bluuebunny/crossref_metadata_2025_split huggingface dataset:
2726. A Retrospective Single Center Study to Assess the Risk Factors for Infection with Multi-Drug-Resistant Organisms in Liver Transplant Recipients
Authors: Swaminathan Neeraja , McCort Margaret E , Frager Shalom , Kinkhabwala Milan , Bartash Rachel , Vasa Aastha 
Published: November 2023

Abstract

Background
Infections with multidrug resistant organisms (MDROs) are common in liver transplant recipients. We aimed to understand the prevalence and risk factors for MDRO infections during the peri-transplant period.

Methods
We conducted a retrospective chart review of adults ( &gt;18 years) who underwent deceased donor liver transplant (LT) from Jan 2018-Dec 2020. Demographics and clinical information, including antibiotic use, microbiological data, and adequacy of perioperative antibiotics based on CLSI breakpoints, were reviewed. Peri-transplant period was defined as 12 months pre- and 3 months post-transplant. MDRO was defined as resistance to one or more classes of antibiotics. Statistical analysis was performed with IBM SPSS 29.0, using Chi2 or Fischer’s exact tests as appropriate for categorical variables and independent t-test for continuous variables.

Results
Baseline demographics for the 121 LT recipients are summarized in Table 1. In the 3 months post-transplant, 47 patients (38.8%) were noted to have positive cultures, of which 22 were MDRO. MDRO distribution for pre- and post-transplant infections is shown in Figure 1. Univariate analyses of predictors for post-transplant MDRO infection are shown in Table 2. Mean length of stay for patients with post-transplant MDRO infection was 65.3 days versus 28.6 days in those without MDRO infection (p&lt; 0.001). Among 36 patients with positive cultures &lt; 1month post-transplant, 55% (n=20) received perioperative antibiotics covering the identified organism. Eleven of 23 patients (47.8%) who received ampicillin-sulbactam (AS) and 3 of 8 patients (37.5%) who received piperacillin-tazobactam (PT) perioperatively developed infections not covered by their respective regimens &lt; 1-month post-transplant. In the first month post-transplant, 17 patients had organisms cultured which were resistant to AS, of which all but one was also resistant to PT.Table 1Baseline Demographics

Conclusion
Admission to the intensive care unit, antibiotic use prior to transplant, and longer transplant hospitalizations were associated with MDRO infections. Tailoring of surgical prophylaxis may be indicated for high-risk patients as PT did not offer superior coverage over AS.

Disclosures
All Authors: No reported disclosures
2729. Clinical characteristics, treatment and outcomes of infections among adult-onset immunodeficiency with anti-interferon (IFN)-γ autoantibodies patients: A single-center 10-year review from tertiary care hospital in Thailand
Authors: Wongpaiboonwatana Sorakai , Feungpunya Thanarak , Diewsurin Jaruwan , Treebupachatsakul Pornpit 
Published: November 2023

Abstract

Background
Adult-onset immunodeficiency (AOI) with anti-interferon (IFN)-γ autoantibodies is an acquired immunodeficiency syndrome increasingly recognized in East and Southeast Asia. Antibody against IFN- γ or its receptor is the main pathophysiology leading to opportunistic infections especially mycobacterial, dimorphic fungal or Salmonella infection. However, clinical information of infectious complications in this patient population remains scarce.

Methods
A retrospective study was conducted in Buddhachinaraj hospital, Phitsanuloke, Thailand. We collected data on demographic, infectious complications, treatment and outcomes in patients with AOI with anti-IFN-γ autoantibodies who presented to our center between March 2013 and February 2023. All patients were diagnosed by elevation of anti-IFN- γ antibody level in serum more than 1.0.

