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Two strains of Chryseobacterium identified from different experiments are proposed to represent new species. Strain WLa1L2M3T was isolated from the digestive tract of an Oryctes rhinoceros beetle larva. Strain 09-1422T was isolated from a cage housing the stick insect Eurycantha calcarata. Sequence analysis of the 16S rRNA and rpoB genes found both strains to be similar but not identical to other Chryseobacterium species. Whole-genome sequencing suggested the isolates represent new species, with average nucleotide identity values ranging from 74.6 to 80.5 %. Genome-to-genome distance calculations produced values below 25.3 %, and digital DNA–DNA hybridization values were 13.7–29.9 %, all suggesting they are distinct species. The genomic DNA G+C content of WLa1L2M3T is approximately 32.53 %, and of 09-1422T is approximately 35.89 %. The predominant cellular fatty acids of strain WLa1L2M3T are C15 : 0 iso, summed feature 9 (C16 : 0 10OH or C17 : 1 iso ω6c), C17 : 0 iso 3OH, summed feature 3 (C16 : 1 ω7c and/or C16 : 1 ω6c), C15 : 0 iso 3OH, C15 : 0 anteiso and C13 : 0 iso, and those of strain 09-1422T are C15 : 0 iso, summed feature 3 (C16 : 1 ω7c and/or C16 : 1 ω6c), C17 : 0 iso 3OH, C15 : 0 anteiso, C15 : 0 iso 3OH, C16 : 1 ω7c, C17 : 0 2OH and C18 : 0. In addition, physiological and biochemical tests revealed phenotypic differences from related Chryseobacterium type strains. These cumulative data indicate that the two strains represent novel species of the genus Chryseobacterium for which the names Chryseobacterium oryctis sp. nov. and Chryseobacterium kimseyorum sp. nov. are proposed with WLa1L2M3T (=BCRC 81350T=JCM 35215T=CIP 112035T) and 09-1422T (=UCDFST 09-1422T=BCRC 81359T=CIP 112165T), as type strains, respectively.

International audience; The Gram-negative, oxidase-negative, catalase-positive, rod-shaped strain Arafor3T was isolated from forest soil (France). Comparative 16S rRNA gene analysis and phylogenetic analysis based on (1) multilocus sequence analysis (MLSA) with four housekeeping genes (atpD, gyrB, infB and rpoB) and (2) genomes indicated that strain Arafor3T shared 98.83% 16S rRNA gene sequence similarity with the type strain of Serratia fonticola DSM 4576T and was closely related to this same strain in the MLSA and in the phylogenomic tree reconstruction. Average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) comparisons of strain Arafor3T with its nearest neighbor S. fonticola DSM 4576T showed 93.5% identity and 55.7% sequence similarity, respectively, and were lower than the 96% and 70% species-level cut-off values relating to these analyses (Logan et al. in Int J Syst Evol Microbiol 59:2114–21, 2009, https://doi.org/10.1099/ijs.0.013649-0). The strain differed from S. fonticola in that it was urease and arginine dihydrolase negative. The major fatty acids of strain Arafor3T are C16:0, C16:1 ω7c/C16:1 ω6c, C14:0, C14:0 3-OH/16:1 isoI, and C18:1 ω7c. The major respiratory quinone is Q8. The polar lipid profile consisted of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, and 6 unknown lipids. The mol G + C% content of the genomic DNA of strain Arafor3T was 53.49%. Hence, Arafor3T represents a novel species within the genus Serratia, for which the name Serratia silvae sp. nov. is proposed. The type strain is Arafor3T (=LMG 32338T = CIP 111939T).

Strain RHZ10T was isolated from an oak rhizosphere sampled in Reims, France, and characterized to assess its taxonomy. Based on 16S rRNA gene sequence similarity, strain RHZ10T was affiliated to the genus Streptomyces and the closest species were Streptomyces anulatus NRRL B-2000T and Streptomyces pratensis ch24T. Average nucleotide identity and digital DNA–DNA hybridization values were 77.3–92.4 % and 23.0–50.9 %, respectively, when compared to the type strains of fully sequenced related species having a 16S rRNA gene sequence similarity over 98 %. These data suggested that strain RHZ10T represented a novel species within the genus Streptomyces . The genome of RHZ10T was 8.0 Mbp long, had 7 894 predicted coding genes, and a G+C content of 71.7 mol%. Cultures of RHZ10T on ISP 2 medium mostly led to the production a green pigmentation of the core of its colonies in the vegetative mycelium, surrounded by white pigmentation of the aerial mycelium. The main fatty acids of RHZ10T were anteiso-C15 : 0, iso-C16 : 0, anteiso-C17 : 0 and C16 : 0. Polar lipids were phosphatidylethanolamine, diphosphatidylglycerol, unidentified lipids, unidentified phospholipids, unidentified aminolipids and unidentified glycolipids. Its main quinones were MK-9(H6) (69.3 %), MK-9(H4) (17.3 %) and MK-9(H8) (17.0%). Phylogenetic, physiological and chemotaxonomic studies clearly supported that strain RHZ10T represents a novel species within the genus Streptomyces , for which the name Streptomyces durocortorensis sp. nov. is proposed and the type strain is RHZ10T (=DSM 112634T=LMG 32187T=CIP 111907T).

