Four bacterial strains were isolated from two different colony sources of the wax moth
. They were characterized by a polyphasic approach including 16S rRNA gene sequence analysis, core-genome ...analysis, average nucleotide identity (ANI) analysis, digital DNA-DNA hybridization (dDDH), determination of G+C content, screening of antibiotic resistance genes, and various phenotypic analyses. Initial analysis of 16S rRNA gene sequence identities indicated that strain GAL7
was potentially very closely related to
and
, having 99.5-99.9 % sequence similarity. However, further analysis of whole genome sequences revealed a genome size of 3.69 Mb, DNA G+C content of 42.35 mol%, and low dDDH and ANI values between the genomes of strain GAL7
and closest phylogenetic relative
NBRC 100478
of 59.0 and 94.5 %, respectively, indicating identification of a putative new
species. In addition, all novel strains encoded the atypical vancomycin-resistance gene
. Results of phylogenomic, physiological and phenotypic characterization confirmed that strain GAL7
represented a novel species within the genus
, for which the name
sp. nov. is proposed. The type strain is GAL7
(=DSM 112306
=NCTC 14608
).
Intestinal macrophages play a vital role in the maintenance of gut homeostasis through signals derived from the microbiota. We previously demonstrated that microbial‐derived metabolites can shape the ...metabolic functions of macrophages. Here, we show that antibiotic‐induced disruption of the intestinal microbiota dramatically alters both the local metabolite environment and the metabolic functions of macrophages in the colon. Broad‐spectrum antibiotic administration in mice increased the expression of the large neutral amino acid transporter LAT1 and accordingly, amino acid uptake. Subsequently, antibiotic administration enhanced the metabolic functions of colonic macrophages, increasing phosphorylation of components of mammalian/mechanistic target of rapamycin signalling pathways, with increased expression of genes involved in glycolysis and oxidative phosphorylation (OXPHOS), increased mitochondrial function, increased rate of extracellular acidification (ECAR; measure of glycolysis) and increased rate of oxygen consumption (OCR; measure of OXPHOS). Small bowel macrophages were less metabolically active than their colonic counterparts, with macrophage metabolism in the small intestine being independent of the microbiota. Finally, we reveal tissue‐resident Tim4+ CD4+ macrophages exhibit enhanced fatty acid uptake alongside reduced fatty acid synthesis compared to recruited macrophages. Thus, the microbiota shapes gut macrophage metabolism in a compartment‐specific manner, with important implications for monocyte recruitment and macrophage differentiation.
Antibiotic‐induced disruption of the intestinal microbiota dramatically alters the local metabolite environment in the intestine and metabolic functions of intestinal macrophages. These effects are compartment specific, with a profound effect on colonic macrophages rather than their small intestinal counterparts. The capacity of antibiotics to modulate intestinal macrophage metabolic function was also subset specific, limited to recruited versus resident macrophages.
Background
Dextran sodium sulphate (DSS) is commonly used to induce intestinal inflammation in rodents. Despite its continuing importance as a model system for examining IBD pathogenesis, the mucosal ...and systemic immune responses have not been comprehensively documented.
Aims
The purpose of this study was to dissect functional and phenotypic changes in both immune compartments associated with acute and chronic DSS-induced colitis.
Methods
C57BL/6 mice were exposed to 3% DSS for 6 days followed by 20 days of water, and organs (spleens, MLN and colons) were harvested during both acute and chronic phases of colitis to examine innate and adaptive cell populations.
Results
As early as 1 day post DSS, significant changes in the percentage, distribution and activation status of all innate cell populations examined were noted. These striking differences continued in systemic and mucosal lymphoid tissues throughout the acute phase (days 5–12). Significantly, during the late acute and chronic phases T and B cells accumulated in the colon. In contrast, in the spleens of chronically inflamed mice T and B cells were significantly decreased whereas neutrophils, macrophages, and IL-6 and IL-17 positive cells were increased.
Conclusions
Our data provides important insights into the mucosal and systemic immune responses induced by DSS administration. Notably, we show that adaptive immune responses are induced during both acute and chronic colitis. This will facilitate a more informed and sophisticated use of this model both for investigating basic mechanisms of intestinal inflammation and for the evaluation of potential new therapeutic agents for IBD.
Prophylactic administration of oral probiotics is associated with significant reductions in the morbidity and mortality of necrotising enterocolitis in preterm infants. We document the first case of ...Bifidobacterium longum subsp. infantis sub-clinical bacteraemia, in an extremely low birth weight preterm infant, since introduction of routine probiotic treatment at the Norfolk and Norwich University Hospital 10 years ago. Whole genome comparisons confirmed the isolated strain likely originated from the probiotic product.
