ABSTRACT
BACKGROUND: Recovery colleges provide personalised educational mental health support for people who self-refer. The research evidence supporting them is growing, with key components and the positive experiences of attendees reported. However, the quantitative outcome evidence and impact on economic outcomes is limited. AIMS: To evaluate the impact of attending a UK recovery college for students who receive a full educational intervention. METHOD: This is a pre- and post-intervention study, with predominantly quantitative methods. Participants recruited over an 18-month period (01.2020-07.2021) completed self-reported well-being (Short Warwick-Edinburgh Mental Wellbeing Scale (SWEMWBS)) and recovery (Process of Recovery (QPR)) surveys, and provided details and evidence of employment and educational status. Descriptive statistics for baseline data and Shapiro-Wilk, Wilcoxon signed-rank and paired t-tests were used to compare pre- and post-intervention scores, with Hedges' g-statistic as a measure of effect size. Medical records were reviewed and a brief qualitative assessment of changes reported by students was conducted. RESULTS: Of 101 student research participants, 84 completed the intervention. Well-being (mean SWEMWBS scores 17.3 and 21.9; n = 80) and recovery (mean QPR scores 27.2 and 38.8; n = 75) improved significantly (P < 0.001; Hedges' g of 1.08 and 1.03). The number of economically inactive students reduced from 53 (69%) to 19 (24.4%). No research participants were referred for specialist mental health support while students. 'Within-self' and 'practical' changes were described by students following the intervention. CONCLUSIONS: Findings detail the largest self-reported pre-post data-set for students attending a recovery college, and the first data detailing outcomes of remote delivery of a recovery college.
ABSTRACT
There is a compelling need to find drugs active against Mycobacterium tuberculosis (Mtb). 4'-Phosphopantetheinyl transferase (PptT) is an essential enzyme in Mtb that has attracted interest as a potential drug target. We optimized a PptT assay, used it to screen 422,740 compounds, and identified raltitrexed, an antineoplastic antimetabolite, as the most potent PptT inhibitor yet reported. While trying unsuccessfully to improve raltitrexed's ability to kill Mtb and remove its ability to kill human cells, we learned three lessons that may help others developing antibiotics. First, binding of raltitrexed substantially changed the configuration of the PptT active site, complicating molecular modeling of analogs based on the unliganded crystal structure or the structure of cocrystals with inhibitors of another class. Second, minor changes in the raltitrexed molecule changed its target in Mtb from PptT to dihydrofolate reductase (DHFR). Third, the structure-activity relationship for over 800 raltitrexed analogs only became interpretable when we quantified and characterized the compounds' intrabacterial accumulation and transformation.
Subject(s)
Mycobacterium tuberculosis , Neoplasms , Quinazolines , Thiophenes , Transferases (Other Substituted Phosphate Groups) , Humans , Mycobacterium tuberculosis/metabolism , Thymidylate Synthase/metabolism , Bacterial Proteins/metabolismABSTRACT
4'-Phosphopantetheinyl transferase (PptT) is an essential enzyme for Mycobacterium tuberculosis (Mtb) survival and virulence and therefore an attractive target for a tuberculosis therapeutic. In this work, two modeling-informed approaches toward the isosteric replacement of the amidinourea moiety present in the previously reported PptT inhibitor AU 8918 are reported. Although a designed 3,5-diamino imidazole unexpectedly adopted an undesired tautomeric form and was inactive, replacement of the amidinourea moiety afforded a series of active PptT inhibitors containing 2,6-diaminopyridine scaffolds.
ABSTRACT
Amyotrophic Lateral Sclerosis (ALS) is a fatal neurodegenerative disease characterized by progressive motor neuron dysfunction and loss. A portion of ALS cases are caused by mutation of the proteasome shuttle factor Ubiquilin 2 (UBQLN2), but the molecular pathway leading from UBQLN2 dysfunction to disease remains unclear. Here, we demonstrate that UBQLN2 regulates the domesticated gag-pol retrotransposon 'paternally expressed gene 10 (PEG10)' in human cells and tissues. In cells, the PEG10 gag-pol protein cleaves itself in a mechanism reminiscent of retrotransposon self-processing to generate a liberated 'nucleocapsid' fragment, which uniquely localizes to the nucleus and changes the expression of genes involved in axon remodeling. In spinal cord tissue from ALS patients, PEG10 gag-pol is elevated compared to healthy controls. These findings implicate the retrotransposon-like activity of PEG10 as a contributing mechanism in ALS through the regulation of gene expression, and restraint of PEG10 as a primary function of UBQLN2.
