Multi-level analysis of gut microbiome extracellular vesicles-host interaction reveals a connection to gut-brain axis signaling.

Unlabelled: Microbiota-released extracellular vesicles (MEVs) have emerged as a key player in intercellular signaling. However, their involvement in the gut-brain axis has been poorly investigated. We hypothesize that MEVs cross host cellular barriers and deliver their cargoes of bioactive compounds to the brain.

Dual bacteriocin and extracellular vesicle-mediated inhibition of by the potential probiotic candidate UO.C249.

Unlabelled: () is one of the most common causes of foodborne infections worldwide and a major contributor to diarrheal diseases. This study aimed to explore the ability of commensal gut bacteria to control infection. Bacterial strains from the intestinal mucosa of broilers were screened against ATCC BAA1153.

Modulation of Staphylococcus aureus gene expression during proliferation in platelet concentrates with focus on virulence and platelet functionality.

Staphylococcus aureus is a well-documented bacterial contaminant in platelet concentrates (PCs), a blood component used to treat patients with platelet deficiencies. This bacterium can evade routine PC culture screening and cause septic transfusion reactions. Here, we investigated the gene expression modulation within the PC niche versus trypticase soy media (TSB) of S.

Comparative virulome analysis of four Staphylococcus epidermidis strains from human skin and platelet concentrates using whole genome sequencing.

is one of the predominant bacterial contaminants in platelet concentrates (PCs), a blood component used to treat bleeding disorders. PCs are a unique niche that triggers biofilm formation, the main pathomechanism of infections. We performed whole genome sequencing of four strains isolated from skin of healthy human volunteers (AZ22 and AZ39) and contaminated PCs (ST10002 and ST11003) to unravel phylogenetic relationships and decipher virulence mechanisms compared to 24 complete genomes in GenBank.

A Two Bacteriocinogenic Ligilactobacillus Strain Association Inhibits Growth, Adhesion, and Invasion of Salmonella in a Simulated Chicken Gut Environment.

In this study, we aimed to develop a protective probiotic coculture to inhibit the growth of Salmonella enterica serovar Typhimurium in the simulated chicken gut environment. Bacterial strains were isolated from the digestive mucosa of broilers and screened in vitro against Salmonella Typhimurium ATCC 14028. A biocompatibility coculture test was performed, which identified two biocompatible strains, Ligilactobacillus salivarius UO.

Proof of concept for detection of staphylococcal enterotoxins in platelet concentrates as a novel safety mitigation strategy.

Background And Objectives: Staphylococcus aureus is a predominant contaminant of platelet concentrates (PCs) that can evade detection during screening with culture methods. Importantly, S. aureus produces staphylococcal enterotoxins (SEs) during PC storage, which are linked to slow growth and enhanced biofilm formation.

Draft Genome Sequences of 18 Strains Isolated from a Human Stool Sample.

We announce the draft genome sequences of 12 , 4 , and 2 strains, among which was a newly isolated species, bacterium UO.H1004. These isolates produce health-benefiting short-chain fatty acids (SCFAs) and the neurotransmitter γ-aminobutyric acid (GABA) in various concentrations.

Contamination of platelet concentrates with Staphylococcus aureus induces significant modulations in platelet functionality.

Background And Objectives: Platelet concentrates (PCs) contaminated with Staphylococcus aureus can escape detection during PC screening, causing septic transfusion reactions. This study aimed to determine the impact of S. aureus contamination on platelet metabolism and functionality during PC storage.

Secondary Metabolites of Actinomycetales as Potent Quorum Sensing Inhibitors Targeting Gram-Positive Pathogens: In Vitro and In Silico Study.

Anti-virulence agents are non-bacteriostatic and non-bactericidal emerging therapeutic options which hamper the production of virulence factors in pathogenic flora. In and , regulation of virulence genes' expression occurs through the cyclic peptide-mediated accessory gene regulator () and its ortholog quorum sensing systems, respectively. In the present study, we screened a set of 54 actinomycetales secondary metabolites as novel anti-virulence compounds targeting quorum sensing system of the Gram-positive bacteria.

Staphylococcus epidermidis undergoes global changes in gene expression during biofilm maturation in platelet concentrates.

