Effectiveness of menthol and folium menthae piperitae against Acinetobacter baumannii

Acinetobacter baumannii is a common Gram negative nosocomial pathogen. Although new agents have been developed against Gram positive microorganisms, there are few new antibacterial agents against Gram negative bacteria. In this environment, herbal medicine has become a flicker of hope. The purpose of this study was to investigate the antibacterial activity of menthol and folium menthae piperitae extract either alone or as a mixture against A. baumannii. A total of 20 multidrug resistant A. baumannii strains that had been isolated from hospitalized patients as nosocomial pathogens was used. The antibacterial activity of test materials was assessed by both quantitative suspension test and an agar well diffusion test. Menthol was found to be effective against A. baumannii. The mixture of menthol and folium menthae piperitae extract was also found to have antibacterial activity. However, folium menthae piperitae extract alone had no antibacterial activity against A. baumannii with a contact time of one minute, whereas it was effective with contact times greater than one minute. We conclude that topical form of menthol can be used for skin and soft tissue infections, burn wounds, diabetic foot infections and decubitus wound infections caused by A. baumannii.