bluuebunny/crossref_metadata_2025 huggingface dataset:
P-1420. Tracking Shadows: Loss to Follow-up in Persons Living with HIV
Authors: Bhatia Mehak , Carrington William , Touleyrou Lauren , Newman Gretchen
Published: January 2025

Background

During the year 2020, HIV viral suppression was 89.4% in clients throughout the United States who receive care through the Ryan White HIV/AIDS program (RYHAP). This was a significant increase compared to 69.5% in 2010. Likewise, Wayne State University (WSU) Tolan Park Infectious Disease Clinic, which is also funded by RYHAP noted a 5% increase in the rate of viral suppression in 2020 compared to the previous year. Eighty-six percent of Tolan Park clients across all Ryan White programs were virally suppressed, eighty-seven percent of women and youth were virally suppressed. However, there was a decline in the overall patient pool in 2019. The goal of this study was to locate those lost-to-care as part of the WSU Tolan Park clinic.

Methods

Clinicians reviewed a list of clients who were lost-to-care during 2019. These clients were individually called by nurse practitioners, patient advocates or early intervention staff (EIS) to re-engage in medical care. The quality improvement team then discussed feedback from staff and clients regarding barriers to medical care.

Results

We contacted a total of 310 clients. Out of these, 40 (13%) were lost-to-care. Among the remaining clients, 95 (31%) were deceased, 64 (21%) were in-care at other clinics, 63 (20%) were currently in-care at Tolan park clinic, 41 (13%) had confirmed clinic appointments and 7 (2%) were out-of-state or incarcerated. Of the 40 clients returned to care at the Tolan Park clinic, route cause analysis revealed the main barriers to care including poor mental health, lack of transportation, schedule conflicts, relocation, poor financial resources, inadequate medication adherence and clinic fatigue.

Conclusion

We report a significant number of patients who were lost-to-care at the WSU Tolan Park clinic. Our patients continue to experience poor mental health, poor medication adherence and several socioeconomic barriers that limit their access to continuity of care. Our results highlight the need for better tracking services and strategies to minimize the loss to follow-up in HIV clinics.

Disclosures

All Authors: No reported disclosures
P-1421. A socioeconomic index of Brazilian municipalities correlates with dengue cases severity status but not with lethality
Authors: Lira Guilherme , Takahashi Marcelo , Ota Victor , Leitão Isabela
Published: January 2025

Background

Social determinants of health (SDOH) affect a wide range of health outcomes and risks. This includes differences in exposure and vulnerability to infectious diseases such as tuberculosis, COVID-19 and arboviral diseases. However, information on SDOH can be difficult to retrieve from medical records. We set out to explore how SDOH measured at populational level can affect natural history and lethality in dengue fever.

ORs from logistic regressions performed

Methods

We performed a retrospective, descriptive study of dengue fever cases in Brazil, using Ministry of Health openly available notification databases. We used GeoSES, a composite index that summarizes the main dimensions of the Brazilian socioeconomic context for research purposes, as a proxy for SDOH in given municipalities. Only laboratory confirmed cases were included. Outcomes considered were case classification (dengue without warning signs, dengue with warning signs or dengue with severity signs) and discharge or death by dengue. We performed logistic regressions of recognized risk factors alongside GeoSES as predictors for outcomes. R software version 4.3.1 was used for analysis. Code will be made public upon abstract acceptance.

Results

We analyzed 2,137,462 cases notified between January 2014 and December 2023. In the proportional odds logistic regression model for case classification, the GeoSES index was associated with case classification (OR = 2.87, 95% CI 2.77-2.98; p-value < 0.0001), indicating an increased risk of dengue with warning signs or severity signs as the index increases. However, in the binomial logistic regression for discharge or death, the index showed no association (OR = 0.99, 95% CI 0.88-1.12; p-value = 0.98) with outcome, holding constant all other variables. Interestingly, peptic ulcer disease stood out as a protective factor against negative outcomes in dengue fever patients.

Conclusion

As a seasonal disease with a recent upsurge in Brazil, reevaluating risk factors for dengue infection and complication is an ever-present necessity. Here, we demonstrate that the GeoSES index is not a strong predictor of dengue fever mortality. This does not excuse policymakers from improving structural conditions, but allows for rational evaluation in epidemic scenarioes.

Disclosures

All Authors: No reported disclosures
P-1481. Short-Treatment with Ceftazidime-Avibactam for Carbapenemase-Producing Enterobacterales Bacteremia
Authors: Herrera Fabián , Leone María V , Torres Diego , Rojas Rocío , Bues Florencia , Carlos Jimena , Temporiti Elena , Querci Marcia , Nicola Federico , Relloso Silvia , Smayevsky Jorgelina , Bonvehi Pablo E
Published: January 2025

Background

Ceftazidime-avibactam (CA) and CA plus aztreonam (ATM) are the preferred treatment options for KPC and metallo-beta-lactamase (MBL) carbapenemase-producing Enterobacterales bacteremia (CPEB). However, data regarding short therapy are scarce.

Methods

Prospective observational cohort study performed in a university hospital in Argentina between August 2018 and February 2024. All adult patients with CPEB who received adequate empirical treatment with CA or CA+ATM, with a median duration of 7 days (IQR: 7-8), with clinical response and source control of infection were included. They were followed for 30 days to evaluate mortality.