Results
A total of 35 patients. 54.3% were men with a median age of 58 years (IQR 14-63). Lymphadenopathy was the most common initial presentation (57%), followed by prolonged fever (40%), cough (11%) and skin lesions (11%). Lymph node involvement was found in 80% while 31% and 11% had intra-abdominal abscess and osteomyelitis.
Organisms were identified in 21 patients (60%). Mycobacterial infections were found in 19 patients (90%) which the main etiologic agent was Mycobacterium abscessus (43%). Six patients (28%) had evidence of mycobacterial infection but were unable to specified. Histoplasma capsulatum was found in 2 patients (9%). Another 14 patients (40%) were presumptive treated as non-tuberculous mycobacterium (NTM) infection without retrieving specific organism.
All patients were treated with antimicrobial agents according to identified causative organism. Fourteen patients with presumptive NTM infection were empirically treated with combination antibiotics. Median time of treatment was 24 months (IQR 12-35). Seven patients (20%) experienced relapse after antimicrobial discontinuation requiring retreatment. Three patients (6%) had died at median duration of 4 months from diagnosis.

Conclusion
AOI with (IFN)-γ autoantibodies should be considered in patient whom suspected mycobacterium or fungal infection among non-HIV patients. Diagnosis and treatment are challenge and recurrent infection is common.

Disclosures
All Authors: No reported disclosures
2730. Clinically significant cytomegalovirus infection in patients with lymphoma and no prior cellular therapy
Authors: Zubovskaia Anna , Khawaja Fareed , Chemaly Roy F , Primeaux Brian , Waleed Mohammad 
Published: November 2023

Abstract

Background
Reactivation of cytomegalovirus (CMV) is commonly reported in lymphoma patients who undergo cellular therapy, with often poor outcomes. The risk for CMV reactivation in patients with lymphoma prior to cellular therapy is not well understood. As new alternative immunosuppressive therapies emerge for lymphoma, understanding baseline risk for CMV reactivation is paramount to improve clinical and oncologic outcomes. Our goal was to identify risk factors, and describe outcomes associated with clinically significant CMV infection (CS-CMVi) in lymphoma patients with no prior cellular therapy.

Methods
We performed a retrospective cohort study for all lymphoma patients who underwent testing for CMV by PCR from blood between 1/2017 and 12/2020. Patients with prior history of transplantation or chimeric antigen receptor therapy were excluded. Patients with and without CS-CMVi were identified for risk factor analysis by univariate analysis.

Results
A total of 217 lymphoma patients were included in our analysis; CS-CMVi was identified in 41 (19%) patients. When compared to patients without CS-CMVi (control group), lymphoma patients with CS-CMVi were more likely to have history of HIV (5% vs 0%; p= 0.0350), primary central nervous system lymphoma (7% vs 1%; p= 0.0220) and relapsed disease (54% vs 25%; p= 0.0005) (Table 1). CS-CMVi was also more common if testing was done at time of relapse diagnosis (32% vs 10%; p= 0.0007), during work up for infection (98% vs 68%; p &lt; 0.0001) and more often (3 vs 1; p &lt; 0.0001) (table 1). Mortality and remission rates within 1 year of testing were worse in patients with CS-CMVi (table 2 and figure 1).

Conclusion
CS-CMVi in lymphoma patients is associated with poor outcomes including oncologic outcomes. Further analysis to better define patients with lymphoma at high-risk for CS-CMVi should be studied for future preventative strategies.

Disclosures
Fareed Khawaja, MBBS, MEDSCAPE: Honoraria|Viracor: Grant/Research Support Roy F. Chemaly, MD/MPH, Eurofins-VViracor: Grant/Research Support|Karius: Advisor/Consultant
2732. Peri-Operative Antibiotic Management for Lung Transplant Recipients with Cystic Fibrosis
Authors: Gordon Melissa , Nichols Courtney , Marschalk Nicholas , Sarwar Sajed 
Published: November 2023

