关键词: 海立啮齿杆菌, OmpA 基因, 基因缺失株, 毒力

Abstract: Objective To explore the role of OmpA gene in the pathogenicity of Rodentibacter heylii. Method The homologous recombination technique was used to construct the OmpA gene deletion strain of R. heylii. Its growth characteristics, genetic stability, biochemical characteristics, mass spectrometry characteristics, biological development and effects on mouse lung type Ⅱ epithelial cell line ( MLE-12 cells ) Adhesion; intraperitoneal injection of the OmpA gene-deficient strain to verify its pathogenicity to mice. Result The OmpA gene deletion strain of R. heylii was successfully constructed. The gene deletion strain could be inherited stably. Compared with the wild-type strain, the biochemical characteristics did not change, the mass spectrogram and growth curve were basically the same, and the biofilm formation ability was significantly enhanced ( P<0. 01) ; Adhesion to MLE-12 cells decreased from 43. 9% to 18. 3% (P<0. 001) ; Intraperitoneal challenge to mice, the lethality rate decreased from 100% to 20% ( P < 0. 01 ) . The pathogenicity of the gene deletion strain to mice decreased significantly. Conclusion The deletion of the OmpA gene significantly weakened the pathogenicity of R. heylii, confirming that OmpA plays an important role in the infection process of R. heylii.

Key words: Rodentibacter heylii, OmpA gene, gene deletion mutant, virulence