title: Antimicrobial efficacy of a novel eucalyptus oil, chlorhexidine digluconate and isopropyl alcohol biocide formulation.
abstract: Effective surface disinfection is a fundamental infection control strategy within healthcare. This study assessed the antimicrobial efficacy of novel biocide formulations comprising 5% and 2% eucalyptus oil (EO) combined with 2% chlorhexidine digluconate (CHG) and 70% isopropyl alcohol (IPA) contained within a wipe. The efficacy of this novel antimicrobial formulation to remove and eliminate methicillin-resistant Staphylococcus aureus (MRSA), Escherichia coli and Candida albicans from steel surfaces was investigated. Adpression studies of pre-contaminated wipes were also utilised to assess their potential to induce cross-contamination between hard surfaces. Furthermore, the bactericidal nature of the EO-formulation was established in addition to time-kill. The EO-containing formulations demonstrated bactericidal antimicrobial efficacy against all microorganisms and did not induce surface cross-contamination. There was no significant difference (p < 0.05) between the 5% and 2% EO formulations in their ability to remove microorganisms from steel surfaces, however both significantly (p < 0.05) removed more than the control formulations. Microbial biofilms were eliminated within 10 min (p < 0.05) when exposed to the EO formulations. Our novel EO-formulation demonstrated rapid antimicrobial efficacy for potential disinfection and elimination of microbial biofilms from hard surfaces and may therefore be a useful adjunct to current infection control strategies currently employed within healthcare facilities.
authors.affiliation: Microbiology, School of Life and Health Sciences, Aston University, Aston Triangle,  Birmingham B4 7ET, UK. t.worthington@aston.ac.uk.
authors.forename: Emma
authors.initials: E
authors.lastname: Hendry
authors.forename: Barbara
authors.initials: B
authors.lastname: Conway
authors.forename: Tony
authors.initials: T
authors.lastname: Worthington
mesh_terms: D019840:2-Propanol / Q000737:chemistry / Q000494:pharmacology*; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D000890:Anti-Infective Agents / Q000737:chemistry / Q000494:pharmacology*; D018441:Biofilms / Q000187:drug effects; D002176:Candida albicans / Q000187:drug effects; D002710:Chlorhexidine / Q000031:analogs & derivatives* / Q000737:chemistry / Q000494:pharmacology; D004202:Disinfectants / Q000737:chemistry / Q000494:pharmacology*; D052978:Disk Diffusion Antimicrobial Tests; D005052:Eucalyptus / Q000737:chemistry*; D008826:Microbial Sensitivity Tests; D010938:Plant Oils / Q000737:chemistry*
chemical_list: D000900:Anti-Bacterial Agents; D000890:Anti-Infective Agents; D004202:Disinfectants; D010938:Plant Oils; C010882:chlorhexidine gluconate; D019840:2-Propanol; D002710:Chlorhexidine