Citations

Abstract Background A decrease in antimicrobial stewardship activities has been observed in our hospital since the beginning of the pandemic. The study aim was to evaluate the impact of decrease in antimicrobial stewardship activities in Klebsiella pneumoniae and Escherichia coli acquired multidrug-resistance. Methods The quarterly percentage of broad-spectrum antibiotic prescriptions evaluated by antimicrobial stewardship team (AMST), the quarterly consumption of broad-spectrum antimicrobials and the quarterly proportion of multidrug-resistant K. pneumoniae and E. coli were assessed between October 2016 and December 2022, with 2 periods of time, before the pandemic (October 2016-March 2020) and after the pandemic (April 2020-December 2022).Time series analysis was performed with ARIMA models to evaluate the association between decrease in AMST activities with multidrug-resistance in K. pneumoniae or E. coli. Correlation between broad-spectrum antibiotic prescriptions reviewed by AMST with broad-spectrum antimicrobials consumption and proportion of multidrug-resistance in K. pneumoniae or E. coli in urine cultures was assessed using the Pearson correlation coefficient. Results Percentage of broad-spectrum antimicrobials evaluated by AMST was 77% in first period and 29% in second period. The mean of broad-spectrum antibiotics consumption in first period was 13.02 DDD/100 bed-days and 15.35 DDD/100 bed-days in second period. Decrease of AMST activities was associated with an 37% increase in multidrug-resistant K. pneumoniae in second period compared with first period (p=0.02). No differences were found in E. coli. Correlation between percentage of AMST-reviewed broad-spectrum antibiotics with consumption of these antibiotics was good (correlation coefficient -0,7; p< 0,01). Correlation between ASMT-reviewed broad-spectrum antibiotics and multidrug-resistant K. pneumoniae was moderate (correlation coefficient -0.44; p=0,02). No correlation between ASMT-reviewed broad-spectrum antibiotics and multidrug-resistant E. coli (correlation coefficient 0,09; p=0,6) was found. Conclusion Decrease in antimicrobial stewardship activities was associated with high isolation of multidrug-resistant K. pneumoniae in urine cultures. Disclosures All Authors: No reported disclosures

Abstract Background Majocchi’s granuloma (MG) is an uncommon deep fungal folliculitis predominantly caused by dermatophytes. Available data regarding predisposing comorbidities/risk factors, clinical characteristics, offending microbiologic pathogens, diagnostics, pathologic findings, and treatment approaches has been inferred from historical cases. Given these limitations in the existing literature of MG, we sought to conduct a detailed review of our institutional experience with biopsy-confirmed cases of MG. Methods Following IRB approval, we retrospectively identified and analyzed a multicenter cohort of adult patients diagnosed with MG between September 1992 and September 2022 at Mayo Clinic campuses (Figure 1). Data extracted included demographics, comorbid conditions, presenting clinical characteristics, diagnostic, microbiologic, and biopsy characteristics, treatment details, and outcomes. Figure 1 Flow Diagram show exclusion of patients from the final cohort. Results A total of 147 patients with MG with the accompanying baseline characteristics met study criteria (Table 1). One-hundred and five patients were male with a median age of 55.6 years. Immunosuppressant and topical corticosteroid use were common prior to development of MG (Table 1). Dermatologic lesions and their sites of involvement did not differ based on the immune status of patients (Table 2). Trichophyton rubrum was the most common causative pathogen of MG, in addition to other dermatophytes and fungal organisms (Table 3a). Treatment duration for all prescribed agents was median 31.5 days. Oral terbinafine was the most frequently utilized agent and clinical resolution was achieved in 96.6% of cases (Table 3b). Baseline Characteristics of 147 Patients with Majocchi’s Granuloma Diagnostic, Microbiologic, and Biopsy Characteristics, Treatment Characteristics and Outcomes Conclusion While rare and clinically variable in presentation, the diagnosis of MG requires careful clinical examination and history-taking, histopathologic confirmation, and frequently fungal culture. Most cases of MG in our study responded well to a course of oral terbinafine at a median of 31.5 days of treatment. Disclosures All Authors: No reported disclosures

