title: Isolation and characterization of transposon-induced mutants of Pseudomonas aeruginosa deficient in production of exoenzyme S.
abstract: Exoenzyme S is an extracellular product of Pseudomonas aeruginosa. This enzyme catalyzes the transfer of ADP-ribose from NAD to a number of as yet unidentified eucaryotic proteins, but it is distinct from toxin A. To evaluate the role of exoenzyme S in the pathogenicity of P. aeruginosa, we isolated transposon-induced mutants of strain 388, a clinical isolate that produces exoenzyme S but no toxin A. The transposon Tn1 was introduced by using a temperature-sensitive derivative of plasmid RP1. A Tn1-induced mutant was found which had no detectable exoenzyme S activity or antigen in culture supernatants or in cell lysates. Except for its lack of exoenzyme S and resistance to carbenicillin, this mutant was indistinguishable from the parent strain. When tested in an experimental mouse burn infection model, this Tn1-induced mutant was reduced in virulence by at least 2,000-fold, suggesting a role for exoenzyme S in the virulence of this strain.
mesh_terms: D036002:ADP Ribose Transferases; D000818:Animals; D001427:Bacterial Toxins; D002056:Burns / Q000382:microbiology; D004251:DNA Transposable Elements; D004195:Disease Models, Animal; D051379:Mice; D008970:Molecular Weight; D009154:Mutation; D009713:Nucleotidyltransferases / Q000235:genetics*; D011065:Poly(ADP-ribose) Polymerases; D011550:Pseudomonas aeruginosa / Q000201:enzymology / Q000235:genetics* / Q000472:pathogenicity
chemical_list: D001427:Bacterial Toxins; D004251:DNA Transposable Elements; D036002:ADP Ribose Transferases; D011065:Poly(ADP-ribose) Polymerases; C444820:exoenzyme S; D009713:Nucleotidyltransferases