Results

Twenty-two patients were included. They had a median age of 61 years (IQR: 49-70.5). The median APACHE II and Pitt scores were 18 (IQR: 13.25-24) and 2 (IQR: 1-4). Sixty-eight percent of the patients were immunocompromised, being hematological malignancies (45.45%), high-dose corticosteroids (40.9%) biological agents/anti-lymphocyte therapies (36.36%), and neutropenia (31.81%) the most frequent causes. Eighty-six percent had a clinical source of bacteremia; abdominal, central venous catheter, and urinary tract being the most common. Klebsiella spp. (72.72%) was the main etiological isolated microorganism, and the resistance mechanisms involved were KPC production (77.2%), MBL production (13.6%), and KPC+MBL production (9%). Recent colonization with KPC-CPE and MBL-CPE was detected in 68.1% and 9% of the patients. Septic shock at onset and intensive care unit requirement were 40.9% and 45.4% respectively. Empirical and definitive antibiotic therapy were combined in 66.6% and 9% of the patients. Thirty-day overall and infection-related mortality were 22.7% and 9%.

Conclusion

This data showed that short-course antibiotic treatment with CA or CA+ATM for patients with CPEB who had clinical response with source control of infection might be adequate.

Disclosures

Diego Torres, Medical Doctor, Gador: Honoraria|GSK: Advisor/Consultant|Khight Therapeutics: Honoraria|MSD: Honoraria
514. The Impact of Xeruborbactam on in vitro Activity of Cefiderocol against a Panel of Acinetobacter baumannii Enriched in Isolates with Reduced Cefiderocol Susceptibility
Authors: Hara Takafumi , Ishibashi Naoki , Miyagawa Dai , Onishi Motoyasu , Lomovskaya Olga , Yamano Yoshinori
Published: January 2025

Background

Cefiderocol (CFDC) is a siderophore cephalosporin with potent activity against resistant gram-negative bacteria. Recent SIDERO-WT surveillance studies demonstrated potent activity of CFDC against 5,225 isolates of Acinetobacter baumannii complex (ACB) (MIC50/90=0.12/1 µg/mL; 96% susceptible using CLSI breakpoint) including 2,810 carbapenem-resistant isolates (MIC50/90=0.25/2 µg/mL; 94% susceptible). CFDC MIC values were higher (MIC50/90=4/8 µg/mL) against metallo-β-lactamase (MBL) producers (N=25 including 21 NDM producers; 0.48% of total ACB) and isolates that produced PER or VEB β-lactamase (N=103; 1.98% of total ACB; MIC50/90=128/256 µg/mL). Xeruborbactam (XER) is a novel beta-lactamase inhibitor that inhibits multiple serine-type β-lactamases (SBLs) and MBLs. In this study, we evaluated the combination of CFDC and XER against a challenge panel of ACB enriched with CFDC-resistant isolates.

MIC50/90 of cefiderocol (CFDC) alone and in the presence of xeruborbactam (XER) against Acinetobacter baumannii

Methods

A challenge panel of 160 ACB isolates that included 59 PER- or VEB-producing and 22 NDM-producing isolates was used for this study. 144 (90%) and 136 (85%) isolates had CFDC MIC > 1 µg/mL (FDA non-susceptible breakpoint) and > 2 µg/mL (EUCAST non-susceptible PK/PD breakpoint), respectively. β-lactamases content was determined by PCR or whole genome sequencing. MICs were determined for CFDC alone and in combination with 1, 2 and 4 μg/mL of XER according to CLSI guidelines for CFDC using iron-depleted CAMHB.

Results

MIC50/MIC90 of CDFC alone and XER alone against 160 ACB were > 32/ > 32 and 16/ > 16 μg/mL, respectively. The addition of xeruborbactam at all concentrations resulted in a reduction of CFDC MICs. For the subset of 59 highly CFDC-resistant PER or VEB producers, XER at ≥ 2 µg/mL reduced CFDC MIC50/90 from > 32/ > 32 to 0.25/1 µg/mL, which is similar to MIC50/90 values observed for CFDC alone for all ACB from recent surveillance studies. XER at 4 μg/mL reduced MIC50/90 of NDM producers from 32/ > 32 μg/mL to 0.5/8 μg/mL.

Conclusion

Addition of XER significantly improved the activity of CFDC against isolates of ACB with elevated CFDC MICs.

Disclosures

Takafumi Hara, MSc, SHIONOGI & CO., LTD.: Employee Naoki Ishibashi, MD, SHIONOGI & CO., LTD.: Employee Dai Miyagawa, n/a, SHIONOGI & CO., LTD.: Employee Motoyasu Onishi, PhD, Shionogi & Co., Ltd.: Employee Olga Lomovskaya, PhD, Qpex Biopharma Inc.: Board Member|SHIONOGI & CO., LTD.: Employee Yoshinori Yamano, PhD, Shionogi & Co., Ltd.: Employee
P-1495. Antibiotic and Phage Susceptibility of Pseudomonas aeruginosa Clinical Isolates From Phage Therapy Patients
Authors: Lee Justin J , Dorozko Sergei Elber , Shields Ryan K , Haidar Ghady , Van Tyne Daria
Published: January 2025

Background

Antibiotic resistance is a rising issue, with the World Health Organization predicting that by 2025, around 10 million deaths annually will be caused by resistant infections. Phage therapy is an alternative form of treatment for multidrug-resistant bacterial infections in which bacterial viruses, called bacteriophages, are used to combat the infection. Before phage therapy can be delivered at the bedside, clinical bacterial isolates from the patient are collected and screened for susceptibility in the laboratory to identify candidate phages that can infect and kill the bacteria causing the infection. Many phages have been isolated from wastewater and assembled into libraries without detailed knowledge of their host range or an understanding of which phages are the best performers.

Methods

Using 40 patient-derived P. aeruginosa clinical isolates collected from 21 phage therapy candidate patients at the University of Pittsburgh Medical Center in the years 2022 and 2023, we investigated the host range of 25 phages in a P. aeruginosa screening library. We also screened the isolates against 11 antibiotics currently used to treat P. aeruginosa infections.

