Caenorhabditis elegans is a model host for Salmonella typhimurium

The idea of using simple, genetically tractable host organisms to study the virulence mechanisms of pathogens dates back at least to the work of Darmo n and Depraitere [1]. They proposed using the predatory amoeba Dictyosteliu m discoideum as a model host, an approach that has proved to be valid in th e case of the intracellular pathogen Legionella pneumophila [2]. Research f rom the Ausubel laboratory has clearly established the nematode Caenorhabdi tis elegans as an attractive model host for the study of Pseudomonas aerugi nosa pathogenesis [3]. P. aeruginosa is a bacterium that is capable of infe cting plants, insects and mammals. Other pathogens with a similarly broad h ost range have also been shown to infect C. elegans [3,4]. Nevertheless, th e need to determine the universality of C. elegans as a model host, especia lly with regards pathogens that have a naturally restricted host specificit y, has rightly been expressed [5]. We report here that the enterobacterium Salmonella typhimurium, generally considered to be a highly adapted pathoge n with a narrow range of target hosts [6], is capable of infecting and kill ing C. elegans. Furthermore, mutant strains that exhibit a reduced virulenc e in mammals were also attenuated for their virulence in C. elegans, showin g that the nematode may constitute a useful model system for the study of t his important human pathogen.