Candida albicans and Candida glabrata are predominant fungi associated with oral 
candidiasis. Histatin 5 (Hst 5) is a small cationic human salivary peptide with 
high fungicidal activity against C. albicans, however many strains of C. 
glabrata are resistant. Since Hst 5 requires fungal binding to cell wall 
components prior to intracellular translocation, reduced Hst 5 binding to C. 
glabrata may be the reason for its insensitivity. C. glabrata has higher surface 
levels of β-1,3-glucans as compared with C. albicans; however these differences 
did not account for reduced Hst 5 uptake and killing in C. glabrata. Similarly, 
the biofilm matrix of C. glabrata contained significantly higher levels of 
β-1,3-glucans compared with C. albicans, but it did not reduce the percentage of 
Hst 5 positive fungal cells in the biofilm. Hst 5 enters C. albicans cell 
through polyamine transporters Dur3p and Dur31p that are uncharacterized in C. 
glabrata. C. glabrata strains expressing CaDur3 and CaDur31 had two-fold higher 
killing and uptake of Hst 5. Thus, neither C. glabrata cell surface or biofilm 
matrix β-1,3-glucan levels affected Hst 5 toxicity; rather the crucial rate 
limiting step is reduced uptake that can be overcome by expression of C. 
albicans Dur proteins in C. glabrata.