Functional characterization of the novel fimbriae in Klebsiella pneumoniae NTUH-K2044
| Autor: | Teng-Kuei Huang, 黃登魁 |
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| Rok vydání: | 2007 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 95 Fimbrial adhesin is an important bacterial virulence factor which affects the adherence specificity to host tissues. In the genome of Klebsiella pneumoniae NTUH-K2044, we found nine fimbrial gene cluters including fim, mrk, and seven novel fimbrial operons, namely kpa, kpb, kpc, kpd, kpe, kpf, and kpg. These fimbrial gene clusters were cloned into the expression plasmid pET30b and then transformed to an afimbriated E. coli. Expression of the major pilin of the recombinant kpa, kpb or kpe fimbriae could be detected by SDS-PAGE analysis. Moreover, the kpa fimbriae appeared to conferr the bacteria an adherence ability to HCT-8 cell and also biofilm formation capability. The adhesin protein at the tip of fimbriae is a major determinant of the adhesion specificity. To investigate the presence of specific adhesion activity, the mrkD adhesin gene of the established type 3 fimbriae expression system was replaced respectively by each of the fimbrial adhesins. Transmission electron microscopy and western blot analysis revealed that most of the recombinant type 3 fimbriae expressed and assembled properly. The hemagglutination (HA) activity assay indicated that the recombinant KpfD could bind to erythrocytes of guinea pig and rabbit. Different binding activity levels of the recombinant adhesins KpaE, KpbD, KpdD and KpgD to rabbit erythrocytes were also demonstrated. Moreover, the HA activity of KpfD to guinea pig erythrocytes was found to be inhibited by 0.5 mM mannose. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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