关键词: 无菌小鼠, 细菌检测, 培养法, PCR, 革兰染色镜检

Abstract: Objective To compare the detection effects of culture method, Gram stain microscopy and 16S rRNA PCR on bacterial detection in fecal samples of germ-free mice,provide a basis for the selection of germile murine bacteria detection method. Method The culture method, Gram stain microscopy and 16S rRNA PCR method were used to detect the feces of GF mice, the feces of SPF mice and the test samples with known bacterial content ( the feces of germ-free mice were mixed with Staphylococcus aureus and Escherichia coli, artificially made) , and the detection limits of the three method on bacteria in the feces of germ-free mice were verified. Three method were used to detect clinical samples at the same time, the advantages and disadvantages of the three detection method were compared, and the feasibility of the three method in actual detection was analyzed. Result The sensitivity of culture method, Gram stain microscopy and 16S rRNA PCR method was 10²CFU / g, 10⁸CFU / g and 10⁶CFU / g, respectively, and the positive rate of clinical samples was 1. 36% ( 6 / 441 ) . Conclusion Culture method, Gram staining microscopy and 16S rRNA PCR method have their own advantages and disadvantages, and they need to be used in combination to learn from each other ’ s strengths to ensure the reliability of the detection result.

Key words: germ-free mice, sterility test, cultivation method, PCR, gram staining microscopic examination