Effects Of Mitochondrial Defects On Intestinal Tract And Intestinal Flora Microecology Of Mice Infected With Candida Albicans

Objective:This study aimed to investigate the virulence and immunity of mitochondrial deficiency strain of Candida albicans in intestinal tract of mice and its effect on microecology of normal intestinal flora.Methods:The mice were randomly divided into five groups(10 mice in each group),the group A,group B,group C,group D and group E and they were given the same amount of C.albicans(ATCC5314)?C.albicans(Agoa31)?C.albicans(?nuo1)?C.albicans(Anuo2)?C.albicans(?ndh51)separately by gavage.All mice were given antibiotic(tetracycline,streptomycin,gentamicin)solution 3 days before and during the experiment.Feces were collected on day 1,3,6,9,12,15,18 and 21 after gavage for counting.Colon tissues were collected after mice were sacrificed by cervical dislocation on the 1st,3rd,7th and 15th days after gavage,and histopathological changes and inflammation in the intestinal tract of each group were compared by histopathological sections and real-time fluorescence quantitative PCR.The grouping and treatment of intestinal microecological experiment were the same as above.The difference was that the mice were given sterile water before and during the experiment.Mouse feces were collected on the first day after gavage and every other two days,and then the feces were sent to the company to extract RNA for high-throughput sequencing of 16srRNA gene,to detect the influence of candida albicans standard strain and mitochondrial defective strain on intestinal flora microecology.Result:(1)Mouse fecal colony count results were as follows:group A(ATCC5314)>group D(?nuo2)>group C(?nuo1)>group B(?goa31)>group E(?ndh51).The peak of colony count in group B,C,D and E occurred on day 6 and the colony count peak less than 10 ^ 2 group A(P<0.05).The fecal colony count of mice gradually decreased with time,and no Candida albicans growth was observed in fecal culture of group B and group E after 9 days of gavage.(2)Real-time fluorescence quantitative PCR results showed that compared with the blank group(NC group),intestinal mucosal inflammatory factors such as IL-17,IFN-y,IL-22and TNF in group A all increased significantly one week after candida albicans(ATCC5314)infection(P<0.05),while no significant changes were observed in group B,C,D and E.(3)The results of histopathology showed that the infiltration of lymphocytes in intestinal mucosa of mice in group A was significantly increased and intestinal villi were destroyed,while the intestinal mucosa of mice in the other four groups showed no infiltration of inflammatory cells.There were more pseudomycelia and spores could be seen in the intestinal mucosa of mice in group A and some of which were embedded in the intestinal epithelial cells.However,no pseudomycelia and spores were found in the intestinal mucosa of the other four groups.(4)Intestinal microecological results showed that the most abundant microflora in the colon of mice were bacteroidetes and firmicutes.Shannon index and Simpson index increased significantly on the third day after gavage compared with that before gavage.The relative abundance of four bacterial groups was significantly increased in the colon microflora of mice in group D3,namely Alistipes SPP.,Bacteroides_acidifaciens app,Bacteroidaceae app,and Bacteroides app.Conclusion1.In this experiment,we preliminarily confirmed that compared with the wild Candida albicans strain,the ability of the four albicans defective strains to infect the intestinal tract was significantly decreased,which was manifested as?nuo2>?nuol>?ndh51>Agoa31.These results suggest that during the process of intestinal infection,the hypha formation ability,virulence and metabolic changes caused by mitochondrial functional defects in four defective candida albicans strains lead to a significant decline in the ability to infect the intestinal tract of mice.2.The intestinal flora abundance of mice was increased gavage of albicans,but the changes in intestinal microecology were temporary.The microecological balance of intestinal flora returned to normal two weeks after the end of gavage,and the microflora playing an important role might be bacteroides.