bluuebunny/crossref_metadata_2025_split huggingface dataset:
P-2311. Logical Versus Absolute Lymphocyte Count-guided Preemptive Therapy for CMV Prevention in Solid Organ Transplant Recipients: A Randomized Controlled Trial
Authors: Lorcharassriwong Piyangkul , Boongird Sarinya , Kantachuvesiri Surasak , Yingchoncharoen Teerapat , Sutharattanapong Napan , Bruminhent Jackrapong 
Published: January 2025

Abstract

Background
A preemptive approach using plasma CMV DNA load monitoring is recommended among CMV-seropositive (R+) solid organ transplant recipients (SOTr). Lately, absolute lymphocyte count (ALC) has been proposed as a surrogate marker to predict CMV infection in SOTr. We hypothesized that a preemptive approach guided by immune assessment, using low ALC, could effectively prevent CMV infection, akin to the proposed routine preemptive therapy. We aimed to assess the efficacy of logical preemptive therapy (LOG) versus ALC-guided preemptive therapy for CMV infection in CMVR+ SOTr, along with cost-effectiveness.

Methods
A 1:1 open-labeled randomized controlled trial was conducted at a single transplant center from February to November 2023. All adult CMVR+ SOTr not receiving anti-thymocyte globulin were randomly assigned to two groups: the LOG Group, where patients underwent plasma CMV DNA load testing every 4 weeks for 12 weeks after transplantation, and the ALC group, where the quantity of CMV DNA load was initiated when the ALC was &lt; 1,000 cells/mm3. Patients were then followed for 6 months after SOT to compare the occurrence of CMV infection and the CMV DNA load testing-related cost.

Results
A total of 98 eligible SOTr were included and assigned into two groups, 49 patients each. They all underwent kidney transplantation (KT) with a mean+SD age of 46+11 years old; 66.3% were male. Demographic data between the two groups were comparable. Twenty-five (25.5%) participants developed CMV infection within 6 months after KT. CMV infection was comparably observed in 13 (26.5%) participants in the LOG group vs. 12 (24.5%) participants in the ALC group, p=0.82. Of those, there were no significant differences in terms of asymptomatic CMV infection, CMV disease, and clinically significant CMV infection (p=NS, all). The total cost of plasma CMV DNA load testing (68 USD per test) was significantly lower in the ALC group compared to the LOG group (2,320 vs.10,014 USD, p&lt; 0.01), respectively.

Conclusion
Immune-guided preemptive therapy directed by low ALC appears to be effective in preventing early CMV infection after SOT. A simple and universally available ALC test could potentially be used as a personalized and cost-effective marker to initiate preemptive therapy in moderate-risk CMVR+ SOTr. TCTR20220720007.

Disclosures
All Authors: No reported disclosures
P-2312. Impact of a Short Course Post-Operative Antibiotic Prophylaxis Duration on Nephrotoxicity in Lung Transplant Recipients
Authors: Stratton Paige , Kenney Rachel M , Veve Michael , Fitzmaurice Mary Grace , Alangaden George J , Franco-Palacios Domingo 
Published: January 2025

Abstract

Background
Vancomycin plus an antipseudomonal β-lactam is used as lung transplant surgical prophylaxis, but an optimal post-operative duration is not defined. The study objective was to assess the impact of a shortened antibacterial surgical infection prophylaxis (SIP) duration on post-operative nephrotoxicity in lung transplant recipients.
Table 1
Variables associated with AKI

Methods
IRB approved quasi experiment of lung transplant recipients who received SIP from 1/1/2016-9/30/2020 (pre-group) to 10/1/2020-7/31/24 (post-group). Intervention: implementation of shortened SIP duration to 72-hours of cefepime and vancomycin post-operatively. Inclusion: eGFR &gt;30 mL/min/1.73m2 between transplant day ±2. Exclusion: renal replacement ≤ 3-months, simultaneous organ transplants, donor bronchi with Gram-positive bacterial growth, or new COVID-19 infection between transplant day ±7. The primary endpoint was the incidence of acute kidney injury (AKI), defined by the KDIGO criteria, while receiving post-operative vancomycin up to 14 days. Secondary endpoints were vancomycin consensus guideline (VCG) AKI definition at 14-days and time to AKI.

