Geraniol disrupts mature MRSA biofilms on venous catheters and shows synergistic activity with oxacillin against planktonic cells

Infections caused by methicillin-resistant Staphylococcus aureus (MRSA), particularly those associated with biofilms on invasive medical devices such as venous catheters, represent a significant public health challenge due to increased antimicrobial resistance. This study evaluated the anti-biofilm potential of geraniol, a natural monoterpene, against MRSA strains. In a catheter-based in vitro model, geraniol substantially inhibited initial biofilm formation and effectively disrupted pre-formed mature MRSA biofilms on catheter surfaces. Scanning electron microscopy (SEM) corroborated structural damage, revealing a marked reduction in bacterial density and the biofilm matrix. Notably, geraniol exhibited a synergistic interaction with oxacillin against planktonic cells in 53.8% of the tested MRSA strains, suggesting a potential to restore antibiotic efficacy. These findings highlight the promising in vitro activity of geraniol against MRSA biofilms on venous catheters and position it as an attractive candidate for further investigation as an anti-biofilm agent for medical device-related infections.