Results

We identified correlations in phage susceptibility profiles both within and between patients’ isolates, finding that a three phage cocktail could target 100% of the isolates. We also examined the antimicrobial susceptibility profiles of the 40 isolates and found that 67.5% of isolates are multidrug resistant.

Conclusion

With this research, we hope to develop methods for identifying candidate phages more quickly, speeding up the process of phage susceptibility testing, and aiding in the assembly of highly active phage cocktails, which may result in increased accessibility of phage therapy to a more diverse patient base.

Disclosures

Ryan K. Shields, PharmD, MS, Allergan: Advisor/Consultant|Cidara: Advisor/Consultant|Entasis: Advisor/Consultant|GSK: Advisor/Consultant|Melinta: Advisor/Consultant|Melinta: Grant/Research Support|Menarini: Advisor/Consultant|Merck: Advisor/Consultant|Merck: Grant/Research Support|Pfizer: Advisor/Consultant|Roche: Grant/Research Support|Shionogi: Advisor/Consultant|Shionogi: Grant/Research Support|Utility: Advisor/Consultant|Venatorx: Advisor/Consultant|Venatorx: Grant/Research Support Ghady Haidar, MD, Allovir: Grant/Research Support|AstraZeneca: Advisor/Consultant|AstraZeneca: Honoraria|Cystic Fibrosis Foundation: Grant/Research Support|Karius: Advisor/Consultant|Karius: Grant/Research Support|NIH: Grant/Research Support|PeerView Institute for Medical Education: Honoraria|PRIME: Honoraria|Regeneron: Grant/Research Support
P-1503. Dual β-Lactam Approach for Treatment of Mycobacterium abscessus Infections in Adults – Results in 19 Patients
Authors: Kalyatanda Gautam , Dousa Khalid M , Lyons Hannah , Mardourian Markos , Rhodes Jackson , Iakovidis Alexandria , El-Helou Guy , Wilson Brigid , Daley Charles L , Holland Steven M , Kreiswirth Barry N , Nguyen David C , Shin Eunjeong , Kurz Sebastian G , Johnson John L , Bonomo Robert A
Published: January 2025

Background

The prevalence of Mycobacterium abscessus (Mab) infection is rising, with immunocompromised individuals being especially susceptible. While treatment success for the subspecies abscessus has been as low as 33%, recent studies and case reports suggest potential efficacy of select dual β-lactam (Dβ). This study evaluated the efficacy and tolerability of select Dβ in treating MDR-Mab infections, guided by in-vitro susceptibility results.

Methods

We reviewed the treatment of 19 adults with Mab infection at the University of Florida Hospital, Gainesville, who underwent Dβ synergy testing between January 2019 and March 2023. Medical histories, laboratory results, and clinical outcomes were reviewed. We summarized patient and infection characteristics and compared the time from diagnosis to Dβs initiation across outcomes

Results

Of the 19 patients (mean age: 54 years; 68% females), 11 (58%) had undergone solid organ transplantation or had cancer, and 6 (32%) were on immunosuppressants for autoimmune diseases. Pulmonary infections predominated (68%), with 47% of isolates were macrolide resistant. 11 patients (58%) were due to subspecies abscessus. The Dβs most frequently used for treatment were imipenem combined with either amoxicillin (31%) or ceftaroline (26%). Successful clinical cure or stable culture conversion with ongoing treatment was observed in 9 (47%) cases. 4 patients died during treatment. We observed a trend towards shorter times before initiation of Dβ treatment among patients who were cured. Time to initiation of Dβ therapy exceeded 90 days in 3 of 4 patients who died. Eighteen of 19 patients tolerated dual β-lactams therapy well. Among the 5 who discontinued treatment, the multi-drug regimen, not specifically the dual β-lactams, was the likely cause

Conclusion

Treatment with Dβ-containing regimens was associated with higher cure rates in this cohort of severely ill, immunocompromised patients. Earlier treatment correlated with better outcomes. Given the poor response to current treatment regimens and the initial promising results of Dβ therapy, clinical trials are planned. Finally, the chosen Dβs may not fully represent the optimal selection due to patient-driven preferences, possibly underscoring a conservative rather than optimal treatment outcome.

Disclosures

All Authors: No reported disclosures
P-1504. Propensity-Matched Comparison of Early vs. Late Antibiotic Therapy in Stenotrophomonas maltophilia Pneumonia: A Five-Hospital Study
Authors: May Elizabeth , Coyne Ashlan Kunz
Published: January 2025

Background

Stenotrophomonas maltophilia is a leading drug-resistant nosocomial pathogen worldwide. First-line antibiotic therapy for S. maltophilia is not a routine part of empiric antibiotic coverage. This study aimed to evaluate clinical outcomes of patients receiving early versus late antibiotic therapy for S. maltophilia pneumonia (PNA).Table 1.Baseline and Clinical Course Characteristics

aData are presented as “number (%)” or “median (interquartile range)”, as appropriate.

Abbreviations: BMI, body mass index; CrCL, creatinine clearance; LTAC, long-term acute care; NH/LTC, nursing home/long-term care.

