flavonoids, carvacrol, thymol, and saponin. Therefore, the current study was conducted to regularly compare the in vitro antibacterial potential of ethanol extract essential oil oregano (Oregano vulgare) on K. pneumonia and S. aureus. In this research, the diffusion method using discs was employed to observe the inhibition zones, while the dilution tube method was utilized to determine the minimum inhibitory concentration (MIC) of the ethanol extract and essential oil of oregano against the test bacteria. The bacterial treatment group received the test material at concentrations of 100%, 50%, 25%, and 12.5%. The obtained data were analyzed descriptively in terms of zone inhibition and MIC values. According to the disc diffusion test, the essential oil of oregano demonstrated greater efficacy as an antibacterial agent against K. pneumoniae at a concentration of 100%, resulting in an average inhibition zone of 18 mm. Conversely, for S. aureus, a concentration of 1.5% of the essential oil exhibited higher effectiveness, yielding an average inhibition zone of 30 mm. Based on the MIC values, the essential oil was more effective as an antibacterial for K. pneumonia at a concentration of 0.2% (2 mg/mL), while for S. aureus it was more effective at a concentration of 0.19% (1.9 mg/mL).

Dynamics of blackleg epizootic process in the Republic of Kazakhstan

In 2012–2021, 2,030 outbreaks of acute infectious animal diseases were registered in the Republic of Kazakhstan. Among all the diseases blackleg accounted for 20.7% (421 outbreaks), which suggests that the nosological unit is of high epizootological significance among other infectious animal diseases in the country. Analysis of the blackleg outbreaks registered over the recent 10years demonstrates asignificant annual growth in the number of outbreaks (from19 to 81outbreaks) in the Republic of Kazakhstan and the disease persistence in the territory. Within the mentioned period, the average number of blackleg-infected animals per one outbreak ranged between1 and 3 animals, which proves that blackleg is anon-contagious disease. The research indicates that blackleg is a seasonal disease in the Republic of Kazakhstan with an incidence rise in autumn. The data analysis for 2012–2022 did not reveal any regular blackleg epizooties. The epizootological zoning made it possible to conclude that the blackleg situation in 6 Oblasts (which account for42.8% of the total territory) was rather tense; in 5 Oblasts (35.7% of the country’s territory) the epizootic situation was less tense and the remaining 3 Oblasts (21.5%) are disease-free. Therefore, blackleg zoning in the Republic makes it possible to use a differential approach to planning preventive veterinary and control measures, depending on the intensity of the epizootic situation. The research results will help to improve the system of blackleg surveillance, to predict the disease spread in animals and can be used to develop anti-epizootic measures.