| Summary: | 碩士 === 東吳大學 === 微生物學系 === 100 === “Viable but non-culturable” (VBNC) represents a state that cells are dormant and can not be cultured by standard growth media. The gram-negative bacteria can be induced to enter the VBNC state by starvation, cultured at low temperature, in high salinity, or in different pH. Many of human pathogenic bacteria can enter into the VBNC state, and retain their virulence during the state. This phenomena causes the blind spot in quarantine. In this paper, we investigate one of the human pathogens - the Vibrio cholera O139 which causing the cholera. In this study, we analyzed the differences among the cells in late log phase, in the progress of starvation-to-death, in the process of induction into VBNC state, and in BVNC state at RNA level by electrophoresis and Northern blot. Besides, specific expression primers were designed and RT-PCR was employed to analyse these 8 rrn operons expression patterns among the cells in late log phase, in the progress of starvation-to death, in the process of induction into VBCN state, and in VBNC state. According to the analysis result, we found that rrn a , rrn c, rrn f, rrn b and rrn b operons were constitutively expressed in the cells in late log phase, in the progress of starvation-to-death, in the process of induction into VBNC state, and in VBNC state. On the contrary, the rrn g operon was expressed in the late log phase and in starvation-to-death, but not in VBNC state. The expression pattern of rrn d, rrn e could not be verified in this study, because the lack of the proper specific expression patterns for these operons.
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