Abstract

Background
Lung transplant (LTx) recipients universally receive peri- and post-transplant antibiotics. Approaches to antibiotics for candidates with cystic fibrosis (CF) are institution specific. Little has been published about these practices. Routine LTx perioperative prophylaxis at our institution is 96 hours of vancomycin and cefepime with antibiotics then adjusted for positive intraoperative donor and recipient cultures. In recipients with CF, perioperative prophylaxis is determined pre-LTx to cover colonizing organisms isolated in culture from the 2 years before LTx, adjusted for intraoperative cultures, and administered for 14-21 days post-LTx. Our study aims to add to the current literature by describing our center’s experience with antibiotic management and outcomes in lung transplant recipients with CF to help guide best practices for prophylaxis strategies for this patient population.

Methods
We performed a retrospective chart review of patients with CF who underwent LTx from 3/1/2015-11/18/21 at our center and were colonized pre-LTx with MRSA, Pseudomonas aeruginosa, or Burkholderia cepacia complex. Peri- and post-operative antibiotic regimens, donor and recipient culture results, changes in antibiotic therapy post-LTx, and duration of antibiotic therapy were documented. Outcomes included rehospitalization, isolation in culture of the prophylaxis-targeted organisms post-LTx, and mortality, within 6 months of LTx.

Results
Nineteen incidents of LTx were included in this study. Pre-LTx colonizing organisms and antibiotics administered are outlined in table 1. Prophylaxis-targeted organisms were infrequently isolated in culture after LTx (table 2), with 7/19 (36.8%) developing post-transplant infection with prior colonizing organisms. Four (21.1%) recipients developed post-LTx Clostridioides difficile infection. One (5.3%) recipient died within 6 months post-LTx.

Conclusion
LTx recipients with CF who received targeted perioperative prophylaxis for pre-LTx colonizing organisms infrequently developed post-LTx culture positivity with the same bacteria including none during the antimicrobial prophylaxis period. Future prospective studies are needed to determine optimal antibiotic duration of peri-LTx antibiotics in this patient population.

Disclosures
All Authors: No reported disclosures
2739. Evaluation of a Perioperative Fungal Prophylaxis Protocol Change in Orthotopic Liver Transplant
Authors: Shulkosky Megan , Xhemali Xhilda , Eckardt Jamie , Ward Jessica , Schlick Heather , Brizendine Kyle D , Palm Nicole 
Published: November 2023

Abstract

Background
Orthotopic liver transplant (OLT) carries a high rate of fungal infections, including invasive fungal infections (IFI). A targeted antifungal prophylaxis protocol can identify OLT patients who warrant antifungal prophylaxis and optimize agent selection. In January 2021, a targeted antifungal prophylaxis post-liver transplant protocol was implemented at Cleveland Clinic. Since its introduction, rates of fungal infections and adherence to the protocol have not been assessed. The goal of this project is to describe the impact of a protocol change in OLT recipients.

Methods
This was a retrospective observational cohort study of patients ≥ 18 years old with an OLT +/- sequential kidney transplant at Cleveland Clinic. Review of perioperative fungal prophylaxis from June 1, 2019 – May 31, 2020 was performed and used as the baseline. The post-intervention period was June 1, 2021 – May 31, 2022. The primary objective was to determine adherence to the new OLT fungal prophylaxis protocol on post-operative day (POD) 0. Secondary objectives included the 90-day incidence of proven or probable IFI post-OLT before and after implementation.
Study Population

