Amadou Hamidou Togo

Culture of previously uncultured members of the human gut microbiota by culturomics

Metagenomics revolutionized the understanding of the relations among the human microbiome, health and diseases, but generated a countless number of sequences that have not been assigned to a known microorganism1. The pure culture of prokaryotes, neglected in recent decades, remains essential to elucidating the role of these organisms2. We recently introduced microbial culturomics, a culturing approach that uses multiple culture conditions and matrix-assisted laser desorption/ionization–time of flight and 16S rRNA for identification2. Here, we have selected the best culture conditions to increase the number of studied samples and have applied new protocols (fresh-sample inoculation; detection of microcolonies and specific cultures of Proteobacteria and microaerophilic and halophilic prokaryotes) to address the weaknesses of the previous studies3–5. We identified 1,057 prokaryotic species, thereby adding 531 species to the human gut repertoire: 146 bacteria known in humans but not in the gut, 187 bacteria and 1 archaea not previously isolated in humans, and 197 potentially new species. Genome sequencing was performed on the new species. By comparing the results of the metagenomic and culturomic analyses, we show that the use of culturomics allows the culture of organisms corresponding to sequences previously not assigned. Altogether, culturomics doubles the number of species isolated at least once from the human gut.

Repeated Artemisinin-Based Combination Therapies in a Malaria Hyperendemic Area of Mali: Efficacy, Safety, and Public Health Impact

Artemisinin-based combination therapies (ACTs) are the first-line treatment of uncomplicated malaria. The public health benefit and safety of repeated administration of a given ACT are poorly studied. We conducted a randomized trial comparing artemether-lumefantrine, artesunate plus amodiaquine (AS+AQ) and artesunate plus sulfadoxine-pyrimethamine (AS+SP) in patients 6 months of age and older with uncomplicated malaria in Mali from July 2005 to July 2007. The patient received the same initial treatment of each subsequent uncomplicated malaria episode except for treatment failures where quinine was used. Overall, 780 patients were included. Patients in the AS+AQ and AS+SP arms had significantly less risk of having malaria episodes; risk ratio (RR) = 0.84 (P = 0.002) and RR = 0.80 (P = 0.001), respectively. The treatment efficacy was similar and above 95% in all arms. Although all drugs were highly efficacious and well tolerated, AS+AQ and AS+SP were associated with less episodes of malaria.

Hugonella massiliensis gen. nov., sp. nov., genome sequence, and description of a new strictly anaerobic bacterium isolated from the human gut

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 AT8T (=CSUR P2118 = DSM 101782) from stool specimens collected from a 51‐year‐old obese French woman. Strain AT8T is a strictly anaerobic, nonmotile, nonspore‐forming gram‐positive coccus that do not exhibit catalase and oxidase activities. 16S rDNA‐based identification of strain AT8T 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 AT8T 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 RNAs. 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 AT8T as the type strain.

Noncontiguous finished genome sequence and description of Paenibacillus ihumii sp. nov. strain AT5

Paenibacillus ihumii sp. nov. strain AT5 (= CSUR 1981 = DSM 100664) is the type strain of P. ihumii. This bacterium was isolated from a stool sample from a morbidly obese French patient using the culturomics approach. The genome of this Gram-negative, facultative anaerobic, motile and spore-forming bacillus is 5 924 686 bp long. Genomic analysis identified 253 (5%) of 3812 genes as ORFans and at least 2599 (50.03%) of 5194 orthologous proteins not shared with the closest phylogenetic species.

Fournierella massiliensis, gen. nov., sp. nov., a new human-associated member of the family Ruminococcaceae.

An anaerobic bacterium, strain AT2T, was isolated from the fresh stool sample of a healthy French man using the culturomics approach. The 16S rRNA gene sequence analysis showed that strain AT2T had 95.2 % nucleotide sequence similarity with Gemmiger formicilisATCC 27749T, the phylogenetically closest species with standing in nomenclature. Cells are Gram-stain-negative, catalase- and oxidase-negative, obligately anaerobic, non-motile, non-spore-forming, rod-shaped, and the bacilli were mesothermophilic. The major fatty acids were C16 : 0 (43.8 %) and C18 : 1n9 (20 %). The DNA G+C content of the strain based on its genome sequence was 56.8 mol%. Based on the phenotypic, biochemical and phylogenetic analysis, we propose the creation of the genus Fournierella gen. nov., which contains strain AT2T (=CSUR P2014T=DSM 100451T) as the type strain of the type species Fournierella massiliensis gen. nov., sp. nov.

'Eisenbergiella massiliensis', a new species isolated from human stool collected after bariatric surgery.

We report the principal characteristics of ‘Eisenbergiella massiliensis’ sp. nov. strain AT11 (CSURP = P2120, DSM = 101499) that was isolated from a stool sample collected after bariatric surgery of a 56-year-old obese French woman.

“Ruminococcus phoceensis,” a new species identified from human stool from an obese patient before bariatric surgery

We report here the main characteristics of a new bacterium species, “Ruminococcus phoceensis” strain AT10 (CSUR = P2086, DSM = 100837). This bacterium was isolated from the faeces of a 37-year-old woman from Marseille, France, with morbid obesity before bariatric surgery.

Noncontiguous finished genome sequence and description of Enterococcus massiliensis sp. nov.

Enterococcus massiliensis strain sp. nov. (= CSUR P1927 = DSM 100308) is a new species within the genus Enterococcus. This strain was first isolated from a fresh stool sample of a man during culturomics study of intestinal microflora. Enterococcus massiliensis is a Gram-positive cocci, facultative anaerobic and motile. E. massiliensis is negative for mannitol and positive for β-galactosidase, contrary to E. gallinarum. The complete genome sequence is 2 712 841 bp in length with a GC content of 39.6% and contains 2617 protein-coding genes and 70 RNA genes, including nine rRNA genes.

'Lactomassilus timonensis,' a new anaerobic bacterial species isolated from the milk of a healthy African mother.

We here report the main characteristics of a new anaerobic bacterial genus and species ‘Lactomassilus timonensis,’ strain Marseille-P4641T (CSUR = P4641), isolated by microbial culturomics from the milk of a 35-year-old healthy lactating mother from Mali.

Butyricimonas phoceensis sp. nov., a new anaerobic species isolated from the human gut microbiota of a French morbidly obese patient

Butyricimonas phoceensis strain AT9 (= CSUR 2478 = DSM 100838) was isolated from a stool sample from a morbidly obese French patient living in Marseille using the culturomics approach. The genome of this Gram-negative-staining, anaerobic and non–spore forming rod bacillus is 4 736 949 bp long and contains 3947 protein-coding genes. Genomic analysis identified 173 genes as ORFans (4.5%) and 1650 orthologous proteins (42%) not shared with the closest phylogenetic species, Butyricimonas virosa. Its major fatty acid was the branched acid iso-C15:0 (62.3%).