bluuebunny/crossref_metadata_2025_split huggingface dataset:
P-1528. In Vitro Activity of Omadacycline and Comparator Agents against a Collection of Neisseria Gonorrhoeae Urine Isolates Collected from the United States During 2018-2020
Authors: Ryan Arends S J , Pierce J V , Becker Holly , Lindley Jill , Serio Alisa W , Castanheira Mariana 
Published: January 2025

Abstract

Background
Omadacycline (OMC) is a third-generation tetracycline (TET) class antibacterial approved for treatment of adults with acute bacterial skin and skin structure infections and community-acquired bacterial pneumonia caused by indicated organisms. OMC is active against bacterial isolates expressing common TET resistance mechanisms and strains resistant (R) to other drug classes. In this study, the in vitro activity of OMC and comparator agents was evaluated against a contemporary collection of N. gonorrhoeae clinical isolates. In addition, analysis of publicly available genomic sequences for these isolates was performed to determine the molecular mechanisms of TET resistance.
Antimicrobial activity of omadacycline and comparators tested against 100 Neisseria gonorrhoeae isolates

Methods
The modal minimal inhibitory concentration (MIC) of OMC and comparator agents was determined by testing in triplicate by agar dilution for 100 N. gonorrhoeae clinical isolates (BEI Resources) collected from the urethra of patients with urethritis within the US (2018-2020). R or non-susceptible (NS) phenotypes were interpreted using breakpoints published by Clinical and Laboratory Standards Institute. Resistance genes were identified from genome sequences using ResFinder 4.0.
Cumulative distribution of omadacycline MIC values tested against comparator-resistant or non-susceptible N. gonorrhoeae subsets

Results
OMC displayed activity against N. gonorrhoeae isolates (MIC50/90, 2/4 µg/mL) that had limited susceptibility (S) to TET (13%), ciprofloxacin (CIP) (60%) and penicillin (PEN) (4%) but high S to azithromycin (AZM), cefixime (CFX), and ceftriaxone (CFN) (Table 1). Among isolates with NS or R phenotypes for comparators, the OMC MIC50/90 (when calculated) were generally not impacted, although some of these subsets had very low numbers (Table 2). The rpsJ mutation was widespread among TET-R isolates, including those with additional mutations in porB, the mtrR promoter and tet(M) (Table 3). The highest OMC MIC (8 µg/mL) correlated with combined mutations in porB and rpsJ. OMC had MICs &lt; 1 µg/mL among isolates (n=3) with high level TET-R (MIC&gt; 16 µg/mL), including those with tet(M).
Tetracycline resistance mechanisms among tetracycline resistant Neisseria gonorrhoeae isolates

Conclusion
OMC MICs were 0.12-8 µg/mL against this set of N. gonorrhoeae clinical isolates and the MIC distribution was minimally impacted by isolates NS/R to AZM, CFX, CFN, CIP, PEN, or TET. These results support the further research of OMC for N. gonorrhoeae infections, especially for those with high level TET-R.

Disclosures
J.V. Pierce, PhD, Paratek Pharmaceuticals: Employee Alisa W. Serio, PhD, Paratek Pharmaceuticals: Employee
P-1531. Two against One: Ceftazidime-Avibactam plus Aztreonam vs Cefiderocol in the Treatment of Metallo-Beta-Lactamase-Producing Bacterial Infections
Authors: Harris Spencer A , Huang Vanthida 
Published: January 2025

Abstract

Background
Metallo-beta-lactamase-producing Gram-negative bacteria (MBL-GNB) has become a global healthcare threat. MBL-GNB are resistant to all first-line antimicrobials, leading to high mortality rates. Ceftazidime-avibactam plus aztreonam (CAZ-AVI+AZT) and cefiderocol (CFDC) are treatment options due to their in vitro activity against MBL-GNB. However, the optimal treatment for MBL-GNB infections remains unclear. Therefore, we sought to evaluate the outcomes of CAZ-AVI+AZT vs CFDC in patients with MBL-GNB infections.

