title: The Susceptibility of Candida albicans to Gamma-Radiations and Ketoco-nazole Depends on Transitional Filamentation.
abstract: The virulence of C. albicans is associated with the transitional evolution from yeast to filamentous forms. We were interested in the effects amphotericin B (AMB), ketoconazole (KTC) and gamma-radiations might have on these broadly defined phenotypes as determined by the CFU procedure. By using collagen gel as the 3-dimensional support of cell culture, diverse experimental conditions were contemplated in order to modulate the differentiation of Candida during sessile and planktonic growth. These conditions included the co-culture with human epithelial and endothelial cells and treatment with farnesol, tyrosol and conditioned medium from P. aeruginosa. The overall results were as follows: 1) The survival of Candida was inhibited by the exposure to gamma-radiations, but only after the organism was induced to progress into excess filamentation, while in normal growth conditions it proved to be radioresistant; 2) AMB inhibited the growth of yeast forms, while KTC was specifically toxic to filamentous forms and 3) the combined treatment of filamentous Candida with KTC and gamma-radiations resulted in the synergistic inhibition of the organism. These findings indicate that both the radiosensitivity of C. albicans and its response to the synergistic effects of gamma-radiations and KTC are filamentation-dependent pharmacological processes.
authors.affiliation: Institute of Microbiology "C.A Romanzi", Department DISCAT, University of Genoa, Largo Rosanna Benzi, 10, 16132, Genoa, Italy.
authors.forename: Simone
authors.initials: S
authors.lastname: Cagnacci
authors.forename: Rachele
authors.initials: R
authors.lastname: Grasso
authors.forename: Anna
authors.initials: A
authors.lastname: Marchese
authors.forename: Renzo
authors.initials: R
authors.lastname: Corvò
authors.forename: Eugenio
authors.initials: E
authors.lastname: Debbia
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Rossi