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Antibiotic resistance is a global threat driven primarily by antibiotic use. We evaluated the effects of antibiotic exposures on the gut microbiomes and resistomes of children at high risk of colonization by antibiotic-resistant bacteria. We performed shotgun metagenomic sequencing of 691 serially collected fecal samples from 80 children (<18 years) undergoing hematopoietic cell transplantation. We evaluated the effects of aerobic (cefepime, vancomycin, fluoroquinolones, aminoglycosides, macrolides, and trimethoprim-sulfamethoxazole) and anaerobic (piperacillin-tazobactam, carbapenems, metronidazole, and clindamycin) antibiotic exposures on the diversity and composition of the gut microbiome and resistome. We identified 372 unique antibiotic resistance genes (ARGs); the most frequent ARGs identified encode resistance to tetracyclines (n = 88), beta-lactams (n = 84), and fluoroquinolones (n = 79). Both aerobic and anaerobic antibiotic exposures were associated with a decrease in the number of bacterial species (aerobic, ß = 0.71, 95% CI: 0.64, 0.79; anaerobic, ß = 0.66, 95% CI: 0.53, 0.82) and the number of unique ARGs (aerobic, ß = 0.81, 95% CI: 0.74, 0.90; anaerobic, ß = 0.73, 95% CI: 0.61, 0.88) within the gut metagenome. However, only antibiotic regimens that included anaerobic activity were associated with an increase in acquisition of new ARGs (anaerobic, ß = 1.50; 95% CI: 1.12, 2.01) and an increase in the relative abundance of ARGs in the gut resistome (anaerobic, ß = 1.62; 95% CI: 1.15, 2.27). Specific antibiotic exposures were associated with distinct changes in the number and abundance of ARGs for individual antibiotic classes. Our findings detail the impact of antibiotics on the gut microbiome and resistome and demonstrate that anaerobic antibiotics are particularly likely to promote acquisition and expansion of antibiotic-resistant bacteria.
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Microbioma Gastrointestinal , Transplante de Células-Tronco Hematopoéticas , Criança , Humanos , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Bactérias/genética , Fluoroquinolonas/farmacologia , Microbioma Gastrointestinal/genéticaRESUMO
BACKGROUND: The molecular mechanisms regulating coronavirus pathogenesis are complex, including virus-host interactions associated with replication and innate immune control. However, some genetic and epigenetic conditions associated with comorbidities increase the risk of hospitalization and can prove fatal in infected patients. This systematic review will provide insight into host genetic and epigenetic factors that interfere with COVID-19 expression in light of available evidence. METHODS: This study conducted a systematic review to examine the genetic and epigenetic susceptibility to COVID-19 using a comprehensive approach. Through systematic searches and applying relevant keywords across prominent online databases, including Scopus, PubMed, Web of Science, and Science Direct, we compiled all pertinent papers and reports published in English between December 2019 and June 2023. RESULTS: The findings reveal that the host's HLA genotype plays a substantial role in determining how viral protein antigens are showcased and the subsequent immune system reaction to these antigens. Within females, genes responsible for immune system regulation are found on the X chromosome, resulting in reduced viral load and inflammation levels when contrasted with males. Possessing blood group A may contribute to an increased susceptibility to contracting COVID-19 as well as a heightened risk of mortality associated with the disease. The capacity of SARS-CoV-2 involves inhibiting the antiviral interferon (IFN) reactions, resulting in uncontrolled viral multiplication. CONCLUSION: There is a notable absence of research into the gender-related predisposition to infection, necessitating a thorough examination. According to the available literature, a significant portion of individuals affected by the ailment or displaying severe ramifications already had suppressed immune systems, categorizing them as a group with elevated risk.
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The use of natural bioactive constituents from various food sources for anticancer purposes has become increasingly popular worldwide. Broccoli (Brassica oleracea var. italica) is on the top of the consumed vegetables by the masses. Its raw matrix contains a plethora of phytochemicals, such as glucosinolates and phenolic compounds, along with rich amounts of vitamins, and minerals. Consumption of broccoli-derived phytochemicals provides strong antioxidant effects, particularly due to its sulforaphane content, while modulating numerous molecules involved in cell cycle regulation, control of apoptosis, and tuning enzyme activity. Thus, the inclusion of broccoli in the daily diet lowers the susceptibility to developing cancers. Numerous studies have underlined the undisputable role of broccoli in the diet as a chemopreventive raw food, owing to the content in sulforaphane, an isothiocyanate produced as a result of hydrolysis of precursor glucosinolates called glucoraphanin. This review will provide evidence supporting the specific role of fresh florets and sprouts of broccoli and its key bioactive constituents in the prevention and treatment of different cancers; a number of studies carried out in the in vitro and in vivo conditions as well as clinical trials were analyzed.
