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Roberta Salaroli,1 Domenico Ventrella,1 Chiara Bernardini,1 Alberto Elmi,1 Augusta Zannoni,1,2 Maria Laura Bacci,1,2 Monica Forni,1,2 Fiorella Calanni,3 Antonella Ferrieri,4 Fabio Baldi5 1Department of Veterinary Medical Science, University of Bologna, Ozzano Emilia, Bologna, Italy; 2Health Sciences and Technologies Interdepartmental Center for Industrial Research, University of Bologna, Bologna, Italy; 3Pre-Clinical Research Department, Alfasigma, Bologna, Italy; 4Division of Clinical Research, Department of Research and Development, Alfasigma, Bologna, Italy; 5Center for the Study of Diseases of the Esophagus, University of Bologna and Gruppo Villa Maria Care & Research, Ravenna, ItalyCorrespondence: Monica ForniDepartment of Veterinary Medical Science, University of Bologna, Via Tolara, 50, Ozzano Emilia 40064, Bologna, ItalyTel +39 051 20 9 7913Email monica.forni@unibo.itPurpose: AL2106 is a new medical device based on a mixture of chondroitin sulphate in a xyloglucan and glycerol solution made to maximize its bioadhesive capability to the esophageal mucosa. The aim of the present study was twofold to evaluate the AL2106 protective effect on the esophageal mucosa when exposed to an acidic solution mimicking gastric reflux and to assess the resilience of this effect to saline washing.Materials and Methods: A porcine ex vivo model was used and the effects of the new medical device were compared to a sodium alginate suspension (SAS) already present on the market which was assumed as reference. Mucosal damage was induced in 19 porcine esophagi by perfusion with an acidic solution added with pepsin, and Evans blue dye (EBD) tissue uptake was used as an indicator of mucosal permeability. The EBD penetration, expressed as EBD μg/g of dry tissue, was assessed in specimens of untreated damaged mucosa and in specimens treated with AL2106 or SAS. The same evaluation was carried out after washing with normal saline.Results: Both topical agents tested significantly reduced the EBD uptake by more than 60% (AL2106 8.4± 4.5, SAS 3.6± 2.7 vs control 23.2± 13.1, p< 0.01). The saline washing did not cause any significant reduction in the protective effect of AL2106 (8.6± 5.9), while it significantly reduced that of SAS (5.9± 4.3, p< 0.05).Conclusion: The new AL2106 medical device showed a good barrier effect against a reflux-like damaging solution and preserved this effect after the mucosal washing test, thus suggesting its possible relevance for the treatment of gastroesophageal reflux disease.Keywords: bioadhesion, Evans blue dye, EBD, animal model, esophagus, gastroesophageal reflux disease, GERD

Borrelia miyamotoi is an emerging tickbome pathogen initially discovered in Japan in 1995 but not recognized as a human pathogen until described in a case series from Russia in 2011 [...]

Massimo P Di Simone,1 Fabio Baldi,2,3 Valentina Vasina,4 Fabrizio Scorrano,5 Maria Laura Bacci,5 Antonella Ferrieri,6 Gilberto Poggioli11Department of General Surgery and Transplants, 2Centre for the Study and Therapy of the Esophageal Diseases, 3GVM Care and Research, MCH Cotignola (RA), 4Department of Pharmacology, Alma Mater Studiorum, University of Bologna, Bologna, 5Department of Veterinary Medical Science – DMSVET – University of Bologna, Bologna, 6Clinical Research Department, Alfa Wassermann Spa, Bologna, ItalyAbstract: The aim of the present study was to assess the potential barrier effect of Esoxx®, a new nonprescription medication under development for the relief of gastroesophageal reflux symptoms. Esoxx is based on a mixture of hyaluronic acid and chondroitin sulfate in a bioadhesive suspension of Lutrol® F 127 polymer (poloxamer 407) which facilitates the product adhesion on the esophageal mucosa. The mucosal damage was induced by 15 to 90 minutes of perfusion with an acidic solution (HCl, pH 1.47) with or without pepsin (2000 U/mL, acidified to pH 2; Sigma-Aldrich). Mucosal esophageal specimens were histologically evaluated and Evans blue dye solution was used to assess the permeability of the swine mucosa after the chemical injury. The results show that: (1) esophageal mucosal damage is related to the perfusion time and to the presence of pepsin, (2) mucosal damage is associated with an increased permeability, documented by an evident Evans blue staining, (3) perfusion with Esoxx is able to reduce the permeability of the injured mucosa, even after saline washing of the swine esophagus. These preliminary results support further clinical studies of Esoxx in the topical treatment of gastroesophageal reflux symptoms.Keywords: bioadhesion, hyaluronic acid, Evans blue dye, animal model, esophagus, reflux esophagitis

Borrelia miyamotoi is an emerging tickborne pathogen that has been associated with central nervous system infections in immunocompromised patients, albeit infrequently. We describe a case-patient in Minnesota, USA, who had meningeal symptoms of 1 month duration. B. miyamotoi infection was diagnosed by Gram staining on cerebrospinal fluid and confirmed by sequencing.

