bluuebunny/crossref_metadata_2025 huggingface dataset:
381. Transplantation of Maternal Intestinal Flora to the Newborn After Elective Cesarean Section - A Randomized Controlled Trial (SECFLOR)
Authors: Carpén Noora K , de Vos Willem M , Salonen Anne , Kolho Kaija-Leena , Andersson Sture , Helve Otto
Published: January 2025

Background

Normal microbial colonization process from the mother to the newborn is disrupted by birth by caesarean section (CS). We assess, whether in CS-delivered infants, the intestinal microbiome could be successfully and safely normalized by postnatal oral transfer of maternal fecal microbiome (FMT). In this double-blinded randomized controlled trial started in autumn 2019, we assess the difference in heterogeneity of the intestinal microbiome between the two groups from birth to 24 months of age.

The randomization code was opened in March 2024 when last transplanted child turned one year of age. Primary outcome measures are assessed from samples collected at 3 months of age.

Methods

90 healthy pregnant women scheduled for elective CS were recruited. After screening and randomization, within two hours of delivery, 31 newborns were given 3.5 mg of the transplant from their own mothers or placebo mixed in mother’s milk.

The children are followed for 24 months. Stool and blood samples from the child and mother are collected during the follow up and analyzed for changes in microbiome heterogeneity between the groups and to assess, for example, immunological changes associated with the transfer.

Results

All mothers were asymptomatic, no prescribed courses of antibiotics or travelling history outside the European Union region within three months of screening. 38 had positive findings in screening tests. 31 infants were included in the study of whom 15 received the transplant and 16 placebo. 3 adverse events were reported in the transplant group: one infant had thrombocytopenia at the age of two days, which normalized within one week. One infant was diagnosed with bilateral grade one intraventricular hemorrhage at the age of two weeks. One infant was treated for transient tachypnea of the newborn after receiving the transplant. None of the adverse events were considered related to the transplant.

Conclusion

In our proof-of-concept study we previously demonstrated the effectiveness and safety of our protocol. The immunology and microbiota samples (fecal and blood) of our first-of-a-kind randomized controlled trial are being analyzed and first results will be available in September 2024.

Disclosures

All Authors: No reported disclosures
161. Prospective Study of Cytomegalovirus (CMV) Reactivation in Patients with Multiple Myeloma Receiving anti-CD38 and BCMA Therapies: An Interim Data Analysis
Authors: Baneman Emily , Moshier Erin , Sanchez Larysa , Rana Meenakshi M , Jacobs Samantha E
Published: January 2025

Background

The landscape of multiple myeloma (MM) treatment has shifted over the past decade, leading to increased cumulative immunosuppression as patients live longer and receive treatment for multiple relapses. Newer MM therapies, including anti-CD38 and BCMA directed agents, impact cell-mediated immunity. We hypothesized that patients receiving such therapies are at risk of CMV infection and we launched a prospective pilot study to assess CMV incidence in this population.Table 1:Characteristics of CMV reactivation among patients with multiple myeloma

Methods

Eligible patients included seropositive adults with MM undergoing treatment with anti-CD38 or anti-BCMA therapies. Plasma CMV PCR was monitored every 14 days (+/- 7 days) for three months (Cobas 6800 System, limit of quantification 34.5 IU/mL). The primary endpoint was CMV viral load >500 IU/mL. Treating providers were blinded to results unless CMV PCR was sent outside of the study for clinical reasons.Figure 1:Proportion with CMV > 500 IU/mL during follow-up period

Results

Twenty-two patients had data available at the time of interim analysis. Eleven (50%) patients received anti-CD38 containing regimens (10 daratumumab, 1 isatuximab), 5 (23%) received anti-BCMA bispecific antibody, and 6 (27%) received BCMA-targeted CAR-T. Eight (36%) patients had newly diagnosed MM and 14 (64%) had relapsed disease. Among relapsed patients, median prior lines of chemotherapy was 4 (range 1-13). Nine (41%) patients had prior autologous stem cell transplant. Fourteen (64%) patients had detectable CMV DNA, but CMV viral load remained < 34.5 IU/mL in the majority (8/14, 57%). Only three (13.6%) patients had CMV viral load >500 IU/mL, including one asymptomatic CAR-T cell recipient who received valganciclovir. Median duration of DNA-emia was 2 weeks (range 1-15). There was a trend toward more DNA-emia in subjects with newly diagnosed compared to relapsed MM (88% vs 29%, HR 2.58 [95% CI 0.86-7.79], p=0.0758). Previous history of CMV infection was also associated with CMV reactivation during the study (HR 5.54 [95% CI 1.36 - 22.48], p=0.0063). There were no patients with end-organ CMV disease and no mortality during the study.Figure 2:Proportion with any CMV DNA detection during follow-up period

Conclusion

Low-level CMV reactivation occurs frequently in patients with MM receiving anti-CD38 and BCMA therapies, but clinically significant CMV infection remains uncommon. Future studies should also evaluate the impact of subclinical CMV DNA-emia on oncologic outcomes.Figure 3:Proportion with any CMV DNA detection, stratified by prior MM treatment

Disclosures

Emily Baneman, MD, Merck: Grant/Research Support Samantha E. Jacobs, MD, MS, Ansun Biopharma: Advisor/Consultant|Eurofins, Viracor, LLC.: Grant/Research Support
172. Impact of 24/7 Rapid Diagnostic Testing Pharmacist Interventions and Infectious Diseases Consultation in Pediatric Staphylococcus aureus Bacteremia
Authors: Aquino Catherine Ann C , Gavaza Paul , Soneji Maulin , Chan Tompkins Noreen
Published: January 2025

Background

The benefits of pharmacist interventions using rapid diagnostic testing (RDT) and Infectious Diseases (ID) consultation for Staphylococcus aureus bacteremia (SAB) have been documented in adults, but data on pediatric patients is sparse. The study objectives were to evaluate the impact of 24/7 pharmacist-led RDT interventions and pediatric ID consultation on clinical outcomes in pediatric SAB.

