Diminished Antimicrobial Peptide and Antifungal Antibiotic Activities against Candida albicans in Denture Adhesive.

Amber Bates,Carol Fischer,Kim Brogden,Jorge Garaicoa

doi:10.3390/antibiotics6010006

Amber Bates, Carol Fischer + Show 2 more

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https://doi.org/10.3390/antibiotics6010006

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Abstract

The underlying causes of denture stomatitis may be related to the long-term use of adhesives, which may predispose individuals to oral candidiasis. In this study, we hypothesize that antimicrobial peptides and antifungal antibiotics have diminished anti-Candida activities in denture adhesive. To show this, nine antimicrobial peptides and five antifungal antibiotics with and without 1.0% denture adhesive were incubated with Candida albicans strains ATCC 64124 and HMV4C in radial diffusion assays. In gels with 1.0% adhesive, HNP-1, HBD2, HBD3, IP-10, LL37 (only one strain), histatin 5 (only one strain), lactoferricin B, and SMAP28 showed diminished activity against C. albicans. In gels with 1.0% adhesive, amphotericin B and chlorhexidine dihydrochloride were active against both strains of C. albicans. These results suggest that denture adhesive may inactivate innate immune mediators in the oral cavity increasing the risk of C. albicans infections, but inclusion of antifungal antibiotics to denture adhesive may aid in prevention or treatment of Candida infections and denture stomatitis.

Highlights

Candida species infections can cause complications for individuals with dentures, such as denture stomatitis
Broth microdilution assays were used to show that antimicrobial peptides (AMPs) lactoferricin B and sheep myeloid antimicrobial peptide 28 (SMAP28)
Garaicoa and colleagues determined that AMPs and antimicrobial lipids endogenous to the oral cavity showed diminished activity when added to 1.0% denture adhesive suggesting that components in adhesives may inactivate local innate immune factors possibly predisposing denture wearers to Candida species infections [1]

Summary

Introduction

Candida species infections can cause complications for individuals with dentures, such as denture stomatitis. Broth microdilution assays were used to show that antimicrobial peptides (AMPs) lactoferricin B and sheep myeloid antimicrobial peptide 28 (SMAP28). Antimicrobial lipids sphingosine, dihydrosphingosine, and phytosphingosine in 1.0% denture adhesive lost antimicrobial activity against Candida albicans (p < 0.05), but amphotericin B (AMB), chlorhexidine dihydrochloride (CHX), chlorhexidine gluconate (CHG), fluconazole (FLC), and nystatin (NYT) in 1.0% denture adhesive did not [1]. Large concentrations (~100.0 μg) of AMPs, antimicrobial lipids, and antifungal antibiotics were needed in the broth microdilution assays. The diluted denture adhesive used was very difficult to mix in 96-well plates due to its thick viscosity. A precipitate often would form when the AMPs were mixed with the denture adhesive [1]

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