Carbapenamase-producing carbapenem-resistant Enterobacterales (CP-CRE) is an urgent public health threat for healthcare facilities. Solid organ transplant (SOT) recipients carry an increased risk for CRE infection and colonization due to prolonged exposures to antimicrobials, healthcare facilities and immunosuppression. CRE infection in SOT patients is associated with an increase in morbidity and mortality. Here, we describe a hospital outbreak investigation of three cases of New Delhi metallo-beta-lactamase (NDM) - CRE that led to novel findings with implications for further interdisciplinary investigations. An NDM-CRE infection in a critically-ill patient was identified during passive surveillance and prompted an investigation. Previous CP-CRE passive surveillance cases were reviewed. Rectal screening was performed for potentially exposed patients. 403 rectal swabs were tested for carbapenemase genes in active surveillance. Patients identified to have a new NDM-CRE isolate on active or passive surveillance were considered cases and underwent in-depth chart review including possible patient-to-patient exposures, hospital locations, procedures, devices, and consultations. NDM-CRE isolates were sent to the Minnesota Department of Health (MDH) for whole genome sequencing (WGS) to assess relatedness. Five NDM-CRE cases were identified, with all isolates harboring blaNDM including three NDM-Klebsiella pneumoniae (NDM-KP) cases (Figure 1). The first NDM-KP case, patient 1, developed mediastinal infection following lung transplantation. Review of United Network for Organ Sharing revealed that respiratory specimens from patient 1’s donor grew NDM-KP and a bronchial wash at the time of transplant yielded NDM-KP. The second NDM-KP case (patient 3) developed ventilator-associated pneumonia and was found to have used sequentially the same ventilator as patient 1. The third NDM-KP case (patient 4) was detected via rectal swab in active surveillance and shared wound care personnel in common with patients 1 and 3 (Figure 2). WGS demonstrated two single nucleotide polymorphisms (SNP) among all three isolates, strongly suggesting relatedness (Figure 3). Best practices for infection prevention were reviewed with wound care personnel. To date, no further NDM-KP isolates have been identified. Investigation was facilitated by in-depth chart review and WGS via the Central Region Antimicrobial Resistance Laboratory Network at MDH. Detection of the NDM-KP from a lung donor specimen appears genetically linked to clinical isolates in other patients, raising the possibility of a donor-derived hospital outbreak. This investigation is the first to describe a donor-derived NDM outbreak in a healthcare facility. Communication between organ procurement agencies, transplant centers, and infection prevention must be optimized to prevent CRE-associated morbidity in SOT receipts and CRE hospital outbreaks.