Methods

This retrospective cohort study analyzed pediatric patients (age < 18 years) with SAB admitted to Children’s Hospital comparing outcomes before and after implementation of 24/7 pharmacist-led RDT interventions. Pre-intervention (Pre-RDT) group included patients admitted from February 2013 to January 2015 and the post-intervention (Post-RDT) group from August 2021 to July 2023. Premature infants (< 36 weeks gestational age) and patients with polymicrobial bacteremia or fungemia were excluded.

Results

A total of 101 patients were included: Pre-RDT (n=51) and Post-RDT (n=50). Most patients were male (68.3%) and white (61.4%) with similar baseline characteristics (Table 1). The median time to optimal antibiotic (TOAT) from blood culture collection was lower in the Post-RDT group than the Pre-RDT group (23.9 vs 29.0 hours; p=0.673) for MRSA and MSSA isolates. The Post-RDT group had lower median TOAT for MSSA (24.8 vs 87.7 hours; p < 0.001) with higher use of beta-lactams (Figure 1), lower hospital length of stay (LOS) (12 vs 17 days; p=0.007), lower ICU admissions (40.0% vs 64.7%; p=0.017), and shorter ICU LOS (14 vs 17 days; p=0.022) than patients in the Pre-RDT group. Post-RDT patients had fewer 30-day readmission (22.0% vs 23.5%; p > 0.05) and in-hospital mortality (4% vs. 7.8%; p > 0.05) than Pre-RDT patients. ID was consulted more frequently in the Post-RDT group (94.0% vs. 56.9%; p < 0.001). In-hospital mortality was lower with ID consultation than without it (2.6% vs. 16.0%; p=0.032).

Conclusion

Integration of 24/7 RDT pharmacist interventions and pediatric ID consultations were associated with improved clinical outcomes (TOAT for MSSA, hospital and ICU LOS and in-hospital mortality) in pediatric patients with SAB, highlighting the effectiveness of these interventions in a pediatric antimicrobial stewardship framework.

Disclosures

All Authors: No reported disclosures
178. Elevating Infectious Diseases Management: Impact of an Inpatient Pharmacist-Led Tele-Antimicrobial Stewardship Program Integrated within a Health System
Authors: Paul Maniara Bejoy , Oommen Jomi , Thomas Jeffery , Millares-Sipin Catherine
Published: January 2025

Background

Antimicrobial resistance (AR) is a growing global threat projected to cause 10 million deaths annually by 2050. Joint Commission requires hospitals to have antimicrobial stewardship programs (ASPs). Centers for Disease Control and Prevention recommends pharmacists co-lead ASPs. Infectious diseases (ID) pharmacists are critical to combat AR and elevate patient care by optimizing antimicrobial use. Tele-ASPs could enhance patient care by extending patient care continuity. This study assesses the impact of an inpatient pharmacist-led Tele-ASP.

This chart depicts monthly ASP-related pharmacist interventions, comparing the amount performed before and after implementation of the Tele-ASP.

Methods

This study evaluated antimicrobial management across 14 Northwell Health hospitals in two phases: Pre-Tele-ASP (August 15, 2021 – August 14, 2022) and Post-Tele-ASP (August 15, 2022 – August 14, 2023). The primary endpoint was the total number of ASP interventions during Tele-ASP hours (i.e., 4 PM – 12 AM). Secondary endpoints included ASP interventions and acceptance rates, cost savings, and length of stay (LOS).

This chart outlines the top 5 antimicrobials that pharmacists performed ASP-related interventions on, as well as the top 5 ASP-related interventions that were performed.

Results

A total of 19,802 patients with ASP interventions were included; 5,919 patients (29.9%) had interventions during Tele-ASP hours. There was a 237% increase in ASP interventions during operating hours in the post-Tele-ASP phase (9,467 vs 2,810; p < 0.001). Overall, there was a 62% increase in accepted ASP interventions (25,192 vs 15,552; p < 0.001), with a 26% increase during the day shift (15,423 vs 12,257; p < 0.001), a 256% increase during the evening shift (9,248 vs 2,601; p < 0.001), and a 25% decrease during the overnight shift (524 vs 694; p < 0.01). The overall ASP intervention acceptance rate was 96.8%. Total cost savings and avoidance across all shifts increased by 74.1% ($10,355,707 vs $5,947,578; p < 0.001). The overall LOS decreased by a mean of 1.1 days (p < 0.001).

This chart stratifies the total number of accepted ASP interventions across each shift.

Conclusion

This unique pharmacist-led Tele-ASP provided services to hospitals across Northwell Health during resource-limited hours and locations. Implementation increased accepted ASP-related interventions without reducing overall interventions, effectively reducing LOS and increasing cost savings and avoidance. This model serves as a blueprint for hospitals to strategically expand ASP services in a clinically and financially efficient manner and optimize antimicrobial use and patient care.

This chart stratifies the total amount of cost savings and cost avoidance, as a result of ASP-related pharmacy interventions, across each shift.

