China Animal Husbandry and Veterinary Medicine ›› 2024, Vol. 51 ›› Issue (3): 1214-1222.doi: 10.16431/j.cnki.1671-7236.2024.03.033

• Preventive Veterinary Medicine • Previous Articles    

Effect of Galactosyltransferase gttA Gene Deletion on Pathogenicity of Listeria monocytogenes Serotype 4b

ZHENG Minghao1, GUO Qian1, LIU Fang2, LIANG Xiongyan1, LIU Jing1, YANG Yuying1, TIAN Guangming1, FANG Chun1   

  1. 1. College of Animal Science, Yangtze University, Jingzhou 434025, China;
    2. Hengshui Institute of Animal Health Supervision, Hengshui 053000, China
  • Received:2023-09-01 Published:2024-02-27

Abstract: 【Objective】 This study was aimed to investigate the effect of deletion of galactosyltransferase gttA gene on the anchoring of surface proteins and pathogenicity of Listeria monocytogenes,so as to provide a reference to the pathogenic mechanism research of Listeria monocytogenes.【Method】 Homologous recombination methods were used to construct the gttA gene deletion strain, the growth and motility of the parental strain ScottA,the deletion strain ΔgttA and the complement strain CΔgttA were analyzed.The effects of gttA gene deletion on the anchoring of two surface virulence proteins InlB and ActA in Listeria monocytogenes were investigated by Western blotting.The adhesion and invasion test of colorectal adenocarcinoma cell line (Caco-2) and mouse infection test were used to evaluate the effect of gttA gene deletion on the adhesion and invasion ability and pathogenicity of Listeria monocytogenes.【Result】 The growth and motility of Listeria monocytogenes were not affected by the deletion of gttA gene.Western blotting results showed that after the deletion of gttA gene,the anchor quantities of virulence proteins InlB and ActA on the bacterial cell wall surface were extremely significantly decreased (P<0.01).The results of cell adhesion and invasion assay showed that ΔgttA had an extremely significantly lower adhesion and invasion ability to Caco-2 cells than ScottA and CΔgttA (P<0.01).The results of mouse infection test showed that the colonization ability of Listeria monocytogenes in liver and spleen of mice was extremely significantly or significantly weakened due to the deletion of gttA gene (P<0.01 or P<0.05).After the gttA gene was replenished,the level of adhesion and invasion in Caco-2 cells,and the colonization ability of the bacteria in liver and spleen were restored to the level of the parental strain ScottA.【Conclusion】 The deletion of gttA gene did not affect the growth and motility of Listeria monocytogenes,but affected the anchoring of the major virulence proteins on the surface of Listeria monocytogenes,which in turn weakened the ability of the bacterium to invade Caco-2 cell line and the pathogenicity of the bacterium in mice.

Key words: Listeria monocytogenes; galactosyltransferase; surface protein; pathogenicity

CLC Number: