Veterynarna biotekhnolohiia– Veterinary biotechnology, 2023, 43, 18-23 [in Ukrainian]. https://doi.org/10.31073/vet_biotech43-02
HUDZ D., e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it., OBOZNENKO N., e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it., MELNYCHENKO O., e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.
Institute of Veterinary Medicine of the NAAS
STUDY OF THE PREVALENCE OF LEPTOSPIRA SEROVARS IN PIGS IN 2020–2022
Introduction. Ukraine belongs to the countries with intensive pig farming.Leptospira spp. in pig farming is the cause of reproductive losses, which are manifested by abortions at each stage of pregnancy, stillbirths, as well as infertility. Leptospirosis can introduce to the herd with new animals brought to the farm that are carriers of Leptospira, via contaminated environment or contact with other infected animal species.
In Ukraine vaccines are widely used for the disease control, therefore studying changes in the dominant serovars of pathogenic Leptospira is an important element of ensuring effective measures to control and prevent the spread of this disease in the country.
The goal of the work. To investigate the etiological structure of leptospirosis in pigs in 2020–2022.
Materials and methods. 279 animal blood serum samples were obtained for the study from farms of 7 regions of Ukraine. Samples were tested using microscopic agglutination test (MAT) using eight reference strains of Leptospira and eight serovars.
The serum samples were mixed with an equal volume of each of the Leptospira cultures. The samples with 1:50 titres or higher considered positive. Test was conducted within 1:50 – 1:2500 titersdilution. The results have been evaluated using a dark field microscope (× 400).
Results of research and discussion. Of 279 blood serum samples, 76 samples (27.2%) were positive.
Studies of the general structure of Leptospira serovars revealed that serovars polonica (40.8%), bratislava (36.8%) and grippotyphosa (32.9%) were dominated ones. Serovar icterohaemorrhagiae was detected in 28.9% of samples, canicola – 27.6%, tarassovi and kabura – in 26.3% of samples, respectively. Serovar pomona was detected the least often – 15.8%.
In the vast majority of blood serum samples, a reaction to several leptospira serovars (mixed reactions) was recorded in one sample – 65.8%. 34.2% of samples were positive for only one Leptospira serovar. Most often samples were positive for two serovars of microorganisms – 31.6%.
In monoreactions, serovar polonica was dominating one (42.3%). Serovars grippotyphosa and tarassovi were recorded less frequently, respectively 19.2% and 11.5%. Serovars bratislava (7.7%), kabura (7.7%), as well as pomona (3.8%), canicola (3.8%) and icterohaemorrhagiae (3.8%) were detected in insignificant number of samples.
In mixed reactions, serovar bratislava dominated – 52.0% of samples. Serovars icterohaemorrhagiae and grippotyphosa were also frequently detected – 42.0% each, as well as polonica and canicola – 40.0% each. Serovars pomona and kabura were registered less frequently, respectively 38.0% and 36.0%. The serovar tarassovi was detected least often – 18.0% of samples.
Conclusions and prospects for further research. The results of research on pig blood serum samples revealed the dominant leptospira serovars, namely polonica (40.8%), bratislava (36.8%) and grippotyphosa (32.9%). In monoreactions, serovar polonica was dominating (42.3%), and in mixed reactions – bratislava (52.0%).
The predominance of the mixed reaction with increasing tendency was also established.
Keywords: pig breeding, leptospirosis, research, serovars, etiological structure.
REFERENCES
