bluuebunny/crossref_metadata_2025_split huggingface dataset:
645. Singulex Clarity Norovirus Assay (In Development) Provides Ultrasensitive Detection of Norovirus Genogroups I and II
Authors: Dave Gipshu , Katzenbach Phoebe , Sandlund Johanna , Estis Joel , Mukherjee Ali , Nolan Niamh , Almazan Anna , Hadass Orr , Noland Brian , Bishop Jeffrey J , Banaei Niaz , Riner Diana K , Todd John 
Published: October 2019

Abstract

Background
Commercially available enzyme immunoassays (EIAs) for detection of norovirus antigen have poor sensitivity and are limited to use in investigations of a gastroenteritis outbreak. Hence, there remains a need for a standalone high-sensitivity assay that enables rapid and accurate detection of norovirus antigen.

Methods
The Singulex Clarity norovirus assay is currently in development for use on the Singulex Clarity® system (Singulex Inc., Alameda, CA, USA), a fully-automated platform powered by Single Molecule Counting technology (registered with the FDA and CE marked). The assay uses paramagnetic microparticles bound to capture antibody and a fluorescently labeled reporter antibody to detect virion capsid protein of norovirus genogroups I (GI) and II (GII) in the stool. For the development of Clarity Norovirus assay, diagnostic performance of 4 antibody pairs (as Capture and Detection reagent) were evaluated by testing 137 stool samples from patients with suspected norovirus infection. Samples were sourced from three providers: (1) 90 genotyped samples of which 75 were positive (19 different genotypes) and 15 were negative by the CDC assay, (2) 3 samples positive and 5 samples negative by the BioFire® FilmArray® Gastrointestinal Panel, and (3) 39 samples negative by a lab-developed test using Cepheid reagents (SmartCycler®).

Results
From all the antibody pairs tested, one of the pairs had best performance with the area under the receiver operating characteristic (AuROC) curve demonstrating a C-Statistic of 0.959 (95% CI 0.921–0.997), compared with AuROC C-statistic of 0.943 (95% CI 0.896–0.990), 0.871 (95% CI 0.807–0.936), and 0.914 (95% CI 0.863–0.964) for the three other pairs. The Clarity assay detected all 19 different genotypes tested (figures).

Conclusion
The ultrasensitive and rapid Clarity norovirus assay (in development) for detection of GI and GII demonstrated excellent performance with one of the antibody pairs tested and detected all 19 tested genotypes. The Clarity assay may offer a standalone solution for norovirus diagnostics.

Disclosures
All authors: No reported disclosures.
651. Multi-Center Evaluation of the BioFire® FilmArray® Blood Culture Identification 2 Panel for the Detection of Microorganisms and Resistance Markers in Positive Blood Cultures
Authors: Lu Yang , Hatch Joseph , Holmberg Kristen , Hurlock Anna , Drobysheva Daria , Spaulding Usha , Vourli Sophia , Pournaras Spyridon , Everhart Kathy , Leber Amy , Barr Becki , Daly Judy , Henry Tai , Johnson Amy , Balada-Llasat Joan-Miquel , Rhoads Daniel D , Jacobs Michael , Mc Kinley Kathleen , Harrington Amanda , Zhang Frank , Berry Gregory J , Hyung Jeong Moon , She Rosemary , Sambri Vittorio , Fantini Michela , Dirani Giorgio , Zannoli Silvia , Bourzac Kevin 
Published: October 2019

Abstract

Background
The BioFire® FilmArray® Blood Culture Identification 2 (BCID2) Panel is a diagnostic test that provides results for 26 bacterial, 7 fungal pathogens and 10 antimicrobial resistance (AMR) genes from positive blood culture (PBC) specimens in about an hour. The BCID2 Panel builds upon the existing BCID Panel with several additional assays that include Candida auris and an expanded AMR gene menu that provides methicillin-resistant Staphylococcus aureus (MRSA) results plus detection for mcr-1, carbapenem resistance, and ESBL. Here, we summarize studies conducted to establish clinical performance using an Investigational Use Only version of the BCID2 Panel.

