| Summary: | 碩士 === 國立臺灣大學 === 生化科學研究所 === 97 === H. pylori can induce duodenal ulcers, gastric ulcers, chronic gastritis, and gastric carcinoma. The eradication of H. pylori can be difficult, usually requiring a multi-drug regimen and a lengthy treatment period. Despite antimicrobial therapy, 10–20% of infections manage to persist. The persistency of H. pylori infection may due to be associated with the biofilm formation. The biofilm protects the bacteria from host immunological defense as well as antibiotic killing. In this study, our purpose was to identify the composition of the biofilm, especially in polysaccharides and proteins. The biofilm matrix mainly included exopolysaccharides and proteins. The exopolysaccharide produced by H. pylori was found to be composed of mannose, glucose and galactose. For four-day liquid culture, mannose was the major component, and galactose and glucose as minor components (80:7:13%). For seven day liquid culture, the ratios of galactose and glucose increased. (15.5%:16.5%). The protein components of biofilm matrix for four and seven day cultures were analyzed and identified by SDS-PAGE and MALDI-Q-TOF-MS/MS, repectively. Those proteins included urease subunit beta, 60 kDa chaperonin, catalase, citrate synthase, urease subunit alpha, probable peroxiredoxin, ferritin, neutrophil-activating protein A. The urease activity experiment showed that the biofilm cell has stronger urease activity than planktonic cell. In addition, H pylori treated with urease inhibitor AHA attenuated the biofilm formation. Nevertheless, the napA mutant strain can still develop biofilm, but not easy to form microcolony in early stage of biofilm life cycle. Its role in biofilm formation was predicted to be associated with cell-cell interaction.
The 16 rRNA of Meiothermus taiwanensis WR-220-R and Meiothermus taiwanensis WR-220-W showed 99.8 % similarity. They both form filamentous morphology. The difference of cell morphology was that M. taiwanensis WR-220-R produce red pigment, but M. taiwanensis WR-220-W dose not. From the growth curve, M. taiwanensis WR-220-R and M. taiwanensis WR-220-W both could grow in 55℃ and 65 ℃. The major difference between them was decreased the growth intensity in M. taiwanensis WR-220-W. In the analysis of lipid composition the results showed that iso- and anteiso-branched fatty acids were predominant in the composition of fatty acids. Moreover, the ratios of iso- to anteiso-branched fatty acids increased with higher culture temperatures. The straight-chain fatty acids represented a minor constituent of fatty acids. The major fatty acids between them were iso-C15:0, iso-C17:0, anteiso-C15:0, and anteiso-C17:0. However, M. taiwanensis WR-220-W have higher ratio of normal-C16:0、normal-C18:1 and normal-C18:0. The different protein expression between them was identified by 2-DE and MALTI-Q-TOF. The higher expressed proteins in M. taiwanensis WR-220-R are chaperonin GroEL、elongation factor Tu、trigger factor、enolase、FeS assembly ATPase SufC、DNA-directed RNA polymerase subunit beta、proabable transaldolase、30S ribosomal protein S、inorganic pyrophosphatase and DNA-directed RNA polymerase subunit omega. The higher expressed protein in Meiothermus taiwanensis WR-220-W are chaperonin GroEL、elongation factor Tu、Candida agglutinin-like protein (ALS) and deoxyhypusine synthase.
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