Abstract Background Catheter-related bloodstream infection (CRBSI) is an important complication of long-term central venous catheters (CVCs) and is associated with high morbidity and cost. While line removal is optimal, it is not always feasible and is not without complications. Antibiotic lock therapy (ALT) may be an alternative strategy for line salvage, but the efficacy of this approach particularly among immunocompromised hosts is unknown. Methods We retrospectively reviewed adult patients with CRBSI managed with ALT between 2018 and 2022 at our tertiary medical center. We reviewed patient comorbidities, type and indications for CVC use, microbiology of CRBSI, ALT, and use of systemic antibiotics. Outcomes included 30-day mortality, 90-day microbiologic relapse (with same bacteria as index case), 90-day recurrent BSI (with different bacteria from index case), and adverse events. Results 86 patients were reviewed, a majority of whom were immunocompromised (91%) due to hematopoietic stem cell transplantation (85%) and thrombocytopenic (platelet count 36; IQR 17-112). 78% had tunneled CVC for indications including peri-transplant therapy (72%), chemotherapy (15%), and TPN (6%) (Table 1). The median time to CRBSI following CVC insertion was 45 days (IQR 19-86). Infections were frequently monomicrobial (80%) due to Gram-positive organisms (n=75) including coagulase-negative staphylococci and Enterococcus spp. The minority of Gram-negative (n=17) infections were due to E coli and Enterobacter spp. 94% of patients received systemic antibiotics and all patients received ALT for a median of 11 days [IQR 6-15] and 11.5 days [IQR 6-14], respectively (Table 2). The 30-day attributable mortality rate was low at 1%. Rates of 90-day microbiologic relapse (20%) and recurrent BSI (16%) were high, occurring at a median of 42 days (IQR 12-55) and 35 days (IQR 25-50) following completion of ALT, respectively (Table 3). Conclusion Despite high rates of microbiologic relapse and recurrent BSI, ALT may be an effective line salvage strategy extending the use of CVC by up to 30 days with minimal impact on mortality even among immunocompromised patients. Disclosures John C. O'Horo, Sr., MD, MPH, Janssen Pharmaceuticals.: Grant/Research Support|nference: Grant/Research Support

Abstract Background Organ transplant recipients are at increased risk of potentially life-threatening opportunistic infections, including Pneumocystis jirovecii pneumonia (PJP). Given the use of effective prophylaxis, PJP has become less common, especially during the first-year post-transplant. Recent data has shown that the risk of infection has shifted within the first 2 years after discontinuing prophylaxis. We aimed to determine risk factors for late posttransplant PJP using a national database. Methods Using the United States Renal Data System database, we performed a retrospective case-control study of patients who underwent kidney transplant from 1998 through 2019. To evaluate risk factors for late PJP, we performed logistic regression analysis by comparing characteristics between infected patients and their matched uninfected controls. Results We identified 407 cases with PJP and matched to 1628 controls (1:4). 60 (14.7%) of the cases occurred within one year post transplant and 347 (85.3%) patients were diagnosed after one year of transplant. In the late period, the median time between transplant and PJP diagnosis was 68.7 (IQR 28 -134.2) months. Seventy cases (20.1%) occurred between 12 and 24 months. In multivariate analysis (table 1), risk factors for late infection included a higher Elixhauser Comorbidity Index (ECI), history of cytomegalovirus disease, older donor age, use of antilymphocyte agents, history of re-transplant and a longer time of hemodialysis prior to transplant. Of note, in the early period, we found that having a living donor was protective. Multivariate analysis of risk factors for late Pneumocystis jirovecii pneumonia Conclusion Our findings highlight the importance of a timely transplant to mitigate the risk of post-transplant PJP in the late post-transplant period where prophylaxis is not routinely used. These results also raise the consideration of PJP prophylaxis in the late period in patients diagnosed with CMV disease, history of re transplant and recent use of antilymphocyte agents. Disclosures Paschalis Vergidis, MD, MSc, AbbVie: Advisor/Consultant|Ansun: Grant/Research Support|Cidara: Grant/Research Support|Scynexis: Grant/Research Support

