Prelimary Research On Metabolomics Of Salmonella Typhimurium Carrying Resistance Plasmids

Salmonellosisis a viral zoonosis that affects animals but also infect humans.The widespread of drug resistant have become serious threatens tothehumanandanimals.The mechanism study of drug-resistant Salmonella has been done more in molecular biology,however there is little research concerning the adaptability of Salmonella carrying resistance plasmids that regulated metabolic expression to improve the survivability in different environment.To investigate the complex mechanism of Salmonella that carrying resistance plasmids,a epidemic plasmid in Salmonella which named p HXY0908 was obtained by previous study,the plasmid was transformed into Salmonella Typhimurium standard strain ATCC14028(strain A)by electro transformation,the Salmonella Typhimurium carrying resistance plasmid p HXY0908(stain J)was obtained.The tigecycline-resistant(MIC=8?g/m L)Salmonella Typhimurium carrying resistance plasmid p HXY0908(strain R),was induced in the Salmonella Typhimurium carrying resistance plasmid p HXY0908 in vitro by progressive concentrations of Tigecycline.Gas chromatography mass spectrometry(GC-MS)has been used to investigate the metabolomics change in different growth stage among above three strains.According to the principal component analysis(PCA),there is a difference in metabolomics of Salmonella Typhimurium in different stage of growth.In the analysis of orthogonal projections to latent structures discriminant analysis(OPLS-DA),a loading plot was constructed,which showed the contribution of variables to difference between two groups.It also showed the important variables which were situated far from the origin.To refine this analysis,the first principal component of variable importance projection(VIP)was obtained.The VIP values exceeding 1.0 were first selected as changed metabolites.The remaining variables were then assessed by Student's T test(P<0.05),variables were discarded between two comparison groups.The results show that there were significant differences among variant metabolites and among metabolic pathways in different strains.By comparing the metabolic abundance among Salmonella Typhimurium standard strain ATCC14028(strain A),Salmonella Typhimurium carrying resistance plasmid p HXY0908(stain J)and tigecycline-resistant(MIC=8?g/m L)Salmonella Typhimurium carrying resistance plasmid p HXY0908(strain R),and found that strains J and R show up regulated metabolomics.Further analysis identified that Salmonella Typhimurium carrying resistance plasmid was correlation to the metabolic difference.According to the enriched metabolic pathways in different strains,ABC transporters,pyrimidine metabolism,glutathione metabolism,beta-alanine metabolism,arginine and proline metabolism,alanine,aspartate and glutamate metabolism are significant important pathway in above three strains,especially ABC transporters and Pyrimidine metabolism.The result of combination of metabolic pathway enrichment and variant metabolites in different metabolic pathways indicatedthat L-Aspartic acid was closely correlated with varied pathways.In summary,we use metabolomics to investigate the relationship among Salmonella Typhimurium standard strain ATCC14028,Salmonella Typhimurium carrying resistance plasmid p HXY0908 and tigecycline-resistant(MIC=8?g/m L)Salmonella Typhimurium carrying resistance plasmid p HXY0908,analyzed the characteristics of each metabolomics,we found an important variable metabolite L-Aspartic acid.In order to provides fundamental base for the further research on the adaptability of Salmonella carrying resistance plasmids.