Pseudomonas aeruginosa killing of Caenorhabditis elegans used to identify P-aeruginosa virulence factors

We reported recently that the human opportunistic pathogen Pseudomonas aeru ginosa strain PA14 kills Caenorhabditis elegans and that many P. aeruginosa virulence factors (genes) required for maximum virulence in mouse patho ge nicity are also required for maximum killing of C. elegans. Here we report that among eight P. aeruginosa PA14 TnphoA mutants isolated that exhibited reduced killing of C. elegans, at least five also exhibited reduced virulen ce in mice. Three of the TnphoA mutants corresponded to the known virulence -related genes lasR, gacA, and lemA. Three of the mutants corresponded to k nown genes (aefA from Escherichia coli, psfP from Azotobacter vinelandii, a nd mtrR from Neisseria gonorrhoeae) that had not been shown previously to p lay a role in pathogenesis, and two of the mutants contained TnphoA inserte d into novel sequences. These data indicate that the killing of C, elegans by P. aeruginosa can be exploited to identify novel P, aeruginosa virulence factors important far mammalian pathogenesis.