Cytogenetic abnormalities in young cattle during vaccination against salmonelloses

Abstract

The spectrum and the frequencies of cytogenetic abnormalities in young cattle immunized with a vaccine against salmonellosis of calves were investigated. The study was carried out on the farm of Novosibirsk region on 10 clinically healthy Holstein black-and-white calves of 10-17 days of age. A concentrated formol-alum vaccine against salmonellosis (paratyphoid) of calves was used at a dose of 2 ml (reimmunization at a dose of 2 ml) with an interval of 10 days between injections. The vaccine was made from the culture of bacteria of the Salmonella dublin strain № 373, inactivated with formalin with the addition of potassium alum and calcium chloride. Cytogenetic analysis of peripheral blood in calves was carried out before vaccination (control), 2 and 9 days after vaccination, 2 and 9 days after revaccination. It was found that the spectrum of somatic chromosomal instability in peripheral blood lymphocytes of calves after vaccination and revaccination is represented by polyploidy, hypoploidy and hyperploidy, chromatid and chromosomal breaks, single and paired fragments of chromosomes. It was revealed that the spectrum of somatic chromosomal instability after double immunizations with an inactivated vaccine against salmonellosis did not differ from the spectrum of spontaneously occurring mutations in this species. Vaccination and subsequent revaccination of calves in comparison with the pre-vaccination period did not lead to a significant increase in the frequency of aneuploid and polyploid cells. During double immunization of calves, a wave pattern in the variation of genomic mutation frequencies from maximum to minimum values in the lymphocytic blood cells of animals was noted, similar to prolonged mutagenesis. A tendency was found for the frequency of structural chromosome abnormalities to increase 2 and 9 days after vaccination and 2 days after revaccination. There was a credible 2.9-fold increase in the frequency of cells with chromosomal aberrations in the blood lymphocytes of animals 9 days after their repeated immunization due to breaks and paired fragments of chromosomes. After vaccination and revaccination, chromatid breaks were most often recorded in the medial regions of one of the chromatids, and chromosomal breaks in the medial and telomeric regions of both chromatids.