Study On The Punction Of Genes Related To Dryness Resistance Of Cronobacter Sakazakii

Cronobacter sakazakii(C.sakazakii)belongs to Enterobacteriaceae,Cronobacter,Gram-negative bacteria,peripheral flagella,can move,spore-free,facultative anaerobic,is a class of opportunistic pathogens that can survive in human and animal intestines.Cronobacter sakazakii is widely found in the environment and food,and enters animals and human body through environmental contact and feeding.The infection of Cronobacter sakazakii may endanger the life of newborns,infants and young children,and also has strong pathogenicity to the elderly and adults with low immune function.At present,the research on the pathogenic mechanism and the important drying resistance factors of this bacterium is not perfect,so the purpose of this study is to study the mechanism related to the dryness resistance of C.sakazakii at gene and metabolic level.Three strains of C.sakazakii with strong and weak dryness resistance were selected for comparative genomics based on previous experiments on dryness resistance screening.These specific genes were found in dry-resistant strains,including helS,lacY,insF,trbL,which encode helicase,MFS transporter,lactospermease,putative transposase,? secretory system protein,etc.12 specific genes encoding unknown function and 1 specific gene encoding known function yeeJ protein,this gene encodes adhesin/invasionin.these genes are likely to have a great influence on the dryness tolerance of cronobacter sakazakii,may play an important role in cronobacter sakazakii,and can be farther studied in the following experiments.In this study,we used gene knockout technique and comparative metabolomics and comparative genomics to screen the drought tolerance related genes of C.sakazakii.The knockdown of SAKA 80417-1 ESA₀1519(nitrate transporter NarK)of C.sakazakii was first performed using knockdown.To verify the dryness resistance of wild-type,deletion-type and tonic-type strains after knock-out,we found that the deletion strains showed obvious dryness resistance and stronger resistance.L-the two metabolites of arginine and coumarin were up-regulated and down-regulated,the main pathways of differential metabolites enrichment were biosynthesis of antibiotics and biosynthesis of secondary metabolites the metabolites of arginine metabolism-related pathway and ABC transport metabolism-related pathway were significantly changed.the differential metabolites of purine metabolism and secondary metabolites biosynthesis pathway were the most,which may be related to the strong dryness the strain,which provided a clear direction for the later experimental research.This study laid a foundation for further understanding the mechanism of drying resistance of C.sakazakii,and provided some reference for the targeted control of C.sakazakii and the effective reduction of its contamination of grain and oil.