Results
A total of 134 patients pre-protocol and 166 patients post-protocol were included. Prior to protocol implementation, 73% patients were prescribed clotrimazole, 13% fluconazole, 13% micafungin, and 1% nystatin. After protocol implementation, 63% were prescribed clotrimazole, 16% fluconazole, and 21% micafungin. In the post-protocol group, there was an adherence rate of 66% on POD0 which increased to 84% over the duration of prophylaxis. Prior to initiation of the antifungal protocol, 6.7% of patients developed an IFI while 3.6% of patients developed an IFI post-protocol (p=0.22). Median time to IFI was 8 days (IQR 2-19) pre-protocol and 15 days (IQR 6-17) post-protocol. Mortality and ICU length of stay were comparable between groups.
Primary and Secondary Results
OLT: orthotopic liver transplant; POD: post-operative day; ICU: intensive care unit; IFI: invasive fungal infection
Characteristics of Patients with Invasive Fungal Infections
IFI: invasive fungal infection; TPN: total parenteral nutrition; IAI: intra-abdominal infection; n/a: not applicable; pRBC: packed red blood cells; OR: operating room; RRT: renal replacement therapy; ICU: intensive care unit; Dose dep.: dose dependent; GI: gastrointestinal

Conclusion
The implementation of a targeted antifungal prophylaxis post-liver transplant protocol can be a powerful strategy for promoting consistency in antifungal prophylaxis within a population at high risk for IFIs. Our study showed an 84% adherence rate to the implemented protocol, with numerically lower rates of IFIs post-protocol compared to pre-protocol.

Disclosures
All Authors: No reported disclosures
2741. Hit Me with Your Best Shot: Improving Pre-Lung Transplant Vaccination Rates with Infectious Disease Evaluation
Authors: Contreras Gustavo , Holubar Marisa , Shen Sa , Dhillon Gundeep , Tulu Zeynep , Nelson Joanna K 
Published: November 2023

Abstract

Background
Vaccine preventable diseases and reactivation of latent infections occur commonly post-solid organ transplant and can result in severe infections. Vaccination and screening for latent infections in the pre-transplant period are important tools to mitigate this risk. Previous studies have shown that, despite guidelines, vaccine uptake in the pre-transplant population is suboptimal.

Methods
We performed a quality improvement project in which all patients &gt;=18 years old being evaluated for lung transplant (LT) were referred for Infectious diseases (ID) evaluation with the endorsement of our LT Quality Council starting in 11/2021. ID evaluation included screening for and treating latent infections, vaccination history and drug allergy review, adjusting peri-operative antibiotics, and patient education. To assess the impact of our intervention, we conducted a retrospective chart review and extracted demographics, transplant status, and recommended and completed vaccinations. We compared vaccination adherence of consecutive patients who underwent ID evaluation (11/2021 – 8/2022) to a historical cohort of patients who were not evaluated by ID but underwent LT (1/2019 – 12/2020). We defined adherence for each vaccine (Table 1) and compared the odds of vaccination between groups using odds ratios. This project was deemed non-human subject research.

Results
We included 59 patients in the pre- and 61 patients in the post-ID group(Table 2). By the end of the observation period, in those patients evaluated by ID, 30(49%) patients had undergone LT, 10 (16%) were active on waiting list,18 (30%) were not yet listed, and 4 (12.5%) were declined for LT. Among those who underwent pre-transplant ID evaluation, 53 (85.5%) patients were seen via telemedicine. Adherence was significantly higher across all vaccines among the patients evaluated by ID; the biggest change was seen in HBV, Tdap, and Zoster (Figure 1).

Conclusion
ID evaluation of patients being evaluated for LT significantly improved vaccination rates. Pre-transplant ID evaluation provides the added value of a focused discussion of infection risk and can help to avoid morbidity and mortality post-transplant.

Disclosures
All Authors: No reported disclosures
2747. Aztreonam-Avibactam Susceptibility Testing Program for Metallo-β-Lactamase-Producing Enterobacterales collected through the Antimicrobial Resistance Laboratory Network, March 2019 to April 2023
Authors: Bhatnagar Amelia , Bumpus-White Porscha , Sabour Sarah , Bodnar Janine , Burks Albert , Chen Arlene , Craft Bradley , Jacobsen Christine , Karlsson Maria , Marmerow Michael , Lonsway David , Neff Lindsay , Maruca Tyler , Nazarian Elizabeth , Perry Zachary , Rossi Alessandro , Vagnone Paula S , Tran Michael , Valley Ann M , Brown Allison C 
Published: November 2023

