Dynamics of lymphocyte subpopulations in immune organs of chickens infected with Salmonella enteritidis

To determine the effect of different doses of Salmonella enteritidis on immunocompetent cells, the thymus, bursa Fabricii, and peripheral blood were examined. One-day-old chickens were orally infected with 2 x 10**2 CFU/mL (low dose, LD) and 8 x 10**8 CFU/mL (high dose, HD) of S. enteritidis PT4. Subsets of T lymphocytes and BU1b cells were analyzed at different intervals till day 27 post inoculation (pi). Salmonella infection accelerated the maturation and differentiation of thymus T cells in the first phase of infection, what was secondarily reflected by increased number of studied T lymphocyte subpopulations in the peripheral blood from day 14 to 27 pi. Similarly, it appears that the activation of B cells in bursa Fabricii caused the decrease of the number of bursal B lymphocytes and increased number of these cells in the peripheral blood from day 14 to 27 pi in both infected groups.