Novel antifungal activity of oligostyrylbenzenes compounds on Candida tropicalis biofilms

QUINTEROS, MELISA A; GALERA, IVANA L D; TOLOSA, JUAN; GARCÍA-MARTÍNEZ, JOAQUÍN C; PÁEZ, PAULINA L; PARAJE, MARÍA G

MEDICAL MYCOLOGY

TAYLOR & FRANCIS LTD

Año: 2021 vol. 4 p. 244 - 252

1369-3786

As sessile cells of fungal biofilms are at least 500-foldmore resistant to antifungal drugs than their planktonic counterparts,there is a requirement for new antifungal agents. Olygostyrylbenzenes (OSBs)are the 1st generation of poly(phenylene)vinylene dendrimers with aGram-positive antibacterial activity. Thus, this study aimedto investigate the antifungal activityof four OSBs (1, 2, 3,and 4) on planktonic cells and biofilms of Candida tropicalis, with the minimuminhibitory concentration (MIC) for the planktonic populationand the sessile minimum inhibitory concentrations (SMIC) being determined. Biofilm eradication was studied bycrystal violet stain and light microscopy (LM). Confocal laser scanningmicroscopy (CLSM) wasalso utilized in conjunction with the image analysis software COMSTAT. Although all the OSBs studiedhad antifungal activity, the cationic OSBs were more effective than the anionicones. A significant reduction of biofilms was observed at MIC andsupraMIC50 (50 times higher than MIC) for compound 2 and at supraMIC50 with compound 3. Alterations in surface topography and the three-dimensional architecture of the biofilms were evident with LM andCLSM. The LM analysis revealed that the C.tropicalis strain produced a striking biofilm with oval blastospores,pseudohyphae and true hyphae, and the CLSM images showed that a decreaseoccurred in the thickness of the mature biofilms treated with the OSBs at themost effective concentration for each one. The results obtained by microscopywere supported by those of the COMSTAT program. Our results revealed an antibiofilmactivity, with compounds 2 and 3 being potential candidates for thetreatment of C. tropicalis infections.