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Extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli can cause invasive infections in infants and immunocompromised children with high associated morbidity and mortality. The gut is a major reservoir of these strains in the community. Current dogma dictates that antimicrobial resistance is associated with a fitness cost. However, recent data show that some contemporary ESBL E. coli strains may be more "fit" compared to nonresistant E. coli strains. Here, we use whole-genome sequencing to first characterize 15 ESBL E. coli strains isolated from infants in a Pakistani community, a clinical extraintestinal pathogenic ESBL E. coli ST131 strain, and a non-ESBL commensal E. coli strain, and then use a novel animal model of early life gut colonization to assess the ability of these strains to colonize the infant mouse gut. We determined that CTX-M-15 was present in all the ESBL strains, as well as additional beta-lactamases and genes conferring resistance to multiple antibiotic classes. In the animal model, 11/16 ESBL E. coli strains had significantly higher burden of colonization at week four of life compared to commensal strains, even in the absence of selective antibiotic pressure, suggesting that these strains may have enhanced fitness despite being highly antimicrobial resistant. IMPORTANCE Antimicrobial resistance is a global public health emergency. Infants, especially preterm infants and those in the neonatal intensive care unit, immunocompromised hosts, and those with chronic illnesses are at highest risk of adverse outcomes from invasive infections with antimicrobial-resistant strains. It has long been thought that resistance is associated with a fitness cost, i.e., antimicrobial-resistant strains are not able to colonize the gut as well as nonresistant strains, and that antibiotic exposure is a key risk factor for persistent colonization with resistant strains. Here, we use a novel infant mouse model to add to the growing body of literature that some highly-resistant contemporary Escherichia coli strains can persist in the gut with a significant burden of colonization despite absence of antibiotic exposure.
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Infecções por Escherichia coli , Escherichia coli , Recém-Nascido , Humanos , Camundongos , Animais , Escherichia coli/genética , Animais Recém-Nascidos , Recém-Nascido Prematuro , beta-Lactamases/genética , Antibacterianos/farmacologiaRESUMO
Coronavirus disease 2019 (COVID-19) is caused by a novel coronavirus, known as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). It originated from the Chinese city of Wuhan and very quickly became a challenging public health problem. On 11 March 2020, the World Health Organization termed this potentially deadly disease a pandemic due to its rapid spread in various parts of the world, giving rise to international health emergencies. This virus is transmitted from human to human in the form of respiratory droplets, and in specific circumstances, airborne transmission may occur. Additional sources of exposure for dentists include blood and infected sharps. Due to the contagious nature of COVID-19 many health care providers have also been disproportionately affected, such as physicians, dentists, nurses, and paramedical staff. Dentists and dental staff are at high risk of cross-infection due to their nature of work. Therefore, they face a dual challenge in protecting themselves and their patients from infection transmission while ensuring that patients receive urgent dental care. In this review, the authors highlight the epidemiology, modes of cross-infection, and recent data on SARS-CoV-2 related to dental practice. The primary purpose is to make dental health care providers aware of the pathophysiology of COVID-19 and to increase their preparedness and understanding of this challenge, which will aid in controlling transmission. The information collected will be useful for the dental community in providing effective patient management through evidence-based recommendations for infection control and disinfection protocols.
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Immunologic responses during sepsis vary significantly among patients and evolve over the course of illness. Sepsis has a direct impact on the immune system due to adverse alteration of the production, maturation, function, and apoptosis of immune cells. Dysregulation in both the innate and adaptive immune responses during sepsis leads to a range of phenotypes consisting of both hyperinflammation and immunosuppression that can result in immunoparalysis. In this review, we discuss components of immune dysregulation in sepsis, biomarkers and functional immune assays to aid in immunophenotyping patients, and evolving immunomodulatory therapies. Important research gaps for the future include: (1) Defining how age, host factors including prior exposures, and genetics impact the trajectory of sepsis in children, (2) Developing tools for rapid assessment of immune function in sepsis, and (3) Assessing how evolving pediatric sepsis endotypes respond differently to immunomodulation. Although multiple promising immunomodulatory agents exist or are in development, access to rapid immunophenotyping will be needed to identify which children are most likely to benefit from which therapy. Advancements in the ability to perform multidimensional endotyping will be key to developing a personalized approach to children with sepsis. IMPACT: Immunologic responses during sepsis vary significantly among patients and evolve over the course of illness. The resulting spectrum of immunoparalysis that can occur due to sepsis can increase morbidity and mortality in children and adults. This narrative review summarizes the current literature surrounding biomarkers and functional immunologic assays for immune dysregulation in sepsis, with a focus on immunomodulatory therapies that have been evaluated in sepsis. A precision approach toward diagnostic endotyping and therapeutics, including gene expression, will allow for optimal clinical trials to evaluate the efficacy of individualized and targeted treatments for pediatric sepsis.
