Biological diversity arises among genetically equal subpopulations in the same environment, a phenomenon called phenotypic heterogeneity. The life cycle of the enteric bacterium Photorhabdus luminescens involves a symbiotic interaction with nematodes as well as a pathogenic association with insect larvae. P. luminescens exists in two distinct phenotypic forms designated as primary (1°) and seco...

Pseudomonas aeruginosa ExoU, a type III secretory toxin and major virulence factor with patatin-like phospholipase activity, is responsible for acute lung injury and sepsis in immunocompromised patients. Through use of a recently updated bacterial genome database, protein sequences predicted to be homologous to Ps. aeruginosa ExoU were identified in 17 other Pseudomonas species (Ps. fluorescens...

Current sequence databases now contain numerous whole genome sequences of pathogenic bacteria. However, many of the predicted genes lack any functional annotation. We describe an assumption-free approach, Rapid Virulence Annotation (RVA), for the high-throughput parallel screening of genomic libraries against four different taxa: insects, nematodes, amoeba, and mammalian macrophages. These host...

Three Gram-stain-negative, rod-shaped, non-spore-forming bacteria, BA1 T , Q614 and PB68.1 isolated from the digestive system of Heterorhabditis entomopathogenic nematodes, were biochemically molecularly characterized to clarify their taxonomic affiliations. The 16S rRNA gene sequences these strains suggest that they belong Gammaproteobacteria, family Morganellacea genus Photorhabdus . Deeper a...

Three Gram-stain-negative, rod-shaped, non-spore-forming bacteria, BA1 T , Q614 and PB68.1 isolated from the digestive system of Heterorhabditis entomopathogenic nematodes, were biochemically molecularly characterized to clarify their taxonomic affiliations. The 16S rRNA gene sequences these strains suggest that they belong Gammaproteobacteria, family Morganellacea genus Photorhabdus . Deeper a...

Photorhabdus luminescens is a symbiont of entomopathogenic nematodes. Analysis of the genome sequence of this organism revealed a homologue of PhoP-PhoQ, a two-component system associated with virulence in intracellular bacterial pathogens. This organism was shown to respond to the availability of environmental magnesium. A mutant with a knockout mutation in the regulatory component of this sys...

A recombinant Escherichia coli K-12 strain, transformed with a modified bacterial luciferase gene (luxABCDE) from Photorhabdus luminescens, was constructed in order to monitor the activity of various antimicrobial agents on a real-time basis. This E. coli-lux emitted, without any addition of substrate, constitutive bioluminescence (BL), which correlated to the number of viable bacterial cells. ...

A proteolytic enzyme, Php-B ( Photorhabdus protease B), was purified from the entomopathogenic bacterium, Photorhabdus luminescens. The enzyme is intracellular, and its molecular mass is 74 kDa. Tested on various peptide and oligopeptide substrates, Php-B hydrolysed only oligopeptides, with significant activity against bradykinin and a 2-furylacryloyl-blocked peptide, Fua-LGPA (2-furylacryloyl-...