•Bifidobacterium probiotics are used to prevent preterm necrotising enterocolitis.•We report our first case of Bifidobacterium bacteraemia in a 10-year period.•The isolated strain was confirmed same as probiotic strain by genomic analysis.•Literature review shows Bifidobacterium longum subsp. infantis bacteraemia is rare.
toxinotype D, toxinotype E, and gastroenteritis-linked BEC/CPILE-positive strains have never been reported in healthy children. We isolated, whole-genome sequenced and bioinformatically characterised ...three
isolates-type D (IQ1), type E (IQ2) and BEC/CPILE-positive (IQ3), recovered from the stools of three healthy two-year-olds, which were further compared to 128
genomes available from NCBI. The analysis uncovered a previously under-described putative toxin gene
(alveolysin) encoded by isolates IQ2 and IQ3, which appeared to be a clade-specific trait associated with strains from domestic animals. A plasmid analysis indicated that the iota-toxin was encoded on a near-intact previously described plasmid pCPPB-1 in type E strain IQ2. The BEC genes
and
were carried on a near-identical pCPOS-1 plasmid previously associated with Japanese gastroenteritis outbreaks. Furthermore, a close phylogenetic relatedness was inferred between the French
type E isolates cp515.17 and newly sequenced IQ2, suggesting geographical links. This study describes novel
isolates from healthy individuals which encode important toxin genes, indicating the potential spread of these veterinary and clinically important strains and mobile genetic elements, and highlights areas for future research.
Bifidobacteria constitute a substantial proportion of the human gut microbiota. There are currently many bifidobacterial strains with claimed probiotic attributes. The mechanism through which these ...strains reside within their host and exert benefits to the host is far from fully understood. We have shown in the case of Bifidobacterium breve UCC2003 that a cell surface exopolysaccharide (EPS) plays a role in in vivo persistence. Biosynthesis of two possible EPSs is controlled by a bidirectional gene cluster which guides alternate EPS synthesis by means of a reorienting promoter. The presence of EPS impacts on host immune response: the wild type, EPS-positive B. breve UCC2003 efficiently evades the adaptive B-cell host response, while its isogenic, EPS-deficient equivalent elicits a strong adaptive immune response. Functionally, EPS positive strains were more resilient to presence of acid and bile and were responsible for reduced colonization levels of Citrobacter rodentium, a gut pathogen. In conclusion, we have found that EPS is important in host interactions and pathogen protection, the latter indicative of a probiotic ability for the EPS of B. breve UCC2003.
Almost one third of Earth's land surface is arid, with deserts alone covering more than 46 million square kilometres. Nearly 2.1 billion people inhabit deserts or drylands and these regions are also ...home to a great diversity of plant and animal species including many that are unique to them. Aridity is a multifaceted environmental stress combining a lack of water with limited food availability and typically extremes of temperature, impacting animal species across the planet from polar cold valleys, to Andean deserts and the Sahara. These harsh environments are also home to diverse microbial communities, demonstrating the ability of bacteria, fungi and archaea to settle and live in some of the toughest locations known. We now understand that these microbial ecosystems i.e. microbiotas, the sum total of microbial life across and within an environment, interact across both the environment, and the macroscopic organisms residing in these arid environments. Although multiple studies have explored these microbial communities in different arid environments, few studies have examined the microbiota of animals which are themselves arid-adapted. Here we aim to review the interactions between arid environments and the microbial communities which inhabit them, covering hot and cold deserts, the challenges these environments pose and some issues arising from limitations in the field. We also consider the work carried out on arid-adapted animal microbiotas, to investigate if any shared patterns or trends exist, whether between organisms or between the animals and the wider arid environment microbial communities. We determine if there are any patterns across studies potentially demonstrating a general impact of aridity on animal-associated microbiomes or benefits from aridity-adapted microbiomes for animals. In the context of increasing desertification and climate change it is important to understand the connections between the three pillars of microbiome, host genome and environment.
The gut microbiota’s function in regulating health has seen it linked to disease progression in several cancers. However, there is limited research detailing its influence in breast cancer (BrCa). ...This study found that antibiotic-induced perturbation of the gut microbiota significantly increases tumor progression in multiple BrCa mouse models. Metagenomics highlights the common loss of several bacterial species following antibiotic administration. One such bacteria, Faecalibaculum rodentium, rescued this increased tumor growth. Single-cell transcriptomics identified an increased number of cells with a stromal signature in tumors, and subsequent histology revealed an increased abundance of mast cells in the tumor stromal regions. We show that administration of a mast cell stabilizer, cromolyn, rescues increased tumor growth in antibiotic treated animals but has no influence on tumors from control cohorts. These findings highlight that BrCa-microbiota interactions are different from other cancers studied to date and suggest new research avenues for therapy development.
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•Microbiota disturbances promote tumor growth in several breast cancer models•Increased tumor volume positively correlates with stromal mast cell density•Supplementation with a commensal restores tumor growth to normal
Pathophysiology; Microbiology; Cancer
ABSTRACT
Here, we describe the draft genome sequence of
Bifidobacterium breve
DSM 32583 isolated from human milk obtained from a healthy mother. Potentially, this
B. breve
strain could serve as a ...probiotic.
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