Factors of cell immunity under exposure to the Eimeria spp

Abstract

One of the actual problems in farming rabbits is a decrease of their resistance, that is often conditioned by the availability of eimeriosis pathogens, which is significantly widespread both in foreign countries and in Ukraine. A lot of researchers studied the particular qualities of the development of prothymeriosis immunity, the role of lymphocyte populations, and the antigenic composition at various stages of development of eimeria. The aim of the research was to study the influence of the association of pathogens Eimeria sрp. with different levels of invasion intensity on indicators of cellular immunity of rabbits. For the experiments, analogue groups of male rabbits of the Californian breed aged 3-5 months were selected. During scatological research, we have found that rabbits with eimeriosis had different levels of invasion intensity (II), according to which the animals were divided into three groups: I - low level of invasion intensity (II = 1838.89 ± 1114.68 oocysts in 1 g of feces), II - medium level (II = 39787.50 ± 13422.34 oocysts in 1 g of feces) and group III - high level (II = 88578.57 ± 17776.32 oocysts in 1 g of feces). In the blood of all rabbits with eimeriosis (association of the pathogens Eimeria magna, E. media, E. perforans, E. stiedae) there were leukocytosis, absolute lymphocytosis against the background of relative segmented neutropenia regardless of the intensity of invasion. At the same time, in the blood of animals of all experimental groups, in comparison with the control, the number of eosinophils was significantly (p <0.001) higher in absolute and percentage (p <0.05) values. The same pattern has been found for basophiles. The absolute number of T- and B-lymphocytes, T-helpers and T-active lymphocytes was significantly higher compared to a low percentage of O-lymphocytes. So, if sick rabbits have pathogens of Eimeria spp., the defense mechanisms of innate and adaptive immunity with the participation of blood cells are activated. With an increase in the intensity of eimeriosis invasion in the blood of sick animals, the number of leukocytes, eosinophils and basophils increases against the background of a decrease in the percentage of segmented neutrophils. In the blood of rabbits with eimeriosis, a higher percentage of B-lymphocytes was noted, which had a weak positive correlation (r=0.28) with the level of invasion intensity, and a smaller number of O-lymphocytes. Key words: eimeriosis, leukogram, T-lymphocyte, B-lymphocyte, О-lymphocyte, T-helper, T-suppressor, T-active lymphocyte.