Subject(s)
Amyotrophic Lateral Sclerosis , Neurodegenerative Diseases , Humans , Amyotrophic Lateral Sclerosis/genetics , Retroelements , Neurodegenerative Diseases/genetics , Adaptor Proteins, Signal Transducing/metabolism , Motor Neurons/metabolism , Mutation , Autophagy-Related Proteins/metabolism , Ubiquitins/metabolism , Cell Cycle Proteins/metabolism , DNA-Binding Proteins/metabolism , RNA-Binding Proteins/metabolism , Apoptosis Regulatory Proteins/metabolismABSTRACT
The COVID-19 pandemic altered the way many people worked. Remote and creative ways were favoured and utilised for consultation activities. In this paper, we draw attention to how we have used creative methods over the teleconferencing platform 'ZOOM' to consult with children and their parents when we were unable to consult with them face-to-face. We document a clear timeline of how we have worked together to co-create an animation and information sheet about receiving outpatient parenteral antimicrobial therapy (OPAT). We identify the opportunities and challenges we faced.
ABSTRACT
Rising antimicrobial resistance challenges our ability to combat bacterial infections. The problem is acute for tuberculosis (TB), the leading cause of death from infection before COVID-19. Here, we developed a framework for multiple pharmaceutical companies to share proprietary information and compounds with multiple laboratories in the academic and government sectors for a broad examination of the ability of ß-lactams to kill Mycobacterium tuberculosis (Mtb). In the TB Drug Accelerator (TBDA), a consortium organized by the Bill & Melinda Gates Foundation, individual pharmaceutical companies collaborate with academic screening laboratories. We developed a higher order consortium within the TBDA in which four pharmaceutical companies (GlaxoSmithKline, Sanofi, MSD, and Lilly) collectively collaborated with screeners at Weill Cornell Medicine, the Infectious Disease Research Institute (IDRI), and the National Institute of Allergy and Infectious Diseases (NIAID), pharmacologists at Rutgers University, and medicinal chemists at the University of North Carolina to screen â¼8900 ß-lactams, predominantly cephalosporins, and characterize active compounds. In a striking contrast to historical expectation, 18% of ß-lactams screened were active against Mtb, many without a ß-lactamase inhibitor. One potent cephaloporin was active in Mtb-infected mice. The steps outlined here can serve as a blueprint for multiparty, intra- and intersector collaboration in the development of anti-infective agents.
Subject(s)
COVID-19 , Mycobacterium tuberculosis , Animals , Drug Industry , Mice , SARS-CoV-2 , Universities , beta-Lactams/pharmacologyABSTRACT
A newly validated target for tuberculosis treatment is phosphopantetheinyl transferase, an essential enzyme that plays a critical role in the biosynthesis of cellular lipids and virulence factors in Mycobacterium tuberculosis. The structure-activity relationships of a recently disclosed inhibitor, amidinourea (AU) 8918 (1), were explored, focusing on the biochemical potency, determination of whole-cell on-target activity for active compounds, and profiling of selective active congeners. These studies show that the AU moiety in AU 8918 is largely optimized and that potency enhancements are obtained in analogues containing a para-substituted aromatic ring. Preliminary data reveal that while some analogues, including 1, have demonstrated cardiotoxicity (e.g., changes in cardiomyocyte beat rate, amplitude, and peak width) and inhibit Cav1.2 and Nav1.5 ion channels (although not hERG channels), inhibition of the ion channels is largely diminished for some of the para-substituted analogues, such as 5k (p-benzamide) and 5n (p-phenylsulfonamide).
Subject(s)
Bacterial Proteins/metabolism , Guanidine/analogs & derivatives , Mycobacterium tuberculosis/enzymology , Transferases (Other Substituted Phosphate Groups)/metabolism , Urea/analogs & derivatives , Bacterial Proteins/antagonists & inhibitors , Binding Sites , Crystallography, X-Ray , Guanidine/chemistry , Guanidine/metabolism , Guanidine/pharmacology , Kinetics , Microbial Sensitivity Tests , Molecular Conformation , Molecular Dynamics Simulation , Mycobacterium tuberculosis/drug effects , Structure-Activity Relationship , Transferases (Other Substituted Phosphate Groups)/antagonists & inhibitors , Urea/chemistry , Urea/metabolism , Urea/pharmacologyABSTRACT
"Viable but nonculturable" states of bacteria pose challenges for environmental and clinical microbiology, but their biological mechanisms remain obscure. Mycobacterium tuberculosis (Mtb), the leading cause of death from infection until the coronavirus disease 2019 pandemic, affords a notable example of this phenotype. Mtb can enter into a "differentially detectable" (DD) state associated with phenotypic antimicrobial resistance. In this state, Mtb cells are viable but undetectable as colony-forming units. We found that Mtb cells enter the DD state when they undergo sublethal oxidative stress that damages their DNA, proteins, and lipids. In addition, their replication process is delayed, allowing time for repair. Mycobacterium bovis and its derivative, BCG, fail to enter the DD state under similar conditions. These findings have implications for tuberculosis latency, detection, relapse, treatment monitoring, and development of regimens that overcome phenotypic antimicrobial resistance.
