China Animal Husbandry and Veterinary Medicine ›› 2023, Vol. 50 ›› Issue (9): 3853-3860.doi: 10.16431/j.cnki.1671-7236.2023.09.041

• Basic Veterinary Medicine • Previous Articles     Next Articles

Effects of Two-component System resE/resD Gene Deletion on Osmotic Stress Resistance and Pathogenicity of Listeria monocytogenes

GUO Qian1, ZHANG Yu1, FANG Xiaowei1, YUAN Mei1, ZHENG Minghao1, LIU Fang2, FANG Chun1   

  1. 1. College of Animal Science, Yangtze University, Jingzhou 434025, China;
    2. Animal Health Supervision Institute of Hengshui City, Hengshui 053000, China
  • Received:2023-01-28 Online:2023-09-05 Published:2023-08-24

Abstract: 【Objective】 This study was aimed to investigate the osmotic stress resistance and pathogenicity of Listeria monocytogenes by constructing a two-component system resE/resD gene deletion strain.【Method】 The two-component system resE/resD gene deletion strain was constructed by homologous recombination.The growth curve assay of Listeria monocytogenes were analyzed to compare the survival performance of the wild strain 10403S and the deletion strain ΔresE/resD.The stress survial test was used to explore the effect of resE/resD gene deletion on the osmotic pressure resistance of Listeria monocytogenes.The effects of resE/resD gene deletion on the cell infiltration ability and pathogenicity of Listeria monocytogenes in mice were evaluated by cell adhesion assay,cell invasion assay and mice virulence assay in colon cancer cells Caco-2 and gastric cancer cells MGC803.【Result】 The growth curve assay results showed that resE/resD gene deletion did not affect the normal growth of Listeria monocytogenes.The growth ability of ΔresE/resD in 5% NaCl was lower than that of wild strain 10403S,and the resistance to osmotic stress in platform stage was significantly decreased (P<0.05).The results of the stress survival test showed that the survival rate of ΔresE/resD was extremely significantly lower than that of wild strain 10403S after 1 h of stress treatment in 10% NaCl (P<0.01).In the Caco-2 and MGC803 cell invasion test,the results showed that ΔresE/resD was significantly weaker in cell adhesion (P<0.05),and extremely significantly lower in cell invasion ability (P<0.01).The results of the mice virulence assay showed that the bacterial load of spleen and liver in mice of ΔresE/resD was extremely significantly or significantly lower than that of wild strain 10403S (P<0.01 or P<0.05).【Conclusion】 Two-component system resE/resD gene deletion did not affect the normal growth of Listeria monocytogenes wild strain 10403S,but ΔresE/resD showed reduced resistance to osmotic stress,and weakened the cell adhesion invasiveness and mice pathogenicity of Listeria monocytogenes.

Key words: Listeria monocytogenes; two-component system; resE/resD gene; osmotic stress; pathogenicity

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