Citations 17
Benchmarking four commercial antimicrobial susceptibility testing systems and disk diffusion to reference broth microdilution in the assessment of gram-negative bacterial isolates
Rhoads, Daniel D. , Sherman, Jingzi , Baker, Kristin, Culbreath, Karissa , McElvania, Erin , Harrington, Amanda, Streva, Vincent , Marino, Jamie , Westblade, Lars F. , Stern, Eric J. , Simner, Patricia J. , Culbreath, Karissa , McElvania, Erin , Streva, Vincent , Marino, Jamie , Westblade, Lars F , Stern, Eric , Simner, Patricia J , Rhoads, Daniel D , Chen, Felicia , Harrington, Amanda
Journal of Clinical Microbiology | September 9, 2026 | Volume: 64 | Issue: 10 | Pages: No page available
ABSTRACT Commercial antimicrobial susceptibility testing (AST) systems for gram-negative bacteria provide operational advantages over reference broth microdilution (BMD) testing, but the results produced by commercial AST systems might not be as accurate as the reference method. Assessing and comparing the performance of AST systems can be informative for clinical microbiology practice. In total, 280 clinical isolates and 100 isolates from the U.S. Centers for Disease Control and Prevention Antimicrobial Resistance Isolate Bank, including Enterobacterales and Pseudomonas aeruginosa, were intended to be tested using disk diffusion (DD) and automated commercial AST systems, such as Selux AST System (Selux Diagnostics), MicroScan (Beckman Coulter), Phoenix (Becton, Dickinson and Company), and Vitek 2 (bioMérieux). These results were compared to BMD as the reference standard. In total, 372 isolates were assessed. For Enterobacterales, the greatest frequency of very major errors was identified with cefepime by Vitek 2 (29.0%) and ertapenem by DD (9.1%); essential agreement less than 90% was identified with the following combinations: aztreonam by MicroScan (86.4%), aztreonam by Vitek 2 (88.9%), cefepime by Selux (86.3%), cefepime by Vitek 2 (76.8%), ceftazidime by Vitek 2 (89.9%), and levofloxacin by MicroScan (83.4%). For P. aeruginosa , essential agreement less than 90% was identified with the following combinations: gentamicin by Selux (87.2%), tobramycin by Selux (86.6%), and ciprofloxacin by Phoenix (88.4%). Overall, antimicrobials that had low demonstrable bias across all automated commercial AST systems included ampicillin, amoxicillin-clavulanate, ceftazidime-avibactam, ertapenem, and trimethoprim-sulfamethoxazole. Comparing commercial testing systems head-to-head against a reference standard provides insight into the strengths and weaknesses of the performance of these test systems, and these insights can subsequently inform local decisions regarding further investigations and potential operational mitigation strategies. IMPORTANCE This study assessed and compared the performance of multiple commercial antimicrobial susceptibility testing (AST) systems and disk diffusion methods. The accuracy of determining minimum inhibitory concentrations or zone diameters of antimicrobials and the associated interpretive categories were studied for 372 isolates of Enterobacterales and Pseudomonas aeruginosa . Performance of the evaluated systems revealed that multiple antimicrobial-organism combinations were below the standards typically required by regulatory agencies and clinical laboratories. These deficiencies varied across the commercial platforms and disk diffusion methods, highlighting the importance of benchmarking studies that compare the performance using identical isolates. These identified performance weaknesses may warrant further study and/or the implementation of mitigation strategies in clinical laboratory operations to prevent the reporting of errant results.
ARGONAUT-IV: susceptibility of carbapenemase-producing Klebsiella pneumoniae to the oral bicyclic boronate β-lactamase inhibitor ledaborbactam combined with ceftibuten
Jacobs, Michael R. , Good, Caryn E., Abdelhamed, Ayman M., Mack, Andrew R , Bethel, Christopher R. , Marshall, Steven H. , Hujer, Andrea M. , Hujer, Kristine M., Patel, Robin , Fowler, Vance G., Rhoads, Daniel D. , Six, David A. , Papp‐Wallace, Krisztina M. , van Duin, David , Rhoads, Daniel D , Six, David A , Moeck, Greg , Uehara, Tsuyoshi , Papp-Wallace, Krisztina M , Bonomo, Robert A , Patel, Robin , Hujer, Kristine M., Fowler, Vance G. , Uehara, Tsuyoshi , Bonomo, Robert A.