Background: Staphylococcus aureus (SA) is the most common pathogen causing surgical site infections (SSIs). In the past decade, strategies incorporating new SA decolonization products have been implemented to prevent SSIs in surgical patients. The objective of this cross-sectional study was to determine which pre-operative screening and decolonization strategies are currently utilized in healthcare institutions. Methods: A survey was programmed in REDCap and emailed to members of the Society for Healthcare Epidemiology of America Research Network, the Minnesota chapter of the Association of Practitioners in Infection Control and Epidemiology, and the Minnesota Hospital Association between May-August 2023. We report the prevalence of institutional screening and decolonization strategies and decolonization products used for the prevention of SA SSIs. Results: A total of 153 unique institutions initiated the survey and 111 provided complete data on their institutional screening and decolonization strategies. The most commonly reported strategies included universal decolonization (decolonization of pre-operative patients without screening for carrier status) (n=31, 27.9%), no screening or decolonization (n=24, 21.6%), targeted screening for methicillin-sensitive Staphylococcus aureus (MSSA) or methicillin-resistant Staphylococcus aureus (MRSA) and decolonization based on carrier status (n=24, 21.6%), or MRSA only screening and decolonization (n=11, 9.9%) (Figure 1). Institutions that utilized targeted screening and decolonization strategies frequently reported using nasal mupirocin (n=18, 66.7%MSSA, n=29, 60.4%MRSA), chlorhexidine gluconate (CHG) bathing (n=16, 59.3%MSSA, n=28, 58.3%MRSA), and CHG cloths (n=7, 25.9%MSSA, n=14, 29.2%MRSA) (Figure 2). Among the 31 institutions that reported implementing the universal decolonization strategy, CHG bathing (n=18, 58.1%), CHG cloths (n=15, 48.4%), and nasal povidone iodine (n=14, 45.2%) were the most prevalent decolonization products. Additionally, a smaller percentage of institutions used nasal alcohol gel (n=5, 16.1%) for universal decolonization. Conclusion: Compared to the survey we conducted in 2012, we report a new shift towards universal decolonization and a small increase in targeted SA screening and decolonization.1 In the 2012 survey we reported 37% of respondents’ institutions screened pre-operative patients for SA carriage and the majority of those institutions decolonized carriers.1 Universal decolonization was not reported in the 2012 survey.1 We highlight the continued heterogeneity in practice at this time, which may reflect the ongoing uncertainty in optimal decolonization practices and emphasizes the need for future research. References: 1. Kline, S. et al. Infect Control Hosp Epidemiol 2014;35(7):880-882.

Abstract Background Undesired intrathecal injections represent an important subset of medical errors, albeit rare. Clinical effects depend on the type and concentration of drug(s) injected. Here we report on the case of a healthy woman with persistent low back pain, treated with a paravertebral injection of lidocaine, thiocolchicoside, and l-acetylcarnitine at an orthopedic practice. Case report A 42-year-old Caucasian woman, with no relevant past medical history, received a lumbar paravertebral injection of lidocaine, thiocolchicoside, and l-acetylcarnitine for persistent low back pain. Approximately 30 minutes after injection, she experienced quick neurological worsening. Upon arrival at the Emergency Department, she was comatose, with fixed bilateral mydriasis, trismus, and mixed acidosis; seizures ensued in the first hours; slow progressive amelioration was observed by day 6; retrograde amnesia was the only clinical relevant remaining symptom by 6 months. Conclusions To our knowledge, this is the first reported case of inadvertent intrathecal thiocolchicoside injection in an adult patient, as well as the first in the neurosurgical literature. Our experience suggests that injection therapy for low back pain should be administered in adequate settings, where possible complications may be promptly treated.

Purpose: A rare case of Thelazia californiensis ocular infestation was diagnosed and treated in an 11-month-old patient. Observations: The patient presented with a visual acuity of 20/130 OU by Teller cards. Exam demonstrated a white, mobile worm in the inferomedial fornix of the right eye. The remainder of the exam was otherwise normal. The worm was removed under anesthesia and identified as Thelazia californiensis by the Division of Parasitic Diseases and Malaria, at the Centers for Disease Control and Prevention. Conclusions and importance: This case demonstrates a rare but important cause of follicular conjunctivitis and mobile foreign bodies, especially in patients with a supportive history of exposure to the intermediate and definitive hosts of Thelazia species.

BackgroundThe circadian clock regulates plant metabolic functions and is an important component in plant health and productivity. Rhizosphere bacteria play critical roles in plant growth, health, and development and are shaped primarily by soil communities. Using Illumina next-generation sequencing and high-resolution mass spectrometry, we characterized bacterial communities of wild-type (Col-0) Arabidopsis thaliana and an acyclic line (OX34) ectopically expressing the circadian clock-associated cca1 transcription factor, relative to a soil control, to determine how cycling dynamics affected the microbial community. Microbial communities associated with Brachypodium distachyon (BD21) were also evaluated.ResultsSignificantly different bacterial community structures (P = 0.031) were observed in the rhizosphere of wild-type plants between light and dark cycle samples. Furthermore, 13% of the community showed cycling, with abundances of several families, including Burkholderiaceae, Rhodospirillaceae, Planctomycetaceae, and Gaiellaceae, exhibiting fluctuation in abundances relative to the light cycle. However, limited-to-no cycling was observed in the acyclic CCAox34 line or in soil controls. Significant cycling was also observed, to a lesser extent, in Brachypodium. Functional gene inference revealed that genes involved in carbohydrate metabolism were likely more abundant in near-dawn, dark samples. Additionally, the composition of organic matter in the rhizosphere showed a significant variation between dark and light cycles.ConclusionsThe results of this study suggest that the rhizosphere bacterial community is regulated, to some extent, by the circadian clock and is likely influenced by, and exerts influences, on plant metabolism and productivity. The timing of bacterial cycling in relation to that of Arabidopsis further suggests that diurnal dynamics influence plant-microbe carbon metabolism and exchange. Equally important, our results suggest that previous studies done without relevance to time of day may need to be reevaluated with regard to the impact of diurnal cycles on the rhizosphere microbial community.

