Outer membrane permeability in Pseudomonas aeruginosa: comparison of a wild-type with an antibiotic-supersusceptible mutant

• DOI: 10.1128/aac.21.2.299
• Publication Date: 2012-06-28T00:03:40Z
• Authors: B L Angus; A M Carey; D A Caron; A M Kropinski; R E Hancock
• Keywords: Porin; Benzylpenicillin; Membrane permeability

The Pseudomonas aeruginosa mutant Z61 has been shown to be highly supersusceptible a wide range of antibiotics, including beta-lactams, aminoglycosides, rifampin, tetracycline, and chloramphenicol (W. Zimmerman, Int. J. Clin. Pharmacol. Biopharm. 17:131-134, 1979). Spontaneous revertants were isolated, using gentamicin or carbenicillin as selective agents, have two patterns susceptibility group 12 antibiotics. Partial had 2- 10-fold greater resistance these antibiotics than Z61, whereas full antibiotic susceptibilities indistinguishable from those the wild-type strain K799, which derived. Uptake chromogenic beta-lactam nitrocefin was studied in both uninduced induced cells all strains by measuring steady-state rate hydrolysis inducible, periplasmic beta-lactamase whole broken cells. This demonstrated that outer membrane permeability decreased increased series partial revertants, wild type, revertants. data consistent with idea low being caused proportion open functional porins reason for high natural P, strains. In addition, it observed levels benzylpenicillin below minimal inhibitory concentration failed induce production. possibility this related increase is discussed. Preliminary evidence presented pore-forming porin protein F not altered Z61.