bluuebunny/crossref_metadata_2025_split huggingface dataset:
183. Combination Antibiotic Therapy vs Monotherapy for Methicillin Resistant Staphylococcus aureus Endocarditis
Authors: Crosby James M , Jo Stoner Bobbi , Cremeans Kelli , El-Dalati Sami 
Published: November 2023

Abstract

Background
Mortality for methicillin-resistant Staphylococcus aureus (MRSA) bacteremia and endocarditis remains unacceptably high. It is unclear whether combination antibiotic therapy results in improved clinical outcomes, which antimicrobials are most efficacious and when to initiate a combination regimen. We retrospectively evaluated patients over 1-year with MRSA endocarditis who were treated with either monotherapy with vancomycin or daptomycin or combination therapy with daptomycin and ceftaroline (D/C) or vancomycin and ceftaroline (V/C).

Methods
Patient cases were identified from the University of Kentucky’s endocarditis team (Figure 1). Demographic variables and clinical outcomes data were collected and reviewed by 2 investigators. Data analysis was conducted using Chi-Square tests and one-way ANOVA assessments. The primary outcome was in-hospital mortality. Secondary outcomes included: time to blood culture clearance and 90-day mortality.

Results
Between September 7th, 2021 and September 6th, 2022 we identified 49 patients with MRSA endocarditis treated with the designated regimens. There were no significant demographic differences between the study groups (Table 1). Twelve patients were treated with monotherapy, 23 patients were treated with D/C and 14 patients were treated with V/C. In-hospital mortality was 8.3% in the monotherapy group, 11.6% in the V/C group and 17.4% in the D/C group (p=0.60; Table 2). Average time to initiating combination therapy was after 4.7 days of bacteremia in the V/C group and 5.2 days in the D/C group (p=0.55). Average duration of bacteremia was 4.3 days in the monotherapy arm. Patients who received D/C cleared blood cultures after 3 days of combination therapy compared to 4.3 days in the V/C group (p=0.26). Receipt of D/C within 72 hours of the first positive blood cultures was associated with the lowest in-hospital and 90-day mortality across all groups, but this was not statistically significant (Table 3).

Conclusion
There was no significant difference in in-hospital or 90-day mortality between patients treated with monotherapy, D/C or V/C. Further studies of larger populations are required to identify which treatment approach results in the best clinical outcomes for patients with MRSA endocarditis.

Disclosures
All Authors: No reported disclosures
188. Plan PDD (patient directed discharge): Oral contingency plans for people who inject drugs (PWID) with Staphylococcus aureus bacteremia (SAB) who leave the hospital prematurely
Authors: Duffield Olivia , Patel Kaya , Schultz Sara K , Spivack Stephanie 
Published: November 2023

Abstract

Background
There has been an increase in infectious complications in PWID and SAB continues to be a serious consequence with treatment options that may not align with patient's agency. High rates of discharges against medical advice and subsequent readmissions contribute to preventable morbidity and mortality plaguing this stigmatized population. Recent research has indicated that oral antibiotic therapy can be non-inferior to IV therapy for SAB infections.

Methods
We queried Epic for admissions with patients with documented opioid use disorder and injection behavior and positive blood cultures from September of 2021 to March of 2022 at our large academic medical center in Philadelphia. We conducted a retrospective chart review of these encounters and collected data regarding their hospital course and treatment.

Results
Over the six-month study period, there were 159 admissions for bacteremia in PWID. Over half (52%) of these patients left the hospital prior to completing IV treatment, 24 (15%) of which still had positive blood cultures at the time of discharge. 90 patients had SAB infection (56.6%). In patients with SAB, only 23 (25.5%) completed a course of IV antibiotics while 52 (57.8%) patients with SAB left the hospital in a PDD and did not complete a course. In addition, there were 6 in-hospital mortalities (6.7%). Of the 52 patients that left the hospital without completing IV antibiotics, 21 (40.4%) were offered an oral antibiotic alternative. For patients who received an oral antibiotic on discharge, only 2 (9.5%) patients were readmitted in 90-days compared to 11 (35.5%) readmissions if oral antibiotics were not received (Figure 1). 19 patients (22.6%) total with SAB were readmitted within 90 days for the same infection or a complication of inadequately treated bacteremia.
Figure 1
Outcomes for PWID with SAB

Conclusion
PWID with SAB experience significant challenges to remaining in a hospital setting for the prescribed duration of intravenous antibiotics. ID physicians should consider including a contingency plan for oral antibiotics should the patient leave the hospital prematurely. Our results show that oral antibiotics are a viable option to prevent 90-day readmission in PWID with SAB.

