In the mammalian innate immune response, the activation of NF-κB in the presence of a pathogen-generated signal is mediated by the interleukin-1 or TOLL receptors ( 1, 2). For example, in response to microbial infection, both mammals and insects use a conserved signal-transduction pathway to activate defense-related genes. Recently, a variety of observations suggest that some of the underlying mechanisms of defense against pathogens by plant, invertebrate, and mammalian hosts may be similar. The outcome of any particular interaction depends on the status of a coevolutionary “arms race” in which advances in pathogen virulence factors are overcome by counteradvances in host defense responses. Host–pathogen interactions are antagonistic relationships in which the success of each organism depends on its ability to overcome the other. elegans pathogenicity model that is genetically tractable from the perspectives of both host and pathogen can be used to model mammalian bacterial pathogenesis. aeruginosa factors required for pathogenicity in disparate eukaryotic hosts. elegans under both fast- and slow-killing conditions, indicating a high degree of commonalty among the P. Among 10 PA14 virulence-related mutants that had been shown previously to affect pathogenicity in plants and mice, 6 were less effective in killing C. Slow killing involves an infection-like process and correlates with the accumulation of PA14 within worm intestines. elegans, indicate that fast and slow killing occur by distinct mechanisms. Several lines of evidence, including the fact that heat-killed bacteria are still capable of fast but not slow killing of C. When PA14 is grown on high-osmolarity medium, killing occurs over the course of several hours and is referred to as “fast” killing. When PA14 is grown on minimal medium, killing occurs over the course of several days and is referred to as “slow” killing. elegans depends on the composition of the agar medium on which PA14 is grown. We show that a single clinical isolate of the human opportunistic pathogen Pseudomonas aeruginosa (strain PA14), which previously was shown to be pathogenic in mice and plants, also kills Caenorhabditis elegans.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |