碩士 / 國立清華大學 / 分子與細胞生物研究所 / 92 / Helicobacter pylori is a Gram-negative microaerophilic bacterium and is an etiologic agent for gastric diseases such as gastric ulcer, gastric cancer, and duodenal ulcer. H. pylori was reported to form communities of surface-adherent organism embedded in an extracellular matrix, or biofilm that is water-insoluble and HCl-resistant. By scanning electron micrographs, our laboratory has observed how individual, spiral bacteria attached onto solid surfaces and progressively developed into a matrix with bacteria, characteristics of other bacterial biofilm. We also found that the thicker biofilm accretions were associated with lower antibiotic penetration rate. As alginate has been shown to be the main extracellular component in Pseudomonas aeruginosa biofilms, this study was aimed to investigate the roles of three alginate biosynthesis related genes (algA, algC, and algI) of H. pylori in the biofilm formation. Other putative proteins related to biofilm formation were identified by proteomic approach. By scanning electronic microscope, we found that the surface structures of algA-, algC-, or algI- biofilms were more smooth, particularly for algC-. There were higher biofilm-adherent cells for algA- and algC- than those for the wildtype strain, while no significant difference was found for algI-. The antibiotic penetration of algA-, algC-, and algI-, respectively, was nevertheless lower than that of the wildtype strain in the biofilm form. Moreover, the susceptibilities of algA- and algI- strains to clarithromycin altered from sensitive to resistant, while that of algC- strain remained the same. These results thus collectively suggest that AlgA, AlgC, and AlgI participate in the formation of the extracellular matrix of H. pylori biofilms and that the knock-out mutation of algA and algC influenced the clarithromycin susceptibility. Finally, forty clones were identified to express differentially between planktonic and biofilm cells by proteomic analysis. These proteins might associate with the regulation or formation of H.pylori biofilms.
| Identifer | oai:union.ndltd.org:TW/092NTHU5061011 |
| Date | January 2004 |
| Creators | Yi-Ling Wu, 吳宜玲 |
| Contributors | Wen-Ching Wang, 王雯靜 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 54 |
Page generated in 0.0088 seconds