Disclosures

All Authors: No reported disclosures
206. A Cluster Randomized Trial Evaluating Universal Gloving for Reducing Clostridioides difficile Acquisition and Infection in VA: The GloRI Study
Authors: McKinley Linda , Ray Cara E , Keating Julie , Brennan Noreen , Crnich Christopher J , Louise Dembry , Dixon Jonah , Evans Charlesnika T , Gelman Michael , Morgan Daniel J , Moriarty Helene , Ndakuya-Fitzgerald Florine , Pacheco Susan M , Pfeiffer Christopher D , Weintrob Amy , Safdar Nasia
Published: January 2025

Background

Clostridioides difficile infection (CDI), the most common healthcare associated infection (HAI) in U.S. hospitals, causes half a million infections and 30,000 deaths annually. Prevention of hospital-onset (HO) CDI has quickly become a priority for most hospitals. Hospital exposure to C. difficile can occur through cross-contamination of healthcare personnel (HCP) hands or through shared environmental surfaces or equipment. Infection prevention measures focus on HCP hand hygiene and barrier precautions (i.e., gowns and gloves) and cleaning of environmental surfaces, especially for patients with known CDI. However, colonized patients can also serve as a reservoir for cross-contamination, and microbiological screening for C. difficile colonization is not routinely performed in healthcare.

Methods

We conducted a cluster randomized trial (CRT) in 10 inpatient units at 5 VA hospitals between April 2022 and December 2023 to evaluate the effectiveness of healthcare worker use of gloves for all patient contact (i.e., universal gloving) in reducing acquisition of C. difficile colonization (defined as negative PCR at admission and positive PCR at discharge) and HO-CDI (per NHSN LabID criteria, as adjudicated by facility infection prevention personnel for routine quality reporting).

Results

Of 9779 admissions, 780 consented to specimen collection. Table 1 displays preliminary data. At admission, 11.6% (intervention group) and 10.3% (control group) of patients tested were colonized with C. difficile. There were 474 patients with both admission and discharge perirectal swabs cultured for C. difficile. The C. difficile colonization acquisition rate was 12.9 per 1000 patient days of care (PDOC) for the intervention group and 10.3 for the control group (p=0.79). Unit-level aggregate data for the HO-CDI rate was 0.29 per 1000 PDOC for the intervention group and 0.57 for the control group (p=0.07).

Conclusion

No universal reduction in the acquisition of C. difficile was detected in acute care units implementing a gloving intervention compared with standard practice, but only 5% (474/9779) of admissions had complete testing data. A numerically lower but statistically nonsignificant HO-CDI rate was detected in the universal gloving group compared to standard practice.

Disclosures

Christopher D. Pfeiffer, MD, MHS, Department of Defense/Medpace: Grant/Research Support|Pfizer: Grant/Research Support
P-808. Enterococcal Bloodstream Infection and Infective Endocarditis in a Population-Based Cohort: An Expanded Rochester Epidemiology Project Investigation
Authors: Bayless David , Baddour Larry M , Lahr Brian , Hagan Grace , Cao Jenny , DeSimone Daniel C
Published: January 2025

Background

The Rochester Epidemiology Project (REP) has been used to examine numerous infectious and non-infectious entities in a population-based approach in Olmsted County, Minnesota. To further investigate patterns of enterococcal bloodstream infection (BSI), we used the Expanded Rochester Epidemiology Project (E-REP) to include additional surrounding counties to conduct a retrospective population-based study of adult patients who developed enterococcal BSI, with or without infective endocarditis (IE).

Methods

The E-REP population under study included eight counties in southeastern Minnesota (including Olmsted County), representing a total population of over 250,000 individuals. Adults (age ≥ 18 years) diagnosed with an initial episode of enterococcal BSI with or without enterococcal IE between January 1, 2018 and December 31, 2022 were included; patients with either polymicrobial BSI with enterococci or a previous bout of enterococcal BSI before the study period were excluded. Cases of enterococcal BSI and IE were identified using ICD-10 codes and underwent complete medical record review. Patient characteristics, microbiology, antibiotic regimens, infectious complications, and outcomes were collected.

Results

A total of 113 cases of enterococcal BSI were identified over the five-year study period. The age- and sex-adjusted incidence rate of enterococcal BSI was 6.9 per 100,000 person-years, with a significantly higher rate among males than females (Figure 1). BSI incidence rate varied by age, with patients 80 years or older having the highest incidence rate (Figures 1 and 2). Twenty-two cases of enterococcal IE were identified, yielding an overall IE prevalence of 20.8% (Figure 3). The cumulative mortality rate at 12 months was high at 41.7% (Figure 3). Five patients (4.4%) had a relapse of enterococcal BSI, defined as recurrence of BSI after negative follow-up blood cultures and within 12 weeks of the initial BSI.

Conclusion

This is the first population-based investigation that has focused on the epidemiology and clinical profile of patients with enterococcal BSI and complicating IE in a US population. This included an IE prevalence of 20.8%, which should be considered when evaluating and managing patients with enterococcal BSI.

Disclosures

Larry M. Baddour, MD, UpToDate, Inc.: Royalty payments (authorship duties).
P-810. Impact of Comorbid Heart Failure among Hospitalized Patients with Escherichia coli Sepsis: a United States Population-Based Cohort Study
Authors: Casipit Carlo Gabriel C , Casipit Bruce Adrian C , Subramanian Apoorva , Arya Yajur , Syal Arshi , Jara-Tantoco Mikaela Nikkola , Wattanachayakul Phuuwadith
Published: January 2025

Background

Sepsis-induced cardiomyopathy was deemed an independent predictor of increased risk for morbidity and mortality, especially for those individuals with pre-existing heart failure (HF). Although previous studies suggested that comorbid HF adversely impacted the outcomes of septic patients in general, there is paucity of data looking specifically at its impact among hospital patients with Escherichia coli (E. coli) sepsis.