Disclosures
Sara K. Schultz, MD FACP FIDSA, AbbVie: Advisor/Consultant
189. Outcomes of High-dose Oral Beta-lactam Step-down Therapy Compared to Alternative Oral Therapy for Bacteremic Urinary Tract Infections
Authors: Geyer Abigail , Dumkow Lisa E , VanLangen Kali , Jameson Andrew 
Published: November 2023

Abstract

Background
Pyelonephritis and associated bacteremia are often treated with intravenous antibiotics followed by oral step-down therapy to a fluoroquinolone (FQ) or trimethoprim/sulfamethoxazole (TMP/SMX). Oral beta-lactams were historically utilized less often due to concern for treatment failure. Literature suggests oral beta-lactams are effective, but there are no preferred oral beta-lactam agents or dosing recommendations. This study evaluates outcomes of high-dose oral beta-lactam therapy for Enterobacterales bacteremia due to a urinary tract infection (UTI) compared to alternative therapy.

Methods
A retrospective, multicenter, observational cohort study was conducted evaluating patients admitted from February 1, 2020, to October 1, 2022, with gram-negative bacteremia from a urinary source. Adult patients were included if they received empiric intravenous antibiotic active against the bacteria isolated and transitioned to appropriately dosed oral cephalexin, amoxicillin, TMP/SMX, or FQ (Table 1). Excluded were patients who received less than 72 hours of oral therapy, had a diagnosis of renal abscess or lobar nephronia, and those who expired during admission. The primary outcome compared the composite of recurrent bacteremia or mortality within 30 days of completing oral therapy. Secondary outcomes included recurrent UTI, emergency department (ED) or hospital readmission, and Clostridioides difficile infections within 30 days of treatment completion.

Results
There were 194 patients who met inclusion criteria. The primary outcome occurred in 1/75 (1.3%) patients in the oral beta-lactam group and 2/119 (1.7%) patients in the FQ or TMP/SMX group (p=1.0). Two patients in the FQ or TMP/SMX expired within 30 days and 1 patient in the beta-lactam group had a recurrent bacteremia. There were 16 (21.3%) and 14 (11.8%) patients in the beta-lactam and FQ or TMP/SMX group, respectively, treated for recurrent UTI (p=0.073). Twenty (27%) patients in the beta-lactam group required ED re-evaluation or hospital readmission compared to 30 (25%) patients who received a FQ or TMP/SMX (p=0.74). Zero patients had a Clostridioides difficile infection.

Conclusion
Oral beta-lactams are as effective as oral FQ and TMP/SMX for the treatment of bacteremia from a urinary source.

Disclosures
All Authors: No reported disclosures
195. Comparative Analysis Between Brucellosis Cases With And Without Liver Involvement
Authors: Hammami Fatma , Koubaa Makram , Rekik Khaoula , Chakroun Amal , Smaoui Fatma , Marrakchi Chakib , Ben Jemaa Mounir 
Published: November 2023

Abstract

Background
Brucellosis, a multisystem disease, involve mostly the reticuloendothelial system, but it can also affect any other organ. Liver involvement is often present during the acute phase. We aimed to compare clinical and laboratory features of brucellosis cases with and without liver involvement.

Methods
We conducted a retrospective study including all acute brucellosis cases hospitalized in the infectious diseases department between 1992 and 2022. Liver involvement were defined as a serum alanine transaminase &gt; 40 U/L and/or a serum aspartate aminotransferase &gt; 40 U/L.

Results
We encountered 105 cases, among which 46 had liver involvement (43.8%). A male predominance was noted among cases with (69.6%) and without (61%) liver involvement, with no significant difference (p=0.363). Vomiting (19.6% vs 5.1% ; p=0.021), nausea (28.3% vs 3.4% ; p&lt; 0.001) and loss of appetite (34.8% vs 10.2% ; p=0.002) were significantly more frequent among cases with liver involvement. Fever (89.1% vs 89.8% ; p=1), arthralgia (52.2% vs 61% ; p=0.364) and myalgia (37% vs 33.9% ; p=0.745) were noted among cases with and without liver involvement. Blood culture positivity was significantly more frequent among cases with liver involvement (43.5% vs 5.1% ; p&lt; 0.001). An elevated C-reactive protein level (85.7% vs 28.8% ; p=0.002), an accelerated erythrocyte sedimentation rate (76.1% vs 54.2% ; p=0.021) and thrombocytopenia (39.1% vs 13.6% ; p=0.003) were significantly more frequent among cases with liver involvement. Anemia (39.1% vs 25.4% ; p=0.133) and leukopenia (21.7% vs 22% ; p=0.971) were noted among cases with and without liver involvement, with no significant difference.