Antimicrobial Agents and Chemotherapy | October 30, 2024 | Volume: 68 | Issue: 12 | Pages: No page available
ABSTRACT Ledaborbactam (formerly VNRX-5236), a bicyclic boronate β-lactamase inhibitor with activity against class A, C, and D β-lactamases, is under development as an orally bioavailable etzadroxil prodrug (VNRX-7145) in combination with ceftibuten for the treatment of urinary tract infections. At ceftibuten breakpoints of ≤1 mg/L (EUCAST) and ≤8 mg/L (CLSI), 92.5% and 99.0%, respectively, of 200 carbapenem-resistant Klebsiella pneumoniae isolates, predominantly K. pneumoniae carbapenemase producing, were susceptible to ceftibuten-ledaborbactam (ledaborbactam tested at a fixed concentration of 4 mg/L) compared to 4.5% and 30.5%, respectively, to ceftibuten alone.
ARGONAUT-III and -V: susceptibility of carbapenem-resistant Klebsiella pneumoniae and multidrug-resistant Pseudomonas aeruginosa to the bicyclic boronate β-lactamase inhibitor taniborbactam comb
Jacobs, Michael R. , Abdelhamed, Ayman M., Good, Caryn E., Mack, Andrew R , Bethel, Christopher R. , Marshall, Steven H. , Hujer, Andrea M. , Hujer, Kristine M., Patel, Robin , Fowler, Vance G. , Rhoads, Daniel D. , Six, David A. , Uehara, Tsuyoshi , Papp‐Wallace, Krisztina M. , van Duin, David , Rhoads, Daniel D , Six, David A , Moeck, Greg , Uehara, Tsuyoshi , Papp-Wallace, Krisztina M , Bonomo, Robert A , Patel, Robin , Fowler, Vance G. , Bonomo, Robert A.
Antimicrobial Agents and Chemotherapy | August 12, 2024 | Volume: 68 | Issue: 9 | Pages: No page available
ABSTRACT Taniborbactam, a bicyclic boronate β-lactamase inhibitor with activity against Klebsiella pneumoniae carbapenemase (KPC), Verona integron–encoded metallo-β-lactamase (VIM), New Delhi metallo-β-lactamase (NDM), extended-spectrum beta-lactamases (ESBLs), OXA-48, and AmpC β-lactamases, is under clinical development in combination with cefepime. Susceptibility of 200 previously characterized carbapenem-resistant K. pneumoniae and 197 multidrug-resistant (MDR) Pseudomonas aeruginosa to cefepime-taniborbactam and comparators was determined by broth microdilution. For K. pneumoniae (192 KPC; 7 OXA-48-related), MIC 90 values of β-lactam components for cefepime-taniborbactam, ceftazidime-avibactam, and meropenem-vaborbactam were 2, 2, and 1 mg/L, respectively. For cefepime-taniborbactam, 100% and 99.5% of isolates of K. pneumoniae were inhibited at ≤16 mg/L and ≤8 mg/L, respectively, while 98.0% and 95.5% of isolates were susceptible to ceftazidime-avibactam and meropenem-vaborbactam, respectively. For P. aeruginosa , MIC 90 values of β-lactam components of cefepime-taniborbactam, ceftazidime-avibactam, ceftolozane-tazobactam, and meropenem-vaborbactam were 16, >8, >8, and >4 mg/L, respectively. Of 89 carbapenem-susceptible isolates, 100% were susceptible to ceftolozane-tazobactam, ceftazidime-avibactam, and cefepime-taniborbactam at ≤8 mg/L. Of 73 carbapenem-intermediate/resistant P. aeruginosa isolates without carbapenemases, 87.7% were susceptible to ceftolozane-tazobactam, 79.5% to ceftazidime-avibactam, and 95.9% and 83.6% to cefepime-taniborbactam at ≤16 mg/L and ≤8 mg/L, respectively. Cefepime-taniborbactam at ≤16 mg/L and ≤8 mg/L, respectively, was active against 73.3% and 46.7% of 15 VIM- and 60.0% and 35.0% of 20 KPC-producing P. aeruginosa isolates. Of all 108 carbapenem-intermediate/resistant P. aeruginosa isolates, cefepime-taniborbactam was active against 86.1% and 69.4% at ≤16 mg/L and ≤8 mg/L, respectively, compared to 59.3% for ceftolozane-tazobactam and 63.0% for ceftazidime-avibactam. Cefepime-taniborbactam had in vitro activity comparable to ceftazidime-avibactam and greater than meropenem-vaborbactam against carbapenem-resistant K. pneumoniae and carbapenem-intermediate/resistant MDR P. aeruginosa .