Methods

We utilized the National Inpatient Sample (NIS) to identify patients with HF who were hospitalized for E. coli sepsis during the index hospitalization using appropriate ICD-10 codes between 2018-2020. We aim to investigate the impact of HF among E. coli septic patients based on in-hospital mortality, risk for acute respiratory failure and cardiogenic shock, and utilization of mechanical ventilation. A multivariable logistic regression analysis was used to calculate adjusted odds ratios (ORs) for the outcomes of interest.

Results

A total of 93,896 hospitalized patients with E. coli sepsis were identified, of which 23.51% (22,075/93,896) had concomitant HF during the index hospitalization. The overall in-hospital mortality rate among patients with E. coli sepsis was 8.71% (8,178/93,896). Among those with concomitant HF, the mortality rate was significantly elevated to 13.05% (2,881/22,075, p= < 0.001). After adjusting for possible confounders, concomitant HF in patients with E.coli sepsis was found to be an independent predictor of increased risk for in-hospital mortality (aOR 1.54; 95% CI, 1.34-1.76; p=< 0.001), acute respiratory failure (aOR 2.45; 95% CI, 2.23-2.69; p=< 0.001), cardiogenic shock (aOR 10.11; 95% CI, 7.11-14.39; p=< 0.001), and utilization of mechanical ventilation (aOR 2.00; 95% CI, 1.78-2.24; p=< 0.001)

Conclusion

Our analysis showed that HF among hospitalized E. coli sepsis patients was associated with an increased risk for adverse outcomes. This is likely due to the hemodynamic alterations in HF that are adversely impacted by sepsis treatment including fluid resuscitation, vasopressor use, and the advanced virulence factors of E. coli in adhesion, toxin production, and iron acquisition. Hence, identification of at-risk patients with HF is needed to mitigate its adverse impact among hospitalized patients with E. coli sepsis.

Disclosures

All Authors: No reported disclosures
P-832. The Skip Phenomenon in Patients with Staphylococcus lugdunensis Bloodstream Infection
Authors: Gasca Luis R , Crowley Patrick , Streck Nicholas , Baddour Larry M , DeSimone Daniel C
Published: January 2025

Background

Staphylococcus lugdunensis (SL) is a coagulase-negative staphylococcus with virulence comparable to that of Staphylococcus aureus. The “skip phenomenon” (SP) is a pattern where blood cultures are intermittently negative before final clearance of bloodstream infection (BSI). SP is well-documented in S. aureus bacteremia but has not been described previously in SL. In this report, we present a cohort with SL BSI and describe its prevalence and their clinical features and outcomes.

Methods

We conducted a retrospective review of patients with blood cultures positive for SL in samples referred to the Mayo Clinic reference lab between June 2012 and June 2022. We assessed clinical characteristics, including time to positivity, prevalence of the skip phenomenon (defined by a positive culture after 24 hours of negative cultures), patient demographics including Charlson Comorbidity Index, mortality and length of hospital stay.

Results

We identified 55 patients with SL BSI and 33 of them had enough laboratory data to determine the prevalence of the skip phenomenon. SP was present in 5 of 33 (15.2%) patients. For all patients with SL BSI, the median age was 67 years (interquartile range [IQR] 61-79); mean CCI in the group with SP was 5.6 (standard deviation 2) and those without SP was 5.9 (standard deviation 2.7); median duration of bacteremia was 3 days (IQR 1-4); median hospital length of stay was 14 days (IQR 8-20); and 1-year mortality was 45%. Oxacillin susceptibility was present in 33 of 34 cases.

Conclusion

A total of 15% of patient cases with SL BSI demonstrated the SP. Recognition of the SP in patients with SL BSI is important as this may impact duration of antibiotic therapy and timing of long-term cardiovascular device placement.

Disclosures

Larry M. Baddour, MD, UpToDate, Inc.: Royalty payments (authorship duties).
P-835. The microbiological characteristics of Acinetobacter baumannii associated with early mortality in patients with bloodstream infection
Authors: Mi Lee Chan , Choi Yunsang , Jin Choi Seong , Mi Moon Song , Suk Kim Eu , Bin Kim Hong , Young Ham Sin , Su Park Jeong , Yeom Jinki , Song Kyoung-Ho
Published: January 2025

Background

Despite the rapid deaths due to Acinetobacter baumannii bacteremia, the clinical impact of the microbiological characteristics of A. baumannii strains on early mortality (EM) is unclear. We aimed to identify the microbiological characteristics of A. baumannii strains associated with EM.

Methods

Clinical information and isolates from patients with A. baumannii bacteremia from January 2015 to December 2021 were collected. We collected patients’ clinical data, including demographic data, clinical severity, source of infection, and antibiotic therapy. EM was defined as death within 3 d of the initial positive blood culture, whereas late mortality meant death within 5–30 d. The microbiological characteristics of A. baumannii were analyzed using multilocus sequence typing, polymerase chain reactions, and a Galleria mellonella in vivo infection model.Figure 1.The virulence of Acinetobacter baumannii isolates by Galleria mellonella infection model.(A) Health index scores of larvae injected with isolates from the early mortality (EM), late mortality (LM), and 30-d survivor groups. (B) Health index scores of larvae injected with ST191 and non-ST191. (C) Health index scores of larvae injected with isolates carrying bfmS and those without bfmS. (D) Health index scores of larvae injected with isolates carrying bauA and those without bauA. The circles, squares, and triangles represent the mean, and the lines indicates standard error of the mean. The health index score of larvae was calculated by summing the scores for activity, cocoon formation, melanization, and survival. Health index scores of fifteen larvae were summed at every 24-h time point.

