【Animal Modeling】-Distribution of Autofluorescent Microorganisms in Rat Intestine

  Objective: To investigate the distribution of autofluorescent microbes in the gut of rats at different developmental stages.

  Methods: The fluorescence detection technology of the Kinetics IVIS small animal in vivo imaging system was used to detect and evaluate the distribution of autofluorescent microorganisms in the intestinal tract of SD rats at different developmental stages. First, the standard strains of Escherichia coli cultured in vitro were subjected to fluorescence detection, and then the distribution positions of Escherichia coli were detected under the same detection conditions. The wavelength range of excitation light for fluorescence detection was expanded, and the fluorescence background from external fluorescent substances such as feed and feces was removed, and the distribution of autofluorescent microorganisms in the intestines of SD rats after birth was detected at 3, 14 and 60 days, respectively.

  Result: Escherichia coli can fluoresce in the excitation wavelength range of 485-535 nm. Escherichia coli was mainly distributed in the stomach and a small amount in the ileum in the intestinal system of SD rats on the 3rd day of birth; in the intestinal system of SD rats on the 14th day of life, it mainly distributed in the stomach and cecum, and a small amount in the ileum; The intestinal system of SD rats at 60 days was mainly distributed in the ileum, and a small amount was distributed in the jejunum, colon and cecum. After expanding the wavelength range of excitation light for fluorescence detection, autofluorescent microorganisms were mainly distributed in the ileum, followed by the stomach in the intestinal system of SD rats on day 3; The second is the cecum, and a small amount is distributed in the ileum and jejunum; it is distributed in the intestinal system of SD rats on the 60th day, mainly in the ileum and cecum.

  Conclusion: The use of fluorescence detection technology of small animal in vivo imaging system to detect autofluorescent gut microbes can help and guide the research on the distribution of gut microbes in the host's gut at different developmental stages. The study of the drug-drug relationship provides a certain basis.