title: Antimicrobial activity of essential oils against Staphylococcus aureus biofilms.
abstract: The present study was aimed to evaluate the potential of essential oils to remove the foodborne pathogen Staphylococcus aureus from food-processing facilities. The effectiveness of 19 essential oils against planktonic cells of S. aureus was firstly assessed by minimal inhibitory concentration. Planktonic cells showed a wide variability in resistance to essential oils, with thyme oil as the most effective, followed by lemongrass oil and then vetiver oil. The eight essential oils most effective against planktonic cells were subsequently tested against 48-h-old biofilms formed on stainless steel. All essential oils reduced significantly (p < 0.01) the number of viable biofilm cells, but none of them could remove biofilms completely. Thyme and patchouli oils were the most effective, but high concentrations were needed to achieve logarithmic reductions over 4 log CFU/cm(2) after 30 min exposure. Alternatively, the use of sub-lethal doses of thyme oil allowed to slow down biofilm formation and to enhance the efficiency of thyme oil and benzalkonium chloride against biofilms. However, some cellular adaptation to thyme oil was detected. Therefore, essential oil-based treatments should be based on the rotation and combination of different essential oils or with other biocides to prevent the emergence of antimicrobial-resistant strains.
authors.affiliation: Seafood Microbiology and Technology Section, Marine Research Institute (IIM), Spanish National Research Council (CSIC), Vigo, Spain.
authors.forename: Daniel
authors.initials: D
authors.lastname: Vázquez-Sánchez
authors.affiliation: Seafood Microbiology and Technology Section, Marine Research Institute (IIM), Spanish National Research Council (CSIC), Vigo, Spain.
authors.forename: Marta L
authors.initials: ML
authors.lastname: Cabo
authors.affiliation: Seafood Microbiology and Technology Section, Marine Research Institute (IIM), Spanish National Research Council (CSIC), Vigo, Spain juanherrera@iim.csic.es.
authors.forename: Juan J
authors.initials: JJ
authors.lastname: Rodríguez-Herrera
mesh_terms: D000890:Anti-Infective Agents / Q000494:pharmacology*; D018441:Biofilms / Q000187:drug effects*; D004202:Disinfectants / Q000494:pharmacology; D024881:Drug Resistance, Bacterial; D005511:Food Handling / Q000295:instrumentation; D005516:Food Microbiology / Q000379:methods; D005517:Foodborne Diseases / Q000382:microbiology / Q000517:prevention & control; D008826:Microbial Sensitivity Tests; D009822:Oils, Volatile / Q000494:pharmacology*; D010938:Plant Oils / Q000494:pharmacology; D013193:Stainless Steel; D013211:Staphylococcus aureus / Q000187:drug effects* / Q000254:growth & development; D013729:Terpenes / Q000494:pharmacology; D046930:Thymus Plant / Q000737:chemistry
chemical_list: D000890:Anti-Infective Agents; D004202:Disinfectants; D009822:Oils, Volatile; D010938:Plant Oils; D013729:Terpenes; D013193:Stainless Steel; C052901:lemongrass oil
keywords: Staphylococcus aureus; benzalkonium chloride; biofilm; essential oil; thyme