Haemophilus parasuis is the etiological agent of Glässer’s disease which is characterized by fibrinous polyserositis, arthritis and meningitis. The pathogenesis of this bacterium remains largely unknown. Genes expressed in vivo may play an important role in the pathogenicity of H. parasuis. The development of in vivo-induced antigen technology (IVIAT) has provided a valuable tool for the identification of in vivo-induced genes during bacterial infection. In this study, IVIAT was applied to identify in vivo-induced antigens of H. parasuis. Pooled swine H. parasuis-positive sera, adsorbed against in vitro-grown cultures of H. parasuis SH0165 and Escherichia coli BL21 (DE3), were used to screen the inducible expression library of genomic proteins from whole genome sequenced H. parsuis SH0165. Finally, 24 unique genes expressed in vivo were successfully identified after secondary and tertiary screening with IVIAT. These genes were implicated in cell surface proteins, metabolism, stress response, regulation, transportation and other processes. Real-time RT-PCR showed that the mRNA levels of 24 genes were all upregulated in vivo relative to in vitro, with 13 genes were detected significantly upregulated in H. parasuis infected pigs. Several potential virulence-associated genes were found to be uniquely expressed in vivo, including espP, lnt, hutZ, mreC, vtaA, pilB, tex, sunT and aidA. The results indicated that the proteins identified using IVIAT may play important roles in the pathogenesis of H. parasuis infection in vivo.

副猪嗜血杆菌是格拉塞尔氏病的病原体，特征是纤维性多发性浆膜炎，关节炎和脑膜炎。这种细菌的发病机理仍然是未知的。体内表达的基因可能在副猪嗜血杆菌的致病性中起重要作用。体内诱导抗原技术（IVIAT）的发展为细菌感染过程中体内诱导基因的鉴定提供了有价值的工具。在这项研究中，IVIAT被用于鉴定在体内诱导的副猪嗜血杆菌抗原。猪猪副猪嗜血杆菌阳性血清，体外吸附的-grown培养副猪嗜血菌SH0165和大肠杆菌BL21（DE3），用于筛选基因组蛋白的可诱导表达文库从全基因组测序，H. parsuis SH0165。最后，在用IVIAT进行二次和三次筛选后，成功鉴定了体内表达的24个独特基因。这些基因与细胞表面蛋白，代谢，应激反应，调节，转运和其他过程有关。实时逆转录-聚合酶链反应（RT-PCR）显示24种基因的mRNA水平在体内均相对于体外上调，其中13种基因在副猪嗜血杆菌中显着上调。被感染的猪。发现几个潜在的毒力相关的基因被独特地表达在体内，包括ESPP，LNT，胡茨，MREC，vtaA，pilB，TEX，必须遵守和AIDA。结果表明，用IVIAT鉴定的蛋白质在体内副嗜血杆菌感染的发病机制中可能起重要作用。