Raoultibacter phocaeensis sp. nov., A New Bacterium Isolated from a Patient with Recurrent Clostridioides difficile Infection.

Strain Marseille-P8396T is a new species isolated from a patient with recurrent Clostridioides difficile infection. Its optimal growth condition was observed at pH of 7.5, at a temperature of 37 °C after 72 h of incubation on Columbia agar (BioMérieux, France) with 5% sheep blood, under an anaerobic atmosphere. Strain Marseille-P8396T cells are Gram-positive rods, nonspore-forming, and nonmotile. 9-Octadecenoic acid (41.9%), hexadecanoic acid (22.5%), and 11-Octadecenoic acid (11.0%) represent the major fatty acid of strain Marseille-P8396T. The optimal growth condition of strain Marseille-P8396T was observed at 37 °C after 72 h of incubation under an anaerobic atmosphere, pH ranging from 6.5 to 8.5, and salinity of 0.5 to 7.5%. Its genome (Genbank Accession Number NZ_CABDUX000000000) size was 3.86 Mb with 59.4 mol% of G+C content, and 3,124 protein-coding genes. The 16S rRNA gene sequence (Genbank accession number NR_148574.1) of strain Marseille-P8396T shared a similarity of 98.71% with Raoultibacter timonensis strain Marseille-P3277T (Genbank accession number NR_148574.1), currently the most closely related species. However, the OrthoANI and digital DNA-DNA hybridization values with Raoultibacter timonensis strain Marseille-P3277T (Genbank accession number OEPT01000000) were 80.15% and 24.6 ± 4.8%, respectively. Taken together, these results clearly demonstrate that strain Marseille-P8396T represents a new species within the genus Raoultibacter described here as Raoultibacter phocaeensis sp. nov. (type strain: Marseille-P8396T=CSUR8396T=CECT 30202T).

Population Diversity of Antibiotic Resistant Enterobacterales in Samples From Wildlife Origin in Senegal: Identification of a Multidrug Resistance Transposon Carrying bla CTX-M-15 in Escherichia coli.

Introduction: The role of wildlife in the transmission of antimicrobial resistant (AMR) is suspected but scarcely reported in current studies. Therefore, we studied the dynamics and prevalence of antibiotic-resistant Enterobacterales in antibiotic-limited areas of Senegal. Materials and Methods: We collected fecal samples from monkeys and apes (N = 226) and non-fecal environmental samples (N = 113) from Senegal in 2015 and 2019. We grew the samples on selective media, subsequently isolated AMR Enterobacterales, and then sequenced their genomes. Results: We isolated 72 different Enterobacterales among which we obtained a resistance rate of 65% for colistin (N = 47/72) and 29% for third generation-cephalosporin (C3G) (29%, N = 21/72). Interestingly, almost 46% of our isolates, among Enterobacter sp., Citrobacter cronae and Klebsiella aerogenes, belong to 34 new STs. Moreover, the genes bla CTX-M-15, bla TEM1B , sul2, dfrA14, qnrs, aph(3''), aph(6), tetA, and tetR harbored within a transposon on the IncY plasmid of ST224 Escherichia coli were transferred and inserted into a ST10 E. coli phage coding region. Conclusion: Wildlife constitutes a rich, unexplored reservoir of natural microbial diversity, AMR genes and international resistant clones pathogenic in humans. The presence of a transposon that carries AMR genes is intriguing since no antibiotics are used in the non-human primates we studied.

Gemella massiliensis sp. nov., a new bacterium isolated from the human sputum.

Thanks to its ability to isolate previously uncultured bacterial species, culturomics has dynamized the study of the human microbiota. A new bacterial species, Gemella massiliensis Marseille-P3249T, was isolated from a sputum sample of a healthy French man. Strain Marseille-P3249T is a facultative anaerobe, catalase-negative, Gram positive, coccus, and unable to sporulate. The major fatty acids were C16:0 (34%), C18:1n9 (28%), C18:0 (15%) and C18:2n6 (13%). Its 16S rRNA sequence exhibits a 98.3% sequence similarity with Gemella bergeri strain 617-93T, its phylogenetically closest species with standing in nomenclature. Its digital DNA-DNA hybridization (dDDH) and OrthoANI values with G. bergeri of only 59.7 ± 5.6% and 94.8%, respectively. These values are lower than the thresholds for species delineation (> 70% and > 95%, respectively). This strain grows optimally at 37 °C and its genome is 1.80 Mbp long with a 30.5 mol% G + C content. Based on these results, we propose the creation of the new species Gemella massilienis sp. nov., strain Marseille-P3249T (= CSUR P3249 = DSMZ 103940).

