Denture-associated biofilm infection in three-dimensional oral mucosal tissue models

Daniel J Morse,David J Bradshaw,Craig Murdoch,Michael A O Lewis,Melanie J Wilson,David W Williams,Xiaoqing Wei

doi:10.1099/jmm.0.000677

Abstract

PurposeIn vitro analyses of virulence, pathogenicity and associated host cell responses are important components in the study of biofilm infections. The Candida-related infection, denture-associated oral candidosis, affects up to 60 % of denture wearers and manifests as inflammation of palatal tissues contacting the denture-fitting surface. Commercially available three-dimensional tissue models can be used to study infection, but their use is limited for many academic research institutions, primarily because of the substantial purchase costs. The aim of this study was to develop and evaluate the use of in vitro tissue models to assess infections by biofilms on acrylic surfaces through tissue damage and Candida albicans virulence gene expression.MethodologyIn vitro models were compared against commercially available tissue equivalents (keratinocyte-only, SkinEthic; full-thickness, MatTek Corporation). An in vitro keratinocyte-only tissue was produced using a cancer-derived cell line, TR146, and a full-thickness model incorporating primary fibroblasts and immortalised normal oral keratinocytes was also generated. The in vitro full-thickness tissues incorporated keratinocytes and fibroblasts, and have potential for future further development and analysis.ResultsFollowing polymicrobial infection with biofilms on acrylic surfaces, both in-house developed models were shown to provide equivalent results to the SkinEthic and MatTek models in terms of tissue damage: a significant (P<0.05) increase in LDH activity for mixed species biofilms compared to uninfected control, and no significant difference (P>0.05) in the expression of most C. albicans virulence genes when comparing tissue models of the same type.ConclusionOur results confirm the feasibility and suitability of using these alternative in vitro tissue models for such analyses.

Highlights

Biofilms are highly significant in human infection, and these complex polymicrobial communities of micro-organisms can develop on biotic or abiotic surfaces [1, 2]
Following polymicrobial infection with biofilms on acrylic surfaces, both in-house developed models were shown to provide equivalent results to the SkinEthic and MatTek models in terms of tissue damage: a significant (P0.05) in the expression of most C. albicans virulence genes when comparing tissue models of the same type
This study developed and evaluated two in vitro tissue models as alternatives to the commercially available constructs, and for the first time used them to assess the effects of infection with denture biofilms

Summary

Introduction

Biofilms are highly significant in human infection, and these complex polymicrobial communities of micro-organisms can develop on biotic or abiotic surfaces [1, 2]. They develop according to a defined series of events, and are highly structured, with distinct microenvironments within the EPS supporting the growth of a diverse range of microorganisms [2,3,4,5,6,7]. Dental plaque is a well-studied example of a polymicrobial biofilm in the oral cavity [19, 20] and is responsible for the most prevalent human infections, namely dental caries and periodontal disease

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