Results

Among 130 patients, 69 (53.1%) died within 30 d, and 38 (55.1% of 30-d deaths) were classified as EM and 27 (39.1% of 30-d deaths) as LM. Sequence type 191 (ST191) was the most prevalent ST, consistently identified throughout the study period. ST191 strain was more prevalent patients with EM than in 30-d survivors (31.6% vs. 6.6%, P = 0.001). Regarding virulence genes, bfmS was more frequent (92.1% vs. 47.5%, P < 0.001), whereas bauA was less frequent (13.2% vs. 52.5%, P < 0.001) in patients with EM than in 30-d survivors. Higher clinical severity, pneumonia, and ST191 infection were identified as independent risk factors for EM. In the G. mellonella infection model, ST191, bfmS+, and bauA- isolates showed higher virulence than non-ST191, bfmS-, and bauA+ isolates, respectively.

Conclusion

ST191 and bfmS were more frequently found in the EM group. ST191 infection was also an independent risk factor for EM and highly virulent in the in vivo model. Tailored infection control measures based on these characteristics are necessary for A. baumannii bacteremia management.

Disclosures

All Authors: No reported disclosures
P-844. Bacteraemia Caused by High Risk AmpC-producing Enterobacterales: Influence of IDSA Guidelines Adequacy and Antimicrobial Stewardship Activity on Outcomes
Authors: Lamas Ferreiro Jose Luis , Sanjurjo Rivo Ana , Ortero Judith Alvarez , Canoa Rico Alejandra , Costas Vila Marta , Gutierrez Garcia Monica , Valerio Laura Intanno , Aguado Javier de la Fuente
Published: January 2025

Background

Treatment of high risk AmpC-producing Enterobacterales bloodstream infections (BSIs) is challenging due to the posibility of development of antibiotic resistance during treatment. The aim of this study was to analyze the impact of antimicrobial stewardship activity and IDSA guidelines adequacy in patients with high risk AmpC-producing Enterobacterales BSIs.

Methods

Patients with Citrobacter spp, Enterobacter spp and Klebsiella aerogenes BSIs were included between June 2019-March 2024. Outcomes of death and relapse of infection at 30 days were assessed. Adequacy of definitive antimicrobial treatment according to IDSA guidelines was evaluated. The impact of antimicrobial stewardship activity in treatment adequacy and outcome was analyzed. Analysis was performed using SPSS version 25.

Results

2049 BSIs were evaluated and 67 were finally included. 80% were monomicrobial. Median patient age was 74 years, 73% were male. The most frequent microorganism isolated was Enterobacter cloacae (55%). 50% were nosocomial and the most frequent origen was biliary tract (35,8%). 35% met sepsis criteria. 30% of cases presented cefotaxim resistance. Empiric and definitive antibiotic treatment was prescribed according IDSA guidelinesi n 34% and 91% of cases, respectively.. Death at 30 days was 6% and a combination outcome of death and relapse of infection at 30 days was 11,9%. Definitive antibiotic treatment adequacy according to IDSA guidelines was associated with lower mortality and relapse at 30 days (OR 0,04; IC95 0,003-0,6; P=0,02). Antimicrobial stewardship team did an intervention in 34% cases. This intervention was associated with a trend toward of lower mortality and relapse (4% vs 15%, P=0,2), a trend toward of higher IDSA guidelines adequacy (100% vs 86%, P=0,08), and a higher switch to oral treatment (78% vs 52%; P=0,03).

Conclusion

Adequacy of definitive antimicrobial treatment in high risk AmpC producing Enterobacterales BSIs according to IDSA guidelines was associated with a better outcome. Antimicrobial stewardship is desired for management of these patients.

Disclosures

All Authors: No reported disclosures
P-862. Hospital administered MOUD is associated with decreased one-year mortality among PWUD admitted with bloodstream infections
Authors: Blair Nicholas , Kopp Adam , Kubin Christine J , Cotton Jesse , Yin Michael , Scherer Matt
Published: January 2025

Background

Bloodstream infections (BSI) including infective endocarditis (IE) are highly morbid complications of substance use that contribute to the syndemic of invasive bacterial infections in persons who use drugs (PWUD). In this retrospective analysis we evaluated whether inpatient administration of medication for opioid use disorder (MOUD) impacted one-year all-cause mortality and antibiotic adherence in PWUD hospitalized with BSI.

Methods

We conducted a retrospective cohort study of index admissions for PWUD admitted with IE cases from 2/2020 through 7/2023 and/or BSI from 7/2022 through 7/2023 at Columbia University Irving Medical Center. Patients were included if they 1) Were aged 18-65 years old 2) Had a positive blood culture with an organism known to cause invasive disease and 3) Had documented substance use (opioid and/or stimulant) within the previous 12 months. One-year all-cause mortality was the primary outcome of interest. Administration of MOUD was counted as a treatment exposure only if received for the majority (≥ 50%) of hospitalized days. We defined the primary antibiotic outcome as a percentage of days a patient received standard of care (SOC) treatment compared to the recommended duration in days for their infection.

Results

Of the 99 patients who met study criteria, the majority were male (69%) with a history of injection drug use (77%). Opioids (79%), cocaine (68%) and methamphetamines (19%) were the most commonly used substances (Table 1). In multivariate logistic regression, hospital administration of MOUD was associated with reduced mortality (aOR 0.14, 0.021 – 0.60, P = 0.017) after adjusting for prosthetic valve endocarditis (Table 2). In sub-analysis of the MOUD group, PWUD who received buprenorphine achieved a higher percentage of SOC antibiotic days (93%, p = 0.011) than either the methadone (61.4%) or no-MOUD (72.9%) groups (Table 3).