Abstract Background Histoplasmosis is an endemic mycosis associated with a wide range of clinical presentations. Cardiovascular histoplasmosis (CVH) was rarely seen at our center before 2007 but has increased in frequency over the last 15 years. Herein, we describe the clinical characteristics of our recent CVH cases. Methods We identified all adults diagnosed with CVH at Mayo Clinic in Rochester, MN, between May 2007 and February 2023. Results Ten cases of CVH were identified, all of whom resided in the Midwest (Table). The majority were male, with a median age of 72 years. Five patients had prosthetic valves, two endovascular grafts, one a prosthetic valve and aortic graft, and one was a heart-kidney transplant recipient. Patients most frequently presented with prolonged night sweats, fever, and dyspnea. Cytopenias, pulmonary nodules, and splenomegaly were common laboratory and imaging findings. The diagnosis was suspected based on a positive Histoplasma antibody (100%) and/or antigen (80%) testing and confirmed by positive culture (blood 60%, explanted valve/graft 20%) and/or histopathology (60%). Identified clinical syndromes included: prosthetic valve endocarditis (PVE; 50%), native valve endocarditis (10%), mycotic aortic aneurysm (10%), aortic graft infection (10%), PVE and aortic graft infection (10%), and myocarditis (10%). Most patients received combined medical and surgical treatment (50%). Three patients (30%) received medical treatment only, including one patient with myocarditis. Two patients (20%) presented progressive clinical decline and were not considered antifungal treatment or surgical candidates. The overall mortality within one year of diagnosis was 50%. Patients with endocarditis and/or graft infection who received only medical treatment had higher mortality than those who received combined medical and surgical treatment (100% vs 20%, respectively).Table.Clinical characteristics of patients presenting with cardiovascular histoplasmosis (N=10) *Patient frequently had more than one comorbidity, symptom, laboratory or imaging finding, positive histoplasmosis testing, or affected valve. **Two patients did not receive treatment given their critical status, and were transitioned to comfort care. Conclusion CVH is being seen more frequently at our institution. One-year mortality of CVH was high, but combined medical and surgical management conferred better outcomes than medical treatment alone. We suggest a high index of suspicion of CVH in patients residing in Histoplasma endemic regions with a history of prior cardiac or vascular surgery presenting with prolonged fevers and/or new cardiomyopathy. Disclosures All Authors: No reported disclosures

Abstract Background Two independent placebo-controlled clinical trials conducted prior to SARS-CoV-2 Omicron demonstrated that sotrovimab and remdesivir reduced hospitalization among high-risk outpatients with mild to moderate COVID-19. However, their effectiveness have not been directly compared. Methods This retrospective study examined all high-risk outpatients with mild to moderate COVID-19 who received either remdesivir or sotrovimab at Mayo Clinic during the Omicron BA.1 surge from January to March 2022. COVID-19-related hospitalization or death within 28 days were compared between the two treatment groups. Results Among 3,257 patients, 2,158 received sotrovimab and 1,099 received remdesivir. Patients treated with sotrovimab were younger (median age, 60 vs. 69 years) and had lower comorbidity (Monoclonal Antibody Screening Score, 5 vs. 6; Charlson Comorbidity Index, 3 vs. 4), but were more likely to be immunocompromised (47.3% vs. 30.2%) than remdesivir-treated patients. The majority (89%) had received at least one dose of COVID-19 vaccine (median, 3 doses [IQR 2-3] for both groups). COVID-19-related hospitalization (1.5% and 1.0% in remdesivir and sotrovimab groups, respectively, p=.15) and mortality within 28 days (0.4% in both groups, p=.82) were similarly low. A propensity score weighted analysis demonstrated