Subject(s)
COVID-19 , Mycobacterium tuberculosis , Tuberculosis , Humans , Mycobacterium tuberculosis/metabolism , Oxidative Stress , SARS-CoV-2 , Tuberculosis/metabolismABSTRACT
Phosphopantetheinyl hydrolase, PptH (Rv2795c), is a recently discovered enzyme from Mycobacterium tuberculosis that removes 4'-phosphopantetheine (Ppt) from holo-carrier proteins (CPs) and thereby opposes the action of phosphopantetheinyl transferases (PPTases). PptH is the first structurally characterized enzyme of the phosphopantetheinyl hydrolase family. However, conditions for optimal activity of PptH have not been defined, and only one substrate has been identified. Here, we provide biochemical characterization of PptH and demonstrate that the enzyme hydrolyzes Ppt in vitro from more than one M. tuberculosis holo-CP as well as holo-CPs from other organisms. PptH provided the only detectable activity in mycobacterial lysates that dephosphopantetheinylated acyl carrier protein M (AcpM), suggesting that PptH is the main Ppt hydrolase in M. tuberculosis. We could not detect a role for PptH in coenzyme A (CoA) salvage, and PptH was not required for virulence of M. tuberculosis during infection of mice. It remains to be determined why mycobacteria conserve a broadly acting phosphohydrolase that removes the Ppt prosthetic group from essential CPs. We speculate that the enzyme is critical for aspects of the life cycle of M. tuberculosis that are not routinely modeled. IMPORTANCE Tuberculosis (TB), caused by Mycobacterium tuberculosis, was the leading cause of death from an infectious disease before COVID, yet the in vivo essentiality and function of many of the protein-encoding genes expressed by M. tuberculosis are not known. We biochemically characterize M. tuberculosis's phosphopantetheinyl hydrolase, PptH, a protein unique to mycobacteria that removes an essential posttranslational modification on proteins involved in synthesis of lipids important for the bacterium's cell wall and virulence. We demonstrate that the enzyme has broad substrate specificity, but it does not appear to have a role in coenzyme A (CoA) salvage or virulence in a mouse model of TB.
Subject(s)
Bacterial Proteins/metabolism , Mycobacterium tuberculosis/enzymology , Pantetheine/analogs & derivatives , Phosphoric Diester Hydrolases/metabolism , Animals , Cell Wall/metabolism , Female , Humans , Lipids/biosynthesis , Mice , Mice, Inbred C57BL , Pantetheine/metabolism , Protein Processing, Post-Translational , Tuberculosis/pathology , Virulence/physiologyABSTRACT
Bacterial chaperones ClpB and DnaK, homologs of the respective eukaryotic heat shock proteins Hsp104 and Hsp70, are essential in the reactivation of toxic protein aggregates that occur during translation or periods of stress. In the pathogen Mycobacterium tuberculosis (Mtb), the protective effect of chaperones extends to survival in the presence of host stresses, such as protein-damaging oxidants. However, we lack a full understanding of the interplay of Hsps and other stress response genes in mycobacteria. Here, we employ genome-wide transposon mutagenesis to identify the genes that support clpB function in Mtb. In addition to validating the role of ClpB in Mtb's response to oxidants, we show that HtpG, a homolog of Hsp90, plays a distinct role from ClpB in the proteotoxic stress response. While loss of neither clpB nor htpG is lethal to the cell, loss of both through genetic depletion or small molecule inhibition impairs recovery after exposure to host-like stresses, especially reactive nitrogen species. Moreover, defects in cells lacking clpB can be complemented by overexpression of other chaperones, demonstrating that Mtb's stress response network depends upon finely tuned chaperone expression levels. These results suggest that inhibition of multiple chaperones could work in concert with host immunity to disable Mtb.
