Comparative in vitro antimicrobial activities of CSA-142 and CSA-192, second-generation ceragenins, with CSA-13 against various microorganisms.

Ceragenins, a novel family of antibiotics, are cationic derivatives of cholic acid and display broad-spectrum antimicrobial activities. Multiple ceragenins have been synthesized and studied, and most published data are with ceragenin CSA-13. This study aimed to investigate the in vitro antimicrobial properties of second-generation ceragenins, CSA-142 and CSA-192, and compare them to CSA-13. The antimicrobial activities of CSA-13, CSA-142 and CSA-192 were studied against 20 strains of Escherichia coli, Acinetobacter baumannii, Pseudomonas aeruginosa, Staphylococcus aureus and Candida albicans. Time-kill curve methods were performed to determine the bactericidal and fungicidal activities of the ceragenins against three strains of each microorganism. Overall, CSA-13 showed the lowest MIC values, but also CSA-142 and CSA-192 had good activities against tested microorganisms. The killing curves showed that ceragenins generally had bactericidal and fungicidal effects. The bactericidal and fungicidal behaviours of CSA-142 and CSA-192 may make them good alternative agents to CSA-13.