Results
77 patients were included: 45 (58%) pre-, 32 (42%) post-intervention. 73% vs. 47% male (p=0.018). 49% vs. 34% (p=0.205) KDIGO AKI while on vancomycin. Post-group associated with approximately 40% decreased odds of developing KDIGO AKI (Table 1). Secondary endpoints: 33% vs. 19% VCG AKI (p=0.157). Median time to AKI was three days, with no differences detected between groups and AKI definitions. Similar rates of C. diff infection, positive bacterial respiratory cultures, new multidrug resistant organisms, surgical site infections. 57.8% vs. 84.4% patients received treatment for new pneumonias after SIP completion (p=0.013), with one new MRSA pneumonia in the pre-group and one in the post-group.

Conclusion
Implementation of a shortened antibacterial prophylaxis protocol for lung transplant resulted in numerically fewer AKIs. Maturation, regression to the mean, and reliance on manual chart review are all limitations of this retrospective study. Ongoing analysis of this intervention, such as with multicenter prospective studies, can help to characterize the decreased nephrotoxicity risk with shorter course prophylaxis post-transplant.

Disclosures
Rachel M. Kenney, PharmD, BCIDP, Medtronic Inc: Spouse is an employee, stockholder
P-2323. Utilizing Nanopore Sequencing Technology to Identify Saporvirus Genotypes in Fecal Samples from Young Children with Diarrhea in Al Ain City, United Arab Emirates
Authors: Alsuwaidi Ahmed R , George Junu , Abdelrahman Mahmoud , Alblooshi Abdulrahman 
Published: January 2025

Abstract

Background
Human sapoviruses are important pathogens causing diarrhea globally. They are increasingly detected in individuals with diarrhea due to the expanded utilization of molecular diagnostic methods. There are 18 genotypes known to infect human (GI.1-7, GII.1-8, GIV.1, and GV.1-2). Notably, the genetic characteristics of sapoviruses circulating in the United Arab Emirates (UAE) remain unclear.
This study aims to use next generation sequencing to analyze sapovirus genotypes in stool samples from children under five with diarrhea in Al Ain city.

Methods
Using multiplex one-step real-time PCR (Allplex™ Gastrointestinal Full Panel Assay), 15 sapovirus-positive stool samples were identified from stool specimens collected for a previous epidemiological study of pathogens causing diarrhea during the period from December 2017 and April 2019. After excluding isolates with low viral load (Ct &gt;30), 8 isolates were used for genotyping studies. Total RNA was extracted using a stool total RNA isolation kit and confirmed by endpoint PCR. Viral RNA was retrotranscribed to cDNA, followed by viral genome amplification, purification, and quantification. After sequencing with Nanopore MinION technology, reads that passed quality control (score &gt;7) were produced. Geneious Prime and Mega11 Software were then used for base-calling, mapping, and phylogenetic analysis.

Results
PCR amplicon-based platform was developed for sequencing human sapoviruses in order to reduce the cost of sequencing per sample. The system produced successful amplification in 7 out of 8 studied sapovirus-positive samples. All isolates showed close similarity with each other showing more than 99% similarity. Blast analysis of sequences of the amplicons revealed close similarity with East Asian isolates (99%). The closest Middle Eastern isolate was from Iran showing 87% similarity with the UAE isolates. Phylogenetic analysis revealed that seven of the eight sapovirus isolates were found to cluster within the GI.1 genotype.

Conclusion
Using Nanopore sequencing technology, GI.1 genotype was found to be the most prevalent sapovirus genotype among the studied isolates. The obtained data will enhance our knowledge on the molecular diversity of sapoviruses in the UAE and enrich the current sapoviruses genotyping protocols.

Disclosures
All Authors: No reported disclosures
P-2325. Can activated partial thromboplastin time (aPTT) be used as a marker to predict bleeding and severity of Dengue fever in resource limited setting?
Authors: Bhalla Ashish , Bhalla Ashish Kumar , Kumar Ashok , Suri Vikas , Singh Harpreet , Dibhar Debaprasad , Sharma Navneet 
Published: January 2025

Abstract

Background
Bleeding in Dengue has been attributed to dysfunction in intrinsic pathway, however, there are no clear evidence of its use as a predictor of severity or mortality in adult patients with Dengue fever.
Our hypothesis is that prolonged aPTT is associated with life threatening bleeding and severity of Dengue fever.

Methods
a retrospective analysis of all patients diagnosed as Dengue fever admitted during the months of July to October 2023 was undertaken. The diagnosis of Dengue fever was established based on NS1 antigen positive (day 1-5) and/or IgM positive (day 7-12). Patients with dual infections, alternate diagnosis or secondary Dengue (IgG positive) were excluded. Details of the clinical parameters, haemogram, coagulation factors, liver and kidney function tests were recorded. The patients were classified as dengue without warning signs (mild), Dengue with warning signs (moderate) and dengue with Dengue shock syndrome(DSS)/ (DHF)Dengue hemorrhagic fever (severe) on the day of presentation. Progression to DSS/DHF during hospital stay, life threatening bleeding and mortality were the outcomes studied.

