bluuebunny/crossref_metadata_2025_split huggingface dataset:
P-2110. Evaluating Different Screening Methods to Assess the Prevalence of Gut Colonization with Multidrug-Resistant Gram-Negative Bacilli in Hospitalized Patients
Authors: Tenner Rebecca A , Riquelme Maria Paz , Acevedo Johanna , Maureira Quezada Lea Paz , Valentina Gonzalez Soto Maite Loreto , Martínez Jose R W , Diaz Lorena , Peters Anne S , Araos Rafael , Munita Jose M 
Published: January 2025

Abstract

Background
Accurate estimates of gut colonization with drug-resistant gram-negative bacilli (GNB) are key to combat antimicrobial resistance. Data on best practices to assess colonization is scarce, limiting the comparability and feasibility of screening efforts. Building upon ongoing projects studying gut colonization with carbapenem-resistant (CR), carbapenemase-producing (CP-CR) and extended-spectrum beta-lactamase-producing (ESBL) GNB in Chile, we compared 3 different screening strategies and assessed the impact of time between swab collection to plating.
Prevalence of Gut Colonization with Multidrug-Resistant Gram-Negative Bacilli Detected with Different Screening Methods

Methods
Rectal swabs were collected for a gut colonization point-prevalence study in 3 Chilean hospitals (n=127, 149, 150). All swabs were plated within 2h of collection onto separate MacConkey agars with CAZ 2µg/mL and CIP 2µg/mL (CAZ|CIP). In hospital A samples were also plated on MacConkey + ceftriaxone 2µg/mL (CAZ|CIP|CRO). In hospital B swabs were also plated onto CHROMagar ESBLTM (CAZ|CIP|CHR). Swabs from Hospital C were plated on CAZ|CIP within 2h(immediate) and were then re-streaked after 48h at room temperature (delayed plating). After 24h of incubation at 37°C, all isolated morphotypes were characterized. Prevalence of gut colonization between CAZ|CIP, CAZ|CIP|CRO and CAZ|CIP|CHR were compared, as were plating times for hospital C.

Results
Results are summarized in Table 1. Prevalence of gut colonization in hospital A using CAZ|CIP vs. CAZ|CIP|CRO was similar for MDR-GNB (24% vs 28%), CR-GNB (13% vs 14%), and CP-CR-GNB (3% vs 4%). The addition of CRO detected a higher prevalence of ESBL-GNB compared to CAZ|CIP alone (50% vs 41%; p=0.04). In hospital B, CAZ|CIP|CHR detected a higher prevalence of colonization with CR-GNB (21% vs 16%, p=0.016) and ESBL-GNB (44% vs 36%, p &lt; 0.001), but similar results for MDR-GNB and CP-CR-GNB as compared to CAZ|CIP. The prevalence of gut colonization did not vary between immediate vs. delayed plating (Hospital C).

Conclusion
The addition of a CRO or CHR agar increased the detection of gut colonization with ESBL-GNB compared to a CAZ|CIP protocol. CHR also provided a higher yield of CR-GNB. However, observed CP-CR-GNB prevalence was similar among all 3 conditions. Finally, a delayed plating strategy (48h) did not impact colonization detection as compared to immediate plating (2h).

Disclosures
Jose M. Munita, MD, MSD: Grant/Research Support|Pfizer: Grant/Research Support
P-2114. Pattern of Clinical Characteristics, Outcome and Comparison of Carbapenem Resistant and Carbapenem Sensitive Klebsiella Species Infections from a Tertiary Care Hospital, Karachi, Pakistan
Authors: Samar Rohama , Farooq Mohammad Kashif , Babar Zaheer Udin , Dodani Sunil 
Published: January 2025

Abstract

Background
The prevalence of carbapenem resistant (CR) Klebsiella species (KS) is greater than 60 % in South Asia with high morbidity and mortality. Data on clinical aspects of KS from Pakistan is scarce. We aimed to study clinical characteristics, outcome and risk factors for mortality among KS infection

Methods
A prospective study conducted from September 2022 to March 2023. All patients greater than 18 years with active KS infection were included. Age, gender, clinical features, Charlson co-morbidity index, source of infection, previous hospitalization, source control and appropriate empirical antibiotics received were noted. Outcome was documented as admitted, discharged or death at day 14.
CRKS and carbapenem sensitive (CSKS) were compared.Table 1:Demographics, Risk factors and outcome of CRKS and CSKS infection.

