Intrinsic Resistance to Inhibitors of Fatty Acid Biosynthesis in Pseudomonas aeruginosa Is Due to Efflux: Application of a Novel Technique for Generation of Unmarked Chromosomal Mutations for the Study of Efflux Systems

Many strains of Pseudomonas aeruginosa are resistant to the antibiotics cerulenin and thiolactomycin, potent inhibitors of bacterial fatty acid biosynthesis. A novel yeast Flp recombinase-based technique was used to isolate an unmarked mexAB-oprM deletion encoding an efflux system mediating resistance to multiple antibiotics in P. aeruginosa . The experiments showed that the MexAB-OprM system is responsible for the intrinsic resistance of this...