The "latent" RNase I of E. coli ribosomes is avtivated by polymyxins in media containing enough magnesium (10~4 to 1 0 3 M) to prevent RNase Iinduced autolysis of ribosomal RNA under normal conditions 2. On the other side RNase I-induced RNA depolymerization in membrane injured cells of E. coli is inhibited by polymyxin B in EDTA containing buffers 3. The following communication presents some m...

In a recent article, Garonzik et al. (4) importantly advanced our knowledge of the pharmacokinetics (PK) of colistin methanesulfonate (CMS) and the active drug that it forms, colistin. In their elegant population PK study of critically ill patients, the authors demonstrated that creatinine clearance (CLCR) significantly affects the total body clearance of CMS and colistin (4). It is important t...

The emergence of multidrug resistance among Acinetobacter baumannii is leading to an increasing dependence on the use of polymyxins as last-hope antibiotics. Here, we utilized genetic and biochemical methods to define the involvement of the pmrCAB operon in polymyxin resistance in this organism. Sequence analysis of 16 polymyxin B-resistant strains, including 6 spontaneous mutants derived from ...

The global emergence and dissemination of multidrug-resistant Gram-negative superbugs, particularly carbapenem-resistant Acinetobacter baumannii and Klebsiella pneumoniae, lead to the limited effectiveness of antibiotics for treating nosocomial infections. In most cases, polymyxins are the last resort therapy, and these antibiotics must be used intelligently to prolong their efficacy in clinica...

We sought to evaluate published evidence regarding clinical or microbiological outcomes related to the use of inhaled antibiotics other than aminoglycosides, polymyxins and aztreonam. A systematic search of PubMed and Scopus databases as well as bibliographies of eligible articles was performed. In total, 34 eligible studies were identified. Among several inhaled β-lactams, ceftazidime was used...