title: Antibacterial properties of EMLA and lidocaine in wound tissue biopsies for culturing.
abstract: If a tissue biopsy from a chronic wound is sampled for culture, the antibacterial properties of local anesthetics may pose a problem in producing false-negative results. The purpose of this study was to investigate the effects of EMLA (AstraZeneca) and lidocaine on common wound pathogenic bacteria. An in vitro study of a total of 25 clinical isolates and ATCC reference strains of Staphylococcus aureus (including methicillin-resistant S. aureus), Escherichia coli, Pseudomonas aeruginosa, and Streptococcus pyogenes was conducted. The isolates were exposed to the local anesthetic drugs (and some of their contents separately) at 35 degrees C over a 24-hour period and time-kill curves were recorded. No culture media were used and saline was used for controls. EMLA was found to have a rapid acting and powerful antibacterial effect and should not be used before culturing tissue samples. Lidocaine 1% was found not to inhibit the bacterial strains when exposure time was held below 2 hours. We conclude that culturing tissue from a wound biopsy is safe within 2 hours when a pure, preservative-free lidocaine 1% solution is used.
authors.affiliation: Department of Plastic Surgery, University Center of Wound Healing, Odense University Hospital, Odense, Denmark. joberg@dadlnet.dk
authors.forename: Jais O
authors.initials: JO
authors.lastname: Berg
authors.forename: Belinda K
authors.initials: BK
authors.lastname: Mössner
authors.forename: Marianne N
authors.initials: MN
authors.lastname: Skov
authors.forename: Jorgen
authors.initials: J
authors.lastname: Lauridsen
authors.forename: Finn
authors.initials: F
authors.lastname: Gottrup
authors.forename: Hans J
authors.initials: HJ
authors.lastname: Kolmos
mesh_terms: D000779:Anesthetics, Local / Q000494:pharmacology*; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001706:Biopsy; D002478:Cells, Cultured; D002908:Chronic Disease; D015169:Colony Count, Microbial; D004926:Escherichia coli / Q000187:drug effects / Q000302:isolation & purification; D005188:False Negative Reactions; D006801:Humans; D008012:Lidocaine / Q000494:pharmacology*; D000077442:Lidocaine, Prilocaine Drug Combination; D008826:Microbial Sensitivity Tests; D011318:Prilocaine / Q000494:pharmacology*; D011550:Pseudomonas aeruginosa / Q000187:drug effects / Q000302:isolation & purification; D013211:Staphylococcus aureus / Q000187:drug effects / Q000302:isolation & purification; D013297:Streptococcus pyogenes / Q000187:drug effects / Q000302:isolation & purification; D014946:Wound Infection / Q000382:microbiology*
chemical_list: D000779:Anesthetics, Local; D000900:Anti-Bacterial Agents; D000077442:Lidocaine, Prilocaine Drug Combination; D011318:Prilocaine; D008012:Lidocaine