Methods
Adult patients admitted to HonorHealth Network (Phoenix, AZ) from January 2018 to December 2024 who received ≥1 dose of either CAZ-AVI+AZT or CFDC with culture-confirmed MBL-GNB were included. Patients who were treated for &lt; 48 h were excluded. The primary outcome was all-cause in-hospital mortality. Secondary outcomes were 14-day microbiological cure, post-diagnosis intensive care unit (ICU) and hospital length of stay (LOS), and duration of therapy.

Results
A total of 24 patients were included, of whom 8 received CAZ-AVI+AZT and 16 received CFDC. Baseline characteristics were similar in both arms; however, CAZ-AVI+AZT patients experienced an increase in ICU admission and sepsis at baseline. Sources of infections included urine (50%), blood (42%), and respiratory tract (42%). For CAZ-AVI+AZT vs CFDC patients, all-cause in-hospital mortality occurred in 2 vs 3 patients (25% vs 19%; p = 0.72); microbiological cure occurred in 7 vs 7 patients (88% vs 44%, p = 0.11), respectively. Hospital length of stay was 9.5 ± 4 days for CAZ-AVI+AZT vs 6.5 ± 3 days for CFDC (p = 0.09). Duration of therapy and post-diagnosis ICU length of stay were similar in both groups.

Conclusion
CAZ-AVI+AZT compared to CFDC demonstrated no mortality benefit; however, it may achieve greater microbiological cure. Further studies are warranted to corroborate these findings.

Disclosures
All Authors: No reported disclosures
P-1544. Outcomes of Multi-Drug Resistant Acinetobacter Baumannii (MDR-AB) Management in a Tertiary Care Hospital in Saudi Arabia: Retrospective Observational Study
Authors: Aljuzair Zahrah H , AlMahasnah Reem A , Sait Afrah , Atta Manal 
Published: January 2025

Abstract

Background
Nosocomial infections caused by multi-drug resistant Acinetobacter baumannii (MDR-AB) are widespread and have been linked to numerous infections, resulting in high rates of morbidity and mortality globally. It has a mortality rate of 17.5%, a resistance rate of 74% to carbapenems, and has been found primarily in immunocompromised patients in Saudi Arabia. There is a lack of a defined treatment standard of care with a limited number of alternatives. To gain additional insight into managing MDR-AB, this study aimed to evaluate the clinical efficacy of various antibiotic regimens and compare the outcomes of monotherapy with those of antibiotic combinations

Methods
A five-years (2018 to 2023) retrospective observational study was conducted at a tertiary care hospital in Saudi Arabia. All patients with positive Acinetobacter baumannii culture were screened. Adult patients ( ≥ 18 years ) with MDR-AB isolated and had received a minimum of 72 hours of antibiotic treatment were included. The primary end point was clinical improvement. Adverse drug events and the 30-day overall mortality rate were evaluated as secondary end points

Results
One hundred patients met the study inclusion criteria. Of those, 45% were oncology or transplant patients and 80% were admitted to the intensive care unit. MDR-AB was associated with several infectious syndromes, including 44% pneumonia, 42% bacteremia, and 13% urinary tract infections. 30% of patients were given meropenem as an empiric treatment, with varying dosage regimens; 26% were given piperacillin/tazobactam. Based on culture sensitivity, 68% of the patients were treated with tigecycline, while 28% were retained on meropenem, despite the fact that 98% of the isolates were carbapenem-resistant. Antibiotic monotherapy has been given only to 39% of patients. Clinical improvement was reported in 66% of the patients with 80% achieved complete improvement. The 30-day mortality rate was 50%. Adverse drug events were rare, with only 3% GI symptoms

Conclusion
MDR-AB in our patients is mainly causing two infectious syndromes in 86%. A combination of antibiotics was used in 61%. High clinical improvement with a simultaneous high 30-day mortality rate highlighted the need for standardized guidelines for the management of MDR-AB infections

Disclosures
All Authors: No reported disclosures
P-1553. Impact of Urinary Tract Infection due to Carbapenem Resistant Gram Negative Bacteria in Patients with Kidney Transplant
Authors: Baldissera Giulia Soska , Gregory Vinicius da Silva , da Silva Pitombeira Maria Helena 
Published: January 2025

Abstract

Background
Carbapenem resistance is a fearsome reality, especially in transplant patients, and urinary tract infections may cause severe illness and graft loss.