Methods
Three studies were performed. The first involves prospective collection and testing of an expected ~1,000 residual PBCs at 7 US and 2 EU sites, which began in October 2018 and will conclude in June 2019. BCID2 Panel performance is compared with reference methods of microbial culture as well as PCR/sequencing for AMR genes. In addition, BCID2 Panel MRSA results are compared with the FDA-cleared Xpert MRSA/SA BC system (Cepheid, Inc). Relevant bacterial isolates recovered from PBCs are also evaluated by various phenotypic antimicrobial susceptibility testing (AST) methods. The prospective evaluation is supplemented with a second study that involves testing of ~300 pre-selected, archived PBCs containing rare organisms. The third study includes over 500 seeded blood cultures containing very rare organisms with an evaluation of co-spiked samples.

Results
With over 1,200 samples tested to date (out of an anticipated 1,800 total), the BCID2 Panel has demonstrated an overall sensitivity of >98% and specificity of >99% for identification of microorganisms compared with culture. Concordance between the BCID2 Panel and the Xpert MRSA/SA BC test is >99% for identification of MRSA. Evaluation of BCID2 Panel AMR gene detection relative to AST and PCR is ongoing.

Conclusion
The FilmArray® BCID2 Panel appears to be a sensitive, specific, and robust test for rapid detection of microorganisms and MRSA in PBCs. With the use of this comprehensive test, improved antimicrobial stewardship is anticipated.

Disclosures
All authors: No reported disclosures
664. Efficacy in Adults With Moderate to Severe Community-Acquired Bacterial Pneumonia (CABP) and Pneumonia Outcomes Research Team (PORT) Risk Class III to V: Results of a Pooled Analysis of Lefamulin Evaluation Against Pneumonia (LEAP) 1 and LEAP 2 Study Outcomes
Authors: Alexander Elizabeth , Schranz Jennifer , Das Anita F , Moran Gregory J , Sandrock Christian , File Thomas M , Gelone Steven P 
Published: October 2019

Abstract

Background
CABP, the second most common cause of hospitalization in the US, has prognoses ranging from rapid resolution to death, the likelihood of which can be estimated via PORT pneumonia severity index. Patients with PORT scores ≤III have predicted mortality rates <3% and may be managed as outpatients; those with scores of IV/V are often hospitalized, owing to higher predicted mortality rates (8%–31%). Lefamulin (LEF), a novel systemic antibiotic, was noninferior to moxifloxacin (MOX) for treatment of adults with CABP in 2 phase 3 trials (LEAP 1 and 2). We report the results of pooled analyses of LEAP 1/2 data in patients with PORT III and IV/V scores.

Methods
In LEAP 1, patients (PORT III–V) received IV LEF 150 mg for 5–7 d or MOX 400 mg for 7 d, with optional IV-to-oral switch. In LEAP 2, patients (PORT II–IV) received oral LEF 600 mg for 5 d or MOX 400 mg for 7 d. In both studies, randomization was stratified by PORT score. The studies assessed early clinical response (ECR; 96±24 h after first dose) in the intent-to-treat (ITT; all randomized patients) population (FDA primary endpoint) and investigator assessment of clinical response (IACR) success at test of cure (5–10 d after last dose) in the modified ITT (received ≥1 dose) and clinically evaluable (met predefined evaluability criteria) populations (EMA coprimary endpoints).

Results
Over 50% of patients (52.8% LEF; 51.9% MOX) were PORT III and >18% (18.7% LEF; 18.2% MOX) were PORT IV/V, reflective of the CABP population. As expected, PORT IV/V patients were older and more likely to have comorbidities (eg, moderate/severe renal impairment) vs. PORT III patients (Table 1). ECR and IACR response rates were high and similar for LEF and MOX in PORT III (Figure 1) and PORT IV/V (Figure 2) patients, with slightly higher rates in PORT III vs. PORT IV/V patients. LEF and MOX had similar safety profiles, with more adverse events overall in PORT IV/V vs. PORT III patients (Table 2). Mortality rates were low, with higher rates in PORT IV/V (4.2% LEF; 5.2% MOX) vs. PORT III (1.5% LEF; 0.6% MOX) patients.

