Genomic Heterogeneity in Klebsiella pneumoniae Strains Is Associated with Primary Pyogenic Liver Abscess and Metastatic Infections
| Autor: | Li-Chen Ma, 馬立珍 |
|---|---|
| Rok vydání: | 2005 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 93 Primary pyogenic liver abscess (PLA) with septic complication by Klebsiella pneumoniae is an emerging infectious disease. Using DNA microarray hybridization, we identified a 20-kb chromosomal region that contained 15 open-reading frames (ORFs), including an iron-uptake system (kfu), a phosphoenolpyruvate sugar phosphotransferase system (PTS), and 6 unknown ORFs. The region was more prevalent among tissue-invasive strains (35/46) than among noninvasive strains (19/98) (p＜0.0001, Chi-Square test). To test the role played by this region in pathogenesis, 3 different deletion mutants (NTUH-K2044 [Δkfu], K2044 [ΔORF7–9], and K2044 [ΔPTS]) were constructed. Only the ΔkfuABC mutants showed decreased virulence in mice, compared with the wild-type strain. An in vitro assay confirmed the involvement of kfu in iron acquisition. There was a high correlation rate (85%) between the kfu/PTS region and 2 tissue invasion–associated chromosomal regions (allS and magA). Moreover, all 3 regions were present in strains that caused PLA plus endophthalmitis or meningitis. Our results suggest that chromosomal heterogeneity is present in tissue-invasive K. pneumoniae strains. A genotype containing all 3 regions is strongly associated with PLA and metastatic infection. These regions may serve as convenient markers for the rapid diagnosis of emergent tissue-invasive strains. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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