Abstract

Background
Metallo-β-lactamase-producing Enterobacterales (MBL-E) are a major public health concern as they cause infections with few effective treatment options. Aztreonam-avibactam (AZA) is a β-lactam/β-lactamase inhibitor combination agent in the drug development pipeline that is active against MBL-E. Though clinical studies are ongoing, the effective components can be administered by combining two FDA-approved drugs: aztreonam and ceftazidime-avibactam. In 2019, CDC initiated a program in the Antimicrobial Resistance Laboratory Network (AR Lab Network), the Expanded Antimicrobial Susceptibility Testing Program for Hard-to-Treat Infections, to provide antimicrobial susceptibility testing (AST) of MBL-E for AZA. We provide a summary of the program’s results.

Methods
Seven AR Lab Network laboratories validated the use of a digital dispenser to create custom broth microdilution panels for AZA AST. Testing requests must be for clinical decision-making purposes. Isolates must be an Enterobacterales and have laboratory results positive for an MBL gene (i.e., blaNDM, blaVIM, or blaIMP), or be not susceptible to all β-lactams tested. AZA testing results for confirmed MBL-E were reported back to submitters within 3 working days from receipt of the isolate and shared with CDC.

Results
From March 2019 through April 2023, AZA AST was performed for 250 isolates: 103 Escherichia coli, 86 Klebsiella pneumoniae, 46 Enterobacter cloacae complex, 8 K. oxytoca, 2 Providencia rettgeri, 1 K. aerogenes, 1 Morganella morganii, 1 Proteus mirabilis, 1 E. hormaechei, and 1 Citrobacter amalonaticus. Carbapenemase genes detected were: 206 blaNDM, 24 blaNDM/blaOXA-48-like, 14 blaKPC/blaNDM, 2 blaIMP, 2 blaKPC/blaIMP, and 2 blaNDM/blaIMP. All isolates were resistant to ceftazidime-avibactam; 227/250 (90.8%) were not susceptible to aztreonam (≥8 µg/mL). For isolates not susceptible to aztreonam, the addition of avibactam resulted in a median 128-fold MIC reduction of aztreonam. The MIC range of AZA was ≤0.03/4 - &gt;64/4 µg/mL. Overall, the MIC50 and MIC90 of AZA were 0.5/4 µg/mL and 8/4 µg/mL, respectively; the MIC50 and MIC90 for E. coli were higher than other species, 4/4 µg/mL and 16/4 µg/mL.

Conclusion
Our data suggest that AZA has potent in vitro activity against MBL-E collected in the United States.

Disclosures
All Authors: No reported disclosures
164. Performance of ePlex® Blood Culture Identification Panels in Clinical Isolates and Characterization of Antimicrobial Stewardship Opportunities
Authors: Thomas Jenni , Clark Justin A , Arora Vaneet , Burgess David , Burgess Donna R , Mynatt Ryan , VanHoose Jeremy , Wallace Katie L , Cotner Sarah 
Published: November 2023

Abstract

Background
Rapid diagnostic testing allows pathogen identification within hours of a positive blood culture. GenMark’s ePlex® Blood Culture Identification (BCID) Panels detect bacteria, fungi, and antibiotic resistance genes. This study assessed concordance of ePlex® organism identification with standard microbiologic identification methods and concordance of ePlex® genotypic resistance mechanism detection and standard susceptibility testing. Secondary outcomes included panel specific performance and characterization of antimicrobial stewardship opportunities.

Methods
This retrospective, single center study included patients with a positive blood culture from May 2020 – January 2021. Polymicrobial cultures were excluded. Identification concordance was evaluated between ePlex® and MALDI-TOF, BD Phoenix™, and biochemical tests. Resistance mechanism/phenotypic susceptibility concordance was evaluated between ePlex® and BD PhoenixTM/ETEST®. MecA was assessed via oxacillin resistance, vanA via vancomycin resistance, CTX-M via ceftriaxone resistance, and KPC via carbapenem resistance. Opportunities for antimicrobial stewardship were also quantified.