no significant difference in the rates of COVID-related hospitalization and death within 28 days between the two groups. Conclusion This study demonstrated favorable outcomes that were not significantly different between patients treated with remdesivir or sotrovimab. As sotrovimab is no longer authorized, these results support the continued use of remdesivir for treating high-risk patients with COVID-19 during the current Omicron-predominant epoch. Disclosures Christina G. Rivera (O'Connor), Pharm.D, Gilead Sciences: Advisor/Consultant|Gilead Sciences: Board Member|Gilead Sciences: Grant/Research Support|Gilead Sciences: Honoraria Maria Gonzalez Suarez, M.D., Ph.D., Gilead: Grant/Research Support Ravindra Ganesh, M.B.B.S., M.D., Alpaca Health: Advisor/Consultant Raymund R. Razonable, MD, Allovir: Endpoint Adjudication Committee|American Society of Transplantation: Board Member|Gilead: Grant/Research Support|Novartis: DSMB|Regeneron: Grant/Research Support|Roche: Grant/Research Support

Abstract Background Remdesivir is FDA-approved for the treatment of hospitalized patients with severe COVID-19. Many patients improve clinically to allow for hospital dismissal before completing the 5-day course. In prior work, those who continued remdesivir in an outpatient setting had better outcomes. Here, we assessed patients’ perspectives and the economic impact of this outpatient practice. Methods During a one-year period, 3,029 patients received remdesivir for COVID-19 in the hospital; of them, 542 were dismissed to continue remdesivir in the outpatient setting and were surveyed. The cost of care was compared between those who remained in the hospital vs. those who were dismissed. Results 470 of 542 patients were surveyed, and 93 (19.8%) responded. Responders were older than non-responders (median, 63 vs. 58 years). The majority (70.5%) had symptoms resolved by the time of the survey. Ten patients (11.4%) had persistent symptoms attributed to long COVID-19, including fatigue (30.1%), brain fog (23.7%), and insomnia (18.3%). 73.8% were excited to learn about the outpatient remdesivir program. The majority (81.0%) felt that receiving therapy at home was the right decision; 79.5% had support and felt the benefits of completing treatment at home. The majority were satisfied with communication before (75.6%) and during (80.5%) the outpatient appointment, information on benefits (80.3%) and risks (58.5%), time spent at the infusion center (88.6%), quality of care (82.3%) and overall experience (76.0%). The benefits of treatment were high-value (82.6%), while the infusions' cost, inconvenience, and discomfort were unimportant for most responders. After adjusting for gender, comorbidity score, and WHO scale, the predicted costs for the groups were $16,544 (inpatient) and $9,097 (outpatient) per patient (difference of $7,447; p< .01). During this study, we estimated a total of 1,077 hospital room-days were made available to other patients. Conclusion An outpatient remdesivir program that allowed for early dismissal was perceived favorably by patients hospitalized for COVID-19. The program resulted in significant cost and resource savings, the latter in terms of the availability of hospital rooms for other patients needing critical services. Disclosures Christina G. Rivera (O'Connor), Pharm.D, Gilead Sciences: Advisor/Consultant|Gilead Sciences: Board Member|Gilead Sciences: Grant/Research Support|Gilead Sciences: Honoraria Bijan J. Borah, Ph.D., Boehringer Ingelheim: Advisor/Consultant|Exact Sciences: Advisor/Consultant Ravindra Ganesh, M.B.B.S., M.D., Alpaca Health: Advisor/Consultant Raymund R. Razonable, MD, Allovir: Endpoint Adjudication Committee|American Society of Transplantation: Board Member|Gilead: Grant/Research Support|Novartis: DSMB|Regeneron: Grant/Research Support|Roche: Grant/Research Support

