Awa Diop

Microbial culturomics unravels the halophilic microbiota repertoire of table salt: description of Gracilibacillus massiliensis sp. nov.

Background Microbial culturomics represents an ongoing revolution in the characterization of environmental and human microbiome. Methods By using three media containing high salt concentration (100, 150, and 200 g/L), the halophilic microbial culturome of a commercial table salt was determined. Results Eighteen species belonging to the Terrabacteria group were isolated including eight moderate halophilic and 10 halotolerant bacteria. Gracilibacillus massiliensis sp. nov., type strain Awa-1T (=CSUR P1441=DSM 29726), is a moderately halophilic gram-positive, non-spore-forming rod, and is motile by using a flagellum. Strain Awa-1T shows catalase activity but no oxidase activity. It is not only an aerobic bacterium but also able to grow in anaerobic and microaerophilic atmospheres. The draft genome of G. massiliensis is 4,207,226 bp long, composed of 13 scaffolds with 36.05% of G+C content. It contains 3,908 genes (3,839 protein-coding and 69 RNA genes). At least 1,983 (52%) orthologous proteins were not shared with the closest phylogenetic species. Hundred twenty-six genes (3.3%) were identified as ORFans. Conclusions Microbial culturomics can dramatically improve the characterization of the food and environmental microbiota repertoire, deciphering new bacterial species and new genes. Further studies will clarify the geographic specificity and the putative role of these new microbes and their related functional genetic content in environment, health, and disease.

The impact of culturomics on taxonomy in clinical microbiology

Over the past decade, new culture methods coupled to genome and metagenome sequencing have enabled the number of isolated bacterial species with standing in nomenclature to rise to more than 15,000 whereas it was only 1791 in 1980. ‘Culturomics’, a new approach based on the diversification of culture conditions, has enabled the isolation of more than 1000 distinct human-associated bacterial species since 2012, including 247 new species. This strategy was demonstrated to be complementary to metagenome sequencing for the exhaustive study of the human microbiota and its roles in health and diseases. However, by identifying a large number of new bacterial species in a short time, culturomics has highlighted a need for taxonomic approaches adapted to clinical microbiology that would include the use of modern and reproducible tools, including high throughput genomic and proteomic analyses. Herein, we review the development of culturomics and genomics in the clinical microbiology field and their impact on bacterial taxonomy.

Olegusella massiliensis gen. nov., sp. nov., strain KHD7T, a new bacterial genus isolated from the female genital tract of a patient with bacterial vaginosis

Strain KHD7T, a Gram-stain-positive rod-shaped, non-sporulating, strictly anaerobic bacterium, was isolated from the vaginal swab of a woman with bacterial vaginosis. We studied its phenotypic characteristics and sequenced its complete genome. The major fatty acids were C16:0 (44%), C18:2n6 (22%), and C18:1n9 (14%). The 1,806,744 bp long genome exhibited 49.24% G+C content; 1549 protein-coding and 51 RNA genes. Strain KHD7T exhibited a 93.5% 16S rRNA similarity with Olsenella uli, the phylogenetically closest species in the family Coriobacteriaceae. Therefore, strain KHD7T is sufficiently distinct to represent a new genus, for which we propose the name Olegusella massiliensis gen. nov., sp. nov. The type strain is KHD7T.

Corrigendum to "Noncontiguous finished genome sequence and description of Bartonellamastomydis sp. nov." [New Microbes New Infect (2018) Mar 28;25:60-70]

[This corrects the article DOI: 10.1016/j.nmni.2018.03.005.].

Noncontiguous finished genome sequence and description of Bartonella mastomydis sp. nov.

Bartonella mastomydis sp. nov. strain 008 is the type strain of B. mastomydis sp. nov., a new species within the genus Bartonella. This strain was isolated from Mastomys erythroleucus rodents trapped in the Sine-Saloum region of Senegal. Here we describe the features of this organism, together with the complete genome sequence and its annotation. The 2 044 960 bp long genomes with 38.44% G + C content contains 1674 protein-coding and 42 RNA genes, including three rRNA genes.

Microbial culturomics to isolate halophilic bacteria from table salt: genome sequence and description of the moderately halophilic bacterium Bacillus salis sp. nov.

Bacillus salis strain ES3T (= CSUR P1478 = DSM 100598) is the type strain of B. salis sp. nov. It is an aerobic, Gram-positive, moderately halophilic, motile and spore-forming bacterium. It was isolated from commercial table salt as part of a broad culturomics study aiming to maximize the culture conditions for the in-depth exploration of halophilic bacteria in salty food. Here we describe the phenotypic characteristics of this isolate, its complete genome sequence and annotation, together with a comparison with closely related bacteria. Phylogenetic analysis based on 16S rRNA gene sequences indicated 97.5% similarity with Bacillus aquimaris, the closest species. The 8 329 771 bp long genome (one chromosome, no plasmids) exhibits a G+C content of 39.19%. It is composed of 18 scaffolds with 29 contigs. Of the 8303 predicted genes, 8109 were protein-coding genes and 194 were RNAs. A total of 5778 genes (71.25%) were assigned a putative function.

