Resumo

Introduction: The volatility property of essential oils is an important feature of essential oils not found in other natural antimicrobial, making them important in studies in medical microbiology, especially with potential use in the gas phase (eg fumigation). The cytotoxicity and antimicrobial activity of essential oils have been mainly investigated in the procedures used in its liquid form. However, relatively little work has been done analyzing biological activities in its gaseous state. The aim of this research was investigate the antimicrobial activity of essential oils of tea tree (Melaleuca alternifolia), geranium (Perlagonium graveolens) and “palmarosa” (Cymbopogon martini) and their major constituents, terpineol, citronelol and geraniol, in the gas phase on numerous bacteria. Methods: Bacterial strains: S. aureus ATCC 25923, E. coli ATCC 43895, S. Enteretidis ATCC 13096, S. epidermidis ATCC 12228, E. faecalis ATCC 10100, P. aeruginosa ATCC 27853 and K. pneumoniae. Vapor Diffusion Assays: RODAC plates with 10 mL of Mueller Hinto Agar (MHA) was inoculated with 5 µL of the standardized bacterial suspension (105CFU/mL) of the each bacteria. A filter paper (10 x 1.7 cm) impregnated with dilutions of 750 and 1000 µg/cm³ air of each compound were placed with the trays without a lid Rodac within a Petri dish and which is sealed, incubated at 37°C/18-24h and subsequent bacterial count. Statistical analysis: ANOVA and Kruskal-Wallis; Mann-Whitney test. Results: There is no statistical difference in reducing the bacterial count between the two dilutions. There were no statistical differences between treatments with essential oils for each strain at both concentrations, but most of the strains showed greater sensitivity to tea tree and its major compound, terpineol. Conclusion: The tested compounds have potential for use in their volatile form for reduction of bacterial counts and for treatment by inhalation.