Question: How does Hst5 (histatin 5) affect infections by Candida glabrata?

Context:
Human salivary histatins, including histatin 5 (Hst 5), are small cationic proteins that are the major source of fungicidal activity of saliva
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.
Hst 5 enters C. albicans cell through polyamine transporters Dur3p and Dur31p that are uncharacterized in C. glabrata. 
the crucial rate limiting step is reduced uptake that can be overcome by expression of C. albicans Dur proteins in C. glabrata.
Histatin 5, a human salivary protein with broad-spectrum antifungal activity, is remarkably ineffective against Candida glabrata.
Our results, taken together, demonstrated that histatin-5 possessed the fungicidal activity against Candida species other than C. glabrata.
The present study shows that a number of basic antifungal peptides, including human salivary histatin 5, a designed histatin analog designated dhvar4, and a peptide from frog skin, PGLa, are active against amphotericin B-resistant Candida albicans, Candida krusei, and Aspergillus fumigatus strains and against a fluconazole-resistant Candida glabrata isolate.
In addition, we tested azole-resistant C. albicans and Candida glabrata strains for their susceptibilities to Hsn-5.
Assessment of the candidacidal activity of Hsn-5 with the well-characterized azole-resistant strains of C. albicans and C. glabrata, however, suggested that the mode of action of histatins against Candida is distinct from that of azole-based antifungal agents because Hsn-5 kills both azole-sensitive and azole-resistant strains equally well.
Histatin 5 resistance of Candida glabrata can be reversed by insertion of Candida albicans polyamine transporter-encoding genes DUR3 and DUR31.
Roles of cellular respiration, CgCDR1, and CgCDR2 in Candida glabrata resistance to histatin 5.
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. 
Biofilms of C. glabrata GDH1407 and 6115/06 were less susceptible to histatin 5, with 50% RMA of 31.2 +/- 4.8 and 62.5 +/- 0.7 microM, respectively. 
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.
These results indicate that histatin 5 exhibits antifungal activity against biofilms of C. albicans and C. glabrata developed on denture acrylic. 
Candida albicans and Candida glabrata are predominant fungi associated with oral candidiasis. 
C. glabrata is significantly less sensitive to histatin 5 than C. albicans.
We investigated whether the distinct resistance of C. glabrata to histatin 5 is related to similar mechanisms.
The authors report a case of disseminated candidiasis due to Candida glabrata with liver metastases.
We examined antifungal activities of histatin 5 against planktonic or biofilm Candida albicans and Candida glabrata.
Histatin 5 resistance of Candida glabrata can be reversed by insertion of Candida albicans polyamine transporter-encoding genes DUR3 and DUR31.
Roles of cellular respiration, CgCDR1, and CgCDR2 in Candida glabrata resistance to histatin 5.
Histatin 5, a human salivary protein with broad-spectrum antifungal activity, is remarkably ineffective against Candida glabrata.
Candida albicans and Candida glabrata are predominant fungi associated with oral candidiasis.

Answer: Human salivary histatins, including histatin 5 (Hst 5), are small cationic proteins that are the major source of fungicidal activity of saliva
Human salivary histatins, including histatin 5 (Hst 5), are small cationic proteins that are the major source of fungicidal activity of saliva. We found that Hst 54-15-Spd was significantly more effective in killing C. albicans and Candida glabrata than Hst 5 alone in both planktonic and biofilm growth and that Hst 54-15-Spd retained high activity in both serum and saliva. 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. We constructed a conjugate peptide using spermidine (Spd) linked to the active fragment of Hst 5 (Hst 54-15), based upon our findings that C. albicans spermidine transporters are required for Hst 5 uptake and fungicidal activity.
Our results, taken together, demonstrated that histatin-5 possessed the fungicidal activity against Candida species other than C. glabrata. 
Human salivary histatins, including histatin 5 (Hst 5), are small cationic proteins that are the major source of fungicidal activity of saliva. Histatin 5, a human salivary protein with broad-spectrum antifungal activity, is remarkably ineffective against Candida glabrata. 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. Hst 5 enters C. albicans cell through polyamine transporters Dur3p and Dur31p that are uncharacterized in C. glabrata. The crucial rate limiting step is reduced uptake that can be overcome by expression of C. albicans Dur proteins in C. glabrata.