Results
Out of 217, 128 (58.9%) CRKS and 89 (41%) CSKS infection. The median age was 48 years, 39.6% female. Around 114 (52%) had previous hospitalization. Bacteremia 103(47.5) was most common. At day 14, all-cause mortality was 29%. CRKS infection was significantly associated with recent hospitalization, fever, altered mental status, ICU admission and mechanical ventilation.
Pneumonia was more common with CRKS (p=value 0.004). Among CRKS, 4 (3.2%) received appropriate empirical antibiotics and had poor bacterial clearance (p=0.048). A survival curve shows significant high mortality in CRKS over 14 days. On multivariate analysis patients with CRKS did not receive appropriate empirical antibiotics.Table 1:Demographics, Risk factors and outcome of CRKS and CSKS infection.

Conclusion
We found a very high proportion of CRKS infection with high morbidity and mortality. Patients with CRKS infection did not receive appropriate empirical antibiotics. Timely availability of antibiogram with good infection control practices are critical in preventing mortality and spread this highly pathogenic organism.

Disclosures
All Authors: No reported disclosures
P-2117. ETEST® Aztreonam-Avibactam (AZA) for Antimicrobial Susceptibility Testing of Enterobacterales: Performance Results From a Muticenter Study
Authors: Prudhomme Sarah , Bossy Louise , CSIKI-FEJER Edith , Hardy Dwight , Wootton Mandy , Yarbrough Melanie L , Pillon Edwige , Franceschi Christine 
Published: January 2025

Abstract

Background
AZA is a combination of Aztreonam, a monobactam not hydrolyzed by metallo-β-lactamases, and Avibactam, a novel non-β-lactam β-lactamase inhibitor with an extended spectrum that protects Aztreonam for hydrolysis by Ambler class A, class C, and some class D serine β-lactamases. Aztreonam-Avibactam is developed by Pfizer for the treatment of infections caused by Gram-negative bacteria, including metallo-β lactamase producers.
This study evaluated the performance of ETEST® AZA (bioMérieux Marcy-L’Etoile, France), a new gradient diffusion strip, for determining antimicrobial susceptibility of Enterobacterales compared to the CLSI/ISO-20776-2 broth microdilution reference method (BMD).

Methods
A population of 650 (clinical and challenge) Enterobacterales isolates (including 150 Escherichia coli; 118 Klebsiella pneumoniae; 48 Klebsiella oxytoca; 67 Enterobacter cloacae complex; 50 Citrobacter freundii complex; 30 Citrobacter koseri; 32 Klebsiella aerogenes; 30 Morganella morganii; 32 Proteus mirabilis; 30 Providencia stuartii ; 30 Proteus vulgaris ; 33 Serratia marcescens) were tested at 4 clinical trial sites, comparing ETEST® AZA and the BMD reference method.
Results were analyzed using preliminary EUCAST breakpoints (Enterobacterales: ≤ 8mg/L (S), &gt; 8 mg/L (R)) and preliminary FDA breakpoints (Enterobacterales: ≤ 8mg/L (S), ≥ 16 mg/L (R)) provided by Pfizer. Results are presented as essential agreement (EA) and Bias for Worldwide registration and as essential (EA) and categorical (CA) agreements, Trend, very major (VME) and major (ME) error rates for US registration.

Results
Results are summarized in Table 1. ETEST® AZA performance for Enterobacterales met ISO acceptance criteria for EA (≥ 90%) and Bias ≤ ±30%, and FDA criteria for EA, CA (≥ 90%), ME (≤ 3%), VME (≤ 2%) and Trend ≤ ±30%.

Conclusion
Results of this multicenter trial support the accuracy of ETEST® AZA for determining MICs of Enterobacterales. As such, the ETEST® AZA test is considered to be equivalent to BMD.

Disclosures
Melanie L. Yarbrough, PhD, bioMerieux: Grant/Research Support|bioMerieux: Honoraria|Pattern Bioscience: Grant/Research Support|Shionogi: Advisor/Consultant
P-2138. The Significance of Low Titer Serum Cryptococcal Antigen Testing from 2017 to 2023
Authors: Wilson Jenna , Ribes Julie A , Irwin Mark , Myint Thein 
Published: January 2025

Abstract

Background
In the fall of 2016, a cluster of low positive serum cryptococcal antigen titers (SCrAg) ≤ 1:20 was traced back to a manufacturing defect. Subsequently, SCrAg ≤ 1:10 were reported with a disclaimer to correlate clinically at our institution. This study aimed to determine the performance of the assay since 2017, after the test improvement.
Comparison of Baseline Characteristics, Laboratory Findings and Outcome Among Three Groups

