| Summary: | 碩士 === 國立臺灣大學 === 醫學檢驗暨生物技術學研究所 === 102 === Proteus mirabilis, a facultative Gram-negative bacterium, is a common cause of catheter-associated urinary tract infections. Recently studies have showed that P. mirabilis can form biofilm on catheter leading to blockage of catheter and cause severe infections. There has been a report that mannose-resistant proteus like (MR/P) fimbriae contributes P. mirabilisbiofilm formation. However, the genes and its mechanisms in P. mirabilisbiofilm formation remain unclear. In previous study, we have showed that mrp operon was regulated by Cpx pathway. In this study, we constructedzapD- mutant by transposon mutagenesis. Data from biofilm formation test demonstrated that, in the absence of zapD, P. mirabilisbiofilm formation dramatically decreased. Further, we also found thatthe expression of MR/P fimbriae and cpxAR gene expression significantly decreased in zapD mutant. Besides, we revealed that zapA, an upstream gene of zapD, was directly regulated by CpxR by use of reporter assay and EMSA. In sum, this study shows that zapD plays an important role in P. mirabilisbiofilm formation involving in Cpx pathway which can impair mrp operon expression. Moreover, we also show that zapD has an influence on its upstream gene, zapA, which contains CpxR-binding site on its promoter and directly regulated by Cpx pathway.&;#8195;
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