Conclusion

Hospital administration of MOUD was associated with improved survival in PWUD admitted with serious bloodstream infections. Buprenorphine receipt was associated with a greater likelihood of completing SOC antibiotic course than methadone or no MOUD. To our knowledge, this is the first study to demonstrate a survival benefit to hospital administration of MOUD in PWUD during infection-related admission.

Disclosures

All Authors: No reported disclosures
P-877. Effectiveness of Oral Step-down Antibiotic Therapy in Uncomplicated Enterococcus faecalis Bloodstream Infection
Authors: Al Mansi Sarah , Pokalsky Margaret , Turnley Katherine , Freeman Andrew , Brandon Bookstaver P , Kohn Joseph , Winders Hana R , Withers Sarah , Al-Hasan Majdi N
Published: January 2025

Background

The transition from intravenous (IV) to oral antibiotic therapy is a common strategy in the management of uncomplicated bloodstream infection (BSI). However, the role of oral step-down therapy in uncomplicated Enterococcus faecalis BSI has not been defined. This retrospective cohort study examines the effectiveness of oral step-down antibiotics compared to standard IV therapy in uncomplicated E. faecalis BSI.

Risk factors for treatment failure in uncomplicated Enterococcus faecalis bloodstream infection (BSI)

*Early clinical failure criteria include systolic blood pressure <100 mmHg or vasopressor use, heart rate >100 beats/minute, respiratory rate ≥ 22 breaths/minute or mechanical ventilation, altered mental status, white blood cell count >12,000/mm3.

Methods

Adults with uncomplicated E. faecalis BSI admitted to 10 Prisma Health hospitals in South Carolina from January 2021 to June 2023 were evaluated. Clinically insignificant positive blood cultures, polymicrobial, recurrent, persistent, and complicated BSI were excluded. Deaths within 7 days were excluded to mitigate immortal time bias. Multivariate Cox proportional hazards regression examined the risk of treatment failure (all-cause mortality or recurrence) within 90-day. Wilcoxon rank sum test compared hospital length of stay (HLOS) between the two groups.

Results

Of 476 screened patients, 131 with uncomplicated E. faecalis BSI were included in the analysis. The median age was 70 years, 84 (64%) were men, and 46 (35%) had a urinary source of infection. Eighty-seven patients (66%) received standard IV therapy and 44 (34%) were transitioned to oral step-down therapy. Median antibiotic treatment durations were 15 and 14 days, respectively. Patients in the oral step-down group received 6 days of IV antibiotics followed by 8 days of oral therapy, most commonly oral aminopenicillins (33/44; 75%). In the multivariate Cox model, oral step-down therapy was not associated with increased risk of treatment failure compared to standard IV therapy (hazard ratio 0.91, 95% confidence intervals 0.31-2.63; Table). HLOS was 7 days in the oral step-down group and 11 days in the standard IV group (p< 0.001).

Conclusion

Transitioning patients with uncomplicated E. faecalis BSI from IV to oral step-down antibiotic therapy appears to be a promising strategy with shorter HLOS and no significant increase in the risk of treatment failure. These results should be confirmed in larger multicenter studies prior to routine implementation in clinical practice.

Disclosures

All Authors: No reported disclosures
P-880. Risk Factors of In-Hospital Mortality among Adult Patients with Burkholderia cepacia Complex Bacteremia Admitted to the Philippine General Hospital: A Retrospective Cohort Study
Authors: Fernandez Sergie Paul Christoffer C , Salamat Maria Sonia
Published: January 2025

Background

Burkholderia cepacia complex (BCC) has emerged as a significant nosocomial pathogen, particularly in immunocompromised patients, leading to various infections with a high mortality rate. There is limited data on BCC bacteremia in the Philippines. Hence, more study is necessary to enhance patient management and outcomes.

This study aims to identify significant risk factors for in-hospital mortality among adult patients with BCC bacteremia at the Philippine General Hospital. Additionally, it seeks to describe clinical characteristics, common foci of infection, and antimicrobial susceptibility patterns of BCC.

Methods

A retrospective cohort study included adult patients admitted to the Philippine General Hospital with documented BCC bacteremia from January 2020 to December 2023. Demographic and clinical data were extracted from medical records, and BCC identification and resistance patterns were determined using the VITEK 2 system and MALDI-TOF technology. Statistical analyses were performed to identify mortality risk factors.

Results

Out of 172 patient charts reviewed, 171 cases were included in the final analysis. Most patients were male, with a mean age of 52.7 years. Central-line associated bloodstream infections (CLABSI) were the most common source of bacteremia. Approximately 65% of cases received inappropriate empirical therapy. Resistance was highest for Meropenem (13.5%), followed by Co-trimoxazole (11.8%), while Ceftazidime and Minocycline showed lower resistance rates. All-cause mortality was 22.2%, with BCC bacteremia accounting for 57.9% of these deaths. Male gender, septic shock, mechanical ventilation, and prolonged duration of ineffective antimicrobial therapy were the significant risk factors for all-cause mortality.

Conclusion

The study revealed a significant in-hospital mortality rate associated with BCC bacteremia, predominantly caused by CLABSI and compounded by high antimicrobial resistance and inappropriate empirical therapy. These findings underscored the need for accurate microbiological diagnostics, appropriate antibiotic usage, and robust infection control practices to improve patient outcomes.

