The Study On Gene Function Of The Campylibacter Jejuni Involved In The Infection

The Campylobacter jejuni(C jejuni)is an enteropathogenic bacteria which exist widely in the food and environment and it can threat food safety and the human health.The infection of Cjejuni can cause inflammation in the intestinal tract,which can lead to the guillain-barre syndrome sometimes.Based on the high pathogenicity of the C.jejuni,we studied the function of the genes involved in the adhesion and invasion.In the infection process,the magnesium was inevitable for the C.jejuni.Therefore,we investigated the effect of growth and proteome expression in magnesium-tolerance condition.As the result showed that,when in the different concentration magnesium-tolerance condition(5 mg/mL,10 mg/mL and 20 mg/mL),the growth all delay,especially the concentration of the magnesium was 20 mg/mL.Compared with the concentration of the magnesium was 20 mg/mL,the surcival rate was more than which in the 10mg/mL magnesium-tolerance condition.And we choose this concentration for the next in vitro infection.The result of the in vitro infection showed that the relative infection rate in the magnesium-tolerance group was higher than the control.Then we used the Data Independent Acquisition(DIA)to study the differential protein expression of the C.jejuni in the magnesium-tolerance group and the control.The result showed that in the magnesium-tolerance group,25 proteins were up-regulated and 43 proteins were down-regulated.Most of them were connected with secreted toxin,the synthesis of flagella,oxidative stress and membrane protein.Based on the previous work in the laboratory,we chose four genes connected with the infection for the konckout,including the gene CJ7510 involved in the ABC-type lipoprotein export,the gene CJ6675 involved in the transcription termination or antitermination,the gene CJ7525 which can encode the membrane protein and the gene CJ3470 involved in the synthesisof the tryptophan.And based on the homologous recombination,we buided four deletion vectors and primarily performed the import for DNA fragment.There was no transformant.This study may promote the research of the pathogenic genes in C.jejuni.