Reply to Kidd et al., “Inconsistencies within the proposed framework for stabilizing fungal nomenclature risk further confusion”
Walsh, Thomas J. , Ahmed, Sarah , Alastruey‐Izquierdo, Ana , Alexander, Barbara D. , Arendrup, Maiken Cavling , Babady, Esther , Balada-Llasat, Joan-Miquel, Borman, Andrew M. , Colgrove, Robert C. , Cornely, Oliver A. , Fuller, Jeff, Gibas, Connie Fe C., Glasgow, Heather, Groll, Andreas H. , Haase, Gerhard , Hanson, Kimberly E. , Harrington, Amanda, Hayden, Randall T. , Hubka, Vít , Johnson, Kristie, Li, Ruoyu , Lanternier, Fanny , Lee, Francesca , Luethy, Paul M. , Kwon‐Chung, Kyung J., Palavecino, Elizabeth , Pancholi, Preeti , Pappas, Peter G. , Procop, Gary W. , Rhoads, Daniel D. , Riedel, Stefan , Stevens, Bryan S. , Sullivan, Kaede Ota, Vergidis, Paschalis , Roilides, Emmanuel , Seyedmousavi, Amir, Tao, Lili , Vicente, Vânia Aparecida , Vitale, Roxana G. , Wengenack, Nancy L. , Westblade, Lars F. , White, Lewis, Wojewoda, Christina , Babady, N. Esther , Seyedmousavi, Seyedmojtaba , de Hoog, Sybren , Walsh, Thomas J , Alastruey-Izquierdo, A , Arendrup, Maiken Cavling , Borman, Andrew , Groll, Andreas H , Hanson, Kimberly , Hayden, Randall T , Hoenigl, Martin , Kus, Julianne V , Meis, Jacques F , Leal, Sixto M , Lockhart, Shawn R. , Kwon-Chung, Kyung J , Nguyen, M Hong , Palavecino, Elizabeth , Pancholi, Preeti , Rhoads, Daniel D , Riedel, Stefan , Vergidis, Paschalis , Roilides, Emmanuel , Wengenack, Nancy L , Wiederhold, Nathan , White, Lewis , Wojewoda, Christina M , Zhang, Sean X , Cornely, Oliver A , Ahmed, Sarah A , Luethy, Paul , Bai, Feng‐Yan , Chowdhary, Anuradha , Clark, Andrew, Dingle, Tanis C. , Dufresne, Philippe J. , Gangneux, Jean‐Pierre , Gräser, Yvonne , Guillot, Jacques , Hawksworth, David L. , Hoenigl, Martin , Kus, Julianne V. , Lackner, Michaela , Leal, Sixto M. , Martin, Isabella W. , Meyer, Wieland , Ostrosky‐Zeichner, Luis , Redhead, Scott A. , Stevens, Bryan, Wang, Qiming , Wiederhold, Nathan P. , Zhang, Sean X.
Journal of Clinical Microbiology | March 5, 2024 | Volume: 62 | Issue: 4 | Pages: No page available
A conceptual framework for nomenclatural stability and validity of medically important fungi: a proposed global consensus guideline for fungal name changes supported by ABP, ASM, CLSI, ECMM, ESCMID-EFISG, EUCAST-AFST, FDLC, IDSA, ISHAM, MMSA, and MSGERC
Walsh, Thomas J. , Ahmed, Sarah , Alastruey‐Izquierdo, Ana , Alexander, Barbara D. , Arendrup, Maiken Cavling , Babady, Esther , Balada-Llasat, Joan-Miquel, Borman, Andrew M. , Colgrove, Robert C. , Cornely, Oliver A. , Fuller, Jeff, Gibas, Connie Fe C., Glasgow, Heather, Gräser, Yvonne , Groll, Andreas H. , Haase, Gerhard , Hanson, Kimberly E. , Harrington, Amanda, Hayden, Randall T. , Hubka, Vít , Johnson, Kristie, Li, Ruoyu , Lanternier, Fanny , Leal, Sixto M. , Lee, Francesca , Luethy, Paul M. , Kwon‐Chung, Kyung J., Palavecino, Elizabeth , Pancholi, Preeti , Pappas, Peter G. , Procop, Gary W. , Rhoads, Daniel D. , Riedel, Stefan , Stevens, Bryan S. , Sullivan, Kaede Ota, Vergidis, Paschalis , Roilides, Emmanuel , Seyedmousavi, Amir, Tao, Lili , Vicente, Vânia Aparecida , Vitale, Roxana G. , Wengenack, Nancy L. , Westblade, Lars F. , Wiederhold, Nathan P. , White, Lewis, Wojewoda, Christina , Babady, N. Esther , Seyedmousavi, Seyedmojtaba , de Hoog, Sybren , Walsh, Thomas J , Ahmed, Sarah A , Alastruey-Izquierdo, A , Arendrup, Maiken Cavling , Borman, Andrew , Groll, Andreas H , Hanson, Kimberly , Hayden, Randall T , Hoenigl, Martin , Kus, Julianne V , Meis, Jacques F , Leal, Sixto M , Lockhart, Shawn R. , Luethy, Paul , Kwon-Chung, Kyung J , Nguyen, M Hong , Pancholi, Preeti , Procop, Gary W , Rhoads, Daniel D , Riedel, Stefan , Vergidis, Paschalis , Vitale, Roxana G , Wengenack, Nancy L , White, Lewis , Wojewoda, Christina M , Zhang, Sean X , Cornely, Oliver A , Roilides, Emmanuel , Wiederhold, Nathan , Bai, Feng‐Yan , Chowdhary, Anuradha , Clark, Andrew, Dingle, Tanis C. , Dufresne, Philippe J. , Gangneux, Jean‐Pierre , Guillot, Jacques , Hawksworth, David L. , Hoenigl, Martin , Kus, Julianne V. , Lackner, Michaela , Martin, Isabella W. , Meyer, Wieland , Ostrosky‐Zeichner, Luis , Redhead, Scott A. , Stevens, Bryan, Wang, Qiming , Zhang, Sean X.
