title: Antimicrobial efficacy of biocides tested on skin using an ex-vivo test.
abstract: An ex-vivo test was used to evaluate the activity of antimicrobials against three microorganisms, Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus. The ex-vivo test is a carrier test using freshly excised animal skin samples maintained in viable conditions for a short period of time. Skin samples came from a veterinary practice and were excised from either dogs or cats. The antimicrobial activity of povidone iodine, chlorhexidine diacetate, cetrimide and benzalkonium chloride was also evaluated with suspension and glass-carrier tests. Generally, the activity of the antimicrobials tested was reduced when applied to the skin surface. Apart from povidone iodine (2%) against S. aureus, the biocides investigated failed to achieve a 5 log10 reduction in bacterial titre when tested with the ex-vivo method. There was no significant difference in reduction of bacterial titres after treatment with antimicrobials between the glass-carrier and the suspension tests. Furthermore, the drying process of bacterial inoculum was less detrimental on skin than on glass surfaces. This study confirmed that the activity of a biocide tested in suspension or on an inanimate surface did not reflect its activity when tested on skin. Further development of the ex-vivo test may be useful, especially for testing the antimicrobial activity of formulations with antiseptic properties.
authors.affiliation: Welsh School of Pharmacy, University of Wales, Cardiff, UK.
authors.forename: J Y
authors.initials: JY
authors.lastname: Maillard
authors.forename: S
authors.initials: S
authors.lastname: Messager
authors.forename: R
authors.initials: R
authors.lastname: Veillon
mesh_terms: D000818:Animals; D000891:Anti-Infective Agents, Local / Q000494:pharmacology*; D001548:Benzalkonium Compounds / Q000494:pharmacology*; D002415:Cats; D000077286:Cetrimonium; D002593:Cetrimonium Compounds / Q000494:pharmacology*; D002710:Chlorhexidine / Q000494:pharmacology*; D015169:Colony Count, Microbial; D004285:Dogs; D004353:Drug Evaluation, Preclinical; D004926:Escherichia coli / Q000187:drug effects*; D011206:Povidone-Iodine / Q000494:pharmacology*; D011550:Pseudomonas aeruginosa / Q000187:drug effects*; D012867:Skin / Q000187:drug effects* / Q000382:microbiology*; D013211:Staphylococcus aureus / Q000187:drug effects*
chemical_list: D000891:Anti-Infective Agents, Local; D001548:Benzalkonium Compounds; D002593:Cetrimonium Compounds; D011206:Povidone-Iodine; D002710:Chlorhexidine; D000077286:Cetrimonium