Subject(s)
Endopeptidase Clp/metabolism , Mycobacterium tuberculosis/metabolism , Stress, Physiological/physiology , Bacterial Proteins/metabolism , HSP70 Heat-Shock Proteins/metabolism , HSP90 Heat-Shock Proteins/metabolism , Heat-Shock Proteins/metabolism , Molecular Chaperones/metabolism , Mycobacterium tuberculosis/geneticsABSTRACT
As ß-lactams are reconsidered for the treatment of tuberculosis (TB), their targets are assumed to be peptidoglycan transpeptidases, as verified by adduct formation and kinetic inhibition of Mycobacterium tuberculosis (Mtb) transpeptidases by carbapenems active against replicating Mtb. Here, we investigated the targets of recently described cephalosporins that are selectively active against non-replicating (NR) Mtb. NR-active cephalosporins failed to inhibit recombinant Mtb transpeptidases. Accordingly, we used alkyne analogs of NR-active cephalosporins to pull down potential targets through unbiased activity-based protein profiling and identified over 30 protein binders. None was a transpeptidase. Several of the target candidates are plausibly related to Mtb's survival in an NR state. However, biochemical tests and studies of loss of function mutants did not identify a unique target that accounts for the bactericidal activity of these beta-lactams against NR Mtb. Instead, NR-active cephalosporins appear to kill Mtb by collective action on multiple targets. These results highlight the ability of these ß-lactams to target diverse classes of proteins.
ABSTRACT
A defining characteristic of treating tuberculosis is the need for prolonged administration of multiple drugs. This may be due in part to subpopulations of slowly replicating or nonreplicating Mycobacterium tuberculosis bacilli exhibiting phenotypic tolerance to most antibiotics in the standard treatment regimen. Confounding this problem is the increasing incidence of heritable multidrug-resistant M. tuberculosis A search for new antimycobacterial chemical scaffolds that can kill phenotypically drug-tolerant mycobacteria uncovered tricyclic 4-hydroxyquinolines and a barbituric acid derivative with mycobactericidal activity against both replicating and nonreplicating M. tuberculosis Both families of compounds depleted M. tuberculosis of intrabacterial magnesium. Complete or partial resistance to both chemotypes arose from mutations in the putative mycobacterial Mg2+/Co2+ ion channel, CorA. Excess extracellular Mg2+, but not other divalent cations, diminished the compounds' cidality against replicating M. tuberculosis These findings establish depletion of intrabacterial magnesium as an antimicrobial mechanism of action and show that M. tuberculosis magnesium homeostasis is vulnerable to disruption by structurally diverse, nonchelating, drug-like compounds.IMPORTANCE Antimycobacterial agents might shorten the course of treatment by reducing the number of phenotypically tolerant bacteria if they could kill M. tuberculosis in diverse metabolic states. Here we report two chemically disparate classes of agents that kill M. tuberculosis both when it is replicating and when it is not. Under replicating conditions, the tricyclic 4-hydroxyquinolines and a barbituric acid analogue deplete intrabacterial magnesium as a mechanism of action, and for both compounds, mutations in CorA, a putative Mg2+/Co2+ transporter, conferred resistance to the compounds when M. tuberculosis was under replicating conditions but not under nonreplicating conditions, illustrating that a given compound can kill M. tuberculosis in different metabolic states by disparate mechanisms. Targeting magnesium metallostasis represents a previously undescribed antimycobacterial mode of action that might cripple M. tuberculosis in a Mg2+-deficient intraphagosomal environment of macrophages.
Subject(s)
Antitubercular Agents/pharmacology , Cation Transport Proteins/genetics , Magnesium/metabolism , Mycobacterium tuberculosis/drug effects , Mycobacterium tuberculosis/genetics , DNA Replication , Homeostasis , MutationABSTRACT
The historical view of ß-lactams as ineffective antimycobacterials has given way to growing interest in the activity of this class against Mycobacterium tuberculosis (Mtb) in the presence of a ß-lactamase inhibitor. However, most antimycobacterial ß-lactams kill Mtb only or best when the bacilli are replicating. Here, a screen of 1904 ß-lactams led to the identification of cephalosporins substituted with a pyrithione moiety at C3' that are active against Mtb under both replicating and nonreplicating conditions, neither activity requiring a ß-lactamase inhibitor. Studies showed that activity against nonreplicating Mtb required the in situ release of the pyrithione, independent of the known class A ß-lactamase, BlaC. In contrast, replicating Mtb could be killed both by released pyrithione and by the parent ß-lactam. Thus, the antimycobacterial activity of pyrithione-containing cephalosporins arises from two mechanisms that kill mycobacteria in different metabolic states.