Journal of Clinical Microbiology | October 26, 2023 | Volume: 61 | Issue: 11 | Pages: No page available
ABSTRACT The rapid pace of name changes of medically important fungi is creating challenges for clinical laboratories and clinicians involved in patient care. We describe two sources of name change which have different drivers, at the species versus the genus level. Some suggestions are made here to reduce the number of name changes. We urge taxonomists to provide diagnostic markers of taxonomic novelties. Given the instability of phylogenetic trees due to variable taxon sampling, we advocate to maintain genera at the largest possible size. Reporting of identified species in complexes or series should where possible comprise both the name of the overarching species and that of the molecular sibling, often cryptic species. Because the use of different names for the same species will be unavoidable for many years to come, an open access online database of the names of all medically important fungi, with proper nomenclatural designation and synonymy, is essential. We further recommend that while taxonomic discovery continues, the adaptation of new name changes by clinical laboratories and clinicians be reviewed routinely by a standing committee for validation and stability over time, with reference to an open access database, wherein reasons for changes are listed in a transparent way.
1063. ARGONAUT-V: Susceptibility of Multidrug-Resistant (MDR) Pseudomonas aeruginosa to Cefepime-Taniborbactam
Bethel, Christopher R. , Marshall, Steven H. , Fowler, Vance G. , Papp‐Wallace, Krisztina M. , Mack, Andrew R , Patel, Robin , van Duin, David , Fowler, Vance G. , Rhoads, Daniel D. , Jacobs, Michael R. , Akker, Focco van den , Six, David A. , Moeck, Greg , Bonomo, Robert A.
Open Forum Infectious Diseases | December 5, 2021 | Volume: 8 | Issue: Supplement_1 | Pages: S623-S624
Abstract Background P. aeruginosa is a Gram-negative pathogen responsible for many serious infections. MDR, both intrinsic and acquired, presents major clinical challenges. Taniborbactam (formerly VNRX-5133; Fig 1) is a β-lactamase inhibitor (BLI) characterized as a bicyclic boronate, uniquely possessing activity toward all four Ambler classes of β-lactamases, both serine and metallo, with the exception of class B IMP β-lactamases. The β-lactam-BLI (BL-BLI) combination cefepime-taniborbactam (FTB; Fig 1) is currently in phase 3 clinical trials. Structures of taniborbactam and cefepime. The β-lactamase inhibitor is in red and the β-lactam antibiotic is in black. Methods The activity of FTB was tested against 197 well-characterized clinical P. aeruginosa isolates that were part of PRIMERS (Platforms for Rapid Identification of MDR-Gram-negative bacteria and Evaluation of Resistance Studies). Nearly 58% of these strains were reported as carbapenem-non-susceptible. Porin changes, efflux pumps, and/or the presence of acquired class A or class B carbapenemases were previously reported. Broth microdilution minimum inhibitory concentrations (MICs) were determined by CLSI M07 Ed. 11 methods with custom Sensititre frozen panels and interpreted using CLSI M100 Ed. 30 breakpoints. American Type Culture Collection strains were used for quality control. FEP breakpoints were provisionally used for FTB, where taniborbactam was fixed at 4 µg/mL. Results Percent susceptibility to BL agents alone was 45.2% for imipenem (IPM), 55.8% for meropenem (MEM), 60.9% for ceftazidime (CAZ), and 67.0% for FEP. The addition of BLI to BL increased % susceptibility for MEM-vaborbactam (MVB), 56.9%; ceftolozane-tazobactam (C/T), 77.7%, CAZ-avibactam (CZA), 79.7%, and FTB, 82.7%. MIC50s were in the susceptible range for all drugs except IPM, which was intermediate, and all MIC90s were in the resistant range (Table 1). Taniborbactam reduced FEP MIC by 2-fold in 32% of isolates and ≥ 4-fold in 13% of isolates. Against carbapenem-non-susceptible strains, % susceptibilities were: FTB, 68.5%, CZA, 63.0%, C/T, 59.3%; and MVB, 21.3% (Table 2). MIC50 and MIC90 values (µg/mL) and percent susceptibility (%S) for all P. aeruginosa