Disclosures

All Authors: No reported disclosures
P-885. Clinical Characteristics and Molecular Epidemiology of Invasive Nontypeable Haemophilus influenzae Disease at a Tertiary Medical Center in Washington, DC
Authors: Stone Stephen , Spence Matthew , Roberts Afsoon , Ruiz Maria Elena , Siegel Marc O , Collins Lauren F , Lohsen Sarah , Satola Sarah W , Yee Rebecca , Lucar Jose A
Published: January 2025

Background

The incidence of invasive nontypeable H. influenzae (NTHi) is on the rise, and NTHi now causes the majority of invasive H. influenzae infections across all age groups. While these presentations are usually among people at the extremes of age, we observed a recent increase in invasive NTHi cases in adults at our institution compared to previous years. Here, we report their clinical presentation and the subsequent molecular epidemiology investigation.

Characteristics of Patients With Invasive Nontypeable Haemophilus influenzae (NTHi) Infection, GW Hospital, December 2022-August 2023

Abbreviations: HIV, human immunodeficiency virus; MSM, men who have sex with men; MSK, musculoskeletal; LOS, length of hospital stay; N/A, information not available; HBV, hepatitis B virus; C1, clonal cluster 1; C2 clonal cluster 2; NC, non-cluster

* in cells/mm3

Methods

We describe the demographics, clinical characteristics, and outcomes of individuals hospitalized at our institution with invasive NTHi disease between December 2022 and August 2023. Invasive NTHi disease was defined as infections beyond the respiratory tract or skin. Data was obtained from retrospective chart abstraction. Available bacterial isolates were sent to the Georgia Emerging Infections Program laboratory for polymerase chain reaction (PCR) and whole genome sequencing (WGS), and were categorized as belonging to clusters 1 or 2 (C1, C2) or as non-cluster, as described previously.

Results

Nine cases [median age 55 (32-76) years, 100% male, 89% Black] were identified. Five individuals were living with HIV (PWH) on antiretroviral therapy, with median CD4 count 348 (range 32-984) cells/mm3, and all except one were virologically suppressed. Six patients identified as men who have sex with men (MSM). Five patients presented with musculoskeletal manifestations. Seven isolates were available for PCR/WGS: one isolate belonged to C1, three to C2, and three as non-cluster. The mean hospital stay was 11 (range 3-28) days. Three patients required admission to the intensive care unit, all of which died.

Conclusion

This case series identified nine patients within a nine-month span presenting with invasive NTHi disease, an abrupt rise from our local historical data. We noted an overrepresentation of PWH and MSM, with over half of isolates belonging to two previously identified clonal clusters associated with similar demographics. Future research is needed to better understand novel transmission routes, clinical characteristics, genotypic relatedness, and geographic spread of invasive NTHi disease.

Disclosures

Rebecca Yee, Ph.D, Biomerieux: Grant/Research Support
P-888. Variability in Durations of Therapy for Gram-Negative Bloodstream Infections Across U.S. Hospitals
Authors: Sutton Jesse , Lee Jae Hyoung , Engers Drew , Fong Karen , Gupta Alok , Karaba Sara M , Malani Anurag , McCoy Christopher , Pillinger Kelly E , Quartuccio Katelyn , Slish Judianne C , Tamma Pranita , Jenkins Timothy C
Published: January 2025

Background

There is a paucity of data on durations of antibiotic therapy utilized in clinical practice for patients with Gram-negative bloodstream infections (GN-BSI). The objectives of this study were to describe treatment durations for patients with GN-BSI and evaluate variability across U.S. hospitals.

Histogram of antibiotic treatment durations

Methods

This was a retrospective cohort study of patients hospitalized at 24 hospitals (16 academic, 4 community, and 4 Veterans Affairs) with a GN-BSI between January 1, 2019 and December 31, 2019. Episodes of GN-BSI from a urinary, intra-abdominal, hepatobiliary, vascular catheter, skin and soft tissue, or respiratory source were included while those associated with a bone, joint, central nervous system, or endovascular infection or prostatitis were excluded. Subgroups of interest were cases of uncomplicated bacteremia and those with underlying immunosuppression. Uncomplicated bacteremia was defined as: (1) achievement of source control, when applicable; (2) absence of immunosuppression; and (3) resolution of fever and hypotension within 3 days.

Variability in median duration of therapy across hospitals

Results

3,956 episodes of GN-BSI were included, of which 2,007 were uncomplicated bacteremia and 1,202 involved underlying immunosuppression. Urinary tract (55%), intra-abdominal (14%), and hepatobiliary (12%) sources accounted for the majority of the infections, while E. coli (53%), K. pneumoniae (12%), and P. aeruginosa (8%) were the most common pathogens. The median duration of therapy in the overall cohort and uncomplicated and immunocompromised subgroups was 12 (interquartile range [IQR] 9 - 15) days, 11 (IQR 8 - 14) days, and 11 (9 - 14) days, respectively (Figure 1). In the overall cohort, there was marked variation in treatment durations across hospitals, with the median duration as low as 5 (IQR 3 - 7) days and as high as 14 (IQR 10 - 17) days (Figure 2). Similar variability was observed in the uncomplicated bacteremia and immunocompromised subgroups.

Conclusion

There is marked variation in treatment durations for GN-BSI across U.S. hospitals. Dissemination of interventions to promote evidence-based short durations of therapy for uncomplicated bacteremia and elucidating the optimal duration of therapy in immunocompromised patients will be necessary to standardize care and reduce unnecessary antibiotic use.