Subject(s)
Antitubercular Agents/pharmacology , Cephalosporins/pharmacology , DNA Replication , Mycobacterium tuberculosis/drug effects , Pyridines/pharmacology , Thiones/pharmacology , Administration, Oral , Animals , Antitubercular Agents/administration & dosage , Callithrix , Cephalosporins/administration & dosage , Drug Discovery , Female , Hep G2 Cells , High-Throughput Screening Assays , Humans , Mice , Mycobacterium tuberculosis/physiology , Pyridines/administration & dosage , Thiones/administration & dosageABSTRACT
The success of Mycobacterium tuberculosis (Mtb) as a pathogen depends on the redundant and complex mechanisms it has evolved for resisting nitrosative and oxidative stresses inflicted by host immunity. Improving our understanding of these defense pathways can reveal vulnerable points in Mtb pathogenesis. In this study, we combined genetic, structural, computational, biochemical, and biophysical approaches to identify a novel enzyme class represented by Rv2466c. We show that Rv2466c is a mycothiol-dependent nitroreductase of Mtb and can reduce the nitro group of a novel mycobactericidal compound using mycothiol as a cofactor. In addition to its function as a nitroreductase, Rv2466c confers partial protection to menadione stress.
Subject(s)
Cysteine/metabolism , Glycopeptides/metabolism , Inositol/metabolism , Mycobacterium tuberculosis/enzymology , Nitroreductases/genetics , Nitroreductases/metabolism , Animals , Bacterial Proteins/chemistry , Bacterial Proteins/metabolism , Binding Sites , Cysteine/chemistry , Disease Models, Animal , Enzyme Activation , Female , Glycopeptides/chemistry , Inositol/chemistry , Mice , Models, Molecular , Mutation , Mycobacterium tuberculosis/classification , Mycobacterium tuberculosis/drug effects , Mycobacterium tuberculosis/genetics , Nitroreductases/chemistry , Oxidation-Reduction , Oxidative Stress , Phylogeny , Protein Binding , Protein Conformation , Structure-Activity Relationship , Tuberculosis/microbiologyABSTRACT
Rare kidney diseases encompass at least 150 different conditions, most of which are inherited. Although individual rare kidney diseases raise specific issues, as a group these rare diseases can have overlapping challenges in diagnosis and treatment. These challenges include small numbers of affected patients, unidentified causes of disease, lack of biomarkers for monitoring disease progression, and need for complex care. To address common clinical and patient issues among rare kidney diseases, the KDIGO Controversies Conference entitled, Common Elements in Rare Kidney Diseases, brought together a panel of multidisciplinary clinical providers and patient advocates to address five central issues for rare kidney diseases. These issues encompassed diagnostic challenges, management of kidney functional decline and progression of chronic kidney disease, challenges in clinical study design, translation of advances in research to clinical care, and provision of practical and integrated patient support. Thus, by a process of consensus, guidance for addressing these challenges was developed and is presented here.
Subject(s)
Kidney Diseases/therapy , Kidney/physiopathology , Nephrologists/psychology , Nephrology/standards , Rare Diseases/therapy , Biomarkers/analysis , Congresses as Topic , Consensus , Disease Progression , Glomerular Filtration Rate , Humans , Interdisciplinary Communication , Kidney Diseases/diagnosis , Kidney Diseases/epidemiology , Kidney Diseases/etiology , Nephrologists/standards , Nephrology/methods , Patient Care Team/standards , Practice Guidelines as Topic , Prevalence , Rare Diseases/diagnosis , Rare Diseases/epidemiology , Rare Diseases/etiologyABSTRACT
Goodpasture's syndrome (GPS) remains a very rare disease entity in the pediatric population characterized by the presence of pulmonary hemorrhage and rapidly evolving glomerulonephritis. We hereby describe the case of a 2-year-old girl who presented with renal failure and was diagnosed with GPS. A brief review of the literature in regard to data on demographics, pathogenesis, clinical features, diagnosis, treatment, and prognosis for renal recovery is also provided.