Background: There are few reports of bacteremia caused by Mobiluncus curtisii in the literature. We present a review of the literature in addition to a case study. Method: We describe the case of an 82-year-old patient who underwent gastrointestinal surgery and subsequently presented with dehydration, nausea, and hyperkalemia secondary to diarrhea. Further clinical work included blood cultures, and the patient was started empirically on piperacillin/tazobactam. Results: After five days, the blood culture bottle showed growth of a gram-variable, curved rod-shaped organism. After culture under anaerobic conditions on sheep blood agar, the organism was identified as Mobiluncus curtisii by MALDI-TOF mass spectrometry and enzymatic technology. A review of the literature reveals five additional cases of Mobiluncus curtisii bacteremia. Conclusions: This is the sixth case in the literature describing Mobiluncus species bacteremia. This organism is rarely identified in blood culture and is most often thought of in the context of bacterial vaginosis. However, the reported cases of bacteremia show gastrointestinal symptoms and presumed gastrointestinal source of infection. The pathogenesis of infection of this organism requires further investigation.

As the use of microbial inoculants in agriculture rises, it becomes important to understand how the environment may influence microbial ability to promote plant growth. This work examines whether there are light dependencies in the biological functions of Azospirillum brasilense, a commercialized prolific grass-root colonizer. Though classically defined as non-phototrophic, A. brasilense possesses photoreceptors that could perceive light conducted through its host’s roots. Here, we examined the light dependency of atmospheric biological nitrogen fixation (BNF) and auxin biosynthesis along with supporting processes including ATP biosynthesis, and iron and manganese uptake. Functional mutants of A. brasilense were studied in light and dark environments: HM053 (high BNF and auxin production), ipdC (capable of BNF, deficient in auxin production), and FP10 (capable of auxin production, deficient in BNF). HM053 exhibited the highest rate of nitrogenase activity with the greatest light dependency comparing iterations in light and dark environments. The ipdC mutant showed similar behavior with relatively lower nitrogenase activity observed, while FP10 did not show a light dependency. Auxin biosynthesis showed strong light dependencies in HM053 and FP10 strains, but not for ipdC. Ferrous iron is involved in BNF, and a light dependency was observed for microbial 59Fe2+ uptake in HM053 and ipdC, but not FP10. Surprisingly, a light dependency for 52Mn2+ uptake was only observed in ipdC. Finally, ATP biosynthesis was sensitive to light across all three mutants favoring blue light over red light compared to darkness with observed ATP levels in descending order for HM053 > ipdC > FP10.

Background Multistep laboratory testing is recommended for the diagnosis of Clostridioides difficile infection (CDI). The aim of this study was to present the impact of multistep CDI diagnostic testing in an academic hospital system and evaluate the toxin B gene polymerase chain reaction (PCR) cycle threshold (Ct) values of PCR-positive tests. Methods In October 2022, our system began reflex testing all PCR-positive stool samples with the C. DIFF QUIK CHEK COMPLETE (Techlab), an enzyme immunoassay–based test with results for the glutamate dehydrogenase antigen (GDH) and C difficile toxin A/B. Hospital-onset (HO) CDI and CDI antibiotic use before and after testing were tracked. Ct values were obtained from the Infectious Diseases Diagnostic Laboratory. Receiver operating curve analysis was used to examine the sensitivity and specificity for identifying GDH+/toxin+ and GDH−/toxin− at various Ct thresholds. Results The HO-CDI rate decreased from 0.352 cases per 1000 patient-days to 0.115 cases per 1000 patient-days post–reflex testing (P <.005). Anti-CDI antibiotics use decreased, but the decrease was not commensurate with CDI rates following reflex testing. PCR+/GDH+/toxin+ samples had a lower mean Ct value than PCR+/GDH–/toxin– samples (23.3 vs 33.5, P <.0001). A Ct value of 28.65 could distinguish between those 2 groups. Fifty-four percent of PCR+/GDH+/toxin− samples had a Ct value below that cut-off, suggesting the possibility of CDI with a negative toxin test. Conclusions Reflex testing for a laboratory diagnosis of CDI results in rapid, systemwide decreases in the rate of HO-CDI. Additional research is needed to distinguish CDI from C difficile colonization in patients with discordant testing. [ABSTRACT FROM AUTHOR]

