title: In vitro inhibition of vancomycin-susceptible and vancomycin-resistant Enterococcus faecium and E. faecalis in the presence of citrus essential oils.
abstract: Glycopeptide-resistant Enterococcus (GRE) is an important healthcare-acquired infection (HCAI) which costs the healthcare service many millions of pounds worldwide. In this study, lemon (Citrus limon), sweet orange (Citrus sinensis) or bergamot (Citrus bergamia) essential oils (EO) and their vapours, alone and in combination, are tested for their antimicrobial activity against vancomycin-resistant and vancomycin-sensitive strains of E. faecium and E. faecalis. A blend of 1:1 (v/v) orange and bergamot EO was the most effective of the oils and/or blends tested with a minimum inhibitory concentration (MIC), at 25 degrees C and pH 5.5, of 0.25-0.5% (v/v) and a minimum inhibitory dose (MID) of 50 mg/L, at 50 degrees C at pH 7.5, when viable counts reduced by 5.5-10 log10 colony forming units (cfu)/mL, suggesting that this blend of citrus oils is effective under a range of conditions for inhibiting the growth and survival of E. faecalis, E. faecium and VRE.
authors.affiliation: University of Northampton, School of Health, Park Campus, Boughton Green Road, Northampton NN2 7AL, UK.
authors.forename: K
authors.initials: K
authors.lastname: Fisher
authors.forename: C
authors.initials: C
authors.lastname: Phillips
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology* / Q000627:therapeutic use; D002957:Citrus; D003428:Cross Infection / Q000191:economics / Q000453:epidemiology / Q000517:prevention & control; D004338:Drug Combinations; D013293:Enterococcus faecalis / Q000187:drug effects* / Q000254:growth & development; D016984:Enterococcus faecium / Q000187:drug effects* / Q000254:growth & development; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008826:Microbial Sensitivity Tests; D009822:Oils, Volatile / Q000494:pharmacology* / Q000627:therapeutic use; D010938:Plant Oils / Q000494:pharmacology / Q000627:therapeutic use; D013696:Temperature; D014640:Vancomycin / Q000494:pharmacology; D020713:Vancomycin Resistance
chemical_list: D000900:Anti-Bacterial Agents; D004338:Drug Combinations; D009822:Oils, Volatile; D010938:Plant Oils; D014640:Vancomycin