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Sepse/imunologia , Biomarcadores/metabolismo , Criança , Humanos , Fatores Imunológicos/uso terapêutico , Sepse/tratamento farmacológicoRESUMO
Measures to prevent coronavirus disease 2019 (COVID-19) spread to household members was assessed by surveying COVID-19-positive physicians and advanced practice providers. Showering and changing were more common than physical distancing. Half of respondents reported a symptomatic household member. Most reported increased stress, worsening of mental health, and concerns about illness and impact on family.
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We present 4 pediatric patients with trisomy 21 (T21) and associated comorbidities who developed coronavirus disease 2019 requiring hospitalization. A review of the literature revealed that comorbidities associated with T21 may predispose patients to severe disease. Children with T21 should be considered high risk and monitored carefully if infected with severe acute respiratory syndrome coronavirus 2.
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COVID-19/complicações , COVID-19/epidemiologia , Comorbidade , Suscetibilidade a Doenças , Síndrome de Down/complicações , Síndrome de Down/epidemiologia , Adolescente , Hospitalização , Humanos , Lactente , Masculino , Fatores de Risco , SARS-CoV-2RESUMO
We previously identified a small-molecule inhibitor of capsule biogenesis (designated DU011) and identified its target as MprA, a MarR family transcriptional repressor of multidrug efflux pumps. Unlike other proposed MprA ligands, such as salicylate and 2,4-dinitrophenol (DNP), DU011 does not alter Escherichia coli antibiotic resistance and has significantly enhanced inhibition of capsule expression. We hypothesized that the potency and the unique action of DU011 are due to novel interactions with the MprA binding pocket and the conformation assumed by MprA upon binding DU011 relative to other ligands. To understand the dynamics of MprA-DU011 interaction, we performed hydrogen-deuterium exchange mass spectrometry (HDX-MS); this suggested that four peptide regions undergo conformational changes upon binding DU011. We conducted isothermal calorimetric titration (ITC) to quantitatively characterize MprA binding to DU011 and canonical ligands and observed a distinct two-site binding isotherm associated with the binding reaction of MprA to DU011; however, salicylate and DNP showed a one-site binding isotherm with lower affinity. To elucidate the binding pocket(s) of MprA, we selected single point mutants of MprA that included mutated residues predicted to be within the putative binding pocket (Q51A, F58A, and E65D) as well as on or near the DNA-binding domain (L81A, S83T, and T86A). Our ITC studies suggest that two of the tested MprA mutants had lower affinity for DU011: Q51A and F58A. In addition to elucidating the MprA binding pocket for DU011, we studied the binding of these mutants to salicylate and DNP to reveal the binding pockets of these canonical ligands.
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Proteínas de Escherichia coli , Escherichia coli , Antibacterianos/farmacologia , Sítios de Ligação , Resistência Microbiana a Medicamentos , Escherichia coli/genética , Escherichia coli/metabolismo , Proteínas de Escherichia coli/genética , Proteínas de Escherichia coli/metabolismo , Ligantes , Polissacarídeos , Ligação ProteicaRESUMO
The prevalence of multidrug-resistant organisms is increasing worldwide, posing a unique challenge to global health care systems. Novel approaches are needed to combat the spread of infection with these organisms. The enteric microbiome, and in particular the resistome, offers a unique target in both the prevention of infection with these organisms and the acquisition and spread within the community. We highlight a novel approach to combat multidrug-resistant organisms: the use of prebiotics, probiotics, and synbiotics to manipulate the microbiome and resistome. This review summarizes the published literature and clinical trials related to these products to date, with a focus on efficacious trials. It highlights the probable mechanism of action for each product, as well as its safety profile in selective populations. Ultimately, although further research is needed before a definitive statement can be made on the efficacy of any of these 3 interventions, the literature to date offers new hope and a new tool in the arsenal in the fight against bacterial drug resistance.
