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Etablierung eines Caenorhabditis elegans-Modells zur Virulenzanalyse von human- und tierpathogenen Bakterienspezies der Gattung Burkholderia
| Content Provider | Semantic Scholar |
|---|---|
| Author | Ebrecht, Doreen |
| Copyright Year | 2002 |
| Abstract | In 1999, FREDERICK M. AUSUBEL and co-workers developed an assay to examine the influence of bacteria on nematodes with regard to the pathogenesis of infections with Pseudomonas (P.) aeruginosa. This assay makes it possible to analyse the interactions between the virulence factors of bacteria and the defense mechanisms of the host. In this work, a Caenorhabditis (C.) elegans pathogenesis assay for Burkholderia (B.) pseudomallei, B. thailandensis and B. cepacia was successfully established. The killing kinetics of C. elegans proved to be fairly similar to the killing kinetics described in the P. aeruginosa- C. elegans model, which means, that it was possible to differentiate a ”slow”- from a ”fast killing” in all of the three species. By using B. cepacia it was able to demonstrate that during the ”slow killing” an accumulation, but no replication of the bacteria occurs in the intestinal tract of C. elegans. The comparison of the B. cepacia wildtype with a ”Quorum sensing”-negative cepR mutant revealed that ”Quorum sensing” is an important factor for the accumulation of bacteria and the death of the nematodes under ”slow killing” conditions. In contrast to the P. aeruginosa-C. elegans assay, the killing under ”fast killing” conditions involved the secretion of heat-labile exotoxins in all tested Burkholderia spp.. By using C. elegans mutants it became obvious that the “fast killing” most likely exerts its toxic effects by exposing C. elegans to oxidative stress. Furthermore, experimental conditions to differentiate virulent B. pseudomallei strains from avirulent B. thailandensis strains with a modified “fast killing” assay were set up. The observed differences in virulence correlate with the situation in the mammalian host. In conclusion, the results show that the conditions of culturing the bacteria have an important influence on the production of virulence factors by all Burkholderia spp. examined and so on their pathogenicity in the C. elegans assay. |
| File Format | PDF HTM / HTML |
| Alternate Webpage(s) | https://elib.tiho-hannover.de/servlets/MCRFileNodeServlet/etd_derivate_00002833/ebrechtd_2002.pdf |
| Language | English |
| Access Restriction | Open |
| Content Type | Text |
| Resource Type | Article |