Disclosures

Sara M. Karaba, MD, PhD, MHS, Entasis: Advisor/Consultant Kelly E. Pillinger, PharmD, AHFS: Contractor Judianne C. Slish, Pharm.D., BCPS, Glaxosmithkline Pharmaceuticals: Honoraria
P-902. Etiology, Clinical Characteristics, Prognosis and Outcomes of Acute Central Nervous System Infections: A Prospective Study
Authors: Pillai Ashwin , Godin Shea-Lee , Edul Nazir
Published: January 2025

Background

Various pathogens can cause central nervous system (CNS) infections. Early recognition and treatment significantly improves outcomes. Clinical features and outcomes vary by etiology and clinical phenotype, making diagnosis challenging. We report a single-center experience emphasizing the clinical profile and prognostic factors of this entity.

Methods

We conducted a two-year prospective, observational study at a tertiary care center in Western India. Patients suspected to have CNS infections underwent a standardized workup that included neuroimaging and CSF polymerase chain reaction panel testing. Patients were followed throughout the admission. The outcomes recorded were duration of intensive care unit (ICU) stay, hospital stay, modified Rankin Scale (mRS) at discharge and mortality.

Results

We included 75 patients (53 male, 22 female). The mean age was 43±19 years. Most infections were viral (69%) – 40% encephalitis, 17% meningitis and 12% meningoencephalitis. Viral infections surged in the monsoon and post-monsoon period (Fig. 1). Tuberculous meningitis accounted for 16% cases, pyogenic meningitis for 7%, and cryptococcal meningitis for 5%. Mucor cerebritis and brain abscesses accounted for 3%. Presenting symptoms, CSF, and neuroimaging findings are listed in Fig. 2-4.

Mortality was highest for cryptococcal meningitis (25%); followed by pyogenic meningitis (20%); and viral encephalitis and tuberculous meningitis (16.7% each). Increased risk of mortality was observed with: new-onset seizures (relative risk [RR] 3.58, 95% confidence intervals [CI] 1.03-12.45, p< 0.001); a Glasgow Coma Scale (GCS) < 8 (RR: 6.85, 95% CI 2.00-23.40, p=0.002); and the presence of dilated ventricles on imaging (RR: 5.25, 95% CI 1.99-13.82, p< 0.001).

Increasing age correlated with a longer ICU stay (r=0.37, p< 0.001), hospital stay (r=0.33, p=0.002), and worse functional status at discharge reflected by a higher mRS (p=0.04). GCS at presentation correlated inversely with functional recovery reflected by the mRS at discharge (p< 0.001).

CSF findings varying by etiology

CSF findings varying by etiology

Conclusion

The etiology and prognosis of acute CNS infectious varies by region and season. A detailed history, thorough

physical examination, neuroimaging and CSF analysis are vital as each provides diagnostic and prognostic information.

Disclosures

All Authors: No reported disclosures
370. Swimming Against the Current: Outcomes of Standard versus Modified Outpatient Parenteral Antimicrobial Therapy (OPAT) Services
Authors: Villacorta Cari Evelyn , Mansoor Armaghan-E Rehman , Thornton Alice C , Clemons Alisha , Mynatt Ryan P , Logan Ashley , Burgess Donna R , Soria Jaime
Published: January 2025

Background

OPAT programs enable intravenous (IV) antibiotic treatment outside the hospital, either at home or in an outpatient facility. We established institutional OPAT criteria to identify patients who could safely complete OPAT at home (standard, or S-OPAT) and those with potential barriers (modified, or M-OPAT). The study aims to compare outcomes in both groups.

Methods

We conducted a retrospective cohort study analyzing data collected via OPAT program operations from July 2019 to March 2024. These data were collected using the REDCap electronic data capture system. Statistical analyses were performed with Stata 17.

Results

The analysis included 3,344 patients referred to the OPAT program, with 2,746 (82.1%) assigned to the S-OPAT group and 598 (17.9%) to the M-OPAT group. The median age was similar in both cohorts, and Male patients were 1,583 (58.9%) in S-OPAT and 389 (65.1%) in M-OPAT (p = 0.001). The most prevalent infection treated in both groups was Osteomyelitis: 535 (19.5%) patients in S-OPAT and 156 (26.1%) patients in M-OPAT (p< 0.001), followed by bacteremia at 484 (17.6%) patients in S-OPAT and 107 (17.9%) in M-OPAT (p= 0.859).

A history of IV drug use was reported in 108 (4.0%) patients of S-OPAT and 200 (33.4%) patients of M-OPAT. M-OPAT patients reported barriers such as lack of social support (homelessness, inability to administer antibiotics at home, or requiring additional medical care) in 422(70.6%) patients, incarceration in 58 (9.7%) patients, and antibiotics received during dialysis sessions in 58 (9.7%) patients.

Reported outcomes, including clinical improvement, were not significantly different between these groups [S-OPAT: 2367 (86.2%) vs. M-OPAT: 530 (88.8%); (p=0.11)]. Treatment completed as expected, extended, or discontinued were as follows: S-OPAT 2106 (76.7%) vs. M-OPAT 486 (81.3%), (p=0.015); S-OPAT 398 (14.5%) vs. M-OPAT 67 (11.2%), p=0.037; and S-OPAT 237 (8.6%) vs. M-OPAT 43 (7.2%), p=0.289.

Conclusion

Despite the higher prevalence of social and medical challenges in the M-OPAT cohort, treatment outcomes, including clinical improvement and completion rates, were comparable to those in the S-OPAT group; the study highlights the feasibility and effectiveness of outpatient antibiotic treatment, even in patients facing significant barriers to care.

Disclosures

Alisha Clemons, APRN, Gilead Sciences: Honoraria