Salmonella Serovars and Vaccination Effect on the Immune Responses of Male and Female Layers

Abstract

Salmonella Enteritidis, S. Gallinarum and S. Pullorum are common serovars to infect poultry and cause diseases differently. The antibody production and cellular immune responses of male and female layers were evaluated before and after inoculation. Before inoculation, S. Gallinarum and S. Pullorum could survive and grow in 10% sera from 6-week-old layers, and S. Enteritidis and E. coli were completely eliminated. The weights of the male and female layers were increased the lowest by inoculation with S. Gallinarum, followed by S. Pullorum, and S. Enteritidis. Inoculation with S. Enteritidis, S. Gallinarum and S. Pullorum increased the antibody titer in the males depending on the serovars and maintained same higher antibody level in females. Furthermore, an increased anti-Salmonella IgG titer was associated with bactericidal ability and the level was reduced by serovars and complemente. Despite the vaccination and serovars, the male layers expressed more IgG2a than IgG1, indicating preferential activation of the Th1 pathway. The inoculation number affected the expression level of IFN-γ and IL-12 in the blood not in the secretion of the peripheral blood mononucleated cells (PBMCs) and more inoculations increased the expression of both cytokines. Inoculation increased more reactive oxygen species (ROS) production in polymorphonuclear (PMN) cells, not the PBMCs. ROS production was greater in cells from the males than from the females and greater in the cells treated with S. Enteritidis than S. Gallinarum and S. Pullorum. These three serovars and their vaccinations differed in sera killing and immune responses.

Keywords: IgG antibody; PBMC; PMN; Salmonella Infection; cytokine; reactive oxygen species.

Fig. 1.

The IFN-γ expression levels in serum of M2 chickens inoculated with S. Gallinarum, S. Pullorum, and S. Eneteritidis before inoculation (0), and after first (1), second (2), and third (3) inoculation (A) and in the secretion by PBMCs from M2 chicken that were interacted with S. Gallinarum, S. Pullorum, and S. Eneteritidis for 2 and 4 hours before (0) and after third (3) inoculation (B).

Fig. 2.

The IL-12 expression level in in serum of M2 chickens inoculated with S. Gallinarum, S. Pullorum, and S. Eneteritidis before inoculation (0), first (1), second (2), and third inoculation (3) (A) and PBMC cells from M2 chicken that were interacted with S. Gallinarum, S. Pullorum, and S. Eneteritidis for 2 and 4 hours before (0) and after third (3) inoculation (B).

Fig. 3.

The superoxide production of the PBMC cells from non-challenged M1, M2 and F2 layers were interacted with Salmonella Gallinariun (SG), S. Pullorum (SP), S. Enteritidis (SE) and E. coli for 1, 2 and 4 hours. NC: control. ^{a, b, c} Different letters indicate significant difference between different challenge time, P<0.05.

Fig. 4.

The superoxide production of the PMN cells from non-chanllenged M1, M2 and F2 layers were interacted with Salmonella Gallinariun (SG), S. Pullorum (SP), S. Enteritidis (SE) and E. coli for 1, 2 and 4 hours. NC: control. ^{a, b, c} Different letters indicate significant difference between different challenge time, P<0.05.

Fig. 5.

The average superoxide production of PBMC cells from M2 (A) and F2 (B) layers before (M2-0 and F2-0), and after first (M2-1 and F2-1), second (M2-2 and F2-2) and third (M2-3 and F2-3) inoculations with S. Enteritidis (SE), S. Gallinarum (SG), and S. Pullorum (SP), respectively. The superoxide level was measured for the cells that were interacted with E. coli and the infected serovar for 1 H, 2 H, and 4 H. SE-E. coli and SE-SE mean that the cells from the layers inoculated with S. Enteritidis were interacted with E. coli and S. Enteritidis, respectively. SG-E. coli and SG-SG mean that the cells from the layers inoculated with S. Gallinarum were interacted with E. coli and S. Gallinarum, respectively. SP-E. coli and SP-SP mean that the cells from the layers inoculated with S. Pullorum were interacted with E. coli and S. Pullorum, respectively.

Fig. 6.

The average superoxide production of PMN cells from M2 and F2 layers after first (1), second (2) and third (3) inoculations with S. Gallinarum (SG), and S. Pullorum (SP), respectively. The superoxide level was measured for the cells that were interacted with E. coli and the serovars for 1 H, 2 H, and 4 H. M2SG-E. coli and M2SG-SG mean that the cells from M2 layers inoculated with S. Gallinarum were interacted with E. coli and S. Gallinarum, respectively. M2SP-E. coli and M2SP-SP mean that the cells from M2 layers inolculated with S. Pullorum were interacted with E. coli and S. Pullorum respectively. F2SG-SG and F2SP-SP mean that the cells from F2 layers inoculated with S. Gallinarum and S. Pullorum were interacted with their infected serovars, respectively.