title: The Sensitivity of Endodontic Enterococcus spp. Strains to Geranium Essential Oil.
abstract: Enterococci are able to survive endodontic procedures and contribute to the failure of endodontic therapy. Thus, it is essential to identify novel ways of eradicating them from infected root canals. One such approach may be the use of antimicrobials such as plant essential oils. Enterococcal strains were isolated from endodontically treated teeth by standard microbiological methods. Susceptibility to antibiotics was evaluated by the disc-diffusion method. The minimal inhibitory concentration (MIC) of geranium essential oil was investigated by microdilution in 96-well microplates in Mueller Hinton Broth II. Biofilm eradication concentrations were checked in dentin tests. Geranium essential oil inhibited enterococcal strains at concentrations ranging from 1.8-4.5 mg/mL. No correlation was shown between resistance to antibiotics and the MICs of the test antimicrobials. The MICs of the test oil were lower than those found to show cytotoxic effects on the HMEC-1 cell line. Geranium essential oil eradicated enterococcal biofilm at concentrations of 150 mg/mL. Geranium essential oil inhibits the growth of endodontic enterococcal species at lower concentrations than those required to reach IC50 against the HMEC-1 cell line, and is effective against bacteria protected in biofilm at higher concentrations. In addition, bacteria do not develop resistance to essential oils. Hence, geranium essential oil represents a possible alternative to other antimicrobials during endodontic procedures.
authors.affiliation: Department of Microbiology and Medical Laboratory Immunology, Medical University of Lodz, 92-231 Lodz, Pomorska 251, Poland. monika.lysakowska@umed.lodz.pl.
authors.forename: Monika E
authors.initials: ME
authors.lastname: Łysakowska
authors.affiliation: Department of Environmental Biology, Medical University of Lodz, 90-752 Lodz, Żeligowskiego 7/9, Poland. monika.sienkiewicz@umed.lodz.pl.
authors.forename: Monika
authors.initials: M
authors.lastname: Sienkiewicz
authors.affiliation: Department of General Dentistry, Medical University of Lodz, 92-231 Lodz, Pomorska 251, Poland. katarzyna.banaszek@umed.lodz.pl.
authors.forename: Katarzyna
authors.initials: K
authors.lastname: Banaszek
authors.affiliation: Department of General Dentistry, Medical University of Lodz, 92-231 Lodz, Pomorska 251, Poland. jerzy.sokolowski@umed.lodz.pl.
authors.forename: Jerzy
authors.initials: J
authors.lastname: Sokołowski
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D000890:Anti-Infective Agents / Q000494:pharmacology; D018441:Biofilms / Q000187:drug effects; D002460:Cell Line; D004707:Endoderm / Q000382:microbiology*; D016983:Enterococcus / Q000187:drug effects*; D031315:Geranium / Q000737:chemistry*; D006801:Humans; D008826:Microbial Sensitivity Tests / Q000379:methods; D009822:Oils, Volatile / Q000494:pharmacology*; D010938:Plant Oils / Q000494:pharmacology*; D012680:Sensitivity and Specificity
chemical_list: D000900:Anti-Bacterial Agents; D000890:Anti-Infective Agents; D009822:Oils, Volatile; D010938:Plant Oils
keywords: endodontic treatment; enterococci; geranium essential oil