Conclusion
ECR and IACR rates with LEF were high and similar to MOX in patients who are candidates for outpatient (PORT III) and inpatient (PORT IV/V) treatment; LEF may be an alternative oral and IV monotherapy option for empiric CABP treatment in both populations.

Disclosures
All authors: No reported disclosures.
692. In Vitro Antibacterial Activity of Cefiderocol Against a Multi-national Collection of Carbapenem-Nonsusceptible Gram-Negative Bacteria From Respiratory Infections: SIDERO-WT-2014–2017
Authors: Rao Sonia N , Nguyen Sean T , Soriano Melinda M , Hayes Jennifer M , Hackel Meredith M , Sahm Daniel F , Tillotson Glenn S , Echols Roger , Tsuji Masakatsu , Yamano Yoshinori 
Published: October 2019

Abstract

Background
Cefiderocol (CFDC) is a new siderophore cephalosporin with potent in vitro activity against a broad range of Gram-negative (GN) pathogens, including carbapenem-nonsusceptible (Carb-NS) strains. We evaluated the in vitro activity of CFDC and comparator agents against recent clinical Carb-NS GN respiratory isolates collected from North America and Europe as part of the multi-national SIDERO-WT surveillance program.

Methods
A total of 2831 Carb-NS GN respiratory isolates collected from 2014 to 2017 were tested centrally (IHMA, Inc., Schaumburg, IL). Minimum inhibitory concentrations (MIC) were determined for CFDC, cefepime (FEP), ceftazidime–avibactam (CZA), ceftolozane-tazobactam (C/T), ciprofloxacin (CIP), colistin (CST), and meropenem (MEM) by broth microdilution and interpreted according to the 2018 CLSI guidelines. CFDC MICs were tested in iron-depleted cation-adjusted Mueller–Hinton broth, and interpreted according to the 2018 CLSI provisional breakpoints. Carb-NS strains were defined as MEM MIC of ≥2 µg/mL for Enterobacteriaceae (ENB) and of ≥4 µg/mL for nonfermenters (NF).

Results
CFDC exhibited predictable in vitro activity against 2807 clinically relevant Carb-NS GN isolates (214 ENB, 1086 A. baumannii complex, 693 P. aeruginosa, 794 S. maltophilia, and 20 Burkholderia cepacia) isolated from respiratory infections. CFDC was the most active agent against Carb-NS ENB with 97.7% susceptibility followed by 78.0% CZA, 59.4% CST, and 16.4% CIP. Against Carb-NS A. baumannii complex, CFDC demonstrated 94% susceptibility vs. 83.7% for CST. CFDC was the most active agent against Carb-NS P. aeruginosa with 99.9% susceptibility followed by 97.8% CST, 77.6% C/T, and 77.5% CZA. 99.7% of S. maltophilia and 100% of B. cepacia isolates had CFDC MICs of ≤4 µg/mL. The MIC90s of tested compounds for clinically relevant pathogens are shown in the table.

Conclusion
In a multinational collection of Carb-NS GN respiratory isolates, CFDC demonstrated potent in vitro activity with MIC90 of ≤4 µg/mL for all clinically relevant ENB and NF. These findings suggest that CFDC can be a potential option for the treatment of respiratory infections caused by Carb-NS ENB, A. baumannii complex, P. aeruginosa, S. maltophilia, and B. cepacia.

