In vitro and in vivo activity of tea tree oil against azole-susceptible and -resistant human pathogenic yeasts.
A tea tree oil (TTO) preparation of defined chemical composition was studied, using a microbroth method, for its in vitro activity against 115 isolates of Candida albicans, other Candida species and Cryptococcus neoformans. The fungal strains were from HIV-seropositive subjects, or from an established type collection, including reference and quality control strains. Fourteen strains of C. albicans resistant to fluconazole and/or itraconazole were also assessed. The same preparation was also tested in an experimental vaginal infection using fluconazole-itraconazole-susceptible or -resistant strains of C. albicans. TTO was shown to be active in vitro against all tested strains, with MICs ranging from 0.03% (for C. neoformans) to 0.25% (for some strains of C. albicans and other Candida species). Fluconazole- and/or itraconazole-resistant C. albicans isolates had TTO MIC50s and MIC90s of 0.25% and 0.5%, respectively. TTO was highly efficacious in accelerating C. albicans clearance from experimentally infected rat vagina. Three post-challenge doses of TTO (5%) brought about resolution of infection regardless of whether the infecting C. albicans strain was susceptible or resistant to fluconazole. Overall, the use of a reliable animal model of infection has confirmed and extended our data on the therapeutic effectiveness of TTO against fungi, in particular against C. albicans.
Mondello
Francesca
F
Laboratory of Bacteriology and Medical Mycology, Istituto Superiore di Sanità, Rome, Italy. mondello@iss.it
De Bernardis
Flavia
F
Girolamo
Antonietta
A
Salvatore
Giuseppe
G
Cassone
Antonio
A
D000818:Animals; D000935:Antifungal Agents / Q000494:pharmacology*; D001393:Azoles / Q000494:pharmacology*; D002176:Candida albicans / Q000187:drug effects; D002181:Candidiasis, Vulvovaginal / Q000188:drug therapy / Q000382:microbiology; D025141:Drug Resistance, Fungal; D005260:Female; D015725:Fluconazole / Q000494:pharmacology; D008401:Gas Chromatography-Mass Spectrometry; D006801:Humans; D017964:Itraconazole / Q000494:pharmacology; D008826:Microbial Sensitivity Tests; D009181:Mycoses / Q000382:microbiology; D051381:Rats; D017208:Rats, Wistar; D020947:Tea Tree Oil / Q000737:chemistry / Q000494:pharmacology*; D015003:Yeasts / Q000187:drug effects*
D000935:Antifungal Agents; D001393:Azoles; D017964:Itraconazole; D020947:Tea Tree Oil; D015725:Fluconazole