An In Vitro Model for Candida albicans⁻Streptococcus gordonii Biofilms on Titanium Surfaces.

Daniel Montelongo-Jauregui,Anand Srinivasan,Jose Lopez-Ribot,Anand Ramasubramanian

doi:10.3390/jof4020066

Abstract

The oral cavity serves as a nutrient-rich haven for over 600 species of microorganisms. Although many are essential to maintaining the oral microbiota, some can cause oral infections such as caries, periodontitis, mucositis, and endodontic infections, and this is further exacerbated with dental implants. Most of these infections are mixed species in nature and associated with a biofilm mode of growth. Here, after optimization of different parameters including cell density, growth media, and incubation conditions, we have developed an in vitro model of C. albicans–S. gordonii mixed-species biofilms on titanium discs that is relevant to infections of peri-implant diseases. Our results indicate a synergistic effect for the development of biofilms when both microorganisms were seeded together, confirming the existence of beneficial, mutualistic cross-kingdom interactions for biofilm formation. The morphological and architectural features of these dual-species biofilms formed on titanium were determined using scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM). Mixed biofilms formed on titanium discs showed a high level of resistance to combination therapy with antifungal and antibacterial drugs. This model can serve as a platform for further analyses of complex fungal/bacterial biofilms and can also be applied to screening of new drug candidates against mixed-species biofilms.

Highlights

Due to superior biocompatibility as well as mechanical and anticorrosive properties, titanium and its alloys have become the biomaterial of choice for a number of biomedical devices [1,2,3]
We developed an in vitro model of single- and mixed-species biofilms of C. albicans and S. gordonii on titanium alloy Ti–6Al–4V
Studies were performed in which C. albicans and S. gordonii were seeded alone or in combination, and using different media including RPMI 1640, THB + 0.02% YE, a combination of the two at a 1:1 ratio, and basal medium mucin (BMM) synthetic saliva, that more closely resembles physiological conditions encountered byFungi microorganisms within the oral cavity

Summary

Introduction

Due to superior biocompatibility as well as mechanical and anticorrosive properties, titanium and its alloys have become the biomaterial of choice for a number of biomedical devices [1,2,3]. The overall success of these dental implants is commonly and severely compromised by infection, including peri-implant mucositis and peri-implantitis [5,6,7]. These infections start with the adhesion and colonization of different pathogenic microorganisms (typically bacteria) on the implant surface, and subsequent biofilm formation [8]. These oral biofilms are complex microbial communities harboring a large number of species, including bacteria and fungi [9,10,11,12].

Methods

Results

Conclusion