Phages and cancer immunity: Gut bacteria are involved in the education of T cell immune responses, and the intestinal ecosystem influences anticancer immunity. Fluckiger et al. report microbial antigens that might cross-react with antigens associated with tumor cells. They found that a type of intestinal bacteria called enterococci harbor a bacteriophage that modulates immune responses. In mouse models, administration of enterococci containing the bacteriophage boosted T cell responses after treatment with chemotherapy or programmed cell death protein 1 (PD-1) blockade. In humans, the presence of the bacteriophage was associated with improved survival after PD-1 immunotherapy. A fraction of human T cells specific for naturally processed melanoma epitopes appeared to be able to recognize microbial peptides. This “molecular mimicry” may represent cross-reactivity between tumors and microbial antigens. Science , this issue p. 936

We report the main characteristics of Haloferax massiliensis strain Arc-Hr(T) (= CSUR P974) isolated from stool specimen of a 22-year-old Amazonian obese female patient.

The human gut is composed of a large diversity of microorganisms, which have been poorly described. Here, using culturomics, a new concept based on the variation in culture conditions and MALDI ‐ TOF MS identification, we proceed to explore the microbial diversity of the complex ecosystem of the human gut. Using this approach, we isolated strain AT 8 ^T (= CSUR P2118 = DSM 101782) from stool specimens collected from a 51‐year‐old obese French woman. Strain AT 8 ^T is a strictly anaerobic, nonmotile, nonspore‐forming gram‐positive coccus that do not exhibit catalase and oxidase activities. 16S rDNA ‐based identification of strain AT 8 ^T demonstrated 92% gene sequence similarity with Eggerthella lenta DSM 2243, the phylogenetically closed validly named type species. Here, we present a set of features for the strain AT 8 ^T and the description of its complete genome sequence and annotation. The 2,091,845 bp long genome has a G+C content of 63.46% and encodes1,849 predicted genes; 1,781 were protein‐coding genes, and 68 were RNA s. On the basis of the characteristics reported here, we propose the creation of a new bacterial genus Hugonella gen. nov. , belonging to the Eggerthellaceae family and including Hugonella massiliensis gen. nov., sp. nov. , strain AT 8 ^T as the type strain.

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.

By applying the culturomics concept and using culture conditions containing a high salt concentration, we herein isolated the first known halophilic archaeon colonizing the human gut. Here we described its phenotypic and biochemical characterization as well as its genome annotation. Strain Arc-Hr^T (= CSUR P0974 = CECT 9307) was mesophile and grew optimally at 37 °C and pH 7. Strain Arc-Hr^T was also extremely halophilic with an optimal growth observed at 15% NaCl. It showed gram-negative cocci, was strictly aerobic, non-motile and non-spore-forming, and exhibited catalase and oxidase activities. The 4,015,175 bp long genome exhibits a G + C% content of 65.36% and contains 3911 protein-coding and 64 predicted RNA genes. PCR-amplified 16S rRNA gene of strain Arc-Hr^T yielded a 99.2% sequence similarity with Haloferax prahovense, the phylogenetically closest validly published species in the Haloferax genus. The DDH was of 50.70 ± 5.2% with H. prahovense, 53.70 ± 2.69% with H. volcanii, 50.90 ± 2.64% with H. alexandrinus, 52.90 ± 2.67% with H. gibbonsii and 54.30 ± 2.70% with H. lucentense. The data herein represented confirm strain Arc-Hr^T as a unique species and consequently we propose its classification as representative of a novel species belonging to the genus Haloferax, as Haloferax massiliense sp. nov.