Methods
In this 10-year retrospective cohort we analyzed kidney transplanted patients with gram-negative carbapenem-resistant urinary tract infection (UTI). We evaluated overall prevalence, risk factors for 14-day clinical response and development of acute kidney injury or graft loss during infection. Patients ≥ 18 years old with symptomatic infections or loss of renal function attributed to UTI were included. We excluded patients with kidney abscesses or intra-abdominal complications, death within 24 h, non-active antimicrobial treatment.

Results
From urocultures collected from 2013 – 2023, 11.583 isolated gram-negative bacteria, of which 14.2% were carbapenem resistant. From these, 87 patients were included. 72.4% were male, aged 56.9 ± 13.6 years old and median transplant time was 15.8 (2 - 89.6) months; 83.9% had upper UTI. The most prevalent bacteria was Klebsiella pneumoniae, with 75 samples (86.2%). 41 (47.1%) were carbapenemase producers: 29.8% serino and 18.3% metallo-beta lactamases. Patients were treated with: amikacin (58.6%) polymyxin B (47.1%), polymyxin E (32.2%), tigecycline (5.7%) ceftazidime-avibactam (8.0%). In 46.0% of the cases, these drugs were combined. 82.8% had complete resolution of symptoms and negative follow-up urine cultures in 14 days. Independent risk factors for non-response were baseline hemodynamic instability (p&lt; 0.01) and polymyxin B treatment (p&lt; 0.01). Control urocultures were collected from 79 (90.8%); 15 (18.9%) had the same bacteria. Sixty-eight patients (79.1%) who were not in dialysis at baseline were evaluated for AKI,from which 45 (66.1%) developed AKI during therapy and 8 (11.7%) had renal graft loss. 12 (13.8%) patients died in 30-days.

Conclusion
Carbapenem resistant bacteria are increasingly prevalent in renal transplant patients and associated to AKI and graft loss potentially due to the use of nephrotoxic drugs. Polymyxin B and hemodynamic instability were independent preditors non-clinical response in 14-days, which should be further evaluated due to the non-urinary concentration of this antibiotic.

Disclosures
All Authors: No reported disclosures
P-1569. Healthcare Disparities Between Racial, Ethnic, and Socioeconomic Backgrounds in Urinary Tract Infection Patients
Authors: Moazamian Ryan J , Amundson Ashley , Fraimow Henry S , Palacios Carlo Foppiano 
Published: January 2025

Abstract

Background
Numerous studies have highlighted persistent health disparities: chronic disease rates, access to care, and outcomes across diverse races, ethnicities, and socioeconomic backgrounds. To address underlying healthcare disparities, we explored differences in outcomes of patients with urinary tract infections (UTIs).Table 1Results of Statistical Analysis

Methods
Patients treated at Cooper University Hospital for UTI between 2019 and 2021 were identified using ICD codes. Inclusion criteria was age over 18, inpatient admissions longer than 48 hours, and diagnosis of UTI. Patient demographics, culture results, treatment, discharge outcomes, and outcomes at 30 and 90 days. Additionally, we collected individual indicators of socioeconomic status, including census tract data associated with American Community Survey, Area Deprivation Index (ADI: ranked on a scale 1 to 10, with 10 being most disadvantaged), and Social Vulnerability Index (SVI: ranked on a scale of 0 to 1, with 1 being most vulnerable). Descriptive statistics, Chi-square, and Kruskal-Wallis tests were performed.