Abstract Background Methicillin-resistant Staphylococcus aureus (MRSA) biofilms can be resilient to the human immune system and antibiotics, a challenge augmented by acquired antimicrobial resistance. Phage therapy is being evaluated for biofilm-associated infections. Methods Here, model phages SaMD07ø1 and SaRB105030ø5 were evaluated against their hosts SaMD07 and SaRB105030, respectively, grown as biofilms in 96-well plates, as biofilms on glass beads and planktonically. Trypticase soy broth (TSB) and phosphate buffered saline (PBS) were evaluated as testing media (Figure 1). Biofilms were incubated with phages in the presence of media containing tetrazolium dye in 96-well plates and assessed for hold times (delays in reaching bacterial log-phase metabolic activity compared to controls) over 48 hours (h) using a Biolog Omnilog® system and by assessing colony forming units (CFUs). Subsequently, using the beads biofilm assay in TSB medium performed on the Omnilog® (BBTO) (Figure 2), test phage SaMD22ø1 was evaluated in quintuplicate against biofilms formed by MRSA isolates IDRL-6130, IDRL-6927, IDRL-6987, IDRL-7381, IDRL-7542 and IDRL-10947, all recovered from periprosthetic joint infection. Test phage K was evaluated against GFP-labelled MRSA AH1263 using BBTO method and simultaneously by fluorescence microscopy.Figure 1.Biofilm phage susceptibility testing methods evaluated (created with BioRender.com)Figure 2.Biofilm phage susceptibility testing using biofilms grown on beads assessed in TSB medium using the Omnilog® (BBTO) method with phage SaMD22ø1. Results A comparison of result of testing of biofilms in wells and on beads and against planktonic bacteria is shown in Figure 3. Phage SaMD07ø1 showed no growth at 4 h; whereas phage SaRB105030ø5 showed ∼1-log decrease in CFUs at 4 h and ∼3-log decrease in CFUs at 8 h (Figure 3). BBTO hold-times of 37, 28 and 15 h were observed for phages SaMD07ø1, SaRB105030ø5 and phage K respectively. Phage SaMD22ø1 had an average hold time of 9 h and showed hold times >6 hours for all isolates tested (Figure 4). Microscopic inspection showed eradication of GFP-labelled MRSA biofilm by phage K (Figure 5).Figure 3.Results of quantitative culture of biofilms treated with phages SaMD07ø1 and SaRB105030ø5 in TSB medium.Panel 1 shows results of phage SaMD07ø1 with biofilms grown in wells (1a), on beads (1b) and planktonically (1c). Panel 2 shows results of phage SaRB105030ø5 with biofilms grown in wells (2a), on beads (2b) and planktonically (2c).Figure 4.Activity of phage SaMD22ø1 against biofilms formed by six MRSA strains determined using the Omnilog® (BBTO) method. The solid blue line indicates a hold time of 8 hours.Figure 5.Efficacy of Phage K to efficiently eradicate GFP-labelled MRSA strain AH1263 observed under the fluorescence microscope at 40X magnification. The authors are thankful to Dr. Alexander Horswill at University of Colorado for providing the GFP-labelled MRSA strain. Conclusion In conclusion, BBTO is a promising method for testing biofilm phage susceptibility although clinical correlation and testing of larger numbers of phage and bacterial isolates are needed. Disclosures Joseph Fackler, n/a, Adaptive Phage Therapeutics, Inc: Employee|Adaptive Phage Therapeutics, Inc: Stocks/Bonds John M. Sowers, n/a, Adaptive Phage Therapeutics: Employee|Adaptive Phage Therapeutics: Stocks/Bonds Robin Patel, MD, Abbott Laboratories: Advisor/Consultant|Adaptive Phage Therapeutics: Grant/Research Support|Adaptive Phage Therapeutics: Mayo Clinic has a royalty-bearing know-how agreement and equity in Adaptive Phage Therapeutics.|BIOFIRE: Grant/Research Support|CARB-X: Advisor/Consultant|ContraFect: Grant/Research Support|Day Zero Diagnostics: Advisor/Consultant|HealthTrackRx: Advisor/Consultant|Mammoth Biosciences: Advisor/Consultant|Netflix: Advisor/Consultant|Oxford Nanopore Technologies: Advisor/Consultant|PhAST: Advisor/Consultant|See details: Patent on Bordetella pertussis/parapertussis PCR issued, a patent on a device/method for sonication with royalties paid by Samsung to Mayo Clinic|See details: continued, patent on an anti-biofilm substance issued|TenNor Therapeutics Limited: Grant/Research Support|Torus Biosystems: Advisor/Consultant|Trellis Bioscience, Inc.: Advisor/Consultant

