International Conference on Antimicrobial Research (ICAR 2012)
Abstract
Biofilms are surface associated communities of microorganisms embedded within a self-produced extracellular
matrix and adhered on inert and biotic surfaces. These biological consortia are considered the most prevalent
growth form of microorganisms. Biofilm formation is a potent virulence factor for a number of Candida species,
as it confers significant tolerance to antimicrobial therapy, primarily by limiting the penetration of substances
through the biofilm matrix. Casbane Diterpenes (CD) belongs to the class of diterpenoids isolated from few
species of plants from Euphorbiaceae family with important anticancer and antibacterial activities.
So, the goal of this study was to assess the antibiofilm effect of a Casbane Diterpene isolated from the stalks of
Croton nepetaefolius against Candida albicans and Candida glabrata. Biofilms were developed within the 96-
well microtiterplates in the presence of the CD. After 24 hours of growth, 100 μL of cells suspensions (1 x 106
cells ml-1 in Nutrient Broth) and 100 μL of solution of CD (500 - 31.5 μg/mL) were pipetted into each well and
incubated for 24 h at 37ºC in an orbital shaker at 120 rpm. Biofilms formation was characterized by total
biomass, through crystal violet (CV), and number of viable cells, expressed as log CFU per cm2.
CD showed to be able to reduce the biofilm formation of C. albicans and C. glabrata. CD reduced C. albicans
biomass in 82, 64, 57 and 27 % at the concentrations of 500, 250, 125 and 62.5 μg/mL, respectively. C.
glabrata biomass was reduced in 68 and 26 % at 500 and 250 μg/mL. Regarding the number of viable cells
embedded in the yeast biofilms, CD at 500 and 250 μg/mL reduced 2 and 1 log of C. albicans biofilm CFUs,
and 2.5 and 1 log for C. glabrata, respectively. Regarding the high resistance and recalcitrance of Candida
biofilms to the traditional therapies, CD emerges as a good prophylactic alternative to be used alone or in
combination with other traditional drugs