Thirty-three Yersinia strains previously characterized by the French Yersinia National Reference Laboratory (YNRL) and isolated from humans and animals were suspected to belong to six novel species by a recently described core genome multilocus sequence typing scheme. These strains and five additional strains from the YNRL were characterized using a polyphasic taxonomic approach including a phylogenetic analysis based on 500 core genes, determination of average nucleotide identity (ANI), determination of DNA G+C content and identification of phenotypic features. Phylogenetic analysis confirmed that the 38 studied strains formed six well-demarcated clades. ANI values between these clades and their closest relatives were 97.5 %. Distinctive biochemical characteristics were identified in five out of the six novel species. All of these data demonstrated that the 38 strains belong to six novel species of the genus Yersinia : Yersinia artesiana sp. nov., type strain IP42281T (=CIP 111845T=DSM 110725T); Yersinia proxima sp. nov., type strain IP37424T (=CIP 111847T=DSM 110727T); Yersinia alsatica sp. nov., type strain IP38850T (=CIP 111848T=DSM 110726T); Yersinia vastinensis sp. nov., type strain IP38594T (=CIP 111844T=DSM 110738T); Yersinia thracica sp. nov., type strain IP34646T (=CIP 111842T=DSM 110736T); and Yersinia occitanica sp. nov., type strain IP35638T (=CIP 111843T=DSM 110739T).

BackgroundThe re-emergence of whooping cough and geographic disparities in vaccine escape or antimicrobial resistance dynamics, underline the importance of a unified definition of Bordetella pertussis strains. Understanding of the evolutionary adaptations of Bordetella pathogens to humans and animals requires comparative studies with environmental bordetellae.MethodsWe have set-up a unified library of Bordetella genomes by merging previously existing Oxford and Pasteur databases, importing genomes from public repositories, and developing harmonized genotyping schemes. We developed a genus-wide cgMLST genotyping scheme and incorporated a previous B. pertussis cgMLST scheme. Specific schemes were developed to define antigenic, virulence and macrolide resistance profiles. Genomic sequencing of 83 French B. bronchiseptica isolates and of B. tumulicola, B. muralis and B. tumbae type strains was performed.ResultsThe public library currently includes 2,581 Bordetella isolates and their provenance data, and 2,084 genomes. The “classical Bordetella” (B. bronchiseptica, B. parapertussis and B. pertussis), which form a single genomic species (B. bronchiseptica genomic species, BbGS), were overrepresented (n=2,382). The phylogenetic analysis of Bordetella genomes associated the three novel species B. tumulicola, B. muralis and B. tumbae in a clade with B. petrii and revealed 18 yet undescribed species. A sister lineage of the classical bordetellae, provisionally named Bbs lineage II, was uncovered and may represent a novel species (average nucleotide identity with BbGS strains: ∼95%). It comprised strain HT200 from India, two strains of ‘genogroup 6’ from the USA and six clinical isolates from France; this lineage lacked ptxP and its fim2 gene was divergent. Within B. pertussis, vaccine antigen sequence types marked important phylogenetic subdivisions, and macrolide resistance markers (23S_rRNA allele 13 and fhaB3) confirmed the current restriction of this phenotype in China with few exceptions.ConclusionsThe genomic platform provides an expandable resource for unified genotyping of Bordetella strains and will facilitate collective evolutionary and epidemiological understanding of the re-emergence of whooping cough and other Bordetella infections.Data summaryBordetella genomes list and accession numbers: Supplementary Table S4Bordetella genus phylogeny dataset (92 isolates):https://bigsdb.pasteur.fr/cgi-bin/bigsdb/bigsdb.pl?db=pubmlst_bordetella_isolates&page=query&project_list=23&submit=1B. bronchiseptica phylogeny dataset (213 isolates):https://bigsdb.pasteur.fr/cgi-bin/bigsdb/bigsdb.pl?db=pubmlst_bordetella_isolates&page=query&project_list=24&submit=1B. pertussis phylogeny (124 isolates):https://bigsdb.pasteur.fr/cgi-bin/bigsdb/bigsdb.pl?db=pubmlst_bordetella_isolates&page=query&project_list=25&submit=1iTOL interactive trees: https://itol.embl.de/shared/1l7Fw0AvKOoCF

