Heterogeneity of metallo and serine extracellular proteinases in oral clinical isolates of Candida albicans in HIV-positive and healthy children from Rio de Janeiro, Brazil

Abstract

Candida yeasts frequently cause life-threatening systemic infections in immunocompromised hosts. In the present study, gelatin-SDS–PAGE analysis was used to characterize extracellular proteinases in 44 oral clinical isolates of Candida albicans from HIV-positive (29/50) and healthy children (15/50). Our survey indicates that these oral clinical isolates of C. albicans have complex extracellular proteolytic activity profiles, which illustrates the heterogeneity of this species. We showed four distinct proteolytic patterns composed of distinct serine (30–58 kDa) and metalloproteinase (64–95 kDa) activities, based on the inhibition profile with phenylmethylsulfonyl fluoride and 1,10-phenanthroline, respectively. This is the first report on secreted serine and metalloproteinases present in the culture supernatant fluids of C. albicans; however, we did not observe a significant correlation between proteolytic profile expressed by the C. albicans isolates from HIV-positive children and CD4 + T cell count and plasma viral load.