DOI: 10.26155/vet.zoo.bio.202007005
UDC 619: 616.98: 579.843.9
Authors
A. V. Kapustin
Doctor of Biological Sciences, Associate Professor, Head of
the Laboratory of Federal Research Center – All-Russian
Research Institute of Experimental Veterinary
Medicine of the Russian Academy of Sciences,
Moscow, Russian Federation
A. I. Laishevtsev
Ph.D., Head of the Laboratory, Federal Research Center –
All-Russian Research Institute of Experimental Veterinary
Medicine of the Russian Academy of Sciences,
Moscow, Russian Federation
E. V. Ivanov
Ph.D., Senior Researcher, Federal Research Center – All-Russian
Research Institute of Experimental Veterinary
Medicine of the Russian Academy of Sciences,
Moscow, Russian Federation
A. M. Gulyukin
Doctor of Veterinary Sciences, Director of Federal Research
Center –All-Russian Research Institute of
Experimental Veterinary Medicine of
the Russian Academy of Sciences,
Moscow, Russian Federation
V. A. Savinov
Researcher, Federal Research Center –All-Russian
Research Institute of Experimental Veterinary
Medicine of the Russian Academy of Sciences,
Moscow, Russian Federation
Abstract
Histophilosis (herd infertility) is an infectious disease of cattle, sheep and goats which is spreading
across the Russian Federation. The disease can occur in the respiratory, septic and reproductive
forms, mainly in combination with other pathogens, particularly Mannheimia haemolytica and
Pasteurella multocida. The use of antibacterial agents for fighting the disease is not always effective,
since the pathogen rapidly develops resistance. The use of specific prevention means is a more appropriate
solution, however, there are currently no domestic vaccines against histophilosis. Due to this,
the purpose of our study was the search for H. somni strains suitable for the production and control
of immunobiological agents against cattle histophilosis, as well as the development of a method for
controlling the immunogenic activity of the vaccine which is being developed. To achieve this goal, we
carried out molecular biological and bacteriological tests of clinical and sectional material from cattle,
sheep and goats with signs of respiratory pathologies, as well as from adult animals with problems of
low fertility. During PCR, the causative agent of histophilosis was detected in 13 out of 15 surveyed
enterprises, which is 86,6%. It was possible to isolate H. somni using bacteriological methods only in
17 enterprises (XNUMX isolates), which can be explained by the complexity of the cultivation of the pathogen
and cross-contamination of the material with rapidly growing microorganisms. In addition, the pathogen
was isolated from a sample of semen of a sire-bull entering the territory of the Russian Federation
from Canada, as well as from lungs of pigs from a pig farm in the Sverdlovsk region.
The study of the pathogenic properties of Histophilus somni isolates showed that only 19 out of
1,5 isolates cause the death of mice after subcutaneous injection of 50 billion m.c. of pathogen. At
the same time, it was shown that both virulent and non-virulent Histophilus cultures can circulate
among a susceptible livestock in one enterprise. The determining of the LD1,45 of four pathogenic
cultures showed that this value is within from 108×2,09 to 108×80 m.c. with a subcutaneous infection.
The study of the immunogenic properties of Histophilus showed that all XNUMX selected strains
have a pronounced protective activity, and their use as a vaccine antigen showed immunization
that protects up to XNUMX% of laboratory animals from infection.
It was also shown that all virulent Histophilus strains isolated in different regions are homologous
in antigenic properties. Based on the results obtained, we proposed two industrial strains Histophilus
somni No. 551-VIEV and No. 1654-VIEV, suitable for the production of vaccines against
histophilosis, and two control strains No. 188-VIEV and No. 533-VIEV to control the immunogenic
activity of vaccines against herd infertility. It is advisable to control the immunogenic activity on
white mice, as it is the most convenient laboratory model.
Keywords
infectious pathology, specific prevention, vaccine, control method.