strains (n=197). AMK, amikacin; ATM, aztreonam; C/T, ceftolozane-tazobactam; CAZ, ceftazidime; CZA, ceftazidime-avibactam; FEP, cefepime; FTB, cefepime-taniborbactam; IPM, imipenem; MEM, meropenem; MVB, meropenem-vaborbactam; TZP, piperacillin-tazobactam; TOB, tobramycin. *The breakpoints for FEP and MEM alone were provisionally applied to FTB and MVB, respectively. Tazobactam, avibactam, and taniborbactam were fixed at 4 µg/mL, while vaborbactam was fixed at 8 µg/mL. Breakpoints from CLSI M100, 31st ed, 2021. MIC50 and MIC90 values (µg/mL) and percent susceptibility (%S) for the subset of carbapenem-non-susceptible P. aeruginosa strains (n=108). AMK, amikacin; ATM, aztreonam; C/T, ceftolozane-tazobactam; CAZ, ceftazidime; CZA, ceftazidime-avibactam; FEP, cefepime; FTB, cefepime-taniborbactam; IPM, imipenem; MEM, meropenem; MVB, meropenem-vaborbactam; TZP, piperacillin-tazobactam; TOB, tobramycin. *The breakpoints for FEP and MEM alone were provisionally applied to FTB and MVB, respectively. Tazobactam, avibactam, and taniborbactam were fixed at 4 µg/mL, while vaborbactam was fixed at 8 µg/mL. Breakpoints from CLSI M100, 31st ed, 2021. Conclusion Compared to MVB, CZA, and C/T, FTB demonstrated the greatest activity against the 197 P. aeruginosa strains tested, including many carbapenem-non-susceptible strains. Pending completion of clinical development, FTB may be a promising therapeutic option for MDR P. aeruginosa infections. Disclosures Robin Patel, MD, 1928 Diagnostics (Consultant)BioFire Diagnostics (Grant/Research Support)ContraFect Corporation (Grant/Research Support)Curetis (Consultant)Hylomorph AG (Grant/Research Support)IDSA (Other Financial or Material Support, Editor’s Stipend)Infectious Diseases Board Review Course (Other Financial or Material Support, Honoraria)Mammoth Biosciences (Consultant)NBME (Other Financial or Material Support, Honoraria)Netflix (Consultant)Next Gen Diagnostics (Consultant)PathoQuest (Consultant)PhAST (Consultant)Qvella (Consultant)Samsung (Other Financial or Material Support, Patent Royalties)Selux Diagnostics (Consultant)Shionogi & Co., Ltd. (Grant/Research Support)Specific Technologies (Consultant)TenNor Therapeutics Limited (Grant/Research Support)Torus Biosystems (Consultant)Up-to-Date (Other Financial or Material Support, Honoraria) Robin Patel, MD, BioFire (Individual(s) Involved: Self): Grant/Research Support; Contrafect (Individual(s) Involved: Self): Grant/Research Support; IDSA (Individual(s) Involved: Self): Editor’s stipend; NBME, Up-to-Date and the Infectious Diseases Board Review Course (Individual(s) Involved: Self): Honoraria; Netflix (Individual(s) Involved: Self): Consultant; TenNor Therapeutics Limited (Individual(s) Involved: Self): Grant/Research Support; to Curetis, Specific Technologies, Next Gen Diagnostics, PathoQuest, Selux Diagnostics, 1928 Diagnostics, PhAST, Torus Biosystems, Mammoth Biosciences and Qvella (Individual(s) Involved: Self): Consultant David van Duin, MD, PhD, Entasis (Advisor or Review Panel member)genentech (Advisor or Review Panel member)Karius (Advisor or Review Panel member)Merck (Grant/Research Support, Advisor or Review Panel member)Pfizer (Consultant, Advisor or Review Panel member)Qpex (Advisor or Review Panel member)Shionogi (Grant/Research Support, Scientific Research Study Investigator, Advisor or Review Panel member)Utility (Advisor or Review Panel member) Vance G. Fowler, Jr., MD, MHS, Achaogen (Consultant)Advanced Liquid Logics (Grant/Research Support)Affinergy (Consultant, Grant/Research Support)Affinium (Consultant)Akagera (Consultant)Allergan (Grant/Research Support)Amphliphi Biosciences (Consultant)Aridis (Consultant)Armata (Consultant)Basilea (Consultant, Grant/Research Support)Bayer (Consultant)C3J (Consultant)Cerexa (Consultant, Other Financial or Material Support, Educational fees)Contrafect (Consultant, Grant/Research Support)Debiopharm (Consultant, Other Financial or Material Support, Educational fees)Destiny (Consultant)Durata (Consultant, Other Financial or Material Support, educational fees)Genentech (Consultant, Grant/Research Support)Green Cross (Other Financial or Material Support, Educational fees)Integrated Biotherapeutics (Consultant)Janssen (Consultant, Grant/Research Support)Karius (Grant/Research Support)Locus (Grant/Research Support)Medical Biosurfaces (Grant/Research Support)Medicines Co. (Consultant)MedImmune (Consultant, Grant/Research Support)Merck (Grant/Research Support)NIH (Grant/Research Support)Novadigm (Consultant)Novartis (Consultant, Grant/Research Support)Pfizer (Grant/Research Support)Regeneron (Consultant, Grant/Research Support)sepsis diagnostics (Other Financial or Material Support, Pending patent for host gene expression signature diagnostic for sepsis.)Tetraphase (Consultant)Theravance (Consultant, Grant/Research Support, Other Financial or Material Support, Educational fees)Trius (Consultant)UpToDate (Other Financial or Material Support, Royalties)Valanbio (Consultant, Other Financial or Material Support, Stock options)xBiotech (Consultant) Daniel D. Rhoads, MD, Becton, Dickinson and Company (Grant/Research Support) Michael Jacobs, MBBS, Venatorx Pharmaceuticals, Inc. (Grant/Research Support) Focco van den Akker, PhD, Venatorx Pharmaceuticals, Inc. (Grant/Research Support) David A. Six, PhD, Venatorx Pharmaceuticals, Inc. (Employee) Greg Moeck, PhD, Venatorx Pharmaceuticals, Inc. (Employee) Krisztina M. Papp-Wallace, Ph.D., Merck & Co., Inc. (Grant/Research Support)Spero Therapeutics, Inc. (Grant/Research Support)Venatorx Pharmaceuticals, Inc. (Grant/Research Support)Wockhardt Ltd. (Other Financial or Material Support, Research Collaborator) Robert A. Bonomo, MD, entasis (Research Grant or Support)Merck (Grant/Research Support)NIH (Grant/Research Support)VA Merit Award (Grant/Research Support)VenatoRx (Grant/Research Support)
1055. ARGONAUT-IV: Susceptibility of Carbapenem-resistant Klebsiellae to Ceftibuten/VNRX-5236
Bethel, Christopher R. , Marshall, Steven H. , Fowler, Vance G. , Papp‐Wallace, Krisztina M. , Mack, Andrew R , Patel, Robin , van Duin, David , Fowler, Vance G. , Rhoads, Daniel D. , Jacobs, Michael R. , Akker, Focco van den , Six, David A. , Moeck, Greg , Bonomo, Robert A.
Open Forum Infectious Diseases | December 5, 2021 | Volume: 8 | Issue: Supplement_1 | Pages: S619-S620
Abstract Background Carbapenem resistance in Klebsiellae spp. arises through mutational and acquired mechanisms and is considered an “urgent threat” by the CDC. VNRX-5236 is a bicyclic boronate β-lactamase inhibitor (BLI) that combines oral bioavailability (via etzadroxil prodrug VNRX-7145; Figure 1) and activity against all three Ambler classes of serine β-lactamases. VNRX-7145 is currently in development with the oral cephalosporin, ceftibuten (CTB) (Figure 1). Figure 1. Structures of VNRX-7145, VNRX-5236, and ceftibuten. The β-lactamase inhibitors are in red and the β-lactam antibiotic is in black. Methods The activity of CTB/VNRX-5236 against 200 carbapenem-resistant Klebsiellae from the Consortium on Resistance against Carbapenems in Klebsiella (CRACKLE) was assessed in this study. Among these, 193 expressed class A KPC enzymes, one expressed a class B NDM enzyme, and six expressed a class D OXA-48 or variant enzyme. Minimum inhibitory concentrations (MIC) were determined by broth microdilution (CLSI M07 Ed. 11) using the ThermoFisher Sensititre system with custom assay panels. MICs were interpreted using CLSI M100 Ed. 30, except the EUCAST breakpoint for CTB (S≤1 µg/mL) was used for CTB and was applied for comparative purposes to CTB/VNRX-5236 MICs where VNRX-5236 was fixed at 4 µg/mL. American Type Culture Collection strains were used for quality control. Results 92.5% of stains studied in this CRACKLE collection were provisionally susceptible to CTB/VNRX-5236. In comparison, strains were 95.5% and 98% susceptible to meropenem-vaborbactam (MVB) and ceftazidime-avibactam (CZA), respectively. MIC50s were in the susceptible range for CZA, MVB, and CTB/VNRX-5236; and resistant for CTB, ceftazidime (CAZ) and meropenem (MEM). MIC90s were in the susceptible range for CZA, MVB, and CTB/VNRX-5236 and resistant range for CAZ, MEM, and CTB (Table 1). One of four CZA-resistant and