ABSTRACT
Mycobacterium tuberculosis (Mtb) encounters stresses during the pathogenesis and treatment of tuberculosis (TB) that can suppress replication of the bacteria and render them phenotypically tolerant to most available drugs. Where studied, the majority of Mtb in the sputum of most untreated subjects with active TB have been found to be nonreplicating by the criterion that they do not grow as colony-forming units (cfus) when plated on agar. However, these cells are viable because they grow when diluted in liquid media. A method for generating such "differentially detectable" (DD) Mtb in vitro would aid studies of the biology and drug susceptibility of this population, but lack of independent confirmation of reported methods has contributed to skepticism about their existence. Here, we identified confounding artifacts that, when avoided, allowed development of a reliable method of producing cultures of ≥90% DD Mtb in starved cells. We then characterized several drugs according to whether they contribute to the generation of DD Mtb or kill them. Of the agents tested, rifamycins led to DD Mtb generation, an effect lacking in a rifampin-resistant strain with a mutation in rpoB, which encodes the canonical rifampin target, the ß subunit of RNA polymerase. In contrast, thioridazine did not generate DD Mtb from starved cells but killed those generated by rifampin.
Subject(s)
Antibiotics, Antitubercular/pharmacology , Bacterial Proteins/antagonists & inhibitors , DNA-Directed RNA Polymerases/antagonists & inhibitors , Mycobacterium tuberculosis/drug effects , Mycobacterium tuberculosis/enzymology , Rifamycins/pharmacology , Antitubercular Agents/pharmacology , Bacterial Proteins/genetics , DNA-Directed RNA Polymerases/genetics , Drug Resistance, Bacterial/genetics , Humans , Isoniazid/pharmacology , Mutation , Mycobacterium tuberculosis/genetics , Thioridazine/pharmacology , Tuberculosis/drug therapy , Tuberculosis/microbiologyABSTRACT
Although the Behavioral Inhibition System (BIS) is associated with threat-sensitivity, little is known about its neurofunctional correlates during cognitive control over task-irrelevant threat distractors. Thirty non-clinical participants, who ranged in BIS sensitivity, completed an attentional control paradigm during fMRI. The paradigm varied in cognitive demand with low perceptual load comprising identical target letters and high perceptual load comprising a target letter in a mixed letter string; each superimposed on threatening and neutral face distractors. Whole-brain results indicated that individuals with higher, relative to lower BIS sensitivity, exhibited enhanced dorsolateral prefrontal cortex activation to angry (vs. neutral) and enhanced dorsal anterior cingulate cortex activation to fearful (vs. neutral) face distractors under low load whereas no differences in activation were observed under high load. These findings are consistent with literature indicating that the BIS is involved in conflict processing, including between cognitive and emotional or motivational goals.
Subject(s)
Attention/physiology , Gyrus Cinguli/physiology , Inhibition, Psychological , Perception/physiology , Prefrontal Cortex/physiology , Adolescent , Adult , Aged , Anger/physiology , Brain Mapping , Facial Recognition/physiology , Fear/physiology , Female , Healthy Volunteers , Humans , Magnetic Resonance Imaging , Male , Middle Aged , Young AdultABSTRACT
BACKGROUND: Observational studies have suggested a relationship between the plasma concentration of indoxyl sulfate (IS) and p-cresyl sulfate (PCS), small gut-derived 'uremic solutes', and the high incidence of uremic cardiomyopathy in patients with end-stage renal disease (ESRD). IS and PCS are derived from the metabolism of dietary components (tryptophan and tyrosine) by gut bacteria. This pilot study was designed to examine the effects of a poorly absorbable antibiotic (vancomycin) on the plasma concentration of two gut-derived 'uremic solutes', IS and PCS, and on the composition of the gut microbiome. METHODS: Plasma concentrations of IS and PCS were measured by MS-HPLC. The gut microbiome was assessed in stool specimens sequenced for the 16S rRNA gene targeting the V4 region. RESULTS: The pre-dialysis mean plasma concentrations of both IS and PCS were markedly elevated. Following the administration of vancomycin (Day 0), the IS and PCS concentrations decreased at Day 2 or Day 5 and returned to baseline by Day 28. Following vancomycin administration, several changes in the gut microbiome were observed. Most striking was the decrease in diversity, a finding that was evident on Day 7 and was still evident at Day 28. There was little change at the phylum level but at the genus level, broad population changes were noted. Changes in the abundance of several genera appeared to parallel the concentration of IS and PCS. CONCLUSIONS: These findings suggest that alteration of the gut microbiome, by an antibiotic, might provide an important strategy in reducing the levels of IS and PCS in ESRD.