Background: Staphylococcus epidermidis forms surface-attached aggregates (biofilms) when grown in platelet concentrates (PCs). Comparative transcriptome analyses were undertaken to investigate differential gene expression of S. epidermidis biofilms grown in PCs.

Metabolic dependent and independent pH-drop shuts down VirSR quorum sensing in Clostridium perfringens.

Clostridium perfringens produces various exotoxins and enzymes that cause food poisoning and gas gangrene. The genes involved in virulence are regulated by the agr-like quorum sensing (QS) system, which consists of a QS signal synthesis system and a VirSR two-component regulatory system (VirSR TCS) which is a global regulatory system composed of signal sensor kinase (VirS) and response regulator (VirR). We found that the perfringolysin O gene (pfoA) was transiently expressed during mid-log phase of bacterial growth; its expression was rapidly shut down thereafter, suggesting the existence of a self-quorum quenching (sQQ) system.

Understanding the antimicrobial activity behind thin- and thick-rolled copper plates.

The aim of this study was to compare the antibacterial properties of the surfaces of copper plates that were rolled to a thickness of 25 and 100 μm. Differences in topology of 25- and 100-μm-thick copper plates were studied using scanning electron microscopy (SEM), atomic force microscopy (AFM), and X-ray diffraction (XRD). Antibacterial activity of the copper surfaces was tested against strains of Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Listeria monocytogenes, Salmonella typhimurium, Streptococcus sp.

The abundance of functional genes, cbbL, nifH, amoA and apsA, and bacterial community structure of intertidal soil from Arabian Sea.

The Gulf of Cambay is a trumpet-shaped inlet of the Arabian Sea, located along the west coast of India and confronts a high tidal range with strong water currents. The region belongs to a semi-arid zone and saline alkaline intertidal soils are considered biologically extreme. The selected four soil types (S1-S4) were affected by salinity, alkalinity and sodicity.

Unravelling the carbon and sulphur metabolism in coastal soil ecosystems using comparative cultivation-independent genome-level characterisation of microbial communities.

Bacterial autotrophy contributes significantly to the overall carbon balance, which stabilises atmospheric CO2 concentration and decelerates global warming. Little attention has been paid to different modes of carbon/sulphur metabolism mediated by autotrophic bacterial communities in terrestrial soil ecosystems. We studied these pathways by analysing the distribution and abundance of the diagnostic metabolic marker genes cbbM, apsA and soxB, which encode for ribulose-1,5-bisphosphate carboxylase/oxygenase, adenosine phosphosulphate reductase and sulphate thiohydrolase, respectively, among different contrasting soil types.

Differential distribution and abundance of diazotrophic bacterial communities across different soil niches using a gene-targeted clone library approach.

Diazotrophs are key players of the globally important biogeochemical nitrogen cycle, having a significant role in maintaining ecosystem sustainability. Saline soils are pristine and unexplored habitats representing intriguing ecosystems expected to harbour potential diazotrophs capable of adapting in extreme conditions, and these implicated organisms are largely obscure. Differential occurrence of diazotrophs was studied by the nifH gene-targeted clone library approach.

Comparative molecular analysis of chemolithoautotrophic bacterial diversity and community structure from coastal saline soils, Gujarat, India.

Background: Soils harbour high diversity of obligate as well as facultative chemolithoautotrophic bacteria that contribute significantly to CO2 dynamics in soil. In this study, we used culture dependent and independent methods to assess the community structure and diversity of chemolithoautotrophs in agricultural and coastal barren saline soils (low and high salinity). We studied the composition and distribution of chemolithoautotrophs by means of functional marker gene cbbL encoding large subunit of ribulose-1,5-bisphosphate carboxylase/oxygenase and a phylogenetic marker 16S rRNA gene.

Application of targeted metagenomics to explore abundance and diversity of CO₂-fixing bacterial community using cbbL gene from the rhizosphere of Arachis hypogaea.

Sequestration of CO(2) by autotrophic bacteria is a key process of biogeochemical carbon cycling in soil ecosystem. Rhizosphere is a rich niche of microbial activity and diversity, influenced by change in atmospheric CO(2). Structural changes in rhizosphere composition influence microbial communities and the nutrient cycling.