Conclusion
Acute brucellosis cases with liver involvement were characterised by frequent vomiting, nausea and loss of appetite as clinical symptoms, besides elevated inflamatory markers and frequent thrombocytopenia, which might be explained by the involvement of the reticuloendothelial system.

Disclosures
All Authors: No reported disclosures
197. Evaluation of Risk Factors and Outcomes Associated with Daptomycin-nonsusceptible Staphylococcus aureus Bacteremia
Authors: Hanna Zachary W , Alangaden George J , Zervos Marcus , Suleyman Geehan 
Published: November 2023

Abstract

Background
Staphylococcus aureus (SA) is a major cause of hospital-associated infections in the US with high morbidity and mortality. With SA developing resistance to many first-line antibiotics, daptomycin (DAP) has become a critical agent for SA therapy. However, increasing use of DAP has resulted in emergence of DAP-nonsusceptible (DNS) SA strains. We aim to elucidate risk factors associated with DNS SA and compare outcomes between patients with DAP-susceptible (DS) and DNS SA bacteremia (SAB).

Methods
Retrospective cohort analysis was performed on patients with DNS (cases) and DS (controls) SAB admitted to Henry Ford Health between 9/2005 and 3/2023. Patients with persistent ( &gt;7 days of positive blood cultures) DS SAB were used as controls. Demographic, risk factors, clinical characteristics, and outcomes were evaluated. Primary outcomes were 30-day relapse or progression, readmission and mortality; secondary endpoint was 90-day mortality.

Results
A total of 122 patients included 59 (48%) cases and 63 (52%) controls. The majority were male (56.6%) with median age of 59. The study population had a high burden of comorbidities as outlined in the Table; central venous catheter use was significantly more common among cases (p=0.049). History of MRSA infection (p&lt; 0.001) and prior hospitalization (p&lt; 0.001) within 1-year, and antibiotic (p=0.017) use, particularly vancomycin (p=0.011), within 90 days were associated with DNS SA. Primary source of infection and infectious complications were not significantly different among cases and controls. There was no significant difference in outcomes between the two groups. Although not statistically significant, 90-mortality was higher in the DNS group (p=0.075).

Conclusion
Our study highlights risk factors for DNS SA, including recent vancomycin use, and prior hospitalization and MRSA infection within 1 year. While there was no significant difference in outcomes between DNS and DS SAB, overall mortality was high. These findings highlight the need for continued surveillance of DNS SA and careful consideration of risk factors when selecting antimicrobial agents for complicated SA infections. Further studies are needed to identify potential mechanisms of vancomycin cross-resistance in DNS SA.

Disclosures
Marcus Zervos, MD, Contrafect: Advisor/Consultant|GSK: Grant/Research Support|Johnson and Johnson: Grant/Research Support|Pfizer: Grant/Research Support
198. Comparison of Standard versus Extended Treatment Duration for Gram-negative Bloodstream Infections with Obstructing Nephrolithiasis or Urolithiasis
Authors: Harpenau Tara L , Clemens Adam C , Brown Douglas A 
Published: November 2023

Abstract

Background
There is minimal data regarding optimal duration of therapy in gram-negative bloodstream infections (GN-BSI) with obstructing nephrolithiasis/urolithiasis. Prescribing practices often include standard antibiotic duration (fixed duration with an antibiotic free period prior to stone management) or extended duration (continuous antibiotics until definitive stone management). This study compares outcomes between standard versus extended antibiotic durations in patients with GN-BSI with obstructing nephrolithiasis/urolithiasis.

Methods
This IRB approved retrospective cohort study screened patients treated between 1/1/2016 and 1/1/2022. The standard duration group had an antibiotic free period of ≥ 7 days before definitive stone management and the extended duration group had continuous antibiotics without an antibiotic free period ≥ 7 days before definitive stone management. The primary outcome was infection recurrence before definitive stone management. Select secondary outcomes included revisit to care, antimicrobial resistance, and mortality. Continuous data utilized a t-test or Mann-Whitney U test and categorical data utilized either Chi-square or Fisher’s exact test.