Results
495 patients with UTI were analyzed: mean age was 67±19 years, 54% were White, and 20% were Latino. Social Mean state ADI was 8.7±2.0, and mean CDC SVI was 0.63±0.24. Social determinants of health were common among patients with UTI: 60% did not have independent level of function, 19% lived alone, 18% had prior mental health history, 14% did not speak English, 8% had history of substance abuse, 2% had housing insecurity. Statistical analysis showed no meaningful difference in patient outcomes for hospital mortality or mortality at 30- or 60-days post discharge. Readmission at 30 or 60 days was associated with census tract median household income, household income less than 10 thousand dollars, per capita income, education with bachelor’s degree, taking public transportation, not having a car, unemployment, and Medicaid coverage (Table 1).

Conclusion
We found no differences in mortality outcomes among patients with UTI across various socioeconomic parameters within our institution. However, hospital readmissions were more likely among patients who lived in census tracts with increased hardships. Future studies should evaluate possible interventions to decrease readmission disparities.

Disclosures
All Authors: No reported disclosures
P-1577. Healthcare utilization, antibiotic spectrum index, and outcomes associated with complicated urinary tract infections in the United States
Authors: Advani Sonali , Zhang Helen L , Ohnuma Tetsu , Spellman Alexandria A , Raghunathan Karthik , Krishnamoorthy Vijay , Anderson Deverick J , Schmader Kenneth , Scales Charles 
Published: January 2025

Abstract

Background
Despite a recent increase in the burden of complicated urinary tract infections (cUTI), contemporary data on healthcare utilization, outcomes and antimicrobial use related to cUTIs are lacking. We describe healthcare utilization, inpatient antibiotic use, and mortality associated with cUTI across a nationwide US hospital network.

Methods
This cohort study included inpatients aged ≥18 years with cUTI (using ICD-10 diagnostic codes) from 240 hospitals in the Premier Healthcare Claims Database between January 2016 – June 2020. Demographics, clinical characteristics, antibiotic use, and healthcare utilization measures were evaluated. In addition to antibiotic days of therapy, we calculated daily average Antibiotic Spectrum Index (ASI) which measures the spectrum of antimicrobial action based on number of organisms susceptible to that drug (total = 14 organism categories, e.g. ASI of penicillin is 2 while meropenem is 10, validated by Gerber et. al, PMID: 28560946). Primary outcome of inpatient mortality was assessed in a multivariable logistic regression model.

Results
In this cohort of 16,011 inpatients with cUTI, median age was 67 years (IQR 54- 77], 52.6% (N=8419) were female and 76.1% (N=12181) were white (Table 1). Over two thirds of patients with cUTI required intensive care unit care, while over 25% were bacteremic and required vasopressors. Median duration of antimicrobial therapy was 11 days [IQR: 7, 18] and median daily ASI was 10.40 [IQR: 7.80, 13.87]. Inpatient mortality was 6.4% and 30 day readmission rates were 17.7%. On multivariable analysis, significant risk factors for inpatient mortality in patients with cUTI included increasing age, with highest risk over 80 years of age (adjusted odds ratio (aOR) 3.25 (2.50 - 4.23); higher Charleston’s comorbidity index (aOR 1.05 (1.04 - 1.06)); admission from skilled nursing facility (aOR 1.39 (1.11 - 1.76) and higher ASI (aOR 1.05 (1.04 - 1.05, Table 2)).

Conclusion
In our cohort of 240 US hospitals, older adults and men experienced more than half of inpatient cUTIs. A large proportion of cUTIs were associated with high severity of illness requiring higher acuity of care. Older age, more comorbidities, and higher ASI were associated with increased mortality in patients with cUTI.

Disclosures
Sonali Advani, MBBS, MPH, FIDSA, Biomerieux: Advisor/Consultant|GSK: Advisor/Consultant|Locus Biosciences: Advisor/Consultant|Sysmex America: Advisor/Consultant Charles Scales, MD MSHS, BMS: Grant/Research Support|Exelixis: Grant/Research Support|Flume Catheter: Grant/Research Support|Lilac Therapeutics: Advisor/Consultant|Merck: Grant/Research Support|Pfizer: Grant/Research Support
P-1578. Impact of a Pharmacist-Driven Carbapenem De-escalation Algorithm for Hospitalized Patients with Urinary Tract Infections
Authors: Gauthier Timothy , Diaz Susana , Williams Kelsey , Dittmar Erika , Cua Jefferson 
Published: January 2025

