Salmonella is a leading cause of foodborne pathogen which causes intestinal and systemic diseases across the world. Vaccination is the most effective protection against Salmonella, but the identification and design of an effective broad-spectrum vaccine is still a great challenge, because of the multi-serotypes of Salmonella. Reverse vaccinology is a new tool to discovery and design vaccine antigens combining human immunology, structural biology and computational biology with microbial genomics. In this study, reverse vaccinology, an in-silico approach was established to screen appropriate immunogen targets by calculating the immunogenicity score of 583 non-redundant outer membrane and secreted proteins of Salmonella. Herein among 100 proteins identified with top-ranked scores, 15 representative antigens were selected randomly. Applying the sequence conservation test, four proteins (FliK, BcsZ, FhuA and FepA) remained as potential vaccine candidates for in vivo evaluation of immunogenicity and immunoprotection. All four candidates were capable to trigger the immune response and stimulate the production of antiserum in mice. Furthermore, top-ranked proteins including FliK and BcsZ provided wide antigenic coverage among the multi-serotype of Salmonella. The S. Typhimurium LT2 challenge model used in mice immunized with FliK and BcsZ showed a high relative percentage survival (RPS) of 52.74 % and 64.71 % respectively. In conclusion, this study constructed an in-silico pipeline able to successfully pre-screen the vaccine targets characterized by high immunogenicity and protective immunity. We show that reverse vaccinology allowed screening of appropriate broad-spectrum vaccines for Salmonella.

沙门氏菌是导致世界各地肠道和全身疾病的食源性病原体的主要原因。接种疫苗是预防沙门氏菌最有效的方法，但由于沙门氏菌的血清型多，因此鉴定和设计有效的广谱疫苗仍是一个巨大的挑战。反向疫苗学是一种将人类免疫学、结构生物学和计算生物学与微生物基因组学相结合的发现和设计疫苗抗原的新工具。在这项研究中，反向疫苗学，通过计算 583 种非冗余外膜和沙门氏菌分泌蛋白的免疫原性评分，建立了一种计算机方法来筛选合适的免疫原靶标. 在此，从评分最高的 100 种蛋白质中，随机选择了 15 种具有代表性的抗原。应用序列保守性测试，四种蛋白质（FliK、BcsZ、FhuA 和 FepA）仍然是体内免疫原性和免疫保护评估的潜在候选疫苗。所有四种候选物都能够触发免疫反应并刺激小鼠产生抗血清。此外，包括 FliK 和 BcsZ 在内的顶级蛋白质在沙门氏菌的多血清型中提供了广泛的抗原覆盖。的S.与FLIK和BcsZ免疫的小鼠的鼠伤寒沙门氏菌用于LT2攻击模型分别显示出52.74％和64.71％的高相对百分比存活（RPS）。总之，本研究构建了一个in-silico管道能够成功预筛选具有高免疫原性和保护性免疫特征的疫苗靶标。我们表明，反向疫苗学允许筛选适当的沙门氏菌广谱疫苗。