Azospirillum brasilense is a prolific grass-root colonizing bacteria well-known for its ability to promote plant growth in several cereal crops. Here we show that one of the mechanisms of action in boosting plant performance is through increased assimilation of the micronutrient manganese by the host. Using radioactive 52Mn2+ (t½ 5.59 d), we examined the uptake kinetics of this micronutrient in young maize plants, comparing the performance of three functional mutants of A. brasilense, including HM053, a high auxin-producing and high N2-fixing strain; ipdC, a strain with a reduced auxin biosynthesis capacity; and FP10, a strain deficient in N2-fixation that still produces auxin. HM053 had the greatest effect on host 52Mn2+ uptake, with a significant increase seen in shoot radioactivity relative to non-inoculated controls. LA-ICP-MS analysis of root sections revealed higher manganese distributions in the endodermis of HM053-inoculated plants and overall higher manganese concentrations in leaves. Finally, increased leaf manganese concentration stimulated photosynthesis as determined by measuring leaf fixation of radioactive 11CO2 with commensurate increases in chlorophyll concentration.

Il periodo dell’epidemia da Covid-19 ha fatto emergere in modo irrevocabile la necessità di un generale ripensamento dei comportamenti, dei valori prioritari, della socialità, della distribuzione delle risorse. Anche le biblioteche e la biblioteconomia si trovano di fronte all’urgenza di un ‘cambio di paradigma’, a seguito dell’usura del concetto e del modello di ‘public library’. Questo saggio cerca di affrontare in parallelo la crisi della biblioteconomia e quella delle biblioteche, evidenziando il ruolo di acceleratore svolto dalla pandemia. In particolare, viene analizzata criticamente la tendenza all’attendismo e al moderatismo che in alcuni casi ha ‘contagiato’ il campo bibliotecario. Come se la difficile situazione e la vulnerabilità globale giustificassero una perdita di essenzialità del servizio bibliotecario, una rinuncia all’attivismo, un ripiegamento sull’ordinaria amministrazione. Al contrario la biblioteca ‘con-vivente’, tratteggiata nell’ultima parte dell’articolo, è quella che sceglie la strada dell’intervento attivo e proattivo durante la pandemia, entrando con empatia e rispetto nella dimensione quotidiana, e lavorando sull’ipotesi di una politica della lettura come ‘motore del cambiamento’.

We describe a case of central venous catheter infection and bacteremia caused by Bosea thiooxidans, which has not been previously described in the literature. Bosea spp. is a gram-negative bacterium that has been isolated from hospital water supplies and may become an important cause of nosocomial infections. Keywords: Bacteremia, Central line infection, Gram-negative bacteria, Bosea thiooxidans

In agriculture, boron is known to play a critical role in healthy plant growth. To dissect the role of boron in maize metabolism, radioactive carbon-11 (t½ 20.4 min) was used to examine the physiological and metabolic responses of 3-week-old B73 maize plants to different levels of boron spanning 0 mM, 0.05 mM, and 0.5 mM boric acid (BA) treatments. Growth behavior, of both shoots and roots, was recorded and correlated to plant physiological responses. 11CO2 fixation, leaf export of [11C]-photosynthates, and their rate of transport increased systematically with increasing BA concentrations, while the fraction of [11C]-photosynthates delivered to the roots under 0 mM and 0.5 mM BA treatments was lower than under 0.05 mM BA treatment, likely due to changes in root growth. Additionally, solid-phase extraction coupled with gamma counting, radio-fluorescence thin layer chromatography, and radio-fluorescence high-performance liquid chromatography techniques applied to tissue extracts provided insight into the effects of BA treatment on ‘new’ carbon (as 11C) metabolism. Most notable was the strong influence reducing boron levels had on raising 11C partitioning into glutamine, aspartic acid, and asparagine. Altogether, the growth of maize under different regimes of boron affected 11CO2 fixation, its metabolism and allocation belowground, and altered root growth. Finally, inductively coupled plasma mass spectrometry provided insight into the effects of BA treatment on plant uptake of other essential nutrients. Here, levels of boron and zinc systematically increased in foliar tissues with increasing BA concentration. However, levels of magnesium, potassium, calcium, manganese, and iron remained unaffected by treatment. The rise in foliar zinc levels with increased BA concentration may contribute to improved 11CO2 fixation under these conditions.