three of nine MVB non-susceptible strains were provisionally susceptible to CTB/VNRX-5236. MIC50 and MIC90 values (µg/mL) and percent susceptibility for Klebsiella pneumoniae strains (n=200). AMK, amikacin; CST, colistin; CAZ, ceftazidime; CZA, ceftazidime-avibactam; FEP, cefepime; MEM, meropenem; MVB, meropenem-vaborbactam; CTB, ceftibuten; TGC, tigecycline. * The breakpoint for CST is intermediate, as no susceptible breakpoint is available. ** The CTB breakpoint is valid only for urinary tract isolates. *** The breakpoint for CTB was provisionally used for CTB/VNRX-5236, where VNRX-5236 was fixed at 4 µg/mL. Conclusion The addition of VNRX-5236 enhanced the activity of CTB against the 200 Klebsiella isolates tested, reaching a total of 92.5% susceptibility. The prodrug (VNRX-7145) allows for oral administration, making it a potential option for step-down therapy. Importantly, VNRX-5236 has a broader spectrum of activity than existing oral BLIs, opening new treatment options for resistant infections as a key addition to the existing antibiotic arsenal. Disclosures Robin Patel, MD, 1928 Diagnostics (Consultant)BioFire Diagnostics (Grant/Research Support)ContraFect Corporation (Grant/Research Support)Curetis (Consultant)Hylomorph AG (Grant/Research Support)IDSA (Other Financial or Material Support, Editor’s Stipend)Infectious Diseases Board Review Course (Other Financial or Material Support, Honoraria)Mammoth Biosciences (Consultant)NBME (Other Financial or Material Support, Honoraria)Netflix (Consultant)Next Gen Diagnostics (Consultant)PathoQuest (Consultant)PhAST (Consultant)Qvella (Consultant)Samsung (Other Financial or Material Support, Patent Royalties)Selux Diagnostics (Consultant)Shionogi & Co., Ltd. (Grant/Research Support)Specific Technologies (Consultant)TenNor Therapeutics Limited (Grant/Research Support)Torus Biosystems (Consultant)Up-to-Date (Other Financial or Material Support, Honoraria) Robin Patel, MD, BioFire (Individual(s) Involved: Self): Grant/Research Support; Contrafect (Individual(s) Involved: Self): Grant/Research Support; IDSA (Individual(s) Involved: Self): Editor’s stipend; NBME, Up-to-Date and the Infectious Diseases Board Review Course (Individual(s) Involved: Self): Honoraria; Netflix (Individual(s) Involved: Self): Consultant; TenNor Therapeutics Limited (Individual(s) Involved: Self): Grant/Research Support; to Curetis, Specific Technologies, Next Gen Diagnostics, PathoQuest, Selux Diagnostics, 1928 Diagnostics, PhAST, Torus Biosystems, Mammoth Biosciences and Qvella (Individual(s) Involved: Self): Consultant David van Duin, MD, PhD, Entasis (Advisor or Review Panel member)genentech (Advisor or Review Panel member)Karius (Advisor or Review Panel member)Merck (Grant/Research Support, Advisor or Review Panel member)Pfizer (Consultant, Advisor or Review Panel member)Qpex (Advisor or Review Panel member)Shionogi (Grant/Research Support, Scientific Research Study Investigator, Advisor or Review Panel member)Utility (Advisor or Review Panel member) Vance G. Fowler, Jr., MD, MHS, Achaogen (Consultant)Advanced Liquid Logics (Grant/Research Support)Affinergy (Consultant, Grant/Research Support)Affinium (Consultant)Akagera (Consultant)Allergan (Grant/Research Support)Amphliphi Biosciences (Consultant)Aridis (Consultant)Armata (Consultant)Basilea (Consultant, Grant/Research Support)Bayer (Consultant)C3J (Consultant)Cerexa (Consultant, Other Financial or Material Support, Educational fees)Contrafect (Consultant, Grant/Research Support)Debiopharm (Consultant, Other Financial or Material Support, Educational fees)Destiny (Consultant)Durata (Consultant, Other Financial or Material Support, educational fees)Genentech (Consultant, Grant/Research Support)Green Cross (Other Financial or Material Support, Educational fees)Integrated Biotherapeutics (Consultant)Janssen (Consultant, Grant/Research Support)Karius (Grant/Research Support)Locus (Grant/Research Support)Medical Biosurfaces (Grant/Research Support)Medicines Co. (Consultant)MedImmune (Consultant, Grant/Research Support)Merck (Grant/Research Support)NIH (Grant/Research Support)Novadigm (Consultant)Novartis (Consultant, Grant/Research Support)Pfizer (Grant/Research Support)Regeneron (Consultant, Grant/Research Support)sepsis diagnostics (Other Financial or Material Support, Pending patent for host gene expression signature diagnostic for sepsis.)Tetraphase (Consultant)Theravance (Consultant, Grant/Research Support, Other Financial or Material Support, Educational fees)Trius (Consultant)UpToDate (Other Financial or Material Support, Royalties)Valanbio (Consultant, Other Financial or Material Support, Stock options)xBiotech (Consultant) Daniel D. Rhoads, MD, Becton, Dickinson and Company (Grant/Research Support) Michael Jacobs, MBBS, Venatorx Pharmaceuticals, Inc. (Grant/Research Support) Focco van den Akker, PhD, Venatorx Pharmaceuticals, Inc. (Grant/Research Support) David A. Six, PhD, Venatorx Pharmaceuticals, Inc. (Employee) Greg Moeck, PhD, Venatorx Pharmaceuticals, Inc. (Employee) Krisztina M. Papp-Wallace, Ph.D., Merck & Co., Inc. (Grant/Research Support)Spero Therapeutics, Inc. (Grant/Research Support)Venatorx Pharmaceuticals, Inc. (Grant/Research Support)Wockhardt Ltd. (Other Financial or Material Support, Research Collaborator) Robert A. Bonomo, MD, entasis (Research Grant or Support)Merck (Grant/Research Support)NIH (Grant/Research Support)VA Merit Award (Grant/Research Support)VenatoRx (Grant/Research Support)
133. ARGONAUT-III: Susceptibility of Carbapenem-resistant Klebsiellae to Cefepime-Taniborbactam
Bethel, Christopher R. , Marshall, Steven, Fowler, Vance G. , Papp‐Wallace, Krisztina M. , Mack, Andrew R , Patel, Robin , van Duin, David , Fowler, Vance G. , Rhoads, Daniel D. , Jacobs, Michael R. , Akker, Focco van den , Six, David A. , Moeck, Greg , Bonomo, Robert A.
Open Forum Infectious Diseases | December 5, 2021 | Volume: 8 | Issue: Supplement_1 | Pages: S81-S82
Abstract Background Klebsiellae are Gram-negative pathogens responsible for serious nosocomial and community-acquired infections. Carbapenem resistance, both intrinsic and acquired, complicates therapy. Taniborbactam (formerly VNRX-5133; Fig 1) is a bicyclic boronate β-lactamase inhibitor (BLI) that inhibits all four Ambler classes of β-lactamase enzymes, both serine- and metallo-, with the notable exception of class B IMP β-lactamases. Taniborbactam is currently undergoing phase 3 clinical trials in combination with cefepime (FEP; Fig 1) as part of the β-lactam-BLI (BL-BLI) combination FEP-taniborbactam (FTB). Figure 1. Structures of taniborbactam and cefepime. The β-lactamase inhibitor is in red and the β-lactam antibiotic is in black. Methods We determined the activity of FTB against 200 carbapenem-resistant Klebsiellae (CRK) strains collected as part of the Antibiotic Resistance Leadership Group (ARLG) Consortium on Resistance against Carbapenems in Klebsiella (CRACKLE) study. Among these strains, 193 expressed class A KPCs, one expressed a class B NDM, and six expressed class D OXA-48 or variants. Broth microdilution minimum inhibitory concentrations (MIC)s were determined using the ThermoFisher Sensititre system with custom assay panels. American Type Culture Collection strains were used for quality control. The susceptible-dose-dependent breakpoint for FEP was provisionally used for FTB, where taniborbactam was fixed at 4 µg/mL. Results Among the 200 Klebsiella strains tested, susceptibility for β-lactams alone ranged from 1% for ceftazidime (CAZ), 2.5% for meropenem, and 13.5% for FEP (Table 1). The addition of BLIs increased % susceptibility compared to BL alone to: 98% for CAZ-avibactam (CZA); 95.5% for MEM-vaborbactam (MVB); and 99.0% for FTB. MIC50 and MIC90 were in the susceptible and provisionally susceptible range for CZA and MVB, and in the provisionally susceptible range for FTB. Analyzing the CZA and MVB non-susceptible strains, 7 of 9 MVB non-susceptible strains and 2 of 4 CZA-resistant strains were provisionally susceptible to FTB. Table 1. MIC50 and MIC90 values (μg/mL) and percent susceptibility for Klebsiella pneumoniae strains (n=200). AMK, amikacin; CST, colistin; CAZ, ceftazidime; CZA, ceftazidime-avibactam; FEP, cefepime; FTB, cