목적: Methicillin-resistant Staphylococcus aureus (MRSA) biofilms on tympanostomy tubes are a major cause of persistent and refractory post- tympanostomy tube otorrhea (PTTO). This study investigated the in vitro antibacterial and antibiofilm effects of multifungin against MRSA associated with tympanostomy tubes. 방법:The antibacterial and antibiofilm activities of multifungin were evaluated using MRSA biofilms through bacterial growth inhibition assays, adhesion assays, biofilm formation and eradication assays, biofilm hydrolytic activity assays, and wheat germ agglutinin (WGA) fluorescence analysis. In addition, the antibiofilm efficacy of varying concentrations of multifungin against MRSA biofilms formed on tympanostomy tubes was assessed using scanning electron microscopy. 결과:Multifungin exhibited potent antibacterial activity against MRSA, with a minimum inhibitory concentration of 1.0 µM. Multifungin significantly inhibited MRSA biofilm formation and effectively reduced bacterial adhesion in a concentration-dependent manner. In preformed mature MRSA biofilms, multifungin enhanced biofilm eradication, reduced metabolic activity as shown by decreased fluorescein diacetate hydrolysis and ATP levels, and markedly decreased residual biofilm biomass. Multifungin also disrupted the MRSA biofilm extracellular polymeric matrix, demonstrated by reduced WGA fluorescence intensity. Scanning electron microscopy revealed substantial, concentration- dependent reductions in MRSA biofilms and bacterial colonies on tympanostomy tube surfaces following multifungin treatment. 결론:Multifungin demonstrated strong antibacterial, antibiofilm, and biofilm-eradication activities against MRSA, including biofilms formed on tympanostomy tubes. These findings indicate that multifungin has significant potential as a repurposed antimicrobial agent for treating PTTO caused by MRSA infection and biofilm formation.