HERALD OF SCIENCE OF S SEIFULLIN KAZAKH AGRO TECHNICAL RESEARCH UNIVERSITY: Veterinary sciences

USING INDIRECT HEMAGGLUTINATION ASSAY FOR THE DIAGNOSIS OF CATTLE BRUCELLOSIS

2024-03-04T15:31:50+05:00

The possibility of using indirect hemagglutination assay (IHA) with milk (IHA/m) to differentiate post-infectious antibodies from post-vaccination ones in cows immunized with the Brucella abortus 82 was studied. Anti-Brucella antibodies by IHA/m were detected in the milk of all lactating animals (n=20) culled on the results of tube agglutination test (AT) and/or complement fixation test (CFT), while the milk ring test (MRT) were negative in 20% of cases. IHA/m, as well as IHA with blood serum (IHA/s), confirmed brucellosis in cows with AT- and/or CFT- negative or questionable results. The correlation coefficient between the results of the two IHA variants was very high (r = 793), and the hemagglutinin titers in the blood serum were significantly higher - 1:760 (+13.3%; -11.7%) than in AT-1:260 (+8.7%; -8.0%) (P≤0.01). Vaccination of cows caused increased production of complementfixing, agglutinating and precipitating antibodies, which tended to weaken during observation of the animals: 30, 60- and 90-days post vaccination (p.v.). By the end of the experiment, all vaccinated animals showed questionable AT; positive RID/O-PS and IHA/s were noted in 10% and 20% of cases, respectively. However, complement-fixing antibodies remained at diagnostic values in all animals until the end of the experiment. Despite the intense antibody immune response to the vaccine injection, there were no Brucella specific agglutinins detected by IHA/m and MRT in the milk of cows even on the 30th day p.v. The results show the need for further study on a large population to determine the diagnostic value of IHA/m for differentiating infected from vaccinated animals.

EPIZOOTOLOGICAL MONITORING OF THE INCIDENCE OF PARVOVIRUS ENTERITIS IN DOGS IN KOSTANAY, REPUBLIC OF KAZAKHSTAN

2024-03-13T12:12:52+05:00

Parvovirus enteritis of dogs is the cause of a highly contagious acute disease of many carnivorous animals, which leads to severe gastroenteritis and myocarditis. Parvovirus infection is characterized by severe enteritis and vomiting, as well as dehydration, fever, leukopenia and diarrhea. The article presents data on the frequency of occurrence of the disease in dogs with parvovirus enteritis in Kostanay, the Republic of Kazakhstan. In order to assess the epizootological situation of parvovirus enteritis, the logs of registration of sick animals, the results of rapid tests for infectious diseases of dogs of private veterinary clinics of the city for the period from 2020 to 2023 were analyzed. The object of the study was dogs of different breeds and age groups. Data analysis has shown that parvovirus enteritis is the most common infectious diseases of dogs. It was diagnosed in 20.3% of veterinary clinic patients, in two forms of intestinal and myocarditis. The disease is seasonal. Infection of dogs with parvovirus occurs mainly in spring (35,6%) and autumn (37,8%). The analysis of the sex and age structure of patients with parvovirus enteritis indicates a greater susceptibility to the disease of puppies under the age of one year. 86% of patients belonged to this age group. Dogs get sick regardless of gender.

MONOCLONAL ANTIBODIES AGAINST CTLA-4 AND PD-L1 RECEPTORS OF THE CATTLE IMMUNE SYSTEM

2024-03-04T12:20:10+05:00

With the progression of bovine leukemia virus (BLV), the concentration of T-cells, as well as CTLA-4 and PD-1 receptors on their cytoplasmic membrane increases. Elevated concentrations of regulatory T-cells lead to increased production of transforming growth factor-β (TGF β), suppression of interferon-γ (IFN-γ) expression, tumor necrosis factor-α (TNF-α), and inhibition of natural killer (NK) cells. Effector and cytotoxic T-lymphocytes, as well as the production of cytokines IFN-γ and TNF-α, play a crucial role in immune response against viral infections. However, at late subclinical stages, T-lymphocyte activity decreases due to the activity of regulatory T-lymphocytes, contributing to infection growth and progression to clinical disease. Blockade of CTLA-4 and PD-1/PD-L1 receptors with specific antibodies restores the immune response against BLV. Monoclonal antibodies (mAbs) against recombinant bovine CTLA-4 and PD-L1 were obtained using hybridoma technology methods. The obtained mAbs were analyzed using enzyme-linked immunosorbent assay (ELISA) and western blotting methods. As a result of the study, hybridoma cell lines producing mAbs to recombinant bovine CTLA-4 and PD-L1 receptors were obtained. The hybridomas produced IgG1 class mAbs that specifically reacted with standard proteins and had a binding constant: 3b3 - 2.9×108 M-1, 4h10 - 1.9×108 M-1. The obtained mAbs effectively blocked the reaction of commercial bovine CTLA 4 and PD-L1 proteins with specific polyclonal antibodies in an indirect fluorescent antibody assay (IFA).