Results
195 patients were admitted but only 163 with complete clinical detail/ laboratory investigations were included in the study. The mean age was 31.8 years (range 13-80 years). Male : female ratio was 56%:44%. Average interval between onset of symptoms to clinical presentation was 7 days (range 5-11 days). Average duration of stay was 6.8 days. 80 patients (49%) had severe dengue at the time of presentation. 71 patients (43%) had bleeding with less than of them 50% having clinically significant bleeding. 103 patients (63%) patients had prolonged aPTT ( &gt;35 seconds) at admission. 52 patients (32%) died. On multivariate analysis, prolonged aPTT and a low platelet count (&lt; 10,000) at admission was not found to be associated with either clinically significant bleeding, severity of illness or mortality.

Conclusion
Severity, clinically significant bleeding and mortality in Dengue is not associated with either platelet count or APTT at presentation.
Limitation: our study included parameters at admission and did not include the lowest platelet counts and highest values of aPTT during admission.

Disclosures
All Authors: No reported disclosures
P-2328. Influenza and RSV Surveillance in the US Veterans Health Administration (VHA): 2023-2024 Season
Authors: Lucero-Obusan Cynthia A , Chung Joyce S , Schirmer Patricia , Edson Connor W , Oda Gina , Holodniy Mark 
Published: January 2025

Abstract

Background
Influenza and Respiratory Syncytial Virus (RSV) cause seasonal epidemics with substantial morbidity and mortality. Veterans Health Administration’s (VHA) large elderly population is at higher risk for complications, including hospitalization and death. Herein we summarize VHA’s annual surveillance data for influenza and RSV activity and vaccinations.

Methods
Influenza-like-illness (ILI) as well as influenza and RSV-coded outpatient visits and hospitalizations, laboratory testing, and antivirals were obtained from VHA data sources (10/1/2023-4/13/2024) and compared to prior years and CDC data. VHA and community vaccinations were captured starting August 1st each year, with rates calculated based on VHA users in each fiscal year. Influenza RT-PCR positive respiratory samples underwent whole genome sequencing (WGS) to analyze clade and antiviral resistance.

Results
Influenza vaccinations (including high dose) were increased compared to 2022-2023 (Table). Weekly ILI ranged from 0.6%-1.6% in primary/urgent care settings. Activity was highest for 2023 Week 52, matching national influenza trends and increased compared to last season (Fig.1). There were 28,853 influenza positives among 438,110 tests performed (6.6%). Median length of stay was 3 days in 4,059 hospitalizations. Among 139 deaths, 129 (92.8%) had Influenza A and 10 (7.2%) Influenza B (Table, Fig.2). 310 samples (in 5 states) were sequenced with no drug resistance mutations identified (237 A/H1; 30 A/H3; 43 B/Victoria), representing 4 subclades, which aligned with CDC reporting (Fig.3). Over 270,000 Veterans received an RSV vaccine in 2023-2024 (over 177,000 administered by VHA). RSV visits, hospitalizations and positive tests were increased compared to 2022-2023.

Conclusion
For 2023-2024, influenza vaccinations (including high dose) increased compared to prior years, and newly licensed RSV vaccines were available in VHA. Influenza and RSV activity was increased compared to the prior season. VHA influenza activity and WGS analysis tracks closely with national CDC reporting. Given risks associated with influenza and RSV in the elderly population, VHA will continue efforts to improve vaccination rates.

Disclosures
All Authors: No reported disclosures
P-60. Lineage dynamics are not the major drivers of Streptococcus pneumoniae serotype 3 vaccine escape
Authors: Stanley Sydney , Silva-Costa Catarina , Gomes-Silva Joana , Malley Richard , Ramirez Mario 
Published: January 2025

Abstract

Background
Streptococcus pneumoniae serotype 3 (Spn3) is included in the pneumococcal 13-valent conjugate vaccine (PCV13) but carriage and invasive disease persist worldwide. Previous work showed that the prevalent clonal complex 180 (CC180) of Spn3 is comprised of 3 genetically distinct lineages: clade Iα, Iβ, and II; a post-PCV13 shift towards increased incidence of clade II strains with a concomitant decrease in clade Iα and 1β incidence has been observed in the United States, England, and Wales. It was hypothesized that PCV13 is controlling clade Iα and 1β but not clade II, resulting in clade II expansion and ultimately rendering the vaccine ineffective against Spn3. It is imperative to test this hypothesis in other regional contexts given the implications on vaccine design and efficacy. Therefore, our group assessed the dynamics of Spn3 population structure and PCV13 in Portugal.
Prevalence of Spn3 clonal complexes before and after the introduction of PCV13 in Portugal