Methods

A retrospective, observational study was conducted at five hospitals within University of Kentucky HealthCare. Patients treated for S. maltophilia PNA between 1/1/2014 and 12/31/2023 receiving sulfamethoxazole/trimethoprim, minocycline or levofloxacin with reported in-vitro susceptibility were included. Patient and bacterial characteristics, all-cause mortality, and desirability of outcome ranking (DOOR) at 30 days were compared between patients receiving early (≤48 hours of culture collection) versus late ( >48 hours of culture collection) therapy (Table 1). Propensity-score matching (PSM) was used to adjust confounding. Subgroup and sensitivity analyses were used to verify the robustness of results.Table 2.Desirability of Outcome Ranking (DOOR)

Results

Median age of patients was 64 years (interquartile range [IQR] 52-71 years). The median Charlson Comorbidity Index and SOFA score were 4 (IQR 2-6) and 4 (2-7). At the time of index culture collection, 219/430 (50.9%) patients were in the intensive care unit, and 142/430 (33%) patients were on mechanical ventilation. Overall mortality at 30 days was 103/430 (24%). DOOR distribution of outcomes is shown in Figure 1. A randomly selected patient with early antibiotic administration had a 69% (95% CI 56%-79%, p< 0.001) likelihood of a better outcome as compared to a randomly selected patient receiving late antibiotic therapy.Figure 1.DOOR Analysis of All Patients with S. maltophilia Pneumonia Receiving Early vs. Late Antibiotic Therapy

Conclusion

S. maltophilia PNA is associated with poor outcomes, especially in patients receiving therapy with in-vitro activity >48 hours from index culture collection.

Disclosures

All Authors: No reported disclosures
P-1509. In Vitro Activity of Aztreonam-Avibactam Against Enterobacterales Isolated from Pediatric and Adult Patients Collected During the ATLAS Global Surveillance Program, 2018-2022
Authors: Estabrook Mark , Dickson Julie , Stone Gregory , Perez Katherine , Sahm Daniel F
Published: January 2025

Background

The spread of antimicrobial resistance among clinically isolated Enterobacterales (Eba) is a threat to public health. Aztreonam (ATM) is a monobactam stable against hydrolysis by metallo-β-lactamases (MBLs) and avibactam (AVI) inhibits class A, class C, and some class D serine β-lactamases. ATM-AVI is being developed for use against infections caused by drug-resistant Eba, especially those co-producing MBLs and other β-lactamases. This study evaluated the in vitro activity of ATM-AVI and comparators against Eba collected in 2018-2022 from pediatric and adult patients as part of the ATLAS global surveillance program.

Methods

87621 Eba isolates were collected from patients in 226 medical centers in 57 countries in Europe, Latin America, Asia/Pacific (excluding mainland China), and Middle East/Africa. Susceptibility testing was performed by CLSI broth microdilution and interpreted using CLSI 2024 breakpoints. PCR and sequencing were used to identify β-lactamase genes among all isolates testing with meropenem MIC >1 µg/mL, and a randomly sampled subset of approximately 80% of Escherichia coli, Klebsiella spp. and Proteus mirabilis testing with ATM or ceftazidime MIC >1 µg/mL.

Results

MIC90 values for ATM-AVI of 0.12 µg/mL (pediatric isolates) and 0.25 µg/mL (adult isolates) were observed. Against all Eba isolates, ≤8 µg/mL of ATM-AVI inhibited 99.9% of both pediatric and adult isolates, whereas only 66.3% (pediatric) and 71.4% (adult) of these isolates were susceptible to ATM alone (table). Among isolates that screened positive for an MBL, MIC90 values for ATM-AVI were 0.5 µg/mL (pediatric) and 2 µg/mL (adult) and ATM-AVI inhibited 100% (pediatric) and 98.6% (adult) at concentrations ≤8 µg/ml. In contrast, only 14.5% (pediatric) and 17.2% (adult) of MBL-positive isolates were susceptible to ATM without AVI.

Conclusion

Based on MIC90 values, ATM-AVI demonstrated potent in vitro activity against Eba isolated both from pediatric and adult patients. Avibactam’s ability to potentiate aztreonam against MBL-positive Enterobacterales isolates warrants its continued development.

Disclosures

Mark Estabrook, MS, Pfizer, Inc.: Advisor/Consultant Julie Dickson, BS, Pfizer, Inc.: Advisor/Consultant Daniel F. Sahm, PhD, Pfizer, Inc.: Advisor/Consultant
P-1518. Activity of Ceftolozane/Tazobactam, Imipenem/Relebactam and Comparators Against Clinical MDR and DTR non-Morganellaceae Enterobacterales and Pseudomonas aeruginosa Stratified by Patient Age and Hospital Ward: SMART United States 2020-2022
Authors: Wise Mark G , Andrew DeRyke C , Esterly John , Bauer Karri A A , Siddiqui Fakhar , Young Katherine , Motyl Mary , Sahm Daniel F
Published: January 2025

Background

Hospital ward and patient age are factors that can guide in the selection of empiric therapy. Imipenem/relebactam (IMR) is a combination of imipenem with the β-lactamase inhibitor relebactam, an inhibitor of class A and C β-lactamases. Ceftolozane/tazobactam (C/T) combines ceftolozane, an anti-pseudomonal cephalosporin, with tazobactam. We evaluated the activity of IMR, C/T and comparators against isolates of non-Morganellaceae Enterobacterales (NME) and Pseudomonas aeruginosa that were collected in the United States as part of the SMART surveillance program from 2020 to 2022 with data stratified by hospital ward (ICU versus general wards), and by patient age (< 60 and ≥60 years old).

Methods

In 2020-2022, 26 clinical labs in the US each collected up to 250 consecutive Gram-negative pathogens per year. MICs were determined using CLSI broth microdilution and interpreted with 2024 CLSI breakpoints. Multi-drug resistance (MDR) was defined as resistance to ≥3 sentinel agents (amikacin, aztreonam, cefepime, ceftazidime [Enterobacterales only], colistin, imipenem, levofloxacin, and piperacillin/tazobactam). Difficult-to-treat resistance (DTR) was defined as non-susceptibility to all β-lactams (including aztreonam, ceftazidime, cefepime, imipenem, meropenem, piperacillin-tazobactam), and fluoroquinolones (levofloxacin).

