Emerging ribotypes have divergent metabolic phenotypes.

Unlabelled: is a gram-positive spore-forming pathogen that commonly causes diarrheal infections in the developed world. Although is a genetically diverse species, certain ribotypes are overrepresented in human infections. It is unknown if metabolic adaptations are essential for the emergence of these epidemic ribotypes.

Clinical Features and Outcomes of Pediatric and Adult Patients Hospitalized for Coronavirus Disease 2019: A Comparison Across Age Strata.

Background: Coronavirus disease 2019 (COVID-19) continues to cause hospitalizations and severe disease in children and adults.

Methods: This study compared the risk factors, symptoms, and outcomes of children and adults hospitalized for COVID-19 from March 2020 to May 2023 across age strata at 5 US sites participating in the Predicting Viral-Associated Inflammatory Disease Severity in Children with Laboratory Diagnostics and Artificial Intelligence consortium. Eligible patients had an upper respiratory swab that tested positive for severe acute respiratory syndrome coronavirus 2 by nucleic acid amplification.

Phylogenetically diverse bacterial species produce histamine.

Histamine is an important biogenic amine known to impact a variety of patho-physiological processes ranging from allergic reactions, gut-mediated anti-inflammatory responses, and neurotransmitter activity. Histamine is found both endogenously within specialized host cells and exogenously in microbes. Exogenous histamine is produced through the decarboxylation of the amino acid L-histidine by bacterial-derived histidine decarboxylase enzymes.

Interrogation of the mammalian gut-brain axis using LC-MS/MS-based targeted metabolomics with in vitro bacterial and organoid cultures and in vivo gnotobiotic mouse models.

Interest in the communication between the gastrointestinal tract and central nervous system, known as the gut-brain axis, has prompted the development of quantitative analytical platforms to analyze microbe- and host-derived signals. This protocol enables investigations into connections between microbial colonization and intestinal and brain neurotransmitters and contains strategies for the comprehensive evaluation of metabolites in in vitro (organoids) and in vivo mouse model systems. Here we present an optimized workflow that includes procedures for preparing these gut-brain axis model systems: (stage 1) growth of microbes in defined media; (stage 2) microinjection of intestinal organoids; and (stage 3) generation of animal models including germ-free (no microbes), specific-pathogen-free (complete gut microbiota) and specific-pathogen-free re-conventionalized (germ-free mice associated with a complete gut microbiota from a specific-pathogen-free mouse), and Bifidobacterium dentium and Bacteroides ovatus mono-associated mice (germ-free mice colonized with a single gut microbe).

Systems biology approach to functionally assess the pangenome reveals genetic diversity with discriminatory power.

Combatting Clostridioides difficile infections, a dominant cause of hospital-associated infections with incidence and resulting deaths increasing worldwide, is complicated by the frequent emergence of new virulent strains. Here, we employ whole-genome sequencing, high-throughput phenotypic screenings, and genome-scale models of metabolism to evaluate the genetic diversity of 451 strains of C. difficile.

Unraveling the Metabolic Requirements of the Gut Commensal .

Bacteroidetes are the most common bacterial phylum in the mammalian intestine and the effects of several spp. on multiple facets of host physiology have been previously described. Of the spp.

Comparison of Whole Genome Sequencing and Repetitive Element PCR for Multidrug-Resistant Pseudomonas aeruginosa Strain Typing.

Hospital-acquired infections pose significant costly global challenges to patient care. Rapid and sensitive methods to identify potential outbreaks are integral to infection control measures. Whole-genome sequencing (WGS)-based bacterial strain typing provides higher discriminatory power over standard nucleotide banding pattern-based methods such as repetitive sequence-based PCR (rep-PCR).

Fecal Microbiota Transplantation Commonly Failed in Children With Co-Morbidities.

Objectives: Fecal microbiota transplantation (FMT) is arguably the most effective treatment for recurrent Clostridioides difficile infection (rCDI). Clinical reports on pediatric FMT have not systematically evaluated microbiome restoration in patients with co-morbidities. Here, we determined whether FMT recipient age and underlying co-morbidity influenced clinical outcomes and microbiome restoration when treated from shared fecal donor sources.

ATCC 6475 metabolites upregulate the serotonin transporter in the intestinal epithelium.

The serotonin transporter (SERT) readily takes up serotonin (5-HT), thereby regulating the availability of 5-HT within the intestine. In the absence of SERT, 5-HT remains in the interstitial space and has the potential to aberrantly activate the many 5-HT receptors distributed on the epithelium, immune cells and enteric neurons. Perturbation of SERT is common in many gastrointestinal disorders as well as mouse models of colitis.

Neurotransmitter Profiles Are Altered in the Gut and Brain of Mice Mono-Associated with .

Background: Accumulating evidence indicates that the gut microbiota can synthesize neurotransmitters as well as impact host-derived neurotransmitter levels. In the past, it has been challenging to decipher which microbes influence neurotransmitters due to the complexity of the gut microbiota.

Methods: To address whether a single microbe, could regulate important neurotransmitters, we examined genomes and explored neurotransmitter pathways in secreted cell-free supernatant using LC-MS/MS.

Systems biology evaluation of refractory Clostridioides difficile infection including multiple failures of fecal microbiota transplantation.

