Immunological changes during Eimeria procera infection in a non-specific host

A study of the most pathogenic species of Eimeria found in the caeca of partridges (Eimeria procera) was carried out on ten-day old chickens. In the histological sections of four intestinal regions (duodenum, jejunum, ileum and caeca), first generation schizonts were found in the epithelial cells at 12, 36, and 60 hours post-infection (hpi) with the highest concentration in the duodenum and caecum. To estimate the immunological response after administration non-specific coccidia to the chicken, subpopulations CD3+, CD4+, CD8+, and BU1b+ in the peripheral blood and spleen were ascertained by flow cytometry. The total number of peripheral blood leukocytes was not significantly increased during the whole experiment in the infected group, whereas the actual number of lymphocytes showed a slight increase at 12 and 48 hours pi. The cell subpopulation values of infected chickens exceeded the number of the control animals in the peripheral blood except of BU1b+. In the spleen only CD3 positive cells were stimulated in infected chickens. The results demonstrated a moderate immune reaction and immunogenecity of a non-specific host-chicken to the partrigde E. procera infection.