The antifungal activity of human parotid secretion is species-specific

Abstract

Candida albicans is the major fungal colonizer of the oral cavity and causes oral candidiasis in immunocompromised patient populations. While antifungal proteins in saliva have been identified and the virulence factors of C. albicans have been well studied, little is known about the role saliva plays in the preferential colonization of the oral cavity by C. albicans. We report that the fungistatic activity of human parotid secretion toward six C. albicans strains is considerably lower than towards nine non-C. albicans fungal species (average IC₅₀ values >1000 mg/l and <70 mg/l, respectively). The species-specific activity of parotid secretion suggests that saliva may play a determining role in oral fungal colonization patterns.

Figure 1

Growth inhibitory activity of human parotid secretion collected from four subjects tested against 15 fungal strains. Represented are the mean IC₅₀ values (mg/L) of four independent experiments each performed in duplicate. The numerical values and standard deviations in the measurements are shown in Table 1.