A bacterial strain, named For3T, was isolated from forest soil sampled in Champenoux, France. Based on its 16S rRNA gene sequence, the strain was affiliated to the family Streptomycetaceae and, more specifically, to the genus Streptomyces . The strain had 99.93% 16S rRNA gene sequence similarity to its closest relative strains Streptomyces pratensis ATCC 33331T, Streptomyces anulatus ATCC 27416T, Streptomyces setonii NRRL ISP-5322T and Kitasatospora papulosa NRRL B-16504T. The phylogenomic tree using the genome blast distance phylogeny method showed that the closest relative strain was Streptomyces atroolivaceus NRRL ISP-5137T and that For3T represents a new branch among the Streptomyces . Genome relatedness indexes revealed that the average nucleotide identity and digital DNA–DNA hybridization values between For3T and its closest phylogenomic relative ( S. atroolivaceus NRRL ISP-5137T) were 88.39 and 39.2 %, respectively. The G+C content of the genome was 71.4 mol% and its size was 7.96 Mb with 7492 protein-coding genes. Strain For3T harboured complete metabolic pathways absent in the closest relative strains such as cellulose biosynthesis, glycogen degradation I, glucosylglycerate biosynthesis I. Anteiso-C15:0, iso-C15:0, anteiso-C17:0 and MK-9(H4)/MK-9(H6) were the predominant cellular fatty acids and respiratory quinones, respectively. Phenotypic and genomic data supported the assignment of strain For3T to a novel species Streptomyces silvae sp. nov., within the genus Streptomyces , for which the type strain is For3T (=CIP 111908T=LMG 32186T).

International audience; Natural products serve as chemical blueprints for most antibiotics in clinical use. The evolutionary process by which these molecules arise is inherently accompanied by the co-evolution of resistance mechanisms that shorten the clinical lifetime of any given class of antibiotics1. Virginiamycin acetyltransferase (Vat) enzymes are resistance proteins that provide protection against streptogramins2, potent antibiotics against Gram-positive bacteria that inhibit the bacterial ribosome3. Owing to the challenge of selectively modifying the chemically complex, 23-membered macrocyclic scaffold of group A streptogramins, analogues that overcome the resistance conferred by Vat enzymes have not been previously developed2. Here we report the design, synthesis, and antibacterial evaluation of group A streptogramin antibiotics with extensive structural variability. Using cryo-electron microscopy and forcefield-based refinement, we characterize the binding of eight analogues to the bacterial ribosome at high resolution, revealing binding interactions that extend into the peptidyl tRNA-binding site and towards synergistic binders that occupy the nascent peptide exit tunnel. One of these analogues has excellent activity against several streptogramin-resistant strains of Staphylococcus aureus, exhibits decreased rates of acetylation in vitro, and is effective at lowering bacterial load in a mouse model of infection. Our results demonstrate that the combination of rational design and modular chemical synthesis can revitalize classes of antibiotics that are limited by naturally arising resistance mechanisms.

Genome sequence analysis of two strains collected in Canada at the end of the 1970s and deposited in 1998 at the Collection de l’Institut Pasteur has led to the taxonomic description of a novel fish-associated species in the genus Flavobacterium . Both strains, CIP 105534T and CIP 105535, were yellow-pigmented, Gram-stain-negative, non-spore-forming rod-shaped bacteria that exhibited gliding motility. They grew aerobically in a temperature range from 5 to 30 °C with optimal growth at 25 °C on trypticase soy or Reasoner's 2A agar but they did not grow on marine agar. Their major fatty acid profiles were similar, consisting of iso-C15 : 0, C16 : 1 ω7c and/or iso-C15 : 0 2-OH (shown as summed feature 3), C16 : 0 3-OH, iso-C17 : 0 3-OH and C16 : 0. The major polyamine was sym-homospermidine. Phosphatidylethanolamine and, most notably, ornithine-containing lipid OL2 and unidentified aminophospholipid APL1 were major polar lipids. A yellow pigment spot was visible after chromatographic analysis. The predominant respiratory quinone was MK-6. The G+C content of the two genomes was 34 mol% and their size was around 5.8 Mb. Comparison of the 16S rRNA gene sequences with those of the closely related type strains showed high levels of relatedness with Flavobacterium collinsii and Flavobacterium pectinovorum . All average nucleotide identity (ANI) and digital DNA–DNA hybridization values estimated against publicly available Flavobacterium genome assemblies were lower than 90 and 30 %, respectively. Phylogenetic, phenotypic and chemotaxonomic data indicated that the two strains represent a novel species of the genus Flavobacterium , for which the name Flavobacterium bizetiae sp. nov. is proposed. The type strain is CIP 105534T (=LMG 1342T). The unique ability of F. bizetiae to use melibiose as a sole source of carbon could provide a simple phenotypic test to discriminate F. bizetiae from its closest relatives.