Disclosures
All authors: No reported disclosures.
700. Safety and Efficacy of Omadacycline in Patients with Diabetes in Phase 3 Clinical Studies
Authors: Pai Manjunath P , Wilcox Mark H , Curran Marla , Chitra Surya , Garrity-Ryan Lynne , McGovern Paul C 
Published: October 2019

Abstract

Background
The risk of serious infections and poor treatment outcomes is reported to be higher in patients with diabetes compared with the general population. Omadacycline (OMC) is an intravenous (IV) and oral aminomethylcycline antibiotic approved in the US to treat acute bacterial skin and skin structure infections (ABSSSI) and community-acquired bacterial pneumonia (CABP) in adults. Here we assessed safety and efficacy results from OMC Phase 3 studies (ABSSSI: Omadacycline in Acute Skin and skin structure Infections Study [OASIS]-1 and OASIS-2; CABP: Omadacycline for Pneumonia Treatment In the Community study [OPTIC]), by diabetes history.

Methods
In OASIS-1 (IV to optional oral medication) and OASIS-2 (oral only), patients were randomized to OMC or linezolid (LZD) for 7–14 days. In OPTIC, patients were randomized to IV OMC or moxifloxacin (MOX) for 7–14 days, with optional transition to oral medication. Data from OASIS-1 and OASIS-2 were pooled, and patient subgroups were defined by any medical history of diabetes (type 1, type 2, or unspecified), or no medical history of diabetes. Efficacy outcomes were early clinical response (ECR) and investigator’s assessment of clinical response at post-treatment evaluation (PTE), as defined for each indication. Safety was assessed by treatment-emergent adverse events (TEAEs) and laboratory measures, and data were pooled across the three studies.

Results
A total of 2,150 patients were included, of whom 238 (11.1%) had any history of diabetes (n = 105 for ABSSSI, n = 133 for CABP). In the pooled ABSSSI studies and the CABP study, clinical success at ECR and PTE was similar between patients with or without diabetes, and between OMC and the respective comparator (figure). TEAEs and serious TEAEs, respectively, were reported in similar numbers of OMC-, LZD-, and MOX-treated patients with diabetes (41.8–49.3%, 4.5–7.0%) and without (41.2–48.3%, 1.6–6.9%). Rates of nausea and vomiting, respectively, in patients with diabetes were similar across treatment arms: OMC (5.0%, 5.0%), LZD (7.5%, 6.0%), MOX (7.0%, 2.8%).

Conclusion
Omadacycline efficacy and safety were similar and consistent in patients with or without diabetes.

Disclosures
All authors: No reported disclosures.
709. In Vitro Antibacterial Activity and In Vivo Efficacy of Sulbactam–Durlobactam (ETX2514SUL) Against Pathogenic Burkholderia Species
Authors: O’Donnell John , Miller Alita , Lane Douglas , Panchal Rekha , Mueller John P 
Published: October 2019

Abstract

Background
The genus Burkholderia contains several pathogenic species with distinct etiologies, including Burkholderia pseudomallei the biothreat pathogen responsible for melioidosis and Burkholderia mallei which causes glanders. β-Lactams, such as ceftazidime and meropenem, are important therapeutic options for these infections. However, clinical resistance to β-lactams, which is primarily mediated by multiple types of β-lactamases in these species, is a growing concern. Durlobactam (ETX2514, DUR) is a novel β-lactamase inhibitor with broad-spectrum activity against Ambler class A, C, and D β-lactamases. Sulbactam (SUL) is an Ambler Class A β-lactamase inhibitor with intrinsic antibacterial activity against a limited number of species, including Acinetobacter spp. SUL-DUR is currently in Phase 3 clinical testing for the treatment of carbapenem-resistant infections caused by Acinetobacter spp. In this study, SUL-DUR was tested for in vitro antibacterial activity against B. pseudomallei and B. mallei as well as for in vivo efficacy in a preclinical model of melioidosis.

Methods
The antibacterial activity of SUL alone or in combination with DUR (fixed at 4 mg/L) against B. pseudomallei (n = 30) and B. mallei (N = 28) was determined following CLSI guidelines. In vivo efficacy was tested in an acute murine model of melioidosis in which 4 × 104 cfu Bp K96423 (SUL-DUR MIC = 1 mg/L) was administered intranasally to BalbC mice. SUL-DUR (100/200 or 400/200 mg/kg) was administered q4h subcutaneously 4 hours post-challenge for 6 days and murine survival was monitored for 45 days. Doxycycline (DOX) and ciprofloxacin (CIP) were dosed as positive controls at 40 mg/kg q12 h for 6 days.