Abstract

Background
This study aims to assess the impact of a pharmacist-driven carbapenem de-escalation algorithm on the use of antibiotics in hospitalized patients with urinary tract infections (UTIs).
Carbapenem De-escalation Algorithm

Methods
This was a single-center, retrospective chart review of patients who received carbapenems with a diagnosis of UTIs before (phase I, Aug – Nov 2022) and after (phase II, Dec 2022 – Mar 2023) implementation of a pharmacist-driven carbapenem de-escalation algorithm. Pharmacists made recommendations based on the algorithm but changes to therapy was at the discretion of the ordering provider. Patients aged ≥ 18 years who were receiving carbapenems for the treatment of UTI without concomitant bacteremia were included. Patients who received carbapenems for other indications, had a urinary stent, had abnormal genitourinary anatomy, or presented with renal calculi were excluded. The primary outcome was the percentage of qualifying patients who were de-escalated from carbapenem to non-carbapenem agent before and after the implementation of the algorithm.
Baseline Characteristics

Results
During phase I, 40 of 60 (67%) patients were found eligible for de-escalation based on the algorithm, while 37 of 60 (62%) were eligible during phase II. Table 1 shows demographic data and baseline characteristics. De-escalation occurred in 27 (68%) versus 33 (90%) (95%Cl 0.03 - 0.38) during phase I and II, respectively. De-escalation was attributed to the intervention in 15 (41%) of the phase II group, with a recommendation acceptance rate of 79%. Approximately 35 minutes of pharmacist daily workload was allocated to review and intervene as appropriate. Median duration of carbapenem therapy pre and post intervention was 72 versus 58 hours (p=0.4237) respectively. Median duration of antibiotic therapy in phase I was 7 days, while in phase II it was 6.7 days (p=0.6745).
Results

Conclusion
Intervention guided by a pharmacist-driven carbapenem de-escalation algorithm for patients with UTI can expedite carbapenem de-escalation without significantly impacting duration of antibiotic therapy and hospital length of stay.

Disclosures
Timothy Gauthier, PharmD, BCPS, BCIDP, AbbVie Pharma: Advisor/Consultant|Antimicrobial Therapy, Inc: Advisor/Consultant|Ferring Pharma: Advisor/Consultant|Firstline Mobile Health: Advisor/Consultant|Gilead Pharma: Advisor/Consultant|GoodRx: Advisor/Consultant|GSK Pharma: Advisor/Consultant|Melinta Pharma: Advisor/Consultant|Pattern Biosciences: Advisor/Consultant|Pfizer Pharma: Advisor/Consultant|ProCE: Honoraria|WWW.LearnAntibiotics.com: Ownership Interest
P-1580. Evaluation of Shorter Versus Longer Antifungal Treatment Durations for Candida Urinary Tract Infections
Authors: Kufel Wesley D , Govel Jacob C , Seabury Robert , Gutierrez Ramiro , Asiago-Reddy Elizabeth 
Published: January 2025

Abstract

Background
Infectious Diseases Society of America guidelines recommend 14 days of antifungal therapy for Candida urinary tract infections (UTIs). For bacterial UTIs, studies have demonstrated that shorter antibiotic durations have comparable outcomes to longer durations. To our knowledge, there are no data to compare shorter (7 days) versus longer (14 days) antifungal durations for Candida UTI.

Methods
This was a single-center, retrospective cohort study between 1/1/15 and 1/1/24 at a 752-bed academic medical center. Inclusion criteria were hospitalized adults with &gt;1 urine culture with Candida spp. and symptoms (dysuria, increased frequency/urgency, hematuria, costovertebral angle tenderness, and/or fever) who received &gt;1 antifungal dose within 96 hours of index culture (IC). Patients were excluded if Candida spp. were isolated from another culture site, received antifungals for a suspected non-UTI, or did not have any UTI symptoms. The primary outcome was to compare symptom resolution between shorter versus longer antifungal durations. Secondary outcomes included hospital readmission due to Candida UTI, candiduria recurrence, and all-cause mortality within 90 days of IC. Categorical and continuous variables were compared using Chi-square/Fisher exact test and the Mann-Whitney U test, respectively.