PREVALENCE OF THEILERIA ANNULATA AMONG CATTLE IN THE TURKESTAN REGION

2024-03-11T15:38:23+05:00

Theileriosis is a severe blood-parasitic disease, an important problem in veterinary protozoology, since the damage it causes remains significant. The recently widespread practice of importing breeding stock to improve local breeds leads to the fact that in the first summer season, upon contact with infested ticks, the imported animals become very seriously ill, with a mortality rate of up to 90-100%. In this work, 738 samples of cattle were examined using the polymerase chain reaction method, which showed the presence of infection in 598 DNA samples isolated from cattle from 10 districts, 19 settlements of the Turkestan region. Whole blood samples were taken from cattle aged 3 years and older. Upon examination, the animals seemed healthy. The overall positivity rate for the entire region was 81%, highlighting the prevalence of infection among livestock. There are different levels of infection in the regions; in 6 settlements the infection rate of cattle was 100%. In addition, 7 villages showed high PCR positivity rates, ranging from 70% to 97%. While the lowest prevalence of infection showed from 18% to 69% in 6 villages, respectively.

EPIZOOTOLOGICAL MONITORING OF EQUINE HERPESVIRUS IN KAZAKHSTAN

2024-03-05T10:52:24+05:00

Equine herpesvirus is one of the most common infectious diseases of horses, causing huge economic losses associated with fetal abortion and subsequent chronic course. At the same time, a difficult epizootological situation regarding herpesvirus infections remains in the republic. Therefore, epizootological surveillance and planned monitoring studies of the epidemiological process in a certain territory are one of the effective tools for preventing the spread of еquine herpesvirus in horse breeding farms. This article presents the results of an analysis of epizootological monitoring and ongoing diagnostic measures regarding еquine herpesvirus on the territory of the Republic of Kazakhstan. According to epizootological data, over the past 10 years, 35 outbreaks of еquine herpesvirus have been registered in Kazakhstan. Serological monitoring confirmed the circulation of the causative agent of equine herpesvirus in the country's horse breeding farms. In a study of 1391 blood serum samples, antibodies to equine herpesvirus were detected in 93 cases (6.7%). The data obtained give reason to believe that in disadvantaged areas it is necessary to take a full range of measures for timely diagnosis, prevention and elimination of foci of infection.

SPECIES DIVERSITY AND PREVALENCE OF ZOOPHILIC FLIES IN KOSTANAY REGION (NORTHERN KAZAKHSTAN)

2024-03-06T12:24:21+05:00

This study delves into the understudied realm of zoophilic flies in the climatically distinct Kostanay region of Northern Kazakhstan. Amidst the region's diverse dipteran fauna, these parasitic flies pose a significant threat to both livestock and human health, acting as vectors for numerous infectious and invasive diseases. This study aimed to elucidate the spatiotemporal dynamics of zoophilic Diptera in the Kostanay region during the summer of 2023. As a result of the research, it was found that zoophilic flies of 8 families - representatives of 16 species - are registered on feedlots and pastures of farm animals of the Kostanay region of Northern Kazakhstan. Of these, the main species of flies (Musca domestica, M. stabulans, Calliphora unralensis, C. vicina and Wohlfartia magnifica) caused the greatest concern to animals. The total summer duration of zoophilic flies per season is 104-162 days or 3.5 - 5.5 months. Of the farm animals examined, cattle were the most intensively attacked.

THE IMMUNITY DURATION AND INTENSITY IN INDUSTRIAL LAYING HENS FOLLOWING VACCINATION WITH INACTIVATED H5N1 AVIAN INFLUENZA VACCINE

2024-03-18T11:17:05+05:00

After the severe AIV H5 outbreak in Kazakhstan in 2020 the extensive use of AIV H5 vaccines started in the industrial poultry farms to limit the H5N1 influenza spread. Traditional methods, such as stamping out are no longer a viable option in countries where Highly Pathogenic Avian Influenza (HPAI) has become endemic. However, available vaccines and vaccination protocols have been widely researched in laboratory conditions, and limited testing has been conducted on commercial layers for the immunity persistence in field conditions. Immunity persistence after AIV vaccination can be quite different between laboratory and field conditions. Our basic goal was to assess the intensity and duration of immunity in commercial layers following 1, 2 and 3 vaccinations. H5N1 hemagglutination inhibition (HI) antibodies were observed 370 days after vaccination of chickens using three schemes of vaccination. However, at 370 days post vaccination 1 experimental group obtaining one vaccination had comparatively low HI titers (mean titer 6,5±1,2 log2), the other two groups having two and three vaccinations showed 8,8±2,4 mean log2 and 9,4±2,2 mean log2 respectively. The described results showed that inactivated H5N1 vaccine can produce lengthy, intense and homogenous immunity under field conditions following 2 and 3 vaccinations.