Proteinase activities of Candida spp. isolated from different anatomical sites of healthy women

Superficial and systemic fungal infections caused by Candida have been increasingly reported in recent times. Hydrolytic enzyme production is an important process in fungal pathogenesis and proteases have been identified as important virulence attributes in Candida species. The aim of the study was to determine and compare the in vitro proteinase activity in sixty Candida spp isolated from three different anatomical sites (vagina, oral cavity and skin) of healthy women. Twenty samples per sample source were collected from apparently healthy female subjects. The recovered Candida isolates were properly identified and screened for proteolytic activity using established procedures. Overall, the recovery rate of Candida albicans was 66.7%, while the non-albicans Candida species represent 25% of the positive samples. Candida albicans recovered from the oral cavity exhibited the highest proteolytic activity (Pz range = 0.41±0.02- 0.65 ± 0.04), followed by skin isolates (Pz = 0.50 ± 0.05 – 0.79 ± 0.06). Isolates from the vagina had the least proteolytic activity (Pz = 0.57 ± 0.03 - 0.95 ± 0.08). The difference in proteolysis was significant between oral and vagina isolates (p = 0.0042), as well as skin and vaginal isolates (p = 0.0364). This study indicates that C. albicans remains the most prevalent species in all the anatomical body sites investigated. Moreover, the secretion of proteases could prove a potent virulence factor during the pathogenesis of the organism in an otherwise immunocompetent host.

 P.E. Chidebelu, C.G. Ogbonna, E.I. Nweze