title: Activity of essential oil-based microemulsions against Staphylococcus aureus biofilms developed on stainless steel surface in different culture media and growth conditions.
abstract: Food safety is a fundamental concern for both consumers and the food industry, especially as the numbers of reported cases of food-associated infections continue to increase. Industrial surfaces can provide a suitable substrate for the development and persistence of bacterial organized in biofilms that represent a potential source of food contamination. The negative consumer perception of chemical disinfectants has shifted the attention to natural substances, such as plant extracts. The aim of this study was to investigate the possibility of using the essential oils (EOs) in the fight against S. aureus biofilms. First, the Minimum Inhibitory Concentration (MIC), Minimum Bactericidal Concentration (MBC), Minimum Biofilm Inhibitory Concentration (MBIC), Minimum Biofilm Eradication Concentration (MBEC) of eleven EOs against S. aureus were determined. Cinnamomum cassia and Salvia officinalis EOs showed the greatest antibacterial properties with 1.25% MIC and MBC, 1.25% MBIC and 2.5% MBEC respectively. Gas Chromatography/Mass Spectrometry analysis revealed cinnamaldehyde (82.66%) and methoxy cinnamaldehyde (10.12%) as the most abundant substances of C. cassia, while cis-thujone (23.90%), camphor (19.22%) and 1.8-cineole (10.62%) of S. officinalis. Three different microemulsions, formulated with C. cassia, S. officinalis or both, were finally tested against S. aureus biofilms in different culture media and growth conditions, causing a >3 logarithmic reductions in S. aureus 24h-old biofilms and desiccated biofilms, and up to 68% of biofilm removal after 90min of exposure. The obtained data suggest the potential use of EOs, alone or in combination, for the formulation of sanitizers as alternative or in support in the disinfection of contaminated surfaces.
authors: Department of Biomolecular Science, University of Urbino "Carlo Bo", Urbino, Italy. Electronic address: raffaella.campana@uniurb.it.
authors: Raffaella
authors: R
authors: Campana
authors: Department of Biomolecular Science, University of Urbino "Carlo Bo", Urbino, Italy.
authors: Luca
authors: L
authors: Casettari
authors: Department of Biomolecular Science, University of Urbino "Carlo Bo", Urbino, Italy.
authors: Laura
authors: L
authors: Fagioli
authors: School of Pharmacy, University of Camerino, Via S. Agostino 1, 62032 Camerino, MC, Italy.
authors: Marco
authors: M
authors: Cespi
authors: School of Pharmacy, University of Camerino, Via S. Agostino 1, 62032 Camerino, MC, Italy.
authors: Giulia
authors: G
authors: Bonacucina
authors: Department of Biomolecular Science, University of Urbino "Carlo Bo", Urbino, Italy.
authors: Wally
authors: W
authors: Baffone
mesh_terms: D000171:Acrolein / Q000031:analogs & derivatives / Q000032:analysis; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D018441:Biofilms / Q000187:drug effects* / Q000254:growth & development; D002164:Camphor / Q000032:analysis; D032904:Cinnamomum aromaticum / Q000737:chemistry; D003470:Culture Media; D003511:Cyclohexanols / Q000032:analysis; D004202:Disinfectants / Q000494:pharmacology*; D004203:Disinfection / Q000379:methods*; D000077591:Eucalyptol; D005506:Food Contamination / Q000517:prevention & control; D059022:Food Safety / Q000379:methods; D008826:Microbial Sensitivity Tests; D039821:Monoterpenes / Q000032:analysis; D009822:Oils, Volatile / Q000494:pharmacology*; D027543:Salvia officinalis / Q000737:chemistry; D013193:Stainless Steel; D013203:Staphylococcal Infections / Q000517:prevention & control*; D013211:Staphylococcus aureus / Q000187:drug effects*
chemical_list: D000900:Anti-Bacterial Agents; D003470:Culture Media; D003511:Cyclohexanols; D004202:Disinfectants; D039821:Monoterpenes; D009822:Oils, Volatile; D013193:Stainless Steel; D002164:Camphor; D000171:Acrolein; D000077591:Eucalyptol; C012843:cinnamaldehyde
keywords: Essential oils; Growth conditions; Microemulsion formulation; Staphylococcus aureus biofilm