Results
After screening 405 encounters, there were 39 standard and 29 extended group patients. Median antibiotic duration was 16 (15,19) vs. 19 (16,23) days, p = 0.06 and time to definitive stone management was 52 (34,71) vs. 22 (15,25.5) days, p&lt; 0.01 in the standard and extended group respectively. Infection recurrence was no different in the two groups, 5% (n=2) vs. 0%, p=0.5. Revisit to care was significantly higher in the standard group 28% (n=11) vs. 3% (n=1), p&lt; 0.01, with the most common patient complaint of “concern for infection.”

Conclusion
This study found no difference in infection recurrence between standard and extended antibiotic treatment strategies but was underpowered. A higher rate of revisit to care in patients who received standard courses of antibiotics is concerning and may also be influenced by a prolonged time to definitive stone management. Further data is necessary to determine the optimal antibiotic treatment strategy and optimal time of definitive stone management after GN-BSI with obstructing stones.

Disclosures
All Authors: No reported disclosures
210. Evaluating the Costs of Escherichia coli Bloodstream Infections: A Population-Based Cohort Study
Authors: King Teagan , Somayaji Ranjani , Leal Jenine , Black Jason , Gregson Dan , Conly John , Rennert-May Elissa 
Published: November 2023

Abstract

Background
Escherichia coli (E. coli) is a frequent cause of blood stream infection (BSI) with associated morbidity and mortality. We evaluated the costs of susceptible and resistant E. coli BSI in children and adults. There is a paucity of studies examining E. coli BSI using micro-costing data within North America.

Methods
Population-based cohort of all blood cultures from 2011 to 2018 in Calgary, Canada, linked to micro- and gross costing data using administrative databases. Compared no BSI to any E. coli infection, classified as resistant to any antimicrobial agent or susceptible, over 90 days. Propensity score matching was done 4:1 by age, sex, and comorbidities. The primary outcome was mean costs, using multivariable linear regression models in R version 4.1.0. Secondary outcomes were length of stay (LOS), readmissions and 90-day all-cause mortality. Comparative analyses were reported using odds ratios (OR) and 95% CIs.

Results
A total of 37,482 children and 89,673 adults were included: 225 susceptible and 21 resistant BSI in children, and 3,870 and 711, in adults. Mean and standard deviation (SD) costs of an E. coli BSI including ED visits and hospitalizations for 90 days in children were $99,214 ($152,809) for susceptible, and $94,628 ($113,281) for resistant infections, and $36,104 ($74,274), and $57,162 ($176,019) in adults. The greatest cost difference in adults was resistant E. coli BSI compared to no BSI ($24,265, 95% CI $11,308-37,223, p&lt; 0.001), with higher odds of readmission (OR 1.54, 95% CI 1.26-1.88, p&lt; 0.001) and increased LOS (4.17 days, 95% CI 1.04-7.30, p=0.009). In children, cost differences were greatest for susceptible infections compared to no BSI ($45,186, 95% CI 27,965-62,406, p&lt; 0.001), with the longest initial hospitalization (17.1 days, 95% CI 10.3-23.9, p&lt; 0.001), and higher readmissions at 90 days (OR 1.65, 95% CI 1.17-2.31, p=0.004). E. coli BSI did not impact mortality for children or adults compared to those with no BSI.

Conclusion
E. coli BSI is associated with substantial morbidity, mortality, and costs. Total cost differences were highest among adults with resistant, and children with susceptible infections compared to no BSI. Further research into cost-effectiveness of BSI diagnosis, treatment and prevention is warranted.

Disclosures
Ranjani Somayaji, M.D, CF Foundation: Grant/Research Support|CIHR: Grant/Research Support|Oncovir: Data and Safety Monitoring Board Fees|Vertex Pharmaceuticals: Advisor/Consultant|Vertex Pharmaceuticals: Grant/Research Support|Vertex Pharmaceuticals: Honoraria Dan Gregson, MD, BioMerieux Canada: Advisor/Consultant
212. Effectiveness of Empirical Piperacillin/tazobactam Compared to Cefepime for Bloodstream Infection Caused by Gram-Negative Bacilli
Authors: Ho Lee Young , Yang Jinyoung , Ko Jae-Hoon , Young Cho Sun , Huh Heejae , Yong Lee Nam , Kang Cheol-In , Ryeon Chung Doo , Ran Peck Kyong , Song Jae-Hoon , Huh Kyungmin 
Published: November 2023

Abstract

Background
Piperacillin/tazobactam (PTZ) and cefepime (CFP) are commonly used antibiotics for healthcare-associated infections and immunocompromised patients. However, few studies have compared the clinical effectiveness of these two antibiotics. Thus, we compared the effectiveness of empirical PTZ and CFP in patients with monomicrobial blood-stream infection (BSI) caused by gram-negative bacilli.

