Distribution of autofluorescent microorganisms in the rat intestine / 中国实验动物学报

ABSTRACT

Objective To study the distribution of intestinal autofluorescent microorganisms in the rat intestine at different developmental stages. Methods The distribution of intestinal autofluorescent microorganisms in rat intestine at va-rious developmental stages was tested and evaluated using a small animals living imaging system. First, standard E. coli strain was tested by fluorescence detection in vitro. Then, the distribution of E. coli under the same test conditions was tested. The intestinal autofluorescent bacteria distribution was detected in the SD rats at 3 days,14 days and 60 days of age. After expanding the range of excitation wavelength fluorescence detection,removing the background of fluorescence feed and feces and other foreign autofluorescent substances. Results E. coli can be excited in the range of 485 -535 nm wave?length and to emit fluorescence. E. coli mainly existed in the stomach and only a few E. coli were found in the ileum of 3?days old SD rat. . In the 14?days old rats, E. coli mainly existed in the stomach and cecum, and only a few E. coli were found in the ileum. In the 60-days old SD rats, E. coli mainly existed in the ileum, and only a few E. coli were found in the colon, cecum and jejunum. After the expansion of the excitation light wavelength range of fluorescence detection, E. co?li were observed mainly in the ileum, and only a few E. coli were found in the stomach in 3?days old SD rat. E. coli mainly existed in the stomach, then the cecum and only a few E. coli were found in the ileum and jejunum in 14-days old SD rats. E. coli could be found in the whole intestinal system but mainly in the ileum and cecumin of the 60-days old rats. Conclu?sions Examining the intestinal autofluorescent microbes with the small animal in vivo imaging system can be helpful and make guidance to study the distribution of intestinal microbes in the host at different developmental stages, and to provide a basis for studying the relationship of intestinal microbes with its host and the gastrointestinal drug administration.