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International audience; Recent years have been marked by a paradigm shift in the study of the human microbiota, with a re-emergence of culture-dependent approaches. Numerous studies have been devoted to the human microbiota, while studies on the oral microbiota still remain limited. Indeed, various techniques described in the literature may enable an exhaustive study of the microbial composition of a complex ecosystem. In this article, we report different methodologies and culture media described in the literature that can be applied to study the oral microbiota by culture. We report on specific methodologies for targeted culture and specific culture techniques and selection methodologies for cultivating members of the three kingdoms of life commonly found in the human oral cavity, namely, eukaryota, bacteria and archaea. This bibliographic review aims to bring together the various techniques described in the literature, enabling a comprehensive study of the oral microbiota in order to demonstrate its involvement in oral health and diseases.

In recent years, metagenomics and then culturomics, which consists of the multiplication of media and culture conditions and the rapid identification of all bacterial colonies, have generated renewed interest in the human microbiota, and diseases associated with modifications in its composition in particular. The sample transport media included in diverse swab transport systems and the storage conditions are among the factors that influence the results of the culturomics. In this study, we compared the results of culturomics from paired skin, oral and rectal swabs from intensive care unit (ICU) patients using Culture Top sample transport medium as compared to our routine one. From 152 clinical samples, we were able to isolate and identify 45 600 colonies, belonging to 338 different bacterial species. The transport system Culture Top identified 282 different bacterial species, while 244 were identified by our routine system. Of these, 188 different bacterial species were commonly identified using both transport systems, while 94 (27.8 %) and 56 (16.5 %) were only identified using Culture Top and our routine system, respectively (P

To date, the axenic culture of

BackgroundTreponema species as commensals of the human microbiome have a prevalence and function depending on the studied niche. In the oral cavity, treponemes are ubiquitous while they have been strictly linked to rural and ancestral populations in the gastro-intestinal tract and are undetected in urban populations. In this study, an in silico analysis of 1481 metagenomes, selected based on the previous detection of treponemes in such sample types, was conducted to predict putative bacterial antagonists of treponemes, i.e. bacteria present when treponemes are lacking and vice versa. Predicted antagonists were subsequently tested in-vitro against Treponema denticola CSUR P7640.ResultsMost frequent predicted antagonists included members of the Bifidobacteriaceae family (23.3%) among which Bifidobacterium longum was the most significant (63.3% in T- group, p Bacteroides (6.7%) and Streptococcus (13.3%) genera. The relative abundance of the aforementioned taxa was also anticorrelated with that of the Treponema genus in the metagenomes analyzed in this study. B. longum CSUR P7400, Bifidobacterium bifidum CSUR P1194, Bifidobacterium breve CSUR P7882, Bacteroides ovatus CSUR P4577, Bacteroides uniformis CSUR P2248 and Bacteroides thetaiotaomicron CSUR P7324 were able to inhibit the growth of T. denticola with B. longum being the most efficient.ConclusionsThese results highlight an antagonism between Bifidobacterium species, known probiotics and bio-preservatives, and Treponema spp. This may help to explain the variation of Treponema prevalence in high-income countries and middle- and low-income countries which might linked to the differential consumption of fermented dairy foodstuff and processed food and therefore to the phenomenon of nutrition transition.

We report the main characteristics of ‘Selenomonas massiliensis’ sp. nov., strain Marseille-P4036T (= CSUR P4036). The culturomic combined with taxonogenomic methods were used to identify and characterize this new anaerobic bacterial species, which was isolated from an oral sample of a 25-year-old healthy woman. Keywords: Culturomics, oral microbiota, ‘Selenomonas massiliensis’, taxonogenomics

Aim The aim of the present study was to create a tool to evaluate the risk of peri-implantitis according its severity. Methods After ethics committee approval, 43 patients provided signed consent and were included prospectively. Forty-five observations were recorded. The following criteria were recorded: number of implant faces showing bleeding and/or suppuration, pocket depth on at least two faces of the implant, bone loss as a function of the length of the implant evaluated on X-rays, number of implant faces with bacterial plaque, the parameters required for determination of excess cement (screwed or sealed prosthesis, burying of sealed prostheses), periodontal status, glycemia, and annual consumption of tobacco. Each of these parameters was plotted on a chart using Microsoft Excel. Results Seventeen of 45 (37.8%) cases were identified as having high peri-implantitis risk, two of 45 (4.4%) had low risk, and 11 of 45 (24.4%) had moderate risk; 33.3% patients did not have peri-implantitis and were considered at very low risk. Conclusion The observed results applied to the evaluation model are an effective diagnostic tool in assessing the risk of peri-implantitis. The tool takes into account parameters, which have not been taken into account until now. The information is automatically processed and allows early management of peri-implantitis.