Background: Although the published literature has grown exponentially during the last few decades, managing medication-related osteonecrosis of the jaws (MRONJ) remains challenging. Since the first description of adipose-derived stem cells, cell therapy showed promising perspectives in surgical treatment of MRONJ. In this study, the beneficial effect of fat graft in surgical treatment of stage 2 and 3 MRONJ patients was assessed. Methods: A retrospective analysis of the evolution pattern of the disease was conducted comparing the outcomes of MRONJ patients who underwent sequestrectomy followed by fat graft (n = 9) and those who received sequestrectomy alone (n = 12). Results: Improvement of the disease stage was observed in 77.8% vs. 22.2% cases in group A and B, respectively (p = 0.030); disease stability was documented in 11.1% vs. 25.0% cases in group A and B, respectively (p = 0.603); worsening of MRONJ stage was observed in 11.1% vs. 50.0% cases in group A and B, respectively (p = 0.159). Conclusions: Despite the small sample size, this study suggests that fat graft may represent a promising low-risk and cost-efficient adjunctive therapy in the surgical treatment of MRONJ patients.

Herbaspirillum seropedicae, as an endophyte and prolific root colonizer of numerous cereal crops, occupies an important ecological niche in agriculture because of its ability to promote plant growth and potentially improve crop yield. More importantly, there exists the untapped potential to harness its ability, as a diazotroph, to fix atmospheric N2 as an alternative nitrogen resource to synthetic fertilizers. While mechanisms for plant growth promotion remain controversial, especially in cereal crops, one irrefutable fact is these microorganisms rely heavily on plant-borne carbon as their main energy source in support of their own growth and biological functions. Biological nitrogen fixation (BNF), a microbial function that is reliant on nitrogenase enzyme activity, is extremely sensitive to the localized nitrogen environment of the microorganism. However, whether internal root colonization can serve to shield the microorganisms and de-sensitize nitrogenase activity to changes in the soil nitrogen status remains unanswered. We used RAM10, a GFP-reporting strain of H. seropedicae, and administered radioactive 11CO2 tracer to intact 3-week-old maize leaves and followed 11C-photosynthates to sites within intact roots where actively fluorescing microbial colonies assimilated the tracer. We examined the influence of administering either 1 mM or 10 mM nitrate during plant growth on microbial demands for plant-borne 11C. Nitrogenase activity was also examined under the same growth conditions using the acetylene reduction assay. We found that plant growth under low nitrate resulted in higher nitrogenase activity as well as higher microbial demands for plant-borne carbon than plant growth under high nitrate. However, carbon availability was significantly diminished under low nitrate growth due to reduced host CO2 fixation and reduced allocation of carbon resources to the roots. This response of the host caused significant inhibition of microbial growth. In summary, internal root colonization did little to shield these endophytic microorganisms from the nitrogen environment.

Gut dysbiosis has been associated with worse allogeneic hematopoietic cell transplantation (allo-HCT) outcomes. We reported an association between intrinsically vancomycin-resistant enterococci (iVRE: E. gallinarum and E. casseliflavus) gut colonization and lower post-transplant mortality. In this study, using an expanded cohort, we evaluated whether our previously observed association is species-specific. We included allo-HCT recipients with ≥1 positive rectal swab or stool culture for iVRE between days -14 and +14 of transplant. To investigate whether iVRE modulate the gut microbiota, we performed agar diffusion assays. To investigate whether iVRE differ in their ability to activate the aryl hydrocarbon receptor, we analyzed iVRE genomes for enzymes in the shikimate and tryptophan pathways. Sixty six (23 E. casseliflavus and 43 E. gallinarum) of the 908 allograft recipients (2011-2017) met our inclusion criteria. Overall survival was significantly higher in patients with E. casseliflavus (91% vs. 62% at 3 years, P = 0.04). In multivariable analysis, E. casseliflavus gut colonization was significantly associated with reduced all-cause mortality (hazard ratio 0.20, 95% confidence interval 0.04-0.91, P = 0.04). While agar assays were largely unremarkable, genome mining predicted that E. casseliflavus encodes a larger number of enzymes in the tryptophan metabolism pathway. In conclusion, E. casseliflavus gut colonization is associated with reduced post-HCT morality. Further research is needed to understand the mechanisms for this association.