title: New insights on the antibacterial efficacy of miconazole in vitro.
abstract: Miconazole is a broad-spectrum antifungal used in topical preparations. In the present investigation the minimal inhibitory concentration (MIC) of miconazole for eighty wild type strains of gram-positive and gram-negative bacteria isolated from infected skin lesions was assessed using a modified agar dilution test (adapted to CLSI, Clinical Laboratory Standards Institute). 14 ATCC reference strains served as controls. Miconazole was found efficacious against gram-positive aerobic bacteria (n=62 species), the MICs against Staphylococcus (S.) aureus, S. spp., Streptococcus spp. und Enterococcus spp. ranged between 0.78 and 6.25 μg/mL. Interestingly, there were no differences in susceptibility between methicillin-susceptible (MSSA, 3) methicillin-resistant (MRSA, 6) and fusidic acid-resistant (FRSA, 2) S. aureus isolates. Strains of Streptococcus pyogenes (A-streptococci) (8) were found to be slightly more sensitive (0.78-1.563 μg/mL), while for gram-negative bacteria, no efficacy was found within the concentrations tested (MIC >200 μg/mL). In conclusion, for the gram-positive aerobic bacteria the MICs of miconazole were found within a range which is much lower than the concentration of miconazole used in topical preparations (2%). Thus topically applied miconazole might be a therapeutic option in skin infections especially caused by gram-positive bacteria even by those strains which are resistant to antibiotics.
authors.affiliation: Labor für Medizinische Mikrobiologie, Rötha/OT Mölbis, Germany.
authors.forename: P
authors.initials: P
authors.lastname: Nenoff
authors.affiliation: Labor für Medizinische Mikrobiologie, Rötha/OT Mölbis, Germany.
authors.forename: D
authors.initials: D
authors.lastname: Koch
authors.affiliation: Labor für Medizinische Mikrobiologie, Rötha/OT Mölbis, Germany.
authors.forename: C
authors.initials: C
authors.lastname: Krüger
authors.affiliation: Almirall Hermal GmbH, Reinbek, Germany.
authors.forename: C
authors.initials: C
authors.lastname: Drechsel
authors.affiliation: Biebertal, Germany.
authors.forename: P
authors.identifier: http://orcid.org/0000-0001-9850-1062
authors.initials: P
authors.lastname: Mayser
mesh_terms: D000362:Agar; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D000935:Antifungal Agents / Q000494:pharmacology*; D006090:Gram-Negative Bacteria / Q000187:drug effects*; D006094:Gram-Positive Bacteria / Q000187:drug effects*; D006801:Humans; D007201:Indicator Dilution Techniques; D008825:Miconazole / Q000494:pharmacology*; D008826:Microbial Sensitivity Tests; D017192:Skin Diseases, Bacterial / Q000188:drug therapy / Q000382:microbiology
chemical_list: D000900:Anti-Bacterial Agents; D000935:Antifungal Agents; D008825:Miconazole; D000362:Agar
keywords: FRSA; MRSA; gram-positive bacteria; miconazole; topical antibacterial therapy