Description of three new Peptoniphilus species cultured in the vaginal fluid of a woman diagnosed with bacterial vaginosis: Peptoniphilus pacaensis sp. nov., Peptoniphilus raoultii sp. nov., and Peptoniphilus vaginalis sp. nov.

Three previously unidentified Gram‐positive anaerobic coccoid bacteria, strains KhD‐2T, KHD4T, and Kh‐D5T, isolated from a vaginal swab, were characterized using the taxonogenomics concept. The phylogenic analysis, phenotypic characteristics, and genotypic data presented in this report attest that these three bacteria are distinct from previously known bacterial species with standing in nomenclature and represent three new Peptoniphilus species. Strain KhD‐2T is most closely related to Peptoniphilus sp. DNF00840 and Peptoniphilus harei (99.7% and 98.2% identity, respectively); strain KHD4T to Peptoniphilus lacrimalis (96%) and strain Kh‐D5T to Peptoniphilus coxii (97.2%). Strains KhD‐2T, KHD4T, and Kh‐D5T DNA G+C contents are, respectively, 34.23%, 31.87%, and 49.38%; their major fatty acid was C16:0 (41.6%, 32.0%, and 36.4%, respectively). We propose that strains KhD‐2T (=CSUR P0125 = DSM 101742), KHD4T (=CSUR P0110 = CECT 9308), and Kh‐D5T (=CSUR P2271 = DSM 101839) be the type strains of the new species for which the names Peptoniphilus vaginalis sp. nov., Peptoniphilus raoultii sp. nov., and Peptoniphilu pacaensis sp. nov., are proposed, respectively.

Characterization of a novel Gram‐stain‐positive anaerobic coccus isolated from the female genital tract: Genome sequence and description of Murdochiella vaginalis sp. nov.

Strain Marseille‐P2341T, a nonmotile, nonspore‐forming, Gram‐stain‐positive anaerobic coccus, was isolated in the vaginal specimen of a patient with bacterial vaginosis using culturomics. Its growth occurred at temperatures ranging from 25 to 42°C, with pH between 6.5 and 8.5, and at NaCl concentrations lower than 5%. The major fatty acids were C18:1n9 (27.7%) and C16:0 (24.4%). Its genome is 1,671,491 bp long with 49.48 mol% of G+C content. It is composed of 1,501 genes: 1,446 were protein‐coding genes and 55 were RNAs. Strain Marseille‐P2341T shared 97.3% of 16S rRNA gene sequence similarity with Murdochiella asaccharolytica, the phylogenetically closest species. These results enabled the classification of strain Marseille‐P2341T as a new species of the genus Murdochiella for which we proposed the name Murdochiella vaginalis sp. nov. The type strain is strain Marseille‐P2341T (=DSM 102237, =CSUR P2341).

Genome sequence and description of Gracilibacillus timonensis sp. nov. strain Marseille-P2481T, a moderate halophilic bacterium isolated from the human gut microflora

Microbial culturomics represents an ongoing revolution in the characterization of the human gut microbiota. By using three culture media containing high salt concentrations (10, 15, and 20% [w/v] NaCl), we attempted an exhaustive exploration of the halophilic microbial diversity of the human gut and isolated strain Marseille‐P2481 (= CSUR P2481 = DSM 103076), a new moderately halophilic bacterium. This bacterium is a Gram‐positive, strictly aerobic, spore‐forming rod that is motile by use of a flagellum and exhibits catalase, but not oxidase activity. Strain Marseille‐P2481 was cultivated in media containing up to 20% (w/v) NaCl, with optimal growth being obtained at 37°C, pH 7.0–8.0, and 7.5% [w/v] NaCl). The major fatty acids were 12‐methyl‐tetradecanoic acid and hexadecanoic acid. Its draft genome is 4,548,390 bp long, composed of 11 scaffolds, with a G+C content of 39.8%. It contains 4,335 predicted genes (4,266 protein coding including 89 pseudogenes and 69 RNA genes). Strain Marseille‐P2481 showed 96.57% 16S rRNA sequence similarity with Gracilibacillus alcaliphilus strain SG103T, the phylogenetically closest species with standing in nomenclature. On the basis of its specific features, strain Marseille‐P2481T was classified as type strain of a new species within the genus Gracilibacillus for which the name Gracilibacillus timonensis sp. nov. is formally proposed.

Draft Genome Sequence of Ezakiella peruensis Strain M6.X2, a Human Gut Gram-Positive Anaerobic Coccus

ABSTRACT We report here the draft genome sequence of Ezakiella peruensis strain M6.X2T. The draft genome is 1,672,788 bp long and harbors 1,589 predicted protein-encoding genes, including 26 antibiotic resistance genes with 1 gene encoding vancomycin resistance. The genome also exhibits 1 clustered regularly interspaced short palindromic repeat region and 333 genes acquired by horizontal gene transfer.