Results

Susceptibility to commonly used β-lactams was lower among isolates from ICU patients compared to those in non-ICU wards, but no clear pattern was linked to patient age. Against the NME, IMR was among the most active agents inhibiting >98% of the isolates in all strata (Table). Meropenem, ceftazidime/avibactam and amikacin also inhibited >98% of the isolates. IMR retained activity against the MDR NME, as >96.9% of the isolates were susceptible. Against P. aeruginosa, C/T was the first or second (after amikacin) most active agent versus isolates in all strata, with >95% susceptible. C/T remained active against ≥77% of MDR and ≥72% of DTR isolates, 7-30 percentage points higher than ceftazidime/avibactam.

Conclusion

IMR is an important treatment option for patients with infections caused by NME, while C/T is an excellent choice against P. aeruginosa, regardless of patient age or treatment in the ICU.

Disclosures

Daniel F. Sahm, PhD, Pfizer, Inc.: Advisor/Consultant
P-1557. Using cefazolin and ceftriaxone via automated susceptibility predicts susceptibility to oral cefpodoxime but not cefuroxime in Enterobacterales
Authors: Sassine Joseph , McCloskey Cindy B , White Bryan , Ibragimova Nayle , Robison Denise , Pan Steven , Alkozah Maria , Siegrist Emily A
Published: January 2025

Background

Current CLSI recommendations suggest using cefazolin to predict susceptibilities of oral cephalosporins for uncomplicated UTI (uUTI) due to Escherichia coli, Klebsiella pneumoniae, or Proteus mirabilis. Most laboratories do not conduct routine susceptibility testing of oral cephalosporins as they are not available on many automated panels. However, there are limited data which evaluate ceftriaxone and cefazolin categorical agreement with oral cefpodoxime and cefuroxime. This study assessed agreement between ceftriaxone or cefazolin via MicroScan with cefuroxime or cefpodoxime via disk diffusion.

Methods

We collected E. coli, K. pneumoniae, or P. mirabilis isolates from urine cultures in a single center between 2/2024 and 3/2024. Identification was performed using MALDI-TOF and susceptibility testing was conducted overnight broth dilution panels (MicroScan, Beckman Coulter) and disk diffusion for cefazolin and ceftriaxone and by disk diffusion for cefuroxime and cefpodoxime. The primary outcome was categorical agreement assessed by Fleiss’ kappa of automated panel susceptibility for cefazolin and ceftriaxone with cefpodoxime and cefuroxime. Secondary outcomes included disk diffusion categorical agreement and rates of very major, major, and minor errors.

Results

We included 132 isolates, 105 (79.5%) E. coli, 16 (12.1%) K. pneumoniae, and 11 (8.3%) P. mirabilis. Ceftriaxone had slightly lower categorical agreement with cefpodoxime than cefazolin (98% vs 100%). Furthermore, very major errors were more common when using ceftriaxone to predict susceptibility (7% vs 0%). Ceftriaxone and cefazolin both were poor predictors of cefuroxime susceptibility (80% vs 80%).

Conclusion

In this sample, both cefazolin and ceftriaxone had high categorical agreement with cefpodoxime; however, cefazolin resulted in fewer very major errors. On the other hand, cefazolin and ceftriaxone had much lower categorical agreement with cefuroxime, mostly driven by isolates intermediate to cefuroxime but susceptible to cefazolin and ceftriaxone. Our data support the CLSI recommendations to use cefazolin over ceftriaxone to predict susceptibility of cefpodoxime but do not support the use of cefazolin to predict activity of oral cefuroxime for uUTI.

Disclosures

Joseph Sassine, MD, Ansun BioPharma: Grant/Research Support|Cidara Therapeutics: Grant/Research Support|Community Infusion Solutions: Grant/Research Support|F2G: Grant/Research Support|Shionogi: Grant/Research Support Bryan White, PharmD, BCPS, BCIDP, Melinta: Advisor/Consultant|Shionogi: Grant/Research Support
P-1572. Epidemiology and Risk Factors for Altered Mental Status Induced by Urinary Tract Infections Amongst Elderly Hospitalized Patients
Authors: Cino Rebecca , Lindley William , Reilly Joseph , Lodise Thomas , Trivedi Manish
Published: January 2025

Background

Elderly patients with urinary tract infections (UTIs) often present with atypical symptoms including altered mental status (AMS). Although UTI-induced AMS is typically reversible, these patients often experience complications and a longer hospital stay. There is a paucity of data on the incidence and risk factors for UTI-induced AMS in elderly patients. The purpose of this study was to describe the epidemiology and risk factors for AMS in elderly patients hospitalized with UTIs.Table 1.Bivariate Comparison of Baseline Characteristics between Patients with and without UTI-induced Altered Mental Status (AMS)

χ2 test, Student’s t-test, or Fisher’s exact test for variable comparisons.

Methods

A retrospective study of hospitalized patients ≥ 70 years of age with a UTI at AtlantiCare Regional Medical Center between 1/2023-12/2023 was performed. Subjects with UTI were categorized in 2 groups, those with new onset UTI-induced AMS and those without AMS. Admitting providers determined the presence of AMS defined as new onset delirium or a significant change in mental status from baseline. Patients were excluded if they displayed evidence of AMS prior to their UTI or had a new comorbid condition at admission that could precipitate AMS. Data collection included patient demographics, body mass index, weight, admission source, comorbid conditions, presence of urinary instrumentation, and concurrent medications. Bivariate analyses were completed for baseline characteristics between patients with and without UTI-induced AMS. Log-binomial regression was performed to determine factors independently associated with the presence of UTI-induced AMS.Table 2.Baseline Characteristics Associated with UTI-induced Altered Mental Status (AMS) in the Log-Binomial Regression Analysis

Results

In total, 100 patients met the study criteria. The mean (SD) age was 74.8 (4.8) years, 54% were female, 15% were admitted from a long-term care facility, and 24% had an indwelling urinary catheter. Comparison of baseline characteristics between patients with and without UTI-induced AMS is shown in Table 1. In the log-binomial regression, female gender [risk ratio (RR) of 4.7, 95% CI: 1.6-13.8], presence of a urinary catheter (RR of 4.5, 95% CI: 1.6-13.0), and age ≥ 80 years (RR of 2.4, 95% CI: 1.1-5.1) were independently associated with UTI-induced AMS (Table 2).