Results
The addition of DUR effectively lowered the SUL MIC50/90 from 8/16 to 0.25/0.5 mg/L vs. B. pseudomallei and from 8/8 to 1/2 mg/L for B. mallei. All untreated mice in the melioidosis model succumbed to infection within 3 days of challenge. 60% survival was observed for both dose arms of SUL-DUR as compared with 40% survival observed for both CIP and DOX.

Conclusion
Preliminary preclinical data demonstrating robust in vitro and in vivo antibacterial activity of SUL-DUR against Burkholderia spp. suggests this combination may be an effective new therapy for the treatment of these challenging pathogens.

Disclosures
All authors: No reported disclosures.
725. WCK 5222 (Cefepime/Zidebactam): An In Vitro Assessment of Activity Compared with Current Dual-Antibiotic Options Against Multidrug-Resistant Pseudomonas aeruginosa
Authors: Mullane Elias M , Avery Lindsay M , Nicolau David P 
Published: October 2019

Abstract

Background
Pseudomonas aeruginosa (PSA) is an opportunistic pathogen known to cause complications in critically ill patients worldwide. In those at risk of infection with multidrug-resistant strains (MDR-PSA), dual antibiotic therapy is often considered. However, this practice may contribute to rising resistance rates and poor outcomes if empirical selection is suboptimal. WCK 5222 (cefepime/zidebactam), a novel β-lactam/β-lactam enhancer, may offer a solution.

Methods
Minimum inhibitory concentrations (MICs) were determined for WCK 5222, amikacin (AMK), fosfomycin (FOF), cefepime (FEP), ceftolozane/tazobactam (C/T), and meropenem (MEM) against 18 clinical PSA isolates using gradient diffusion strip (GDS) methods. Activities of FEP, C/T, and MEM in combination with AMK and FOF were assessed using GDS for isolates nonsusceptible to the β-lactam (MICs >8 mg/L, >4/4 mg/L, and >2 mg/L, respectively). Synergy was defined as a fractional inhibitory concentration index ≤ 0.5. Instances of restored β-lactam susceptibility when tested in combination were compared with the proportion of WCK 5222 MICs ≤ 8 mg/L.

Results
WCK 5222 MICs ranged from 2 to 32 mg/L (MIC50, 8 mg/L). Rates of susceptibility were: AMK (67%), FOF (44%, MIC ≤ 64 mg/L), FEP (6%), C/T (33%), MEM (0%). Combinations with C/T most frequently demonstrated synergy (C/T-FOF, 42%; C/T-AMK, 33%) and restored C/T susceptibility was observed in 42% of assessments with FOF and in 50% with AMK. For FEP combinations, synergy was observed in 29% and 18% of assessments with FOF and AMK, respectively, with restored susceptibility in 6% for both combinations. Synergy occurred in 11% and 6% of assessments of MEM with FOF and AMK, respectively, with zero instances of restored susceptibility. In total, β-lactam susceptibility was restored in 14% (13/94) of combinations compared with 78% (14/18) of WCK 5222 MICs ≤ 8 mg/L.

Conclusion
In a selection of MDR-PSA isolates that included carbapenem- and C/T-resistant strains, WCK 5222 MICs ≤ 8 mg/L (cefepime susceptible) were observed more frequently than restoration of susceptibility in select β-lactams in combination with FOF or AMK. WCK 5222 monotherapy may offer enhanced coverage of MDR-PSA over empirically selected combination therapies.

Disclosures
All authors: No reported disclosures.
728. Activity of Eravacycline Against Contemporary Gram-Negative Clinical Isolates From New York City Hospitals
Authors: Iregui Alejandro , Khan Zeb , Landman David , Quale John M 
Published: October 2019

Abstract

Background
Antibiotic-resistant Gram-negative bacteria, including KPC-producing Enterobacteriaceae and carbapenem-resistant A. baumannii, have been problematic hospital pathogens in NYC and other areas. Eravacycline (ERV), a fluorocycline antibiotic released in the USA in 2018, has demonstrated in vitro activity against many of these strains. We tested the activity of ERV against a recent collection of clinical isolates from NYC hospitals.

