Coumarin (2H-1-Benzopyran-2-one) act against planktonic and biofilm forms of Staphylococcus aureus, Klebsiella pneumoniae and Pseudomonas aeruginosa

Introduction: biofilm-related infections caused by Staphylococcus aureus, Klebsi-ella pneumoniae and Pseudomonas aeruginosa are difficult to treat and few effective pharmacological options are currently available for this purpose. In this context, coumarin (2H-1-Benzopyran-2-one) has been reported to have antibacterial and antibiofilm activity, but this potential remains poorly understood. Aim: to investi-gate the action of coumarin on planktonic and biofilm forms of S. aureus, K. pneu-moniae and P. aeruginosa. Results: a minimum inhibitory concentration (MIC) of coumarin ranging from 256 to 1024 μg/mL was observed, with a remarkable ability to inhibit the formation of biofilms and to act on mature biofilms in concentrations close to MIC. Conclusion: coumarin has strong activity against planktonic and biofilm forms on the three species of great relevance in the clinical scenario. These results are interesting to enable a pharmacological alternative for the treatment of these infections.