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Prebióticos/administração & dosagem , Probióticos/administração & dosagem , Simbióticos/administração & dosagem , Farmacorresistência Bacteriana Múltipla , Humanos , Probióticos/uso terapêuticoRESUMO
Certain anaerobic bacteria are important for maintenance of gut barrier integrity and immune tolerance and may influence the risk of graft-versus-host disease (GVHD) after allogeneic hematopoietic stem cell transplantation (HSCT). We conducted a single-center retrospective cohort study of allogeneic HSCT recipients to evaluate associations between receipt of antibiotics with an anaerobic spectrum of activity and GVHD outcomes. We identified 1214 children and adults who developed febrile neutropenia between 7 days before and 28 days after HSCT and compared GVHD risk and mortality among patients who received anaerobic antibiotics (piperacillin-tazobactam or carbapenems; n = 491) to patients who received only antibiotics with minimal activity against anaerobes (aztreonam, cefepime, or ceftazidime; n = 723). We performed metagenomic sequencing of serial fecal samples from 36 pediatric patients to compare the effects of specific antibiotics on the gut metagenome. Receipt of anaerobic antibiotics was associated with higher hazards of acute gut/liver GVHD (hazard ratio [HR], 1.26; 95% confidence interval [CI], 1.03 to 1.54) and acute GVHD mortality (HR, 1.63; 95% CI, 1.08 to 2.46), but not chronic GVHD diagnosis (HR, 1.04; 95% CI: .84 to 1.28) or chronic GVHD mortality (HR, .88; 95% CI, .53 to 1.45). Anaerobic antibiotics resulted in decreased gut bacterial diversity, reduced abundances of Bifidobacteriales and Clostridiales, and loss of bacterial genes encoding butyrate biosynthesis enzymes from the gut metagenome. Acute gut/liver GVHD was preceded by a sharp decline in bacterial butyrate biosynthesis genes with antibiotic treatment. Our findings demonstrate that exposure to anaerobic antibiotics is associated with increased risks of acute gut/liver GVHD and acute GVHD mortality after allogeneic HSCT. Use of piperacillin-tazobactam or carbapenems should be reserved for febrile neutropenia cases in which anaerobic or multidrug-resistant infections are suspected.
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Doença Enxerto-Hospedeiro , Transplante de Células-Tronco Hematopoéticas , Adulto , Anaerobiose , Antibacterianos/uso terapêutico , Criança , Doença Enxerto-Hospedeiro/tratamento farmacológico , Doença Enxerto-Hospedeiro/etiologia , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Humanos , Estudos Retrospectivos , Transplante HomólogoRESUMO
The recent rapid rise of multi-drug resistant Enterobacteriaceae (MDR-E) is threatening the treatment of common infectious diseases. Infections with such strains lead to increased mortality and morbidity. Using a cross-sectional study, we aimed to estimate the prevalence of gut colonization with extended spectrum beta-lactamase (ESBL) producing Enterobacteriaceae among healthy infants born in Pakistan, a setting with high incidence of MDR-E infections. Stool samples were collected from 104 healthy infants between the ages of 5 and 7 months. Enterobacteriaceae isolates were screened for resistance against several antimicrobial classes. Presence of ESBL and carbapenemase genes was determined using multiplex PCR. Sequence types were assigned to individual strains by multi-locus sequence typing. Phylogenetic analysis of Escherichia coli was done using the triplex PCR method. Forty-three percent of the infants were positive for ESBL-producing Enterobacteriaceae, the majority of which were E. coli. We identified several different ESBL E. coli sequence types most of which belonged to the phylogenetic group B2 (23%) or D (73%). The widespread colonization of infants in a developing country with ESBL-producing Enterobacteriaceae is concerning. The multiple sequence types and reported non-human sources support that multiple non-epidemic MDR lineages are circulating in Pakistan with healthy infants as a common reservoir.
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There has been a rapid spread of multidrug-resistant (MDR) bacteria across the world. MDR efflux transporters are an important mechanism of antibiotic resistance in many pathogens among both Gram positive and Gram negative bacteria. These pumps can recognize a variety of chemically and structurally different compounds, including innate and clinically administered antibiotics. Intriguingly, these efflux pumps are often regulated by transcription factors that themselves bind a diverse set of substrates thereby allowing them to regulate the expression of their cognate MDR efflux pumps. One significant family of such transcription factors is the Multiple antibiotic resistance Repressor (MarR) family. Members of this family are well conserved across different bacterial species and in some cases are known to regulate vital bacterial functions. This review focusses on the role of MarR family transcriptional factors in antibiotic resistance within a select group of clinically relevant pathogens.
