High-throughput characterization of interspecies interactions in oral implant-associated biofilms

Abstract text (incl. figure legends and references)
Introduction

During polymicrobial biofilm formation on implant surfaces, the involved species of oral microorganisms interact on different levels. In this regard, exploitation of metabolites released by other species can be an important survival strategy that contributes to biofilm fitness and leads to disease development and progression. Identification and characterization of these hallmark interactions are therefore imperative to detect early pathology and prevent implant-associated diseases.

Characterization of synergistic metabolic interactions in implant-associated biofilms and tracing of chemical compounds that are actively involved in these inter-species metabolite flows are the primary goals of this study. The knowledge gained should contribute to the decoding of these interaction networks in complex clinical biofilms.

Interspecies metabolic interactions were characterized using diverse agar diffusion assays. Clinical oral biofilm samples, more than one hundred reference strains of diverse species, various metabolites and their corresponding combinations were studied. Liquid biofilm cultures were used to verify selected interactions.

Porphyromonas gingivalis showed satellite growth exclusively around colonies of other species from classes such as Actinobacteria, Bacteroidia, Negativicutes and Gammaproteobacteria, thereby indicating metabolite exploitation under experimental conditions. Chemical complementation experiments identified menaquinones and their related precursors as major drivers of these interactions.

We were able to characterize exploitation interactions involving the key oral pathogen Porphyromonas gingivalis. Targeting these interactions may support the development of innovative preventive and therapeutic strategies for implant-associated infections.

Fenn et al. Quinones are the growth factors of human gut microbiota. Microbiome 2017; Vol. 5(1): 1-11