Effects of the deletion of RsbV gene on virulence of Listeria monocytogenes

Abstract:

Abstract:［Objective］To study the effect of RsbV gene deletion on the virulence of Listeria monocytogenes.［Methods］The fragment with RsbV deletion was generated by gene overlap extension PCR (SOE-PCR) and the mutant with RsbV deletion was obtained by homologous recombination based on the wild strain LM-XS5．The differences in virulence between the two strains were determined by LD50，bacterial counts in liver and spleen，and qRT-PCR experiments．［Results］LD50 of the RsbV gene-deleted strain was 104higher than that of the wild strain．The numbers of gene-deleted strain in the mouse's liver and spleen were significantly fewer than that of the wild strain (P＜0.05)．Results of qRT-PCR show that four virulence factors' expression levels of the RsbV gene-deleted strain were significantly lower than that of the wild strain (P＜0.05). The RsbV gene-deleted strain induced a strong immune response in mice against the wild strain．［Conclusion］RsbV regulates the expression of four virulence gene (inlA，LLO，PlcA and PrfA) of Listeria monocytogenes; The virulence of the RsbV genedeleted strain is significantly reduced，but it still has good immunogenicity．