Salmonella Typhimurium Causes Metabolic Changes In Worms And Eggs Of Schistosoma Japonicum

Co-infection refers to the concurrent infection of two or more pathogens in the same host organism.Co-infection is widespread globally with about 1 billion people around the world at risk,Co-infection is estimated to be more prevalent than single infection.At present,there are few studies on co-infection,which mainly focused on HIV,HBV and other parasitic diseases.Schistosoma japonicum is one of the most prevalent parasites in China,mainly in the Yangtze River basin.Praziquantel,as a specific agent for pathogen treatment,has shown resistance to S.japonicum.It is an urgent scientific task to find new specific drugs before the Sjaponicum vaccine is developed.Salmonella typhimurium,as facultative anaerobe of intracellular bacteria,is the ideal carrier for vaccine research with its clear genetic background and mature development of virulence attenuated strains.Herein,this paper focused on the changes in the metabolism of adult worms and eggs of S.japonicum from mice co-infected with S.typhimurium and S.japonicum.In this thesis,an experimental animal model of co-infection was established using S.japonicum and S.typhimurium.After successful modeling,a series of symptoms of infection were detected,male worms,female worms,eggs in liver and feces of S.japonicum were collected,and the metabolic profiles of these samples were collected using nuclear magnetic resonance(NMR)technology.Subsequently multivariate statistical data analysis was applied to these data and metabolic effects of co-infection were extracted.In addition,the eggs of S japonicum were treated with different concentrations of itaconic acid for the first time.Finally,the enzyme-linked immunosorbent experiment was performed to determine the host immune changes.We found that itaconic acid can significantly reduce the hatching rate of S.japonicum eggs.the survival rate of the host was significantly improved,the number of adult worms and eggs of S.japonicum decreased significantly,the metabolites of adult worms and eggs of S.japonicum also significantly changed,and the immune polarization state of the host changed from Th2 to Th1 after co-infection.Compared to single infection,the sugar metabolism,lipid metabolism and amino acid metabolism of the adult and eggs of S.japonicum in the co-infection group have changed.The metabolic changes mainly manifested as an increase in glucose,glycine,glycogen and a decrease in lipid,pyruvate,glycoprotein,succinic acid in male adults.Glycogen in eggs obtained from feces increased with concurrent decrease in the levels of lactic acid,pyruvate,and leucine.Glucose,citric acid,and inositol in eggs collected from the liver of co-infected mice increased,while acetic acid,alanine,lipids,leucine,pyruvate,and succinic acid decreased.Interestingly,the metabolism of female schistosomes did not change after co-infection,which may imply that female worms were protected by male worm in the unique male-female worm pairing phenomenon of schistosome development.In addition,we observed the metabolic differences between eggs obtained from the liver and fecesIn conclusion,the study provided important information on metabolic interactions of co-infection and demonstrated that NMR-based metabonomics is an important tool to investigate metabolic consequences of co-infection.