Conclusion

Identified risk factors for UTI-induced AMS included female gender, presence of an indwelling urinary catheter, and age 80 years or greater. Further studies are warranted to determine the clinical implications and significance of these potential risk factors.

Disclosures

Joseph Reilly, B.S., Pharm.D., Melinta Therapeutics: Advisor/Consultant Thomas Lodise, Jr., Pharm.D., PhD, MERCK: Advisor/Consultant
P-1582. Comparing Contamination Rates in Single-Site vs Multi-Site Blood Culture Sampling
Authors: Borad Abhilasha , Azim Ahmed Abdul , Boruchoff Susan , Ibrahim Ali , Weinstein Melvin P , Kaye Keith S
Published: January 2025

Background

The utility of blood cultures relies on optimal sampling - two samples obtained from separate sites at different times. We noted repeated instances where, according to the electronic medical record (EMR), 2 sets of blood cultures were obtained in the emergency department (ED) with identical time stamps. When these cultures, presumed to be from a single site, return positive for commensal organisms in both sets, treatment might be initiated for a probable contaminant. This study aimed to compare the recovery rate of commensal organisms in both sets of blood cultures obtained from presumed single-site sampling (SSS) versus multi-site sampling (MSS).

Methods

This is a retrospective analysis utilizing data from microbiology and hospital administrative databases. The incidence rates of blood culture contaminants in patients who had two sets of blood cultures drawn with an identical time stamp for both sets (aka SSS) and in patients who had different time stamps within 1 hour of each other for each set (aka MSS) were compared. Rates from ED and selected non-ED inpatient locations were also compared.

Results

There were 1500 positive blood cultures from 720 patients, and 385 patients had 2 sets of blood cultures drawn with at least 1 positive culture for a commensal pathogen (Table). 312/385 patients (81.0%) had samples obtained via SSS and 73 (19.0%) via MSS. Of the 312 SSS patients, 99 (31.7%) had 2/2 sets positive for a commensal, while 15 of 73 MSS patients (20.5%) had 2/2 sets positive for a commensal (p=0.06). In the ED, 251 patients had samples obtained via SSS and 55 via MSS. 84/251 SSS patients (33.4%) had 2/2 sets positive for a commensal, while 12/55 MSS patients (21.8%) had 2/2 sets positive for a commensal (p=0.09).

Conclusion

Blood cultures obtained via SSS had higher rates of 2/2 set positivity for a commensal as compared to cultures obtained via MSS; however, this study was underpowered to demonstrate statistical significance. Other limitations include the assumption that EMR time stamp for collection of blood cultures accurately represents blood culture collection time. Diagnostic stewardship opportunities include potential EMR modifications and/or additional training related to documentation of timing of blood culture collection.

Disclosures

Melvin P. Weinstein, MD, Helixbind: Advisor/Consultant|Safeguard Biosystems: Advisor/Consultant|Selux Diagnostics: Advisor/Consultant Keith S. Kaye, MD, MPH, Allecra: Advisor/Consultant|CARB-X: Advisor/Consultant|GSK: Advisor/Consultant|Merck: Advisor/Consultant|Shionogi: Advisor/Consultant|Spero: Advisor/Consultant
P-1590. Diagnostic Stewardship as a CAUTI Prevention Strategy: Implementation of a Urine Culture Wizard to Drive Institutional Change
Authors: Reisenauer Claire , Castillo Alyssa Y , Hansen Shane , Bovaird Jennifer , Moylan Keri , Robbins Emily , Pisney Larissa
Published: January 2025

Background

Standardized urine culture ordering is an essential practice in the prevention of catheter-associated urinary tract infections (CAUTI). Historically, the University of Colorado Hospital (UCH) offered a stand-alone urine culture order, which required documentation of the culture indication. Frequently, the attestation was incongruent with the clinical scenario, and a preceding urinalysis (UA) was not performed. As a result, cultures often resulted in the detection of asymptomatic bacteriuria, leading to inappropriate antibiotic prescribing. We hypothesized that the creation of a Urine Culture Wizard would decrease unnecessary urine cultures with downstream implications on antibiotic usage and CAUTI reporting.

Year-Over-Year % Change by Month and Fiscal YearFigure 1:Year-over-year Reduction in Urine Cultures Performed at UCH by Inpatient Teams

Methods

In 2021, key stakeholders across the UCHealth system began the development of a Urine Culture Wizard. This replaced all orders for urine cultures in inpatient settings. Multiple synonyms push providers to the wizard, which performs data mining to determine if a urine culture is appropriate. For most, it requires that a preceding UA showing pyuria has been performed. The wizard also allows the ordering of a urine culture without documentation of pyuria if unique patient characteristics are detected in the electronic medical record. These are identified by discrete fields that correspond to criteria as outlined by an institutional governance committee, including specific clinical diagnoses. Educational material was developed to support the launch of the wizard.

Year-Over-Year % Change by Month and Fiscal YearFigure 2:Year-over year Reduction in Urine Cultures Performed at UCH by Inpatient Teams

Results

The Urine Culture Wizard went live in November 2023. Results show a sustained decrease of more than 30% in the number of urine cultures ordered at UCH, and this change meets the criteria for special cause variation. (Figures 1, 2, and 3).

