大鼠肠道自发荧光微生物的分布

目的 探讨不同发育阶段大鼠肠道自发荧光微生物在肠道内的分布。方法 采用Kinetics IVIS小动物活体成像系统的荧光检测技术对不同发育阶段SD大鼠肠道内自发荧光微生物在肠道内的分布位置进行检测和评估。先对体外培养的大肠杆菌标准菌株进行荧光检测，然后在同一检测条件下分别对大肠杆菌的分布位置进行检测。扩大荧光检测激发光波长范围，去除饲料和粪便等外来自发荧光物质的荧光背景，分别检测出生3、14 d和60 d的SD大鼠肠道内自发荧光微生物的分布。结果 大肠杆菌在485～535 nm激发波长范围内能发荧光。大肠杆菌在出生3 d的SD大鼠肠道系统中主要分布于胃，少量分布于回肠；在出生14 d的SD大鼠肠道系统中主要分布于胃和盲肠，少量分布于回肠；在出生60 d的SD大鼠肠道系统中主要分布于回肠内，少量分布于空肠、结肠和盲肠内。扩大荧光检测激发光波长范围后，自发荧光微生物在出生3 d的SD大鼠肠道系统中主要分布于回肠，其次是胃；在出生14 d的SD大鼠肠道系统中主要分布于胃，其次是盲肠，少量分布于回肠和空肠；在出生60 d的SD大鼠肠道系统中均有分布，主要分布于回肠和盲肠。结论 采用小动物活体成像系统荧光检测技术检测自发荧光肠道微生物，对研究肠道微生物在寄主不同发育阶段肠道内的分布有一定的帮助和指导作用，为肠道微生物与寄主和经胃肠道给药关系的研究提供一定的依据。

Distribution of autofluorescent microorganisms in the rat intestine

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 various 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 wavelength 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. coli 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. Conclusions 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.