Construction Of YbiH Gene Mutant Of Salmonella Typhimurium And Analysis Of Its Biological Function

[Objective] Salmonella typhimurium is a zoonotic pathogenic microorganism that can infect multiple hosts,which has important public health research significance.Early laboratory proteomics research found that under the thymol selection pressure,the expression level of YbiH protein,a functional unknown factor in Salmonella,was significantly reduced.Preliminary verification found that it was closely related to bacterial pathogenicity,but YbiH was closely related to bacterial pathogenicity It is unclear what kind of function it plays in the pathogenic process.It is necessary to understand its biological function during the growth of Salmonella,so as to provide a certain theoretical basis for the control of Salmonella contamination and the effective control of Salmonellosis.[Method] In this paper,the mutant ST?ybiH of S.typhimurium standard strain was successful constructed by ?-Red homologous recombination system,and the complementary strain ST?ybiH / pybiH and the over-expression strain of the gene were also constructed.The growth characteristics and motility of the ybiH mutant strain,biochemical characteristics,adhesion,invasiveness,virulence and pathogenicity were studied to confirm the biological role of YbiH in the growth of Salmonella.[Results] The research showed that compared with the standard strain of Salmonella typhimurium ST and the supplementary strain,the growth rate of ST?ybiH was slightly faster,and there was no significant difference in its motility,biochemical characteristics and drug resistance.Cell experiments showed that the deletion of the ybiH gene significantly increased the adhesion and invasiveness of Salmonella typhimurium to IEC-6 cells,and the expression of invasive genes was also significantly increased during q RT-PCR detection.Cell experiments showed that the deletion of the ybiH gene significantly increased the adhesion and invasiveness of Salmonella typhimurium to IEC-6 cells,and the expression of invasive genes was also significantly increased during q RT-PCR detection.In the mice challenge experiment,the missing strain was more toxic to mice and died faster,and the spleen of the mice was significantly larger than the liver.[Conclusion] YbiH plays an important role in the change of adhesion and invasion of Salmonella typhimurium.After its deletion,it will increase the virulence of Salmonella and increase its pathogenicity in mice.This indicates that YbiH is directly involved in the change of Salmonella virulence and pathogenicity regulation.This article provides a certain theoretical basis for further elucidating the molecular mechanism of YbiH to regulate the pathogenicity of Salmonella.