Methods
We whole-genome sequenced 501 Spn3 strains from Portugal and analyzed over 1400 Spn3 whole genome sequences from published datasets for global comparisons. Phylogenetic tree construction, clade identification, clonal complex typing, and annotation of antimicrobial resistance (AMR) and virulence genes was used to evaluate changes in bacterial genetics.
Prevalence of Spn3 clades before and after the introduction of PCV13 in Portugal

Results
Consistent with previous work, the prevalence of clonal complexes significantly changed before and after the introduction of PCV13 in Portugal (p=4.94-12): CC180 increased from 29% of Spn3 strains to 65%. The prevalence of lineages also changed (p=2.33-13): clade Iα increased from 21% to 54% of Spn3 strains, while clade II was not detected pre-PCV13 but increased to only 5% post-PCV13. This contrasts with studies conducted elsewhere. The phylogenetic distribution of AMR alleles is similar across different regions, so altered antibiotic fitness does not explain the continued success of clade Iα over clade II in Portugal.

Conclusion
Our data suggests clade II is not the global driver of Spn3 PCV13 vaccine escape as clade Iα remains dominant in Portugal. Current work aims to determine if clade Iα allelic variants augment virulence and thus competitive fitness against clade II in Portugal. Informed vaccine design requires an understanding of the region-specific bacterial population structure and genetic features to optimize efficacy.

Disclosures
Richard Malley, MD, Amplitude Therapeutics: Board Member|Corner Therapeutics: Board Member|GSK: Advisor/Consultant|Merck: Advisor/Consultant Mario Ramirez, PhD, GSK: Advisor/Consultant|Merck Sharp and Dohme: Advisor/Consultant|Pfizer: Honoraria
P-64. Variations in the treatment of Cutibacterium acnes Infections of the Bones and Joints and Associated Outcomes
Authors: Elizabeth Yun Adrienne , Bhargava Ashish , Szpunar Susan M , Johnson Leonard B 
Published: January 2025

Abstract

Background
Cutibacterium acnes is an emerging pathogen in bone and joint infections. While treatment guidelines recommend the use of β-lactam therapy for C. acnes infections, the lack of routine susceptibility testing may result in wide variation in treatment regimens among physicians. We assessed the treatment regimens chosen by physicians for patients with bone and joint infections with C. acnes and the treatment outcomes of β-lactam and non-β-lactam regimens.

Methods
This was a multi-center, historical cohort study comparing treatment regimens in patients diagnosed with C. acnes for both native and prosthetic bone and joint infection. The study included patients with monomicrobial cultures positive for C. acnes and diagnosed with septic arthritis, prosthetic joint infections, osteomyelitis, or discitis between 7/1/2018- 6/30/2023. Data collected included antimicrobial therapeutic regimens, surgical intervention, as well as treatment failure and success. Data were analyzed using chi square test, Student’s t-test, and the Mann-Whitney U test.

Results
Among 49 included patients, 65.3% of infections resulted from prosthetic joint infection, 26.5% from osteomyelitis, and 8.2% from septic arthritis. The most common intravenous antibiotics chosen to treat C. acnes were ceftriaxone (51%), vancomycin (16.3%), and penicillin (6.1%) with a mean treatment duration of 43.4 days. The most common oral antibiotic treatment was doxycycline (20.4%), amoxicillin (18.4%), cephalexin/cefadroxil (12.2%) with a median outpatient treatment duration of 38 days (range 5, 364). Overall, there were no difference in treatment outcomes between patients treated with β-lactams vs, non-β-lactams at six months, including cure (58.8% vs. 71.4%, p=0.53), persistence of symptoms (26.5% vs. 14.3%, p=0.49), recurrence (17.6% vs. 28.5%, p=0.51), and requiring suppressive therapy (23.5% vs. 28.6%, p=0.78), respectively.

Conclusion
Physicians preferred β-lactam antibiotics for treating patients with bone and joint infections caused by C. acnes. There were no differences in outcomes for treating C. acnes bone and joint infections between β-lactam and non-β-lactam antibiotic regimens. Further studies should be performed to confirm this observation.

