Mapping and Characterization of Two Mutations to Antibiotic Supersusceptibility in Pseudomonas aeruginosa

Publisher Website
Google Scholar
Abstract
Two mutations associated with antibiotic supersusceptibility in Pseudomonas aeruginosa strain Z61 were transferred separtely into strain PA O222, using R68.=45-mediated conjugation and phage F116L transduction. One mutation (absA) was 40% contransducible with pro-82 at 26 min on the P. aeruginosa chromosome and was associated with increased susceptibility to .beta.-lactams, gentamicin and hydropholic agents. Strains carrying the absA mutation also displayed enhanced uptake of a hydrophobic fluorescent probe, 1-N-phenylnaphthylamine, and were found, by SDS-PAGE, to be altered in the pattern of lipopolysaccharide O-antigen distribution. The other mutation (absB), associated with increased susceptibility to .beta.-lactams and gentamicin but not to hydrophobic agents, was cotransducible with met-28 and proC at 20 min on the chromosome. The absB mutation caused a structurally undefined alteration in the physical interaction of EDTA and gentamicin with the outer membrane.