(formerly
), a non-fermentative bacterium, has been isolated from animals and human clinical specimens. It is naturally resistant to polymyxins, including colistin (CO), and may cause opportunistic ...infections in humans. We isolated six
strains from Senegalese monkey stool. In order to determine whether an efflux pump mechanism was involved in CO resistance in
we evaluated the effects of verapamil (VRP), reserpine (RSP), phe-arg β-naphthylamide dihydrochloride (PAβN) and carbonyl cyanide 3-chloro phenyl hydrazone (CCCP), four efflux pump inhibitors, on these colistin-resistant strains. Using the broth microdilution method, a CO and CCCP combination of 2 µg/mL and 10 µg/mL, respectively, significantly reduced the CO minimal inhibitory concentration (MIC) of
, supporting an efflux pump mechanism. In contrast, VRP, PAβN and RSP did not restore CO susceptibility. A time kill assay showed a bactericidal effect of the CO-CCCP combination. Genomic analysis revealed a potential implication in the CO resistance mechanism of some conserved efflux pumps, such as YejABEF, NorM and EmrAB, as previously reported in other bacteria. An inhibitory effect of the CO-CCCP combination was observed on biofilm formation using the crystal violet method. These results suggest that the intrinsic CO resistance in
is linked to an efflux pump mechanism and that the synergistic effect of CO-CCCP may open a new field to identify new treatments to restore antibiotic efficacy in humans.
Helicobacter pylori
, a human pathogen that colonizes the stomach of 50% of the world’s population, is associated with gastritis, gastric adenocarcinoma, and mucosa-associated lymphoid tissue (MALT) ...lymphoma. Diseases are characterized by severe inflammatory responses in the stomach that are induced by various chemokines and cytokines. Recently, oncostatin M (OSM), an IL-6 family cytokine, was detected in early gastric cancer biopsies. In this study, we showed that
Helicobacter pylori
induced secretion of OSM and overexpression of its type II receptor OSMRβ (OSM/OSMRβ) in a human gastric adenocarcinoma cell line (AGS) over 24 h of infection. Furthermore, we showed that the induction of OSM and OSMRβ was carried out by heat-sensitive
Helicobacter pylori
outer membrane vesicle (OMV) protein. Collectively, our results established, for the first time, a direct relation between
Helicobacter pylori
OMVs and the OSM/OSMRβ signaling axis.
Strain Marseille-Q6994 was isolated from a 72-year-old patient with pneumonia from Bouches-du-Rhône department, in France. Cells were Gram positive, non-motile, catalase and oxidase-negative cocci. ...The major fatty acids were hexadecanoic (47.4%) and tetradecanoic acids (28.3%). 16S rRNA gene sequence comparison suggested that strain Marseille-Q6994 was affiliated to the
Streptococcus
genus.
GroEL
phylogenetic analysis separated strain Marseille-Q6994 in a distinct branch from the closely related
Streptococcus
-type strains with standing in nomenclature. Whole genome sequencing-based methods (OrthoAverage Nucleotide Identity, digital DNA–DNA hybridization and pangenome analysis) supported the classification of the strain into a novel species. Therefore, based on the phenotypic, genomic, and phylogenetic analyses, we propose the name
Streptococcus bouchesdurhonensis
sp. nov for which strain Marseille-Q6994
T
(CSUR Marseille-Q6994 = DSMZ 113892) is the type strain.
Here, we reported two draft genomes of Fusobacterium simiae: strain DSM 19848, initially isolated from monkey dental plaque, and its close relative strain Marseille-Q7035, cultivated from a human ...intra-abdominal abscess puncture fluid. Their genome sizes are 2.4 Mb and 2.5Mb, respectively. Their G+C contents were 27.1% and 27.2%, respectively.
The novel bacterial strain Marseille-P4005
T
was isolated from the stool sample of a healthy donor. It is a Gram-stain negative, non-motile, non-spore-forming rod. It grew optimally at 37 °C and at ...pH 7.0 on 5% sheep blood-enriched Columbia agar after preincubation in a blood-culture bottle supplemented with rumen and blood. This strain does not ferment monosaccharides (except D-tagatose), disaccharides, or polymeric carbohydrates. The major cellular fatty acids were hexadecenoic (24.6%), octadecanoic (22.8%), and tetradecanoic (20.1%) acids. Next-generation sequencing revealed a genome size of 3.2 Mbp with a 56.4 mol% G + C. Phylogenetic analysis based on the 16S rRNA gene highlighted
Agathobaculum desmolans
strain ATCC 43058
T
as the closest related strain. The OrthoANI, AAI, and digital DNA-DNA hybridization values were below the critical thresholds of 95%, 95–96%, and 70%, respectively, to define a novel bacterial species. Antibiotic resistance genes APH(3′)-IIIa,
erm
(B), and
tet
(W) were detected with high identity percentages of 100%, 98.78%, and 97.18% for each gene, respectively. The APH(3′)-IIIa gene confers resistance to amikacin,
erm
(B) gene confers resistance to erythromycin, lincomycin, and clindamycin, while
tet
(W) gene confers resistance to doxycycline and tetracycline. Based on KEGG BlastKOALA analyses, the annotation results showed that our strain could use glucose to produce L-lactate and pyruvate but not acetate or ethanol. Also, strain Marseille-P4005
T
was predicted to use phenylalanine to produce indole, a major intercellular signal molecule within the gut microbial ecosystem. Through having a gene coding for tryptophan synthase beta chain (
trpB
), strain Marseille-P4005
T
could produce L-tryptophan (an essential amino acid) from indole. Strain Marseille-P4005
T
showed its highest prevalence in the human gut (34.19%), followed by the reproductive system (17.98%), according to a query carried out on the Integrated Microbial NGS (IMNGS) platform. Based on phylogenetic, phenotypic, and genomic analyses, we classify strain Marseille-P4005
T
(= CSUR P4005 = CECT 9669), a novel species within the genus
Agathobaculum
, for which the name of
Agathobaculum massiliense
sp. nov. is proposed.