Methods
We conducted a retrospective cohort study of consecutive, non-duplicate monomicrobial BSIs caused by 1 of 4 taxa (Escherichia coli, Klebsiella pneumonia, Pseudomonas aeruginosa and Acinetobacter species) identified from a nationwide, prospective surveillance (Korean Antimicrobial Resistance Surveillance Network [KARS-Net]). Patients who were treated with PTZ or CFP as the only active empirical antibiotic were included. The primary outcome was all-cause, in-hospital 30-day mortality. Logistic regression with backward selection was used to adjust for imbalance in baseline characteristics.

Results
A total of 120 cases were included, among which 87 (72.5%) were treated with PTZ and 33 (27.5%) with CFP. Underlying renal disease was more common in the PTZ group whereas malignancy, septic shock, and neutropenia were more common in the CFP group. (Table 1). All-cause 30-day in-hospital mortality was comparable between the two groups (16.1% vs 12.1%, p=0.777; table 2), as well as attributable mortality. However, the early clinical response at 72 hr was significantly more common in the patients treated with CFP (25.3% vs 57.6%, p=0.001)
The choice of empirical antibiotics was not significantly associated with mortality in a multivariable logistic regression model (Table 3). Older age (≥65 years; adjusted OR. 16.24; 95% CI, 2.21-119.60), lower ECOG (aOR, 2.91 per 1 point, 95% CI, 1.35-6.25), high PITT score (aOR, 1.68; 95% CI, 1.17-6.25) and chronic liver disease (aOR, 39.70; 95% CI, 2.56-615.13) were significant independent risk factors for 30-day in-hospital mortality.

Conclusion
In patients with BSI caused by gram-negative bacilli, empirical use of either PTZ or CFP was associated with comparable clinical outcomes.

Disclosures
All Authors: No reported disclosures
213. Do Patients with Candidemia Need an Ophthalmology Exam?
Authors: Lehman Alice , Tessier Katelyn , Sattarova Victoria , Rocio Montezuma Sandra , Kline Susan E , Edwin Erayil Serin 
Published: November 2023

Abstract

Background
Candidemia can lead to hematogenous seeding of the eye resulting in chorioretinitis or endophthalmitis. IDSA recommends a screening dilated retinal examination for patients with candidemia, whilst American Academy of Ophthalmology (AAO) recently declared this a low value practice. Using an inter-disciplinary team, we evaluated ophthalmology examination for patients with candidemia.

Methods
We performed a retrospective study of patients with candidemia at an academic medical center and affiliated hospitals between January 2011 – June 2022. Electronic medical records were reviewed for demographics and baseline characteristics. The primary outcome was chorioretinitis and/or endophthalmitis. The study was adjudicated by independent review from infectious disease and ophthalmology providers.

Results
We included 308 patients with a blood culture positive for candida species. 149 patients (48%) received an ophthalmologic exam, of which 55% (82) were asymptomatic. Abnormal ocular findings concerning for presumed ocular candida complications were found in 12 patients (8%, 12/149), of which 4 had alternative diagnoses to candida choriorentinits or endophthalmitis. All of the remaining 8 patients (5%, 8/149) had presumed candida chorioretinitis with no cases of candida endophthalmitis and this led to a change in management in 88% (7/8) of patients (Table 1). Of the 8 patients, 3 patients were asymptomatic, making the number needed to screen 28 to detect presumed candida chorioretinitis amongst asymptomatic patients. We did not identify statistically significant risk factors for development of abnormal ocular findings (Table 2).
Table 1
Clinical diagnosis and management of patients with candida chorioretinitis and/or endophthalmitis
Table 2
Clinical features of patients with and without ocular candidiasis

Conclusion
IDSA and AAO recommend ophthalmologic examination in symptomatic and intubated patients with candidemia. We found a 5% incidence of presumed ocular candidiasis in patients with candidemia. Given the limitations of our study, we could not conclude for or against screening in asymptomatic patients as this did not lead to a significant change in patient outcomes. Inter-disciplinary decisions involving ophthalmology and infectious diseases can help inform best practices for screening in asymptomatic patients. Future studies should evaluate ocular photography and teleophthalmology as screening strategies.

Disclosures
All Authors: No reported disclosures