In vitro susceptibility of dermatophytes to conventional and alternative antifungal agents.
The minimum inhibitory concentrations (MICs), the minimal fungicidal concentrations (MFCs), the fungal biomass (FB) and hyphal viability employing the dye 3-4,5 dimethyl- 2-thiazolyl- 2,5- diphenyl- 2H tetrazolium bromide (MTT) were used to compare the in vitro effects of fluconazole (FLU) with those of the N-terminal palmitoyl-lipidated peptide, Pal-Lys-Lys-NH(2) (PAL), and a tea tree oil component, gamma-Terpinene (TER), against several clinical isolates of Microsporum canis and Trichophyton rubrum. In general, FLU and PAL MICs were significantly lower than those observed with TER, while no differences in the three drugs were found in the MFCs. However, they were from two to 16-times higher than their respective MICs. FB of M. canis treated with either FLU or PAL, but not with TER, was significantly reduced over untreated controls. Only PAL and TER, in a medium-dependent fashion, but not FLU, reduced the FB of T. rubrum. Finally, PAL was found to be significantly more active than FLU at reducing the hyphal viability against both genera of dermatophytes. This study shows that PAL exerts an in vitro activity against dermatophytes at least similar to that observed with FLU and suggests that this compound might be a promising candidate in the treatment of infections due to dermatophytes.
Barchiesi
Francesco
F
Istituto di Malattie Infettive e Medicina Pubblica, Università Politecnica delle Marche, Azienda Ospedaliero-Universitaria, Torrette, Ancona, Italy. f.barchiesi@univpm.it
Silvestri
Carmela
C
Arzeni
Daniela
D
Ganzetti
Giulia
G
Castelletti
Sefora
S
Simonetti
Oriana
O
Cirioni
Oscar
O
Kamysz
Wojciech
W
Kamysz
Elzbieta
E
Spreghini
Elisabetta
E
Abruzzetti
Alessandra
A
Riva
Alessandra
A
Offidani
Anna M
AM
Giacometti
Andrea
A
Scalise
Giorgio
G
D000935:Antifungal Agents / Q000494:pharmacology*; D003883:Arthrodermataceae / Q000187:drug effects* / Q000378:metabolism; D018533:Biomass; D000081005:Cyclohexane Monoterpenes; D015725:Fluconazole / Q000494:pharmacology*; D006801:Humans; D055666:Lipopeptides / Q000494:pharmacology*; D008826:Microbial Sensitivity Tests; D050296:Microbial Viability; D008864:Microsporum / Q000187:drug effects* / Q000302:isolation & purification; D039821:Monoterpenes / Q000494:pharmacology*; D009181:Mycoses / Q000382:microbiology; D013778:Tetrazolium Salts / Q000378:metabolism; D013844:Thiazoles / Q000378:metabolism; D014249:Trichophyton / Q000187:drug effects* / Q000302:isolation & purification
D000935:Antifungal Agents; D000081005:Cyclohexane Monoterpenes; D055666:Lipopeptides; D039821:Monoterpenes; D013778:Tetrazolium Salts; D013844:Thiazoles; C018669:gamma-terpinene; D015725:Fluconazole; C022616:thiazolyl blue