Disclosures
All Authors: No reported disclosures
P-111. Promising Efficacy of Nasal-Spraying Bacillus Spore probiotics for Supportive Treatment of Pneumonia in Children with RSV and Bacterial Co-infections
Authors: Bich Phung Thuy Thi , Van Nguyen Anh Thi , Thi Bui Huyen , Hoa Nguyen Anh , Minh Nguyen Hang , Hong Le Hanh Thi , Le Hoa Thi 
Published: January 2025

Abstract

Background
: Respiratory syncytial virus (RSV) and bacterial co-infections are primary cause of pneumonia. Recently, nasal-spraying Bacillus spore probiotics (LiveSpo NAVAX containing ≥ 5 billion/5mL B. subtilis and B. clausii spores) have demonstrated its effectiveness in supporting the treatment of acute respiratory tract infections caused by RSV and Influenza virus1,2.

Methods
A randomized, double-blind, controlled clinical trial was conducted to evaluate the efficacy of LiveSpo NAVAX in the supportive treatment of severe pneumonia due to RSV and bacterial co-infections. A total of 120 eligible pediatric patients were randomly assigned to two groups: the Control group received 0.9% NaCl physiological saline, and the probiotic-intervention group (Navax group) received LiveSpo NAVAX three times a day.

Results
At day 3, the Navax group demonstrated significant reductions in both RSV and bacterial co-infection 15.7 and 40.8-fold greater than those observed in the control group. Notably, H. influenzae and S. pneumoniae were reduced by 22.8 and 17.2 folds, respectively. Additionally, the Navax group exhibited significant decreases in pro-inflammatory cytokines (IL-6, IL-8, TNF-α), with levels reduced by 1.4 - 3.6 folds, while also enhancing the immune system (IgA) by over 67.04%. Furthermore, the 16S rRNA metagenomic analysis revealed the restoration of nasal microbiota, with an increase in the density of beneficial genus such as Corynebacterium, Bacillus and a reduction in the density of harmful genus including Streptococcus, Haemophilus, and Moraxella.

Conclusion
Our data demonstrate that nasal-spray Bacillus spore probiotics supported the treatment of pneumonia in children by reducing RSV, co-infection bacterial loads, and pro-inflammatory cytokines.

Disclosures
All Authors: No reported disclosures
P-134. Sarcina ventriculi, pathogen or commensal? Case series and review of the literature
Authors: Al khouri Zaid , Al Qura'an Anood , Koppada Satya , Mubashir Maryam , Zia Hassaan , Pinargote Paulette , Salazar Wilmer 
Published: January 2025

Abstract

Background
Sarcina, or Clostridium, ventriculi (SV), is a non-motile, gram-positive coccus with anaerobic fermentative properties. Due to its rarity, comprehensive knowledge about it is lacking. This study aims to elucidate its epidemiology and common manifestations.

Methods
We searched PUBMED and EMBASE utilizing terms as 'Sarcina', 'Ventriculi', and 'Clostridium' with no restrictions. Figure 1 contains the PRISMA diagram for case selection.

Results
We identified 88 cases and included 2 cases from our institution. The mean age was 48 ranging from 10 months to 89 years with an equal distribution between genders. 21% had Diabetes mellitus type 2 and 50% had baseline GI comorbidity primarily affecting the esophagus or stomach in 27% respectively. 37% were concurrently on antacids and prokinetics. The most common symptoms were abdominal pain (58%), nausea/vomiting (41%), anorexia/weight loss (18%), and diarrhea (12%).  Pertinent labs were anemia, leukocytosis, and elevated inflammatory markers. Mural inflammation, ulcers, retained food with distension, pneumatosis, perforation, necrosis, masses, or obstruction were common on radiological and endoscopic workup. Organism was mostly isolated from gastric (73%) and esophageal (18%) tissue using endoscopic and/or surgical procedures (76 and 27%, respectively). It was also isolated from respiratory tissue (3%), anaerobic blood culture (3%), lymph nodes (2%), urine (1%), and cerebral ventricles (1%). Co-infection with candida in 8% and H. Pylori in 4% was noted. 57% received antibiotics, being combination therapy with metronidazole and fluroquinolones, the most therapy used.
77% had successful clinical recovery, 11% expired; the outcome for 12% of patients remains unknown. Antibiotic therapy was used in 67% and 40% of patients who clinically recovered and expired respectively.

Conclusion
In most cases, SV is a true pathogen responsible for symptoms rather than a commensal; however, larger-scale studies are needed to discern pathophysiology. Most cases present with an underlying GI comorbidity including dysmotility which might predispose to colonization. Metronidazole and fluroquinolones provide optimal clinical response.

Disclosures
All Authors: No reported disclosures