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Antibacterianos/farmacologia , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Proteínas de Escherichia coli/antagonistas & inibidores , Escherichia coli/efeitos dos fármacos , Proteínas Repressoras/antagonistas & inibidores , Antibacterianos/química , Proteínas de Escherichia coli/metabolismo , Testes de Sensibilidade Microbiana , Modelos Moleculares , Proteínas Repressoras/metabolismoRESUMO
The gastrointestinal tract is the predicted reservoir for most bloodstream infections (BSIs) after hematopoietic stem cell transplantation (HSCT). Whole-genome sequencing and comparative genomics have the potential to improve our understanding of the dynamics of gut colonization that precede BSI in HSCT recipients. Within a prospective cohort study of children (age <18 years) undergoing HSCT, 9 subjects met criteria for mucosal barrier injury BSI. We performed whole-genome sequencing of the blood culture isolate and weekly fecal samples preceding the BSI to compare the genetic similarity of BSI isolates to fecal strains. We evaluated temporal associations between antibiotic exposures and the abundances of BSI strains in the gut microbiota and correlated the detection of antibiotic resistance genes with the phenotypic antibiotic resistance of these strains. The median patient age was 2.6 years, and 78% were male. BSIs were caused by Escherichia coli (nâ¯=â¯5), Enterococcus faecium (nâ¯=â¯2), Enterobacter cloacae (nâ¯=â¯1), and Rothia mucilaginosa (nâ¯=â¯1). In the 6 BSI episodes with evaluable comparative genomics, the fecal strains were identical to the blood culture isolate (>99.99% genetic similarity). Gut domination by these strains preceded only 4 of 7 E. coli or E. faecium BSIs by a median of 17 days (range, 6 to 21 days). Increasing abundances of the resulting BSI strains in the gut microbiota were frequently associated with specific antibiotic exposures. E. cloacae and R. mucilaginosa were not highly abundant in fecal samples preceding BSIs caused by these species. The detection of antibiotic resistance genes for ß-lactam antibiotics and vancomycin predicted phenotypic resistance in BSI strains. Bacterial strains causing mucosal barrier injury BSI in pediatric HSCT recipients were observed in the gut microbiota before BSI onset, and changes in the abundances of these strains within the gut preceded most BSI episodes. However, frequent sampling of the gut microbiota and sampling of other ecological niches is likely necessary to effectively predict BSI in HSCT recipients.
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Bactérias , Infecções Bacterianas , Farmacorresistência Bacteriana , Microbioma Gastrointestinal , Transplante de Células-Tronco Hematopoéticas , Mucosa Intestinal , Aloenxertos , Bactérias/classificação , Bactérias/genética , Bactérias/crescimento & desenvolvimento , Infecções Bacterianas/genética , Infecções Bacterianas/microbiologia , Criança , Pré-Escolar , Feminino , Humanos , Mucosa Intestinal/lesões , Mucosa Intestinal/microbiologia , Mucosa Intestinal/patologia , Masculino , Estudos ProspectivosRESUMO
Infections and graft-versus-host disease (GVHD) have historically resulted in high mortality among children undergoing umbilical cord blood transplantation (UCBT). However, recent advances in clinical practice have likely improved outcomes of these patients. We conducted a retrospective cohort study of children (<18years of age) undergoing UCBT at Duke University between January 1, 1995 and December 31, 2014. We compared 2-year all-cause and cause-specific mortality during 3 time periods based on year of transplantation (1995 to 2001, 2002 to 2007, and 2008 to 2014). We used multivariable Cox regression to identify demographic and UCBT characteristics that were associated with all-cause mortality, transplantation-related mortality, and death from invasive aspergillosis after adjustment for time period. During the 20-year study period 824 children underwent UCBT. Two-year all-cause mortality declined from 48% in 1995 to 2001 to 30% in 2008 to 2014 (Pâ¯=â¯.0002). White race and nonmalignant UCBT indications were associated with lower mortality. Black children tended to have a higher risk of death for which GVHD (18% versus 11%; Pâ¯=â¯.06) or graft failure (9% versus 3%; Pâ¯=â¯.01) were contributory than white children. Comparing 2008 to 2014 with 1995 to 2001, more than half (59%) of the reduced mortality was attributable to a reduction in infectious mortality, with 45% specifically related to reduced mortality from invasive aspergillosis. Antifungal prophylaxis with voriconazole was associated with lower mortality from invasive aspergillosis than low-dose amphotericin B lipid complex (hazard ratio, .09; 95% confidence interval, .01 to .76). With the decline in mortality from invasive aspergillosis, adenovirus and cytomegalovirus have become the most frequentinfectious causes of death in children after UCBT. Advances in clinical practice over the past 20years improved survival of children after UCBT. Reduced mortality from infections, particularly invasive aspergillosis, accounted for the largest improvement in survival and was associated with use of voriconazole for antifungal prophylaxis.
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Transplante de Células-Tronco de Sangue do Cordão Umbilical/mortalidade , Estudos de Coortes , Feminino , História do Século XX , História do Século XXI , Humanos , Masculino , Estudos Retrospectivos , Taxa de Sobrevida , Fatores de TempoRESUMO
Recurrent urinary tract infection (rUTI) continues to challenge pediatric care providers. The diagnosis of an rUTI can be difficult, especially in young febrile children. Antibiotic resistance rates continue to rise, which limits oral treatment options. Prophylactic antibiotics are used commonly to manage rUTI, but their use increases the risk of rUTI with antibiotic-resistant strains without significantly reducing renal scarring. Alternative therapies for rUTI include probiotics and anthocyanidins (eg, cranberry extract) to reduce gut colonization by uropathogens and prevent bacterial adhesion to uroepithelia, but efficacy data for these treatments are sparse. The future of rUTI care rests in addressing the following contemporary issues: best diagnostic practices, risk factors associated with rUTI, and the prevention of recurrent infection. In this review, we summarize the state of the art for each of these issues and highlight future studies that will aim to take an alternative approach to managing rUTI.
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Antibioticoprofilaxia/métodos , Infecções Urinárias/diagnóstico , Infecções Urinárias/tratamento farmacológico , Antocianinas/uso terapêutico , Antibacterianos/uso terapêutico , Aderência Bacteriana , Circuncisão Masculina/métodos , Resistência Microbiana a Medicamentos , Sucos de Frutas e Vegetais , Humanos , Masculino , Probióticos/uso terapêutico , Recidiva , Fatores de Risco , Doenças da Bexiga Urinária , Infecções Urinárias/epidemiologia , Infecções Urinárias/prevenção & controle , Vacinas , Vaccinium macrocarponRESUMO
BACKGROUND: Rates and risk factors for recurrent enterococcal bloodstream infection (R-EBSI) and whether the same genetic lineage causes index EBSI and R-EBSI are unknown in patients with acute leukemia (AL) receiving chemotherapy. METHODS: Ninety-two AL patients with EBSI from 2010 to 2015 were included. Enterococcal bloodstream infection was defined by 31 positive blood cultures for Enterococcus faecium or Enterococcus faecalis and fever, hypotension, or chills. Clearance was defined by 31 negative cultures 324 hours after last positive culture and defervescence. Recurrent enterococcal bloodstream infection was defined by a positive blood culture for Enterococcus 324 hours after clearance. Categorical variables were reported as proportions and compared by the χ2 test. Continuous variables were summarized by median and interquartile range (IQR) and compared by the Wilcoxon-Mann-Whitney Test. P values <.05 were considered significant. Whole-genome sequencing was performed on available paired BSI isolates from 7 patients. RESULTS: Twenty-four patients (26%) had 31 episodes of R-EBSI. Median time to R-EBSI (IQR) was 26 (13-50) days. Patients with R-EBSI had significantly longer durations of fever and metronidazole exposure during their index EBSI. Thirty-nine percent of E. faecium R-EBSI isolates became daptomycin-nonsusceptible Enterococcus (DNSE) following daptomycin therapy for index EBSI. Whole-genome sequencing analysis confirmed high probability of genetic relatedness of index EBSI and R-EBSI isolates for 4/7 patients. CONCLUSIONS: Recurrent enterococcal bloodstream infection and DNSE are common in patients with AL and tend to occur within the first 30 days of index EBSI. Duration of fever and metronidazole exposure may be useful in determining risk for R-EBSI. Whole-genome sequencing analysis demonstrates that the same strain causes both EBSI and R-EBSI in some patients.