Fowl typhoid is caused by Salmonella enterica serovar Gallinarum biovar Gallinarum (SG), and live attenuated, rough vaccine strains have been used. Both humoral and cellular immune responses are involved in protection, but the humoral responses to different forms of SG antigens are unclear. In this study, we compared humoral responses to a killed oil-emulsion (OE) smooth vaccine (SG002) and its rough mutant vaccine (SR2-N6) strains using proteomics techniques. We identified two immunogenic outer membrane proteins (OmpA and OmpX), and the selected linear epitopes were successfully applied in peptide-ELISA. Our peptide- and total OMP-ELISAs were used to compare the temporal humoral responses to various SG antigens: OE SG002 and SR2-N6; live, killed [PBS-suspension (PS) and OE)] and mixed (live and PS) formulations of another rough vaccine strain (SG 9R); and orally challenge with a field strain. Serum antibodies to the linear epitopes of OmpA and OmpX lasted only for the first 2 weeks, but serum antibodies against OMPs increased over time. The rough strain (SR2-N6) and mixed SG 9R induced higher serum antibody titers than the smooth strain (SG002) and single SG 9R (OE, live and PS SG 9R), respectively. Infection with the field strain delayed the serum antibody response by ~2 weeks. Mucosal immunity was not induced by any formulation, except for infection with the field strain after SG 9R vaccination. Thus, our results may be useful to understand humoral immunity against various SG antigens and to improve vaccine programs and serological diagnosis in the field.

禽伤寒是由肠沙门氏菌已使用鸡血清型鸡生物型（SG）和减毒活疫苗株。体液和细胞免疫反应都参与保护，但对不同形式 SG 抗原的体液反应尚不清楚。在这项研究中，我们使用蛋白质组学技术比较了灭活油乳剂 (OE) 光滑疫苗 (SG002) 及其粗糙突变疫苗 (SR2-N6) 菌株的体液反应。我们鉴定了两种免疫原性外膜蛋白（OmpA 和 OmpX），并将选定的线性表位成功应用于肽-ELISA。我们的肽-和总 OMP-ELISA 用于比较对各种 SG 抗原的时间体液反应：OE SG002 和 SR2-N6；另一种粗疫苗株（SG 9R）的活的、灭活的[PBS-悬浮液（PS）和OE）]和混合（活的和PS）制剂；以及现场应变的口头挑战。针对 OmpA 和 OmpX 线性表位的血清抗体仅持续前 2 周，但针对 OMP 的血清抗体随着时间的推移而增加。粗糙菌株(SR2-N6)和混合SG 9R分别比光滑菌株(SG002)和单一SG 9R(OE、活的和PS SG 9R)诱导更高的血清抗体滴度。野生菌株感染使血清抗体反应延迟约 2 周。除 SG 9R 疫苗接种后现场菌株感染外，任何制剂均不会诱导粘膜免疫。因此，我们的结果可能有助于了解针对各种 SG 抗原的体液免疫，并改进该领域的疫苗计划和血清学诊断。