title: A new mathematical model of bacterial interactions in two-species oral biofilms.
abstract: Periodontitis are bacterial inflammatory diseases, where the bacterial biofilms present on the tooth-supporting tissues switch from a healthy state towards a pathogenic state. Among bacterial species involved in the disease, Porphyromonas gingivalis has been shown to induce dysbiosis, and to induce virulence of otherwise healthy bacteria like Streptococcus gordonii. During biofilm development, primary colonizers such as S. gordonii first attach to the surface and allow the subsequent adhesion of periodontal pathogens such as P. gingivalis. Interactions between those two bacteria have been extensively studied during the adhesion step of the biofilm. The aim of the study was to understand interactions of both species during the growing phase of the biofilm, for which little knowledge is available, using a mathematical model. This two-species biofilm model was based on a substrate-dependent growth, implemented with damage parameters, and validated thanks to data obtained on experimental biofilms. Three different hypothesis of interactions were proposed and assayed using this model: independence, competition between both bacteria species, or induction of toxicity by one species for the other species. Adequacy between experimental and simulated biofilms were found with the last hypothetic mathematical model. This new mathematical model of two species bacteria biofilms, dependent on different substrates for growing, can be applied to any bacteria species, environmental conditions, or steps of biofilm development. It will be of great interest for exploring bacterial interactions in biofilm conditions.
authors.affiliation: EA 1254 Microbiologie Risques infectieux, Université de Rennes 1, Université Européenne de Bretagne, Rennes, France.
authors.forename: Bénédicte
authors.initials: B
authors.lastname: Martin
authors.affiliation: EA 1254 Microbiologie Risques infectieux, Université de Rennes 1, Université Européenne de Bretagne, Rennes, France.
authors.forename: Zohreh
authors.initials: Z
authors.lastname: Tamanai-Shacoori
authors.affiliation: EA 1254 Microbiologie Risques infectieux, Université de Rennes 1, Université Européenne de Bretagne, Rennes, France.
authors.forename: Julie
authors.initials: J
authors.lastname: Bronsard
authors.affiliation: Institut de Recherche Mathématique de Rennes, Université de Rennes I, CNRS, Université Européenne de Bretagne, Rennes, France.
authors.forename: Franck
authors.initials: F
authors.lastname: Ginguené
authors.affiliation: EA 1254 Microbiologie Risques infectieux, Université de Rennes 1, Université Européenne de Bretagne, Rennes, France.|Centre hospitalo-universitaire, Rennes, France.
authors.forename: Vincent
authors.initials: V
authors.lastname: Meuric
authors.affiliation: Institut de Recherche Mathématique de Rennes, Université de Rennes I, CNRS, Université Européenne de Bretagne, Rennes, France.
authors.forename: Fabrice
authors.initials: F
authors.lastname: Mahé
authors.affiliation: EA 1254 Microbiologie Risques infectieux, Université de Rennes 1, Université Européenne de Bretagne, Rennes, France.|Centre hospitalo-universitaire, Rennes, France.
authors.forename: Martine
authors.initials: M
authors.lastname: Bonnaure-Mallet
mesh_terms: D018441:Biofilms; D006801:Humans; D008855:Microscopy, Electron, Scanning; D008954:Models, Biological; D009055:Mouth / Q000382:microbiology*; D016966:Porphyromonas gingivalis / Q000254:growth & development / Q000472:pathogenicity / Q000502:physiology*; D054773:Streptococcus gordonii / Q000254:growth & development / Q000472:pathogenicity / Q000502:physiology*