单核增生李斯特氏菌LPXTG基序锚定蛋白Lmo0175介导的抗氧化应激和感染生物学研究

Oxidative resistance and infection ability mediated by LPXTG motif-anchored protein Lmo0175 in Listeria monocytogenes

摘要:

目的 通过比较单核增生李斯特氏菌参考菌株EGD-e、lmo0175基因缺失株Δlmo0175和回补株CΔlmo0175在细菌生长、抗氧化应激、细胞和宿主感染等方面的差异，明确LPXTG基序锚定蛋白Lmo0175在单核增生李斯特氏菌抗氧化应激和感染致病中的作用。方法 通过构建lmo0175的基因缺失株和回补株，探究Lmo0175对单核增生李斯特氏菌生长、抗氧化应激、细胞黏附、细胞侵袭、胞内增殖和组织定殖能力及小鼠致病力等方面的影响，从而明确Lmo0175在该菌抗氧化应激和感染宿主中的作用。结果 lmo0175基因缺失后，单核增生李斯特氏菌在抗氧化应激、胞内增殖和小鼠脏器定殖等方面的能力显著降低，但在生长能力、细胞黏附和侵袭能力方面无显著差异。结论 本研究阐明了LPXTG基序锚定蛋白Lmo0175参与单核增生李斯特氏菌抗氧化应激、胞内增殖和组织定殖等过程，且有助于该菌对小鼠的致病力。

Abstract:

Objective To compare the bacterial growth, oxidative resistance, and bacterial infection in cells and host among Listeria monocytogenes EGD-e, lmo0175 (LPXTG motif-anchored protein)-deleted and complementary strains, so as to investigate the roles of Lmo0175 in anti-oxidative resistance and bacterial infection.Methods The lmo0175-deleted and complementary strains were constructed to compare the difference in bacterial growth, oxidative resistance, adhesion, invasion, intracellular proliferation, survival of infected mice, and bacterial loads in organs of Listeria monocytogenes.Results The deletion of lmo0175 remarkably decreased oxidative resistance, cell proliferation, colonization in the liver and spleen, and pathogenicity in mice. However, it had no significant impact on bacterial growth, adhesion or invasion.Conclusion The LPXTG motif-anchored protein Lmo0175 contributes to the anti-oxidative resistance, proliferation, and colonization in specific organs of Listeria monocytogenes.