Isolation,culture And Identification Of Specific Intestinal Bacteria Associated With Colorectal Cancer

Objective:Colorectal cancer is a malignant tumor of the digestive system with an increasing incidence and has been troubling human beings for a long time.If it can be detected and treated early,its 5-year survival rate can be significantly improved.Early colorectal cancer lacks specific clinical symptoms,and the existing screening methods includes:fecal immunochemistry test,fecal occult blood test,colonoscopy,CT colon imaging,etc.,but each has its own defects.In recent years,with the development of high-throughput sequencing technology,more and more studies have shown that intestinal microorganisms are involved in the occurrence and development of colorectal cancer.The relationship between specific bacteria and the development of CRC has been reported continuously.Intestinal microorganisms are involved in the occurrence and development of colorectal cancer,showing great potential in early diagnosis and early treatment of CRC,but the types,mechanism of action and diagnostic value of key strains remain to be further studied.The aim of this study was to combine 16S rDNA high-throughput sequencing technology with the classical bacteria line isolation and culture method,to find specific strains related to the occurrence and development of CRC,and to explore its correlation with the occurrence and development of colorectal cancer through in vitro cell function study.Methods:1.Through 16S rDNA high-throughput sequencing technologies,analyzed taking colorectal cancer patients and healthy people intestinal flora structure difference,appraisal to a lot of colorectal cancer related to specific species and OTUs.2.According to the result of sequencing design selective medium,using the classic crossed way of cultivation of microorganism,are in conformity with the previous sequencing results of strain as target strain.3.The effects of the target strain on the proliferation,migration and invasion of SW480 cells were detected by CCK8,EDU and Transwell experiments respectively.Results:1.Through 16S rDNA sequencing analysis of fecal samples from colorectal cancer patients and healthy people,it was found that there were significant differences in intestinal microbial composition between CRC patients and healthy people,and some bacteria genera with significant differences were found.2.Multiple strains associated with colorectal cancer were purified,isolated and identified,and a potential target strain(Veillonella sp.CP-25)that may be related to the occurrence and development of CRC was selected.3.It was further verified that Veillonella CP-25 could significantly promote the proliferation and invasion ability of SW480 cells.Conclusion:The changes of intestinal flora are closely related to the development of colorectal cancer,and specific bacteria may play a significant role.A colorectal cancerrelated strain Veillonella sp.CP-25 was isolated and purified from the feces of colorectal cancer patients.Veillonella sp.CP-25 promotes the occurrence and development of colorectal cancer.