Background: Fecal microbiota transplantation (FMT) aims to cure Clostridioides difficile infection (CDI) through reestablishing a healthy microbiome and restoring colonization resistance. Although often effective after one infusion, patients with continued microbiome disruptions may require multiple FMTs. In this N-of-1 study, we use a systems biology approach to evaluate CDI in a patient receiving chronic suppressive antibiotics with four failed FMTs over two years.

The metabolic profile of Bifidobacterium dentium reflects its status as a human gut commensal.

Background: Bifidobacteria are commensal microbes of the mammalian gastrointestinal tract. In this study, we aimed to identify the intestinal colonization mechanisms and key metabolic pathways implemented by Bifidobacterium dentium.

Results: B.

-derived y-glutamylcysteine suppresses ER-mediated goblet cell stress and reduces TNBS-driven colonic inflammation.

Endoplasmic reticulum (ER) stress compromises the secretion of MUC2 from goblet cells and has been linked with inflammatory bowel disease (IBD). Although can beneficially modulate mucin production, little work has been done investigating the effects of on goblet cell ER stress. We hypothesized that secreted factors from downregulate ER stress genes and modulates the unfolded protein response (UPR) to promote MUC2 secretion.

Secretes Outer Membrane Vesicles and Promotes Intestinal Inflammation.

Multiple studies have implicated microbes in the development of inflammation, but the mechanisms remain unknown. Bacteria in the genus have been identified in the intestinal mucosa of patients with digestive diseases; thus, we hypothesized that promotes intestinal inflammation. The addition of >50 kDa conditioned media, which contain outer membrane vesicles (OMVs), to colonic epithelial cells stimulated secretion of the proinflammatory cytokines interleukin-8 (IL-8) and tumor necrosis factor (TNF).

Bacteroides ovatus Promotes IL-22 Production and Reduces Trinitrobenzene Sulfonic Acid-Driven Colonic Inflammation.

The intestinal microbiota influences the development and function of the mucosal immune system. However, the exact mechanisms by which commensal microbes modulate immunity is not clear. We previously demonstrated that commensal Bacteroides ovatus ATCC 8384 reduces mucosal inflammation.

Mucin-Degrading Microbes Release Monosaccharides That Chemoattract and Facilitate Colonization of the Human Intestinal Mucus Layer.

It is widely accepted that the pathogen exploits an intestinal environment with an altered microbiota, but the details of these microbe-microbe interactions are unclear. Adherence and colonization of mucus has been demonstrated for several enteric pathogens and it is possible that mucin-associated microbes may be working in concert with . We showed that ribotype-027 adheres to MUC2 glycans and using fecal bioreactors, we identified that associates with several mucin-degrading microbes.

Systems biology analysis of the Clostridioides difficile core-genome contextualizes microenvironmental evolutionary pressures leading to genotypic and phenotypic divergence.

Hospital acquired Clostridioides (Clostridium) difficile infection is exacerbated by the continued evolution of C. difficile strains, a phenomenon studied by multiple laboratories using stock cultures specific to each laboratory. Intralaboratory evolution of strains contributes to interlaboratory variation in experimental results adding to the challenges of scientific rigor and reproducibility.

Reuterin disrupts metabolism and pathogenicity through reactive oxygen species generation.

Antibiotic resistance is one of the world's greatest public health challenges and adjunct probiotic therapies are strategies that could lessen this burden. infection (CDI) is a prime example where adjunct probiotic therapies could decrease disease incidence through prevention. Human-derived is a probiotic that produces the antimicrobial compound reuterin known to prevent colonization of antibiotic-treated fecal microbial communities.

Human intestinal enteroids as a model of -induced enteritis.

is an important nosocomial pathogen that produces toxins to cause life-threatening diarrhea and colitis. Toxins bind to epithelial receptors and promote the collapse of the actin cytoskeleton. toxin activity is commonly studied in cancer-derived and immortalized cell lines.

Healthy Human Gastrointestinal Microbiome: Composition and Function After a Decade of Exploration.

The human gastrointestinal (GI) tract contains communities of microbes (bacteria, fungi, viruses) that vary by anatomic location and impact human health. Microbial communities differ in composition based on age, diet, and location in the gastrointestinal tract. Differences in microbial composition have been associated with chronic disease states.

Microbial Metabolic Capacity for Intestinal Folate Production and Modulation of Host Folate Receptors.

Microbial metabolites, including B complex vitamins contribute to diverse aspects of human health. Folate, or vitamin B, refers to a broad category of biomolecules that include pterin, para-aminobenzoic acid (pABA), and glutamate subunits. Folates are required for DNA synthesis and epigenetic regulation.

Complete Genome Sequence of the Multidrug-Resistant Pseudomonas aeruginosa Endemic Houston-1 Strain, Isolated from a Pediatric Patient with Cystic Fibrosis and Assembled Using Oxford Nanopore and Illumina Sequencing.

Hybrid assembly of Illumina/Nanopore sequence data produced complete circular sequences of the chromosome and a plasmid for the multidrug-resistant Houston-1 strain. This provides a high-quality representative sequence for a lineage endemic to a pediatric cystic fibrosis care center at Texas Children's Hospital.