碩士 / 長庚大學 / 基礎醫學研究所 / 96 / The Gram-negative bacterium, Klebsiella pneumoniae (KP), is an opportunistic pathogen. In Taiwan, KP associated liver abscess has recently become an important emerging infectious disease. Our previous studies revealed that the KP strains isolated from diabetic patients with liver abscess exhibited greater virulence than that from urinary tract infection patients in mice survival test. We also found the capsule of liver abscess-causing KP contained prominent amount of fucose that was not found in urinary tract infection ( UTI ) strains. Our goal is to investigate the fucose synthesis genes, GDP-mannose-4,6-dehydratase (gmd) and GDP-4-keto-6-deoxymannose-3,5-epimerase-4-reductase (wcaG) in KP strains and their association with bacterial virulence. Our results identified both gmd and wcaG from two liver abscess strains and both showed the same DNA sequences as NTUH-K2044 KP strain expect one base difference in wcaG gene. Three other UTI strains were screened using polymerase chain reaction and Southern blotting hybridization and were shown to have no signal for these two enzyme in these strains. We found that these two genes were transcribed in these two liver abscess strains. The gmd and wcaG were cloned into expression vector and the expressed proteins were enzymatically active. The two liver abscess strains cultured in glucose were found not to enhance gmd and wcaG mRNA expression. We currently are trying to create a gmd-mutant KP strain by in vivo recombination. The virulence of the mutant KP will be examined in mice. The gmd and wcaG may play a role in KP liver infection and may serve as a marker for clinical identification.
| Identifer | oai:union.ndltd.org:TW/096CGU00325002 |
| Date | January 2007 |
| Creators | CHANG-HSIN YU, 張欣宇 |
| Contributors | June-Hsieh Wu, 謝絹珠 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 79 |
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