Salmonella enterica serovar Enteritidis (S. Enteritidis, SE) is a major cause of foodborne diseases for humans. The completeness of the O-chain antigen of Lipopolysaccharide (LPS) determines whether a S. Enteritidis strain is smooth or rough. However, genes that are involved in the synthesis of LPS and rough-smooth variation are not completely understood. In this study, we used monoclonal antibody against O-antigens (O₉ mAb) to identify novel factors that are involved in LPS synthesis and rough variation in S. Enteritidis by using signature-tagged mutagenesis (STM) technique. Our results showed that transposon insertion in the gene rfbH led to different LPS phenotype, auto-aggregation characteristic, motility and resistance to environmental stress compared with SE wild-type strain C50041. In addition, sera tests showed that rfbH mutant does not elicit specific antibodies against O-antigens in vaccinated animals. Taken together, the S. Enteritidis rfbH gene is implicated in LPS biosynthesis, rough variation, sera distinguishable reaction, motility and stress resistance. The rfbH mutant strain could be potentially used as a distinguishable vaccine or a live vector to deliver drugs and antibodies in vivo.

肠炎沙门氏菌肠炎沙门氏菌（S. Enteritidis，SE）是人类食源性疾病的主要原因。脂多糖（LPS）的O链抗原的完整性决定了肠炎沙门氏菌菌株是平滑的还是粗糙的。但是，尚未完全了解参与LPS合成和平滑变化的基因。在这项研究中，我们使用了针对O抗原的单克隆抗体（O ₉ mAb），通过使用特征标记诱变（STM）技术来鉴定参与LPS合成和肠炎沙门氏菌粗略变异的新型因子。我们的结果表明转座子插入基因rfbH与SE野生型菌株C50041相比，可导致不同的LPS表型，自动聚集特性，运动性和对环境胁迫的抵抗力。另外，血清测试表明rfbH突变体不会在接种动物中引起针对O抗原的特异性抗体。总之，肠炎沙门氏菌rfbH基因与LPS生物合成，粗略变异，血清可分辨反应，运动性和抗逆性有关。该rfbH突变株可以潜在地作为区分疫苗或活载体以在体内输送药物和抗体。