Urine Tests Per MonthFigure 3:Statistical Process Control Chart Demonstrating Special Cause Variation

Conclusion

It has been shown that inappropriate ordering of urine cultures leads to misclassification of colonization as infection and unnecessary prescribing of antibiotics. A standardized approach to ordering urine cultures based on clinical criteria was created for all UCHealth hospitals through the development of a Urine Culture Wizard. Since implementation there has been a continual significant reduction in the number of urine cultures performed, signaling the success of this diagnostic stewardship tool.

Disclosures

All Authors: No reported disclosures
584. Implementation and Evaluation of an Interactive Infectious Diseases Online Curriculum for Trainees on ID electives
Authors: Krishnan Gayathri , Mattar Caline , Kirmani Nigar , Lawrence Steven
Published: January 2025

Background

Infectious Diseases Online Curriculum (IDOC) is an online asynchronous interactive educational resource for trainees on ID electives to augment their ID knowledge and complement their clinical training. The curriculum mapping with details of modules and methods of assessment are elaborated in TABLE 1. A program evaluation of the IDOC with the aim to analyze program outcomes was done in 2023.Table 1:Curriculum mapping including goals, objectives, conceptual framework, educational strategies and assessments for Infectious Diseases Online Curriculum

Methods

IDOC was piloted with medical students and residents from August 2022 to December 2022 and assesses Kirkpatrick level 2 learning. The primary assessment was of Program Outcome, set up using a Pragmatism paradigm with Mixed Methods research methodology to assess quantitative and qualitative data. Following IRB approval, data collection was conducted through web-based surveys (Qualtrics). Each surveyor was asked to assign a unique alphanumeric number to their pre and post survey so these could be used for comparison. The primary outcome assessed was change in knowledge. Each question in the pre- and post-assessment was awarded 1 for correct answer and 0 for incorrect answer. A paired sample t test was used to compare pre and post cumulative scores and analyzed using SPSS v26.Table 2:Paired sample T test analysis of quantitative outcomes

Results

During the pilot phase 16 pre- and 20 post assessment surveys were received (8 phase-3 students, 4 phase-2, 3 phase-1, 3 interns, 2 with no level of training). 11 respondents had allotted the same alphanumeric number to both pre- and post-surveys and these were used for comparative analyses of knowledge change. Interest in pursuing ID as a career prior to and after revision of modules was sought on a 5-point Likert scale and received 12 responses. Paired t test showed significant improvement in knowledge and increase in interest of trainees to pursue ID as a career (TABLE 2). Majority of trainees also rated the modules to be extremely clear and relevant to clinical practice (TABLE 3). Qualitative feedback was overwhelmingly positive (TABLE 4).Table 3:Results of self-perceived clarity and self perceived relevance of the modules by the trainees

Conclusion

IDOC functions as a novel, accessible, quick, engaging, and effective way to improve ID related knowledge in trainees and is an adjunct to their clinical elective experience. Although this was a small study, the results are significant and transferable, and IDOC can be disseminated to smaller training programs where educators and ID learning resources are not available.Table 4:Qualitative feedback for Infectious Diseases Online Curriculum as well as individual interview response from trainee

Disclosures

All Authors: No reported disclosures
586. Let's Have a Chat: How Well Does an Artificial Intelligence Chatbot Answer Clinical Infectious Diseases Questions?
Authors: Hanrahan Kathleen , Steele Jeffrey , Seabury Robert , Parsels Katie A , MacDougall Conan , Britt Rachel S , Chahine Elias , Covington Elizabeth W , Gallagher Jason C , Kufel Wesley D
Published: January 2025

Background

ChatGPT is an artificial intelligence tool used by practitioners to answer clinical questions. It’s unknown whether ChatGPT provides quality responses to infectious diseases (ID)-specific questions. This study surveyed ID pharmacist subject matter experts (SMEs) to assess the quality of ChatGPT responses.

Methods

The primary outcome was percentage of ChatGPT responses considered useful. Secondary outcomes were SME’s ratings of correctness, completeness, and safety (C/C/S). One hundred clinically encountered questions by ID pharmacists were assembled and internally validated. Questions were entered into ChatGPT version 3.5 and responses were recorded. Definitions for useful and C/C/S were based on prior definitions and literature. A 0-10 rating scale for C/C/S was developed and validated for interrater reliability using a random sample. Questions with ChatGPT responses were sent to five SMEs for evaluation. Ordinal and categorical variables were assessed for interrater reliability using an average measures intraclass correlation coefficient (ICC) and Fleiss Multirater Kappa (FMK), respectively. SMEs’ responses were compared using the Kruskal-Wallis and Chi-square tests for ordinal and categorical variables, respectively. A post-hoc analysis was performed to identify the location of differences between SME ratings based on question difficulty and category for C/C/S using a Mann-Whitney U test with Bonferroni correction.

Results

SMEs considered 41.8% of responses useful. Median (IQR) ratings for C/C/S were 7 (IQR 4-9), 5 (IQR 3-8), and 8 (IQR 4-10), respectively. The FMK for useful was 0.379 (95% CI 0.317-0.441) indicating fair agreement, and ICC were 0.820 (95% CI 0.758-0.870), 0.745 (95% CI 0.656-0.816), and 0.833 (95% CI 0.775-0.880) for C/C/S, respectively, indicating substantial agreement. No significant difference was observed between SME responses for the percentage of responses considered useful. Neither question category nor difficulty resulted in a difference in SMEs’ ratings for C/C/S or percentage of responses considered useful.

Conclusion

Fewer than half of ChatGPT responses were considered useful by SMEs. However, responses were mostly considered correct and safe, but often deemed incomplete.

