title: Inibitory effects of linalool on fungal pathogenicity of clinical isolates of Microsporum canis and Microsporum gypseum.
abstract: In humans worldwide, Microsporum sp. is a frequent agent of dermatophytsosis. When considering the emergence of resistant fungi and the clinical relevance of dermatophytosis, terpene antifungal activity is of great interest. Linalool is a monoterpene alcohol with pharmacological properties. In this study, antifungal in vitro activity of linalool and ketoconazole (as a positive control) were evaluated against clinical isolates of M. canis and M. gypseum. The minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) of each drug were determined by broth microdilution. The effects of the drugs (1/2MIC, MIC, 2xMIC) on radial mycelial growth, conidial production and germination were analysed. The effect on the fungal cell membrane (release of intracellular material) was also investigated. Linalool (MIC: 128 μg/mL) and ketoconazole (MIC: 64 μg/mL) were effective in inhibiting all dermatophytes studied. The MFC values of linalool ranged between 128 and 256 μg/mL, whereas ketoconazole showed MFC values of from 64 to 256 μg/mL. Linalool (at MIC and 2xMIC) and ketoconazole (at 1/2MIC, MIC, 2xMIC) inhibited mycelial growth (P < 0.05). The drugs (1/2MIC, MIC, 2xMIC) were also active on conidiogenesis and conidia germination, causing complete inhibition (P < 0.05). Linalool caused leakage of intracellular material. Our study supports the use of linalool as a potential antifungal agent against M. canis and M. gypseum.
authors.affiliation: Laboratory of Biochemistry, Academic Unit of Health, Education and Health Center, Federal University of Campina Grande, Cuité, Brazil.
authors.forename: Kaltz V S
authors.initials: KVS
authors.lastname: Silva
authors.affiliation: Laboratory of Biochemistry, Academic Unit of Health, Education and Health Center, Federal University of Campina Grande, Cuité, Brazil.
authors.forename: Maria I O
authors.initials: MIO
authors.lastname: Lima
authors.affiliation: Laboratory of Biochemistry, Academic Unit of Health, Education and Health Center, Federal University of Campina Grande, Cuité, Brazil.
authors.forename: Gustavo N
authors.initials: GN
authors.lastname: Cardoso
authors.affiliation: Laboratory of Biochemistry, Academic Unit of Health, Education and Health Center, Federal University of Campina Grande, Cuité, Brazil.
authors.forename: Aldeir S
authors.initials: AS
authors.lastname: Santos
authors.affiliation: Laboratory of Biochemistry, Academic Unit of Health, Education and Health Center, Federal University of Campina Grande, Cuité, Brazil.
authors.forename: Gezaíldo S
authors.initials: GS
authors.lastname: Silva
authors.affiliation: Laboratory of Biochemistry, Academic Unit of Health, Education and Health Center, Federal University of Campina Grande, Cuité, Brazil.
authors.forename: Fillipe O
authors.identifier: http://orcid.org/0000-0002-3081-4174
authors.initials: FO
authors.lastname: Pereira
mesh_terms: D000080462:Acyclic Monoterpenes; D000935:Antifungal Agents / Q000494:pharmacology*; D007654:Ketoconazole / Q000494:pharmacology; D008826:Microbial Sensitivity Tests; D008864:Microsporum / Q000187:drug effects* / Q000472:pathogenicity; D039821:Monoterpenes / Q000494:pharmacology*
chemical_list: D000080462:Acyclic Monoterpenes; D000935:Antifungal Agents; D039821:Monoterpenes; C018584:linalool; D007654:Ketoconazole
keywords: 
  Microsporum
  ; antifungal; linalool; monoterpenes