Multidrug-Resistant Klebsiella pneumoniae Clones from Wild Chimpanzees and Termites in Senegal.

Antibiotic resistance genes exist naturally in various environments far from human usage. Here, we investigated multidrug-resistant Klebsiella pneumoniae, a common pathogen of chimpanzees and humans. We screened antibiotic-resistant K. pneumoniae from 48 chimpanzee stools and 38 termite mounds (n = 415 samples) collected in protected areas in Senegal. The microsatellite method was used to identify chimpanzee individuals (n = 13). Whole-genome sequencing was performed on K. pneumoniae complex isolates to identify antibiotic-resistant genes and characterize clones. We found a high prevalence of carbapenem-resistant K. pneumoniae among chimpanzee isolates (18/48 samples from 7/13 individuals) and ceftriaxone resistance among both chimpanzee individuals (19/48) and termite mounds (7/415 termites and 3/38 termite mounds). The blaOXA-48 and the blaKPC-2 genes were carried by international pOXA-48 and pKPC-2 plasmids, respectively. The ESBL plasmid carried blaCTX-M-15, blaTEM-1B, and blaOXA-1 genes. Genome sequencing of 56 isolates identified two major clones associated with hospital-acquired infections of K. pneumoniae (ST307 and ST147) in chimpanzees and termites, suggesting circulation of strains between the two species, as chimpanzees feed on termites. The source and selection pressure of these clones in this environment need to be explored.

Running after ghosts: are dead bacteria the dark matter of the human gut microbiota?

The human gut microbiota has been explored by a wide range of culture-dependent and culture-independent methods, revealing that many microbes remain uncharacterized and uncultured. In this work, we aimed to confirm the hypothesis that some of the species present in the human gut microbiota remain uncultured not because of culture limitations, but because all members of such species are dead before reaching the end of the gastro-intestinal tract.We evaluate this phenomenon by studying the microbial viability and culturability of the human gut microbiota from the fresh fecal materials of eight healthy adults. For the first time, we applied fluorescence-activated cell sorting (FACS) combined with 16S metagenomics analysis and microbial culturomics.We identified a total of 1,020 bacterial OTUs and 495 bacterial isolates through metagenomics and culturomics, respectively. Among the FACS metagenomics results, only 735 bacterial OTUs were alive, comprising on average 42% of known species and 87% of relative abundance per individual. The remaining uncultured bacteria were rare, dead, or injured.Our strategy allowed us to shed light on the dark matter of the human gut microbiota and revealed that both metagenomics and culturomics approaches are needed for greater insight into the diversity and richness of bacteria in the human gut microbiota. Further work on culture is needed to enhance the repertoire of cultured gut bacteria by targeting low abundance bacteria and optimizing anaerobic sample conditioning and processing to preserve the viability of bacteria.

Anaerococcus urinimassiliensis sp. nov., a new bacterium isolated from human urine.

To date there are thirteen species validly assigned to the genus Anaerococcus. Most of the species in this genus are anaerobic and of human origin. Anaerococcus urinimassiliensis sp. nov., strain Marseille-P2143T is member of family Peptoniphilaceae, which was isolated from the urine of a 17-year-old boy affected by autoimmune hepatitis and membranoproliferative glomerulonephritis using the culturomic approach. In the current study, a taxono-genomics method was employed to describe this new species. The strain Marseille-P2143T was gram positive cocci with translucent colonies on blood agar. Its genome was 2,189,509 bp long with a 33.5 mol% G + C content and exhibited 98.48% 16S rRNA similarity with Anaerococcus provencensis strain 9,402,080. When Anaerococcus urinomassiliensis strain Marseill-P2143T is compared with closely related species, the values ranged from 71.23% with A. hydrogenalis strain DSM 7454T (NZ_ABXA01000052.1) to 90.64% with A. provencensis strain 9402080T (NZ_HG003688.1). This strain has implemented the repertoire of known bacteria of the human urinary tract.