Methods
For a 3-month period in 2017, all unique patient isolates of E. coli, K. pneumoniae, Enterobacter spp., and A. baumannii were collected from 7 hospitals in Brooklyn, NY. MICs were performed by broth microdilution for ERV and Tigecycline (TGC) and agar dilution for other antibiotics according to CLSI methodology. Cephalosporin-resistant isolates were screened by PCR for common carbapenemases.

Results
The susceptibility results for tetracycline and ERV are listed in the Table. Overall, 95% of the Enterobacteriaceae were inhibited by ≤ 0.5 μg/mL of ERV, the FDA-suggested breakpoint. Of 1,876 isolates of E. coli, 4 possessed KPC. ERV MICs for these 4 isolates were 0.125–0.25 μg/mL. Of 518 isolates of K. pneumoniae, 20 possessed KPC. The ERV MIC50 and MIC90 for these isolates were 1 and 1 μg/mL, respectively. Of 172 isolates of Enterobacter spp., 3 possessed KPC. ERV MICs for these 3 isolates were 0.5–1 μg/mL. Of 45 isolates of A. baumannii, 11 isolates possessed a carbapenemase (OXA23 in 8, OXA24 in 2, and KPC in 1). The ERV MIC50 and MIC90 for these isolates were 1 and 2 μg/mL, respectively. Overall, ERV MICs were two-fold lower than TGC MICs for A. baumannii.

Conclusion
ERV possesses significant in vitro activity against contemporary clinical isolates of Enterobacteriaceae and A. baumannii from NYC, including many carbapenemase producing strains.

Disclosures
All authors: No reported disclosures.
731. Pharmacokinetics of Gepotidacin (GSK2140944) in Subjects with Hepatic Impairment
Authors: Hands Jonathan T , Tao Yu , Tiffany Courtney , Perry Caroline R , Dumont Etienne , Hossain Mohammad 
Published: October 2019

Abstract

Background
Gepotidacin (GEP), a first in class novel triazaacenaphthylene bacterial topoisomerase inhibitor, inhibits bacterial replication and has in vitro and in vivo efficacy activity against key pathogens, including drug-resistant strains, associated with a range of infections. In a previous absorption, distribution, metabolism, and excretion study for GEP, the mean recovery of radioactivity in urine and feces accounted for approximately 31.2% and 52.5%, respectively, of [14C]-GEP administered as a single oral dose. GEP was eliminated mainly as parent in urine, accounting for approximately 20% of the administered dose. Elimination via metabolism accounted for a total of 13% to 19% of the dose. Average total intravenous clearance of approximately 43 L/hour and renal clearance (CLr) of approximately 16 L/hour provides a hepatic clearance of 27 L/hour, suggesting that hepatic clearance is a major route of elimination of GEP.

Methods
Participants with normal and varying degrees of hepatic impairment (HI) received a single oral dose of GEP 1,500 mg. PK collections of blood, urine and saliva were performed.

Results
Relative to normal hepatic function, GEP Cmax and AUC(0-∞) in plasma were increased by 1.2-fold in subjects with moderate, and between 1.7-fold to 1.9-fold in severe HI. The fraction of dose excreted in urine increased with an increase in hepatic impairment. GEP urine concentrations remained high over a 12-hour period. Saliva concentrations displayed a linear relationship with plasma (both total and unbound) concentrations (R2 = 0.76). The geometric mean ratio of saliva AUC to unbound plasma AUC values ranged from 0.746 to 0.839 across all groups. Administration of 1,500 mg oral GEP was generally tolerated.

Conclusion
An increase in the dosing interval or dose reduction may be required in patients with severe hepatic impairment.

Disclosures
All authors: No reported disclosures.