Methods
This was a retrospective study of patients with first time low titer SCrAg (≤1:20) tested at UK HealthCare from Jan 2017-Oct 2023. Patients were classified as true positives (TP), likely false positive (FP) and indeterminate based on repeat SCrAg, PCR or culture (CSF, Blood, respiratory, other), histology, correlating symptoms and/or detection of nodular infiltrates on CT, all extracted via chart review from the electronic medical record.
Number of Positive Serum Cryptococcal Antigen Samples Based on Titers​

Results
Of 3716 SCrAg performed during the study, 181 (4.9%) were positive. 69/180 (38%) positive samples were SCrAg ≤1:20. We excluded 32 TP tests due to prior higher SCrAg or prior history of cryptococcal meningitis and focused on the significance of newly identified low titer patients. 37 (0.9%) low titer SCrAg samples were seen in 27 patients. 19/27 patients (70.4%) were classified as TP, 2 (7%) FP, and 6 (22.2%) were classified as indeterminate (Table 1). Lumbar puncture (LP) was performed in 57.9% (11/19) of those classified as TP, and of those, 27.3% (3/11) had confirmed cryptococcal meningitis. Five of the nine patients that had histologic examination demonstrated organisms consistent with cryptococcosis. Antifungal therapy was administered in 100% (19/19) TP compared to 0% (0/2) FP (p &lt; 0.01).

Conclusion
False positive low titer SCrAg are not frequent. When newly detected, these low titer positives are associated with additional corroborating evidence suggesting cryptococcosis. Patients with likely true positive SCrAg had respiratory and CNS symptoms and abnormal imaging more often than those with FP SCrAg. Low positive SCrAg should be extensively investigated for evidence of cryptococcal infection.

Disclosures
All Authors: No reported disclosures
P-2149. The Spectrum of Non-Valvular Cardiac Aspergillosis: What We Know So Far
Authors: Al khouri Zaid , Alqura’an Anood , Munshi Ruhul , Alam Mohammad , Malek Alexandre 
Published: January 2025

Abstract

Background
Invasive aspergillosis is a life-threatening infection that affects immunocompromised hosts. Cardiac involvement is rare, but it is associated with a high-mortality rate. Most cases reported infective endocarditis secondary to Aspergillus. However, there is limited data about non-valvular cardiac aspergillosis (NVCA). We performed a systematic review and added one case seen at our institution to highlight more on NVCA.
PRISMA Flow Diagram NVCA

Methods
Three reviewers searched PUBMED and EMBASE for all adult cases diagnosed with NVCA between 1950 and 2024 and assessed studies for eligibility (Fig 1). We added our case of 48 yo female with only congenital kyphoscoliosis diagnosed with isolated NVCA and was successfully treated with 6-month course of Voriconazole.

Results
We found 67 cases including ours. A 36% were females and 64% males with a mean age of 44.6 y (range, 18-79). 30% of patients did have underlying hematologic malignancy and in 15% there were no comorbidities identified. Diagnosis was made by cultures and histopathology either from the pericardial fluid, cardiac masses, or from the cardiac layers, and it was antemortem only in 39%. It was identified in the pericardium alone in 40%. In 51% of cases, the Aspergillus species were not identified, while the remaining were secondary to A. fumigatus. TTE was done in 60% and showed pericardial effusion or tamponade in 31.5%. A 67% had lung involvement and 52% had invasive aspergillosis. In terms of outcomes, 19% remained alive, and those Pts received anti-fungal therapy including voriconazole in 69% & amphotericin in 46% +/- intervention in 61.5%, while 75% expired including 38% who did not receive management, but the remaining did mostly use amphotericin in 30%.

Conclusion
NVCA is rare but highly fatal. Clinicians should keep a high-level of suspicion of this clinical entity, primarily in patients with liquid tumors and pericardial effusion. A combination of antifungal therapy, especially voriconazole along with minimally invasive or surgical intervention showed success in most cases.

Disclosures
All Authors: No reported disclosures
P-24. Toward the clinical development of ATI-1701, a genetically defined live attenuated tularemia vaccine
Authors: Nabors Gary S , Baran Arthur , Gelhaus Carl 
Published: January 2025

Abstract

Background
Tularemia is a life-threatening disease caused by the bacterium Francisella tularensis. While rare, the disease is notable for its wide host range, low infectious dose, high case fatality rate, and having been previously weaponized. Type A (F. t. tularensis) strains are found predominantly in North America and are generally more virulent than Type B (F. t. holarctica) strains. Both a killed whole cell (KWC) and a live attenuated (LA) vaccine were initially developed and underwent clinical testing in the pre-antibiotic era. While both types of vaccines generated strong antibody responses, later human challenge studies demonstrated that the KWC vaccine failed to protect against aerosol exposure. The LA strain designated LVS, which provided better protection against aerosol challenge but less robust protection against type A strains, was used until recently to immunize laboratory workers. Obstacles for approval of LVS include concerns regarding its undefined attenuation and potential for reversion to virulence. No acellular vaccines have proven to be as effective as LA vaccines.