Results
There were 2399 patient encounters with candiduria screened. After inclusion and exclusion criteria were applied, 103 patients were included for analysis with 45 and 58 in the &gt;14 day and &lt; 14-day cohorts, respectively. No significant differences were identified between cohorts in demographics, urologic procedures, urinary devices, nephrolithiasis, vasopressor use, mechanical ventilation, or hospital length of stay. ID consultation occurred in 60% and 62.1% of the &gt;14 day and &lt; 14-day cohorts, respectively, and all recommended antifungal treatment. Median (IQR) fluconazole duration was 14 days (14-14) and 7 days (5-7). No significant differences were identified in the primary and secondary outcomes (Table 1).

Conclusion
No significant differences in treatment outcomes were identified between patients who received a median of 7 days versus 14 days of fluconazole for Candida UTI supporting shorter antifungal durations.

Disclosures
Wesley D. Kufel, Pharm.D., BCPS, BCIDP, Merck & Co.: Grant/Research Support|Shionogi, Inc: Grant/Research Support Elizabeth Asiago-Reddy, MD, Abbvie: Grant/Research Support|GSK/Viiv: Grant/Research Support|Pfizer: Grant/Research Support|Theratechnologies, Inc.: Grant/Research Support
P-1585. The Impact of MRSA Nasal PCR on Antibiotic De-escalation
Authors: Silverman Adam , Gautam-Goyal Pranisha , Gandhi Shivanthidevi , Oppenheim Michael , Ramirez Guillermo , Karkenny Gabriel , Sohail Rubab 
Published: January 2025

Abstract

Background
The MRSA nasal PCR is a screening tool that may help decrease the use of antimicrobials. The MRSA PCR as a screening test has shown a high negative predictive value associated with various infections - including pneumonia, intra-abdominal infections, wounds, and bacteremia. Despite this, MRSA PCR has been under-utilized for the purposes of deescalating antibiotics targeting MRSA.
Odds Ratios

Methods
This was a retrospective, observational, single-center cohort study within the Northwell Health system, approved by the Institutional Review Board. Data was collected from the electronic medical record between January 1, 2020, to December 1, 2021. We included adults admitted for inpatient care who had a MRSA PCR performed during the admission and were receiving antimicrobial therapy directed at treating MRSA. Clinical and demographic data were collected, in addition to the type of anti-MRSA therapy the patient was receiving, date the MRSA PCR resulted, date the anti-MRSA therapy was discontinued, and total days of anti-MRSA therapy. The primary objective was to determine if a negative MRSA PCR led to the discontinuation of anti-MRSA therapy within 48 hours of the result. Secondary objectives included the total days of anti-MRSA therapy, acute kidney injury (AKI) as discharge diagnosis, and hospital length of stay (LOS).

Results
Of the 5,047 patients included for analysis, 89% (n = 4505) had a negative MRSA PCR result. The odds of anti-MRSA therapy discontinuation were 264% greater among subjects with a negative PCR compared to subjects with a positive PCR result (OR: 3.64, 95% CI: 3.03 – 4.37, p&lt; 0.0001). After adjusting for covariates, this observation remained statistically significant, with the odds of anti-MRSA therapy discontinuation being 274% greater among subjects with a negative PCR compared to subjects with a positive PCR result (OR: 3.74, 95% CI: 3.04 – 4.59, p&lt; 0.0001).

Conclusion
A negative MRSA PCR result was significantly associated with anti-MRSA therapy discontinuation within 48 hours, both before and after adjusting for covariates. MRSA PCR is being increasingly recognized as a powerful antimicrobial stewardship tool and should continue to be utilized to help guide clinical decision making.

Disclosures
All Authors: No reported disclosures