Spectrophotometric analysis of the expression of secreted aspartyl proteinases from Candida in leukoplakia and oral squamous cell carcinoma

Candida species are a normal commensal of the oral cavity in healthy individuals, but can become an opportunistic pathogen when the oral ecosystem is unbalanced. Several virulence attributes have been identified in candidal infection, among which are the hydrolases, including the secreted aspartyl proteinases (Saps). This study evaluated and compared the in vitro level of Saps from Candida albicans in nonsmokers, smokers, and patients with leukoplakia and oral squamous cell carcinoma (OSCC). Candida cell count (CCC) at 48 h was also assessed. The Sap level was measured by spectrophotometry in 38 clinical isolates of C. albicans obtained from the oral cavity of the four different groups. Culturing was done in yeast carbon base-bovine serum albumin. Speciation of Candida was performed by using a Candida identification kit, and CCC was measured by hemocytometer. Sap levels and CCC were higher in individuals with leukoplakia and OSCC than in nonsmokers or smokers (P = 0.001); however, there was no significant difference in Sap levels or CCC between smokers and nonsmokers (P = 0.529). Further, an intragroup correlation between CCC and Sap level was also observed. The higher level of Saps from C. albicans in individuals with leukoplakia and OSCC suggests that this pathogen plays a role in disease development and could aid in identifying the pathogenic commensal.