Methods
ATI-1701 is a next-generation LA vaccine with a targeted, well-characterized mechanism of attenuation. ATI-1701 carries a clpB gene deletion, which is thought to inhibit its ability to escape from phagosomes, thereby limiting replication in host macrophages.

Results
Mice immunized ID with 10 CFU of ATI-1701 were fully protected from lethal challenge with the SCHU S4 strain. Rats vaccinated with one dose of ATI-1701 and challenged via aerosol exposure to 5,600 LD50 of virulent SCHU S4 survived infection up to one year post-challenge, whereas all unvaccinated rats died. Regardless of immunizing dose (103-109 CFU), spleens from vaccinated rats contained 103-105 CFU of ATI-1701 14 days after vaccination, and bacteria were cleared from the spleen prior to day 42. Immunization of cynomolgus macaques with a single dose of 105 CFU ATI-1701 protected 80-100% of animals challenged with up to 157,000 LD50 of SCHU S4 via aerosol exposure up to three months after vaccination. One year after vaccination approximately 30% of vaccinated macaques survived challenge whereas control animals died.

Conclusion
ATI-1701 is a promising tularemia vaccine candidate and is being positioned for a Phase 1 clinical trial.

Disclosures
All Authors: No reported disclosures
P-2169. Establishment of multiplex PCR method for nearly whole-genome sequencing of human parainfluenza/rubula virus 4 from a clinical sample
Authors: Sayama Yusuke , Sakamoto Masahiro , Okamoto Michiko , Saito Mayuko , Tamaki Raita , Saito-Obata Mariko , Joboco Christina Dahlia , Negosa Quicho Reynaldo Frederick , Lupisan Socorro P , Oshitani Hitoshi 
Published: January 2025

Abstract

Background
Human parainfluenza/rubula virus 4 (HPIV4) has two subtypes (4a/4b). HPIV4 infection is usually mild but can be severe in young children, older adults, and immunocompromised individuals. However, sequence information on HPIV4 is limited worldwide, including in tropical areas. Whole-genome sequencing is useful for the molecular epidemiological analysis of virus introduction and transmission routes. Thus, this study aimed to establish nearly whole-genome sequencing of HPIV4 subtypes using multiplex PCR (mPCR) methods and to identify genetic characterization in the Philippines.

Methods
We collected 29 (4a; n=17, 4b; n=12) HPIV4-positive samples from children (&lt; 5 years old) with severe pneumonia at three hospitals (Leyte, Biliran, and Palawan) in the Philippines from 2012 to 2019. HPIV4 positive samples showed cycle threshold (Ct) values ranging from 21.1 to 36.9. An online pipeline tool (Primal Scheme) was used to design mPCR primer panels for HPIV4 subtype-specific viruses to cover the whole genome. For the sequencing experiment, viral RNA was purified from clinical samples and synthesized cDNA. cDNA was amplified using mPCR with each primer panel. The PCR amplicon was library preparation with a tag for the Illumina sequencing platform. Data of whole-genome sequencing was obtained using a CLC genomic workbench.

Results
All of the 29 HPIV4-positive samples were amplified by mPCR for whole-genome sequencing. The whole-genome sequencing results for HPIV4a showed that the length of consensus sequences generated at a coverage depth of 30X ranged from 85% to 99%. The sample with the lowest coverage (85%) had a Ct value 28.9. The results for HPIV4b showed that at a coverage depth of 30X, the length of consensus sequences ranged from 97% to 99%. The Ct values of the samples that showed 97% coverage were 22.6 and 30.4. Although some HPIV4 strains detected in the Philippines belonged to the same clade, others were in different clades. These clades included strains detected in various areas, such as Asia and North America.

Conclusion
This study established that the HPIV4 subtype-specific primer panels allow users to obtain the whole genome of HPIV4 directly from clinical samples. This method provides a universal, rapid, and effective tool for genomics surveillance.

Disclosures
All Authors: No reported disclosures
P-2186. Implementing Updated Hepatitis B Virus Screening Guidelines in an Underserved Resident Clinic
Authors: White Cole J , Weis John C , Barlow Mariah P 
Published: January 2025

Abstract

Background
An estimated 580,000 to 2.4 million Americans are living with hepatitis B virus (HBV) infection putting them at increased risk of cirrhosis, hepatocellular carcinoma, and death. Given these adverse outcomes, the Centers for Disease Control and Prevention recommended universal hepatitis B screening with a triple panel for all adults aged 18 and older starting in 2023. The purpose of our quality improvement (QI) project was to increase HBV screening rates in our internal medicine residency program outpatient clinic in accordance with updated CDC recommendations.
Table 1
The number of new patients screened for HBV and the total number of patients screened for HBV, organized by month.

Methods
This QI project took place at a single outpatient internal medicine residency clinic from August 2023 to April 2024. HBV screening rates were obtained at baseline and monthly thereafter. All patients 18 years and older were included unless prior billing and coding data demonstrated a diagnosis of hepatitis B. 2798 patients were identified in the population at the beginning of the study. Patients were deemed as successfully screened if they had a documented HBV triple screen [hepatitis B surface antigen (HBsAg), antibody to hepatitis B surface antigen (anti-HBs), and antibody to hepatitis B core antigen (anti-HBc)]. Two Plan-Do-Study-Act (PDSA) cycles were implemented; the first consisted of resident education and the second was the creation of an electronic medical record (EMR) reminder.
Figure 1
The number of patients screened for HBV by month.

Results
Only 32 patients were screened for HBV at baseline. In the six months following PDSA-1, 50 patients were screened. This brought the total number of patients screened to 82, representing a 156% increase in HBV screening after PDSA-1. In the month following the start of PDSA-2, 89 additional patients were screened for HBV, increasing the overall number screened to 171.
Figure 2
The cumulative number of patients that have been screened for HBV, measured monthly.

Conclusion
PDSA-1 (resident education) showed an initial increase in HBV screening followed by a slow decline in screening over time. This suggests that education may transiently increase screening rates; however, screening will decline over time as the recency effect abates. PDSA-2 (EMR reminder) led to a more rapid increase in screening rates which suggests this may be a more impactful way to quickly identify patients in need of HBV screening. Ongoing data collection is needed to determine if EMR-generated reminders are capable of sustaining screening rates over time.

Disclosures
All Authors: No reported disclosures
P-2190. Gender Differences in Hepatitis C Treatment in the New York City Jail System, 2019-2023
Authors: Enemchukwu Chibuzo U , Simonson Raphael , Koenigsberg Batya , Varela Natalia Gonzalez , LaPene Jacqueline , Figueroa Richard , Wiersema Janet 
Published: January 2025

Abstract

Background
Little is known about Hepatitis C (HCV) care outcomes among women experiencing incarceration. Women make up only 7% of the New York City (NYC) jail population, but represent 18% of individuals diagnosed with active HCV. This study examines progress through the HCV care cascade among women and men in the NYC jail system and describes potential gender-related factors in cascade outcomes.

Methods
Persons admitted to the NYC jail system and who completed a medical intake between October 2019 and December 2023 were included in this retrospective cohort analysis. We constructed a care cascade describing rates of universal opt-out HCV screening, confirmatory testing, diagnosis, linkage to jail-based clinical HCV care, and jail-based HCV treatment among the jail population stratified by documented gender. Demographic characteristics and medical history were also examined and stratified by documented gender.

Results
71,130 persons were included in our analysis, of whom 5,085 (7.1%) were women and 66,045 (92.9%) were men. Compared to men, women were screened at higher rates (88.7% vs. 28.1%; p&lt; 0.001), underwent confirmatory testing at lower rates (9.6% vs 11.2%; p=0.002), and had similar rates of active HCV (51.2% vs 47.8%; p=0.22). Women with active HCV were seen by an HCV clinician at similar rates as men (55.4% vs. 59.6%; p=0.32) but initiated HCV treatment at nearly half the rate of men (15.3% vs. 30.3%; p&lt; 0.001). Additionally, women in the NYC jails had significantly higher rates of homelessness (23.5% vs. 19.5%), HIV (3.7% vs. 2.7%), mental health needs (53.7% vs. 30.8%), and history of select substance use disorders (58.6% vs. 45.8%) when compared to men (p&lt; 0.001).

Conclusion
Large HCV treatment gaps exist between women and men experiencing incarceration. Disproportionally higher rates of comorbid medical, mental health, and substance use disorders and more re-entry support needs likely contribute to treatment disparities. Gender-specific strategies centered on the needs of women with justice involvement are needed to enhance the equitable uptake of jail-based HCV treatment. Enhancing treatment access for all persons with justice involvement is critical for HCV elimination efforts.

Disclosures
All Authors: No reported disclosures