In vitro activities of the cationic steroid antibiotics CSA-13, CSA-131, CSA-138, CSA-142, and CSA-192 against carbapenem-resistant pseudomonas aeruginosa

Abstract

Objectives: Pseudomonas aeruginosa is an important opportunistic pathogen that is difficult to treat because of the antibiotic resistance that has developed in recent years. Increasing carbapenem resistance has led to a rise in hospital infections caused by this bacterium. As a result, researchers have begun to search for new molecules. Ceragenins are the general name for membrane-acting cationic steroid antimicrobial molecules that have activity similar to that of antimicrobial peptides. In this study, we investigated the in vitro activities of the cationic steroid antibiotics (CSAs) CSA-13, CSA-131, CSA-138, CSA-142, CSA-192, and colistin on carbapenem-resistant Pseudomonas aeruginosa (CRPA). Materials and Methods: Minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs) were determined by broth dilution method. Results: The MIC50 (µg/mL) values of CSA-13, CSA-131, CSA-138, CSA-142, CSA-192, colistin, and meropenem were 8, 4, 8, 16, 32, 1, and 16, respectively. The MBC values were equal to or twice the MIC values. Conclusion: CSA-131 and CSA-138 appear to be good candidates for CRPA treatment. However, the lack of stability, efficacy, and pharmacokinetic properties of CSA requires further research in the future in vivo and in vitro.