Disclosures

Conan MacDougall, PharmD, MAS, Merck: Grant/Research Support Elias Chahine, Pharm.D., Seqirus: Advisor/Consultant|Seqirus: Honoraria Wesley D. Kufel, Pharm.D., BCPS, BCIDP, Merck & Co.: Grant/Research Support|Shionogi, Inc: Grant/Research Support
P-1664. Shifting Susceptibilities and Clinical Outcomes of Oncology Patients with Streptococcus mitis/oralis Bacteremia
Authors: Handley Guy , Shah Shivan , Bruning Rebecca , Katzman Ju Hee , Greene John , Pasikhova Yanina
Published: January 2025

Background

Streptococcus mitis/oralis cause most viridans group infections in oncology patients and may cause more severe clinical disease. Antimicrobial resistance to beta-lactams is not uncommon, and patients, including those with severe neutropenia, may be at higher risk. We sought to describe changes in susceptibility patterns of S. mitis/oralis and clinical characteristics in these patients.

Methods

Patients at an NCI-designated comprehensive cancer center from 01/01/2022-03/15/2024 with S. mitis/oralis in blood cultures were identified. Clinical and laboratory data were evaluated to describe susceptibility patterns and clinical outcomes.

Results

There were 126 patients included in the study. 58 (46%) had AML and 59 (46.8%) had undergone bone marrow transplantation. Severe neutropenia at the onset of bacteremia was present in 107 (84.9%). The median time to clearance was 1 day (IQR 1-2). Antibacterial prophylaxis was prescribed in 105 (83.3%), most of which was fluoroquinolones (96.2%). Polymicrobial bacteremia occurred in 22 (17.5%) patients. Hypoxic respiratory failure developed in 34 (27%) and 13 (10.3%) required ICU admission. In-hospital mortality occurred in 15 (11.9%) patients. Non-susceptibility was common for penicillin (41.6%) and levofloxacin (54.9%) but rare for ceftriaxone (2.4%) and vancomycin (0%). Ceftriaxone non-susceptibility was associated with cefepime non-susceptibility in all cases (3/3, 100%), while 6 (8.2%) isolates susceptible to ceftriaxone were non-susceptible to cefepime (p=0.001). Of 98 patients receiving fluoroquinolone prophylaxis, levofloxacin prophylaxis had a greater association with levofloxacin non-susceptibility than ciprofloxacin prophylaxis (86.7% vs 54.4%; p=0.002). Patients receiving ciprofloxacin prophylaxis had similar rates of levofloxacin non-susceptibility to those not receiving ciprofloxacin prophylaxis (54.4% vs 55.6%; p=0.900). Beta-lactam non-susceptible rates rose over time and were statistically higher for ampicillin in 2023 compared to 2022 (41.7% vs 18.0%; p=0.007).

Conclusion

Beta-lactam non-susceptibility among S. mitis/oralis isolates may be increasing. Cefepime susceptibility cannot be inferred from ceftriaxone susceptibility.

Disclosures

All Authors: No reported disclosures
P-1669. Effect of Antimicrobial Stewardship Program on Antibiotic Prescribing for Veterans Affairs Nursing Homes
Authors: Jacob Matthew , Froehlich Morgan , Belanger Debra , Psevdos George
Published: January 2025

Background

The CDC strongly recommends nursing homes take resolute steps to improve antibiotic prescribing practices and reduce inappropriate use. This is because studies have shown that up to 70% residents of US nursing homes receive 1 or more courses of antibiotics in a year while 75% of these prescriptions may be unnecessary or inappropriate. Antibiotic stewardship programs (ASP) are committed to optimize treatment of infections and reduce adverse events by close monitoring, education, and preventing unsuitable use. We analyzed the effect of our ASP over antibiotic prescribing of four Veterans Affairs (VA) community living centers (CLC).

Table 1.

Methods

Retrospective review of ASP notes in the year 2023- the inaugural year for ASP reviewing CLCs- addressing requests for restricted antibiotics over 4 CLCs at Northport VA campus. The 4 CLCs are structured nursing homes with a 139 total bed capacity with two long term residential care units, one mental health, and one combined subacute rehab/hospice. We compared antibiotic use as days of therapy (DOT)/1000 days, for total antibiotics use, and analyzing cephalosporins, fluoroquinolones anti-MRSA, anti-MSSA, for years of pandemic 2020-2022 vs. 2023.

Figure 1a

Results

Comparing 2020-22 vs. 2023 there was a decrease in all antimicrobial use in the CLCs, from 142 DOT/1000 days to 88. In 2023 the ASP team reviewed 135 CLC requests for restricted antibiotics, and 56 E-advice requests for guidance. 10% of the requests were denied. See table 1. The most common request for E- advice was whether to treat asymptomatic bacteriuria with/or without presence of urinary catheter. Comparing 2020-22 vs. 2023 there was a decrease in cephalosporins use by DOT/1000 days, 29.3 vs. 10.8, P: 0.09. There was no difference in Fluoroquinolones 2.0 vs. 6.0 P: 0.953, anti-MRSA antibiotics, 7.02 vs. 4.04 P:0.348, anti MSSA 0.67 vs. 0.8 P: 0.574. See figures 1a/1b. Figure 2 shows a downward trend of C. difficile infections in our CLCs.

Figure 1b

Conclusion

Our ASP was overall successful in decreasing antibiotic use in our CLCs, notably for cephalosporins, while keeping FQ and other antibiotics use low. We were successful in education and preventing antibiotics especially for asymptomatic bacteriuria. An equally important achievement for our program was the decreasing rate of C. difficile infections.

Figure 2

Disclosures

All Authors: No reported disclosures