Results
The overall identification concordance rate in 1276 positive blood cultures was 98.2%, with rates of 98.5%, 98.1%, and 93.3% for Gram-positive, Gram-negative, and fungal isolates, respectively. In 381 staphylococcal isolates, concordance rates were 98.3% and 100% for the presence and absence of mecA. Both the presence and absence of vanA were 100% concordant in 63 enterococcal isolates. CTX-M and KPC were evaluated in 189 Enterobacterales. Concordance rates were 96.8% for the presence of CTX-M and 60% for the presence of KPC, demonstrating that 40% of carbapenem resistance was due to non-enzymatic mechanisms. Ceftriaxone and carbapenem susceptibility correlated with the absence of CTX-M and KPC, respectively, in 100% of cultures. A majority of ePlex results (69.5%) represented opportunities for potential antimicrobial stewardship intervention.

Conclusion
High concordance rates between ePlex® and standard identification and susceptibility testing methods enable rapid antimicrobial optimization. Numerous opportunities for antimicrobial stewardship were identified based on ePlex® results.

Disclosures
All Authors: No reported disclosures
2765. Dalbavancin for challenging left ventricular assist device driveline infections
Authors: Doligalski Christina , Lachiewicz Anne , Friedland Anne , Snider Cynthia , Bowen Amanda , Marx Ashley H , Byku Mirnela , Bartelt Luther A 
Published: November 2023

Abstract

Background
Driveline tract and exit site infections (DLI) in patients on left ventricular assist device (LVAD) support occur frequently and are associated with significant morbidity, mortality and recurrence. Dalbavancin is a gram+ active lipoglycopeptide antibiotic with a prolonged half-life. Given a variety of scenarios including prior antibiotic failure, interacting concurrent therapies and socioeconomic factors, dalbavancin may be of interest for use in LVADs with challenging gram+ DLIs.
Case Series Details

Methods
A chart review was conducted for all LVADs at a single center who received at least one dose of dalbavancin prior to 1/1/2023 to assess safety and to describe utilization. Demographic data, microbiologic and antibiotic histories, and dalbavancin therapies along with further suppressive antibiotics were recorded.

Results
Six patients on LVAD support received dalbavancin for different gram+ infections (Figure 1). Five of the six had confirmed DLI. Three patients received two doses of dalbavancin 1500mg 1-2 weeks apart, followed by suppressive doxycycline with no infection recurrence to date. Three patients received dalbavancin initial doses 1-2 weeks apart followed by planned suppressive dalbavancin at 3-4 week intervals. One of these patients developed anaphylaxis with dose #5 and was subsequently changed to suppressive sulfamethoxazole/trimethoprim. Another received 10 of 14 planned doses over a 14 month period, with controlled infection while adherent to infusion. The final patient remains on suppressive dalbavancin ( &gt;1100 days). Apart from the anaphylactic reaction, no other adverse events were documented related to dalbavancin therapy.

Conclusion
In our limited case series, adherence with dalbavancin was a successful therapeutic option for patients with LVAD-related gram+ infections after failure of other therapies or socioeconomic limitations. Anaphylaxis was observed in one patient during infusion #5, suggesting the need for ongoing monitoring despite prior tolerability. One patient remains on prolonged suppressive intermittent dalbavancin, suggesting extended use may be viable in highly select patient scenarios. Further data is needed on prolonged durations and optimal dosing strategies in complex device-related infections.

Disclosures
Anne Lachiewicz, MD, MPH, Cidara: Grant/Research Support|Contrafect: Grant/Research Support|Novartis: Grant/Research Support|Pfizer: Grant/Research Support|Shiongi: Grant/Research Support Mirnela Byku, MD, Abbott: Advisor/Consultant