Abstract Background Vancomycin resistant enterococcus (VRE) infective endocarditis (IE) is associated with poor outcomes. There are limited data to guide the antimicrobial choice and duration of therapy. Several in vitro and limited clinical studies demonstrate the synergistic effect of β-lactams with other agents, particularly daptomycin, in this setting. We sought to compare clinical outcomes in patients with VRE IE treated with adjunctive β-lactam therapy. Methods This was an IRB-approved, retrospective, single-center cohort study. The study included patients ≥18 years of age diagnosed with VRE IE via modified Duke criteria from 2011-2021. Data were collected by electronic medical record review. Descriptive statistics were obtained. The primary outcome was 90-day treatment failure compared between those receiving and not receiving adjunctive β-lactams. Treatment failure was defined as recurrence of bloodstream infection (BSI) or death within 90 days of diagnosis. Failure-free survival was analyzed by Kaplan-Meier curve with log-rank test. Results A total of 32 cases were identified. 12 received adjunctive β-lactams. Mean age was 67 years, and 71% were male. 13 (41%) had a prosthetic valve and 6 (19%) had a CIED (Table 1). A majority (78%) had E. faecium IE. Mean duration of bacteremia was 9 days (Table 2). About one-third had treatment failure with 7 deaths and 4 BSI recurrences. Adjunctive β-lactams included ampicillin (3), cefepime (1), ceftaroline (6) and ceftriaxone (2). There was no statistical difference in failure-free survival in patients treated with adjunctive β-lactam therapy (Figure 1). The results were similar when restricted only to those who received daptomycin with or without adjunctive β-lactam therapy.Table 1.Patient CharacteristicsTable 2.Disease characteristics Figure 1. Kaplan-Meier curve comparing failure-free survival between patients who were primary treated with adjunctive β-lactams versus non-adjunctive therapy. The p-value is calculated via the log-rank test. Conclusion VRE IE is associated with poor prognosis, including high rates of mortality and relapses. In our experience, adjunctive B-lactam use did not result in improved outcome. Limitations include small sample size, and heterogenous antibiotic use. More prospective randomized data are needed. Disclosures All Authors: No reported disclosures

Abstract Background As the acute phase of the COVID-19 pandemic subsides, an increasing number of individuals are recognized as having long COVID, affecting over 65 million people worldwide. Recent studies have suggested a potential link between long COVID and alterations in the gut microbiome. In this study, we examined the gut microbiome of a large outpatient cohort during acute phase of infection, with the ultimate goal of determining predictors of long-term COVID-19 health outcomes. Methods We conducted a study of 394 COVID-19 patients with positive SARS-CoV-2 testing from November 2020 to September 2021 at a multi-site healthcare system. Long COVID was defined as the persistence of symptoms for four weeks or more after illness onset. DNA extraction was performed using the MoBio PowerSoil Pro DNA isolation kit. Samples were sequenced using shotgun metagenomics. Stool SARS-CoV-2 RNA was tested using qRT-PCR of the E gene, and stool ELISA was performed for calprotectin levels. Standard biostatistical tools in R (v 4.2.3) were used for statistical analysis. Results Of the 394 COVID-19 patients, 84 (21%) had long COVID, with fatigue being the most common persistent symptom (Table 1). No significant differences were seen in age, BMI, and antibiotic use. Those with long COVID were more likely to be female, had higher Charlson's comorbidity scores, more severe index illnesses. However, the two groups had no difference in SARS-CoV-2 stool PCR positivity or stool calprotectin levels (Table 2). Principal coordinate analysis of Bray Curtis dissimilarities revealed that patients with long COVID had a distinct microbial composition compared with those without long COVID during the acute phase of infection (ANOSIM R2= 0.005, P= 0.01). Categorizing patients by number of long COVID symptoms showed significant differences among groups (ANOSIM R2=0.1, P=0.007), mainly between patients with >3 symptoms and those with 0-1 symptoms (Bonferroni, P= 0.018). Alpha diversity was lower in patients with > 3 symptoms, although this was not statistically significant (Shannon diversity, two-way-ANOVA, P=0.051). Figure 1 Conclusion Long COVID patients show distinct gut microbial composition during the acute phase of infection, suggesting a potential role in predicting long-term COVID health outcomes. Disclosures John C. O'Horo, Sr., MD, MPH, Janssen Pharmaceuticals.: Grant/Research Support|nference: Grant/Research Support Purna C. Kashyap, MD, Intrinsic Medicine: Advisor/Consultant|Novome Biotechnologies: Advisor/Consultant|Pendulum Therapeutics: Advisor/Consultant