bluuebunny/crossref_metadata_2025_split huggingface dataset:
2350. LiaF is required for LiaX mediated protection against Daptomycin and LL-37 in Enterococcus faecalis OG1RF
Authors: Botero Diana Panesso , Singh Kavindra , Gomez-Villegas Sara-Isabel , Khan Ayesha , Supande Adeline , Nguyen April , Rincon Sandra , Hood Kara S , Dinh An , Deyanov Alexander , Miller William R , Shamoo Yousif , Tran Cecilia , Arias Cesar A 
Published: December 2022

Abstract

Background
Daptomycin (DAP) resistance in enterococci is regulated by the LiaFSR three-component regulatory system. Mutations in liaF have been linked to activation of this system, with increased expression of the protein LiaX, and resistance to DAP in clinical isolates. LiaX functions by recognizing DAP in the extracellular medium, and serves as a signal transduction molecule. However, the role of LiaF in signaling and its relationship with LiaX are unknown.

Methods
We generated a liaF null mutant in E. faecalis OG117 by adding four stop codons at amino acid positions 11–14 (OG117liaF*11-14) using a CRISPR-Cas9 system. The mutant was complemented by restoring wild-type liaF in its chromosomal location (OG117liaF*11-14::liaF). Mutants were confirmed with whole genome sequencing (WGS). Anionic phospholipid (AP) microdomain distribution was assessed on microscopy using 10-N-nonyl-acridine-orange (NAO). LiaFSR activation was assessed by surface expression of LiaX via ELISA. DAP MICs were performed by broth microdilution in the presence/absence of exogenous LiaX (eLiaX). LL37 (50µg/ml) and DAP (1.5µg/ml) killing assays with eLiaX were also performed in triplicate.

Results
Truncation of liaF did not have any effect on DAP MICs, AP microdomain distribution or LiaX surface expression compared to OG117. No additional mutations were observed by WGS in the mutants. In the presence eLiaX, DAP MIC increased 8-fold in wild-type OG117 but remained the same (1 µg/mL) in OG117liaF*11-14. Complementation of liaF restored the increase in DAP MIC in the presence of eLiaX. In the LL37 killing assay, survival of OG117 was significantly increased on the addition of eLiaX (2.9% vs 11.8%, respectively, P &lt; .002). Addition of eLiaX was unable to rescue OG117liaF*11-14 in the presence of LL-37 (2.4% vs 2.5% respectively, P=0.51), but was able to increase survival in the complemented strain (2.8% vs 7.6%, respectively, P &lt; .002). A similar trend was seen in the DAP killing assay, with increased survival for OG117 (8.7% vs 20%) and OG117liaF*11-14::liaF (11.6% vs 17%), but not OG117liaF*11-14 (0.38% vs 1%).

Conclusion
LiaF is required for full tolerance to the cathelicidin LL37 and DAP in E. faecalis OG1RF. These results suggest that LiaF may interact with LiaX as a part of the LiaFSR stress response.

Disclosures
William R. Miller, MD, Entasis: Grant/Research Support|UpToDate: Honoraria Cesar A. Arias, MD, PhD, Entasis: Grant/Research Support|MeMed Diagnostics Ltd: Grant/Research Support|Merck: Grant/Research Support.
1944. Effectiveness of COVID-19 Vaccines Against Severe Disease and Death and its Durability Over Time Against the Omicron Variant
Authors: Lytras Theodore , Mellou Kassiani , Gkolfinopoulou Kassiani , Gerolymatos Gerasimos , Paraskevis Dimitrios , Zaoutis Theoklis , Tsiodras Sotirios 
Published: December 2022

Abstract

Background
We aimed to estimate COVID-19 Vaccine Effectiveness (VE) and its durability against severe disease (intubation) and death in the Greek population, for all vaccines currently in use.

Methods
Nationwide active surveillance and vaccination registry data between January 2021 – April 2022 were used to estimate VE via quasi-Poisson regression as one minus Incidence Rate Ratio, adjusted for age and calendar time. Interaction terms were included to assess VE by age group, by variant (delta vs omicron) and by time since vaccination (compared to the first month after vaccination).

Results
VE results are summarized in Figures 1-3. After 2-doses (of any vaccine) VE was &gt;95% against delta and &gt;85% against omicron in the 15-59 and 60-79 age groups, but waned significantly at 6 months by 5-10% in the 15-59 group and 15-20% in the 60-79 group. In the 80+ age group, 2-dose VE was much lower against omicron at around 60%, waning to 50% at 6 months. With 3 vaccine doses VE surged to &gt;95% against both delta and omicron in all age groups except 80+, who had VE against omicron of ≈90%; however there was again substantial waning at 6 months by about 10-15% in all groups. In the 80+ age group, VE against omicron dropped to 81.4% (95% CI 76.7–85.2%) for death and 57.7% (95% CI 38.5–70.9%) for intubation. There was little to no evidence of variation in VE between combinations of different vaccines (BNT162b2, mRNA-1273, ChAdOx1 nCov-19 and Ad26.COV2.S), although the majority of the population received 2- or 3-dose BNT162b2. Vaccination prevented an estimated 39,018 COVID-19 deaths (95% CI: 37,791–40,608) over the study period. Figure 1.Vaccine Effectiveness for 1, 2 and 3 doses (any vaccine), ages 15-59Figure 2.Vaccine Effectiveness for 1, 2 and 3 doses (any vaccine), ages 60-79Figure 3.Vaccine Effectiveness for 1, 2 and 3 doses (any vaccine), ages

Conclusion
COVID-19 vaccination remains extremely effective in preventing severe disease and death, even in the context of the omicron variant, as long as 3 doses have been administered. Even after 3 doses, however, effectiveness wanes substantially in the course of 6 months. Additional strategies will be therefore needed in order to minimize COVID-19 mortality and morbidity, including boosting doses especially in the elderly, improved vaccines, early diagnosis and treatment of high-risk groups and measures to reduce community transmission of current or novel SARS-CoV-2 immune escape variants.

Disclosures
All Authors: No reported disclosures.
2354. Implementation of BPaL in the United States: Experience using a novel all-oral treatment regimen for rifampin-resistant or treatment-intolerant TB disease
Authors: Haley Connie A , Ashkin David , Peloquin Charles A 
Published: December 2022

Abstract

Background
Tuberculosis (TB) remains a leading infectious cause of death and morbidity globally. Rifampin-resistance or intolerance requires prolonged treatment using less effective, more toxic regimens. Recent trials demonstrated that the all-oral six-month “BPaL” regimen, Bedaquiline, Pretomanid and Linezolid, is 90% effective. In these trials, linezolid-induced hematologic and neurologic toxicity was high using 1200mg daily, whereas lower exposure (dose or duration) reduced toxicity. Therapeutic drug monitoring (TDM) is used by U.S. TB experts to maintain a serum linezolid trough &lt; 2ug/ml, which correlates with reduced toxicity. Since U.S. FDA approval in 2019, BPaL has been widely implemented for the treatment of rifampin-intolerant or resistant TB disease.

Methods
We evaluated a cohort of patients with TB treated from October, 2019 through April, 2022, describing patient demographics, BPaL treatment dosing, and adverse events. TDM was performed for clinical purposes using liquid chromatography–mass spectrometry to measure serum levels at trough and 2 and 6h post-linezolid dose. Clinical providers adjusted linezolid dose and dosing interval targeting a trough &lt; 2ug/ml and peak of 12–26ug/ml.

Results
Among 64 BPaL patients, ages were 15–83 years, 22 (34.3%) were female, 6 (9.3%) U.S.-born, 4 (6.3%) HIV-infected. 50 (78.1%) had only pulmonary disease, 6 extrapulmonary, and 8 had both; 61 (91.0%) were culture-confirmed. Most (n=62) started linezolid 600mg daily. Linezolid was adjusted for 39 (66.1%) of the 59 patients with TDM; 18 had a trough &gt;2ug/ml, 30 had dosing interval increased to thrice-weekly, and 17 had a dose increase. 52 (81.3%) patients completed BPaL and 12 remain on therapy. One 81-year-old female with diabetes, hypothyroidism, and B12 deficiency discontinued linezolid at 12 weeks for worsened neuropathy (linezolid trough=1.13ug/ml). She completed 26 weeks of bedaquiline/pretomanid and her symptoms returned to baseline.

Conclusion
Use of BPaL with clinical and TDM monitoring has transformed treatment of rifampin-resistant or intolerant TB in the U.S. Patients previously sentenced to 18–24 months of treatment with 5–7 hard-to-tolerate medications and modest efficacy can now complete treatment in 6–9 months with little toxicity and exceptional cure rates.

Disclosures
All Authors: No reported disclosures.
2358. Dementia and Cognitive Concerns are Risk Factors for Mortality in People with Human Immunodeficiency Virus and COVID-19
Authors: Mukerji Shibani S , Wilcox Douglas R , Rudmann Emily A , Ye Elissa , Noori Ayush , Magdamo Colin , Alabsi Haitham , Triant Virginia A , Robbins Gregory , Brandon Westover M , Das Sudeshna 
Published: December 2022

Abstract

Background
Despite higher prevalence of cognitive disorders in people with human immunodeficiency virus (PWH) and dementia being a risk factor for COVID-19 mortality, the association between dementia and adverse outcomes in PWH with COVID-19 has not been well established.

Methods
This was a matched case-control study (1:10) of patients with and without HIV at an academic institution with documented SARS-CoV-2 polymerase chain reaction (PCR) positivity from March 2020-March 2021. Data were extracted from the electronic health record data registry. PWH were matched to people without HIV (PWoH) by age, sex, race, and zip code. The primary exposures were dementia (identified using International Classification of Diseases, Tenth Revision codes) and cognitive concerns, defined as documentation of possible cognitive impairment up to 12 months prior to COVID-19 diagnosis and ascertained using a semi-automated natural language processing annotation tool. VACS 2.0 Index (including age, sex, body mass index, CD4+ T-cell count and HIV-1 RNA) was calculated. Logistic regression models assessed the effect of dementia and cognitive concerns on the odds of death (OR [95% confidence interval]), adjusted for VACS 2.0 Index.

Results
Sixty-four (0.45%) PWH were identified among 14129 patients with COVID-19 and were matched to 463 PWoH. Among PWH, 59% were virally suppressed, and 14% had CD4&lt; 200 cells/μL. Compared to 463 matched PWoH, PWH had higher prevalence of dementia (16% vs. 6%, p=0.01) and cognitive concerns (22% vs. 16%, p=0.04). Death was more frequent in PWH (17% vs. 6%, p&lt; 0.01) and at younger ages (58 vs. 66 years, p=0.03). Cognitive concerns (2.5 [1.1–5.9], p=0.03) and dementia (3.4 [1.3–8.1], p=0.01) were significantly associated with increased adjusted odds of death in the overall group. Among PWH, cognitive concerns (7.2 [1.1–48], p=0.04) and dementia (6.0 [0.8–43.8], p=0.08) remained associated with mortality.

Conclusion
Dementia and cognitive concerns were associated with mortality among PWH with COVID-19. The magnitude of the effect of cognitive impairment on COVID-19 outcomes may be greater in HIV, and additional studies with larger cohorts will help to assess this association further. Assessment of cognitive status is an important component to care for aging PWH in the COVID-19 era.

Disclosures
All Authors: No reported disclosures.
2090. The Impact of Structural Racism and Discrimination on the HIV Pre-exposure Prophylaxis Continuum: Evidence from a Systematic Review of the Published Literature
Authors: Ghadimi Fatemeh , Seyedroudbari Sara , Nkwihoreze Hervette , Momplaisir Florence 
Published: December 2022

Abstract

Background
Pre-exposure prophylaxis (PrEP) is an evidence-based intervention shown to effectively reduce HIV infection. However, PrEP is under-utilized, especially among racial and ethnic minority groups where HIV incidence is the highest. Here, we aim to describe the impact of structural racism and discrimination (SRD) on the PrEP continuum.

Methods
We performed a systematic review of the published literature using MEDLINE database for keywords such as HIV, PrEP, racism, and healthcare disparities. Inclusion criteria were original, U.S.-based studies in English published since 2012. Our main exposure was SRD defined as a socially structured action that is unfair and harms individuals and groups on the basis of race, ethnicity and/or other statuses. Outcome measures included ≥ 1 step of the PrEP continuum. Qualitative analyses were excluded.

Results
The search returned 297 papers, from which 37 studies met inclusion criteria. SRD was described at the individual level in 1 studies, at the interpersonal in 17 studies, and the societal level in 15 studies with some studies including multiple levels of SRD. In 4 studies, there were no reported differences by race and 1 study reported no differences by neighborhood socioeconomic status. Disparities were observed across each step of the PrEP continuum with Black and Hispanic patients being less likely to have a discussion about PrEP, less likely to receive a PrEP prescription and less likely to adhere or be retained in PrEP care compared to White patients. In two large studies, race-based differences in PrEP prescription were particularly stark: one study with 25,886 patients reported that Black race was found to be an independent factor for non-PrEP prescription and the other with 32,853 patients found that PrEP prescription was 6 times higher among Whites compared to Black patients. Potential mediators to poor PrEP continuum outcomes included perceived healthcare-related discrimination, provider related implicit bias and racial stereotypes, housing instability, food insecurity, insurance status, and history of incarceration.

Conclusion
SRD at multiple levels contribute to racial disparities across the PrEP continuum. Strategies that reduce SRD may help to mitigate racial/ethnic disparities in PrEP continuum outcomes.

Disclosures
All Authors: No reported disclosures.
2101. CMV Infections in Multiple Myeloma Patients
Authors: Ilyas Sahrish , Jacobs Samantha E , Rana Meenakshi , Baneman Emily 
Published: December 2022

Abstract

Background
Substantial progress in the treatment of multiple myeloma (MM) has led to improved patient outcomes and prolonged survival of patients. These therapeutic advances have resulted in increased cumulative immunosuppression leading to increased susceptibility to opportunistic infections including CMV infection. The significance of CMV infection in MM patients is not well understood. We sought to describe the clinical characteristics and outcomes of patients with MM who develop CMV infection.

Methods
Retrospective chart review of MM patients at Mount Sinai Hospital in NY who had CMV DNA PCR sent. The Mount Sinai Multiple Myeloma Database was utilized to identify patients who developed CMV viremia. Demographic, clinical and laboratory data were abstracted from electronic medical records. IRB approval was obtained.
Statistical Analysis
Factors associated with 30-day mortality by univariate analysis were evaluated using Fischer’s exact and Wilcoxon rank-sum test.

Results
Demographics
414 MM patients had CMV PCR sent at least once. Forty-six cases of CMV infection were identified.
CMV Infection Characteristics
Forty-six patients were found to have CMV viremia, defined as PCR &gt;500 IU/mL. Twenty-two (47%) had symptomatic infection. One patient had CMV pneumonitis and in 7/46 (15%) patients, CMV end-organ disease was suspected. Twenty (43%) patients had progressive disease status, 73% had prior history of autologous stem cell transplant and 85% had received steroids within 30 days of CMV infection. Twenty-nine (63%) patients had concurrent infections within 30 days of CMV infection, including bloodstream infection (n=16), bacterial pneumonia (n=9), respiratory viral infection (n=6), infectious colitis (n=5), and fungal infection (n=3).
Outcomes
9/46 (19%) patients died within 30 days of CMV infection and 12/46 (26%) required ICU admission during that hospitalization. In univariate analysis of risk factors associated with mortality, higher weekly steroid dose approached statistical significance (p=0.06) and peak CMV PCR &gt;1000 IU/mL (p.008) was associated with lower mortality.

Conclusion
CMV infection is associated with morbidity and mortality in MM patients. Prospective studies are needed to better assess the clinical significance of CMV reactivation in this population.

Disclosures
Emily Baneman, MD, Merck: Grant/Research Support.
128. Association of PBP4 Variants and β-lactam Susceptibility in Enterococcus faecalis
Authors: Tran Truc Cecilia , Simar Shelby R , Egge Stephanie L , Atterstrom Rachel , Dinh An , Hanson Blake M , Contreras German , Zervos Marcus , Abbo Lilian M , Shimose Luis , Shelburne Samuel A , Arias Cesar A , Miller William R 
Published: December 2022

Abstract

Background
Penicillin-binding protein 4 (PBP4) is a low affinity PBP that has been associated with decreased susceptibility to penicillins in Enterococcus faecalis (Efs). In vitro data have shown that changes in the promoter region leading to increased pbp4 gene expression and amino acid changes resulting in active site remodeling contribute to this phenotype. There is limited data on the prevalence of these strains in the United States. We investigated β-lactam susceptibility trends in association with variations in PBP4 (allotypes) and the upstream promoter region.

Methods
Efs bloodstream isolates (n=184) were selected from the multicenter VENOUS cohort from 2016 to 2021. Whole genome sequencing (WGS) was performed on all isolates, and changes in the pbp4 gene and promoter region 200 bp upstream of the start codon were identified using Efs JH2-2 as reference. Broth microdilution (BMD) testing for ampicillin (AMP), penicillin (PCN), piperacillin (PIP), and imipenem (IMI) was performed for 81 isolates. Analysis of MICs vs. WGS results was performed.

Results
A total of 31 PBP4 allotypes and 10 promoter variations were identified. ST6 isolates most frequently carried the promoter mutation ΔA117 (P6), previously shown to increase expression of the pbp4 gene, with allotype 1 PBP4 (Fig 1). ST179 isolates most frequently carried the JH2-2 wild type promoter (P1) with the allotype 30 PBP4. All isolates were susceptible to AMP (MIC50 ≤1 µg/mL, MIC90 2 µg/mL) and PCN (MIC50 ≤2 µg/mL, MIC90 4 µg/mL; Table 1). PIP was the least potent β-lactam, with an MIC50 4 µg/mL and an MIC90 of 8 µg/mL. Isolates with the P6 promoter had significantly higher piperacillin MICs (p&lt; 0.0001) as compared to P1. Figure 1.Phylogenetic Tree of E. faecalis Strains

Conclusion
Changes in the pbp4 gene promoter correlated with an increase in PIP MICs. Caution should be used when choosing β-lactams other than AMP for definitive treatment deep-seated Efs infections.

Disclosures
Cesar A. Arias, MD, PhD, Entasis Phramceuticals: Grant/Research Support|MeMed Diagnostics: Grant/Research Support|Merck: Grant/Research Support William R. Miller, MD, Entasis Therapeutics: Grant/Research Support|UpToDate: Royalties - Topic Contributor.
153. Molnupiravir Exhibits a High Barrier to the Development of SARS-CoV-2 Resistance in vitro
Authors: Strizki Julie , Murgolo Nicholas , Gaspar John , Howe John , Hutchins Beth , Mohri Hiroshi , Ho David D , Hazuda Daria , Grobler Jay 
Published: December 2022

Abstract

Background
Molnupiravir is an orally available prodrug of the antiviral nucleoside analog N-Hydroxycytidine (NHC). In preclinical studies NHC has shown broad-spectrum antiviral activity against multiple RNA viruses including SARS-CoV-2. Incorporation of NHC by viral polymerases impairs replication by introducing errors into the viral genome. NHC has been shown to have a high barrier to the development of resistance in vitro with RSV, Influenza and Venezualen Equine Encephalitis viruses. In these studies, we have explored the potential for SARS-CoV-2 to develop resistance to NHC in cell culture.

Methods
Vero E6 cells were infected with SARS-CoV-2 (WA-1) in triplicate in the presence of NHC or a C3L-protease inhibitor (MRK-A). Culture supernatants from wells with the highest drug concentration exhibiting a cytopathic effect (CPE) score of ≥ 2+ were repassaged and at each passage, IC50 values were estimated based on CPE scoring. At each passage, full genome next generation sequencing (NGS) was performed on the viral RNA

Results
No change in susceptibility to NHC (EC50 fold change ≤ 1.1) was noted in 2 of 3 cultures and a 2-fold change was observed in one culture after 30 passages. In contrast, a 3- to 4-fold decreases in susceptibility to the 3CL protease inhibitor were seen by passage by 12, with increasing resistance of 4.6- to 15.7-fold observed by passage 30. NHC passaged viruses exhibited 53 to 99 amino acid changes, including substitutions and deletions (both in-frame and frameshift), across 25 different viral proteins as compared with 10 to 13 changes in 13 proteins in the MRK-A cultures. With NHC, 3 to 4 changes were observed in the viral polymerase; however, these were randomly distributed, and none were observed more than once. In contrast, the 3CL protease passaged virus had a nsp5 T21I substitution detected in all 3 cultures.

Conclusion
No evidence of SARS-CoV-2 phenotypic or genotypic resistance was observed following 30 passages with NHC. A random pattern of amino acid changes were observed across multiple proteins consistent with the mechanism of action of NHC. In the same study, resistance was readily selected to a control 3CL protease inhibitor. Together these data support previous reports demonstrating the high barrier to resistance of NHC.

Disclosures
Julie Strizki, PhD, Merck and Co.: Stocks/Bonds Nicholas Murgolo, PhD, MERCK: Employee|MERCK: Stocks/Bonds John Howe, PhD, Merck & Co Inc: Employee|Merck & Co Inc: Stocks/Bonds Beth Hutchins, PhD, Merck & Co.: Employee|Merck & Co.: Stocks/Bonds Hiroshi Mohri, PhD/MD, Merck: Grant/Research Support Daria Hazuda, PhD, Merck: Employee|Merck: Stocks/Bonds Jay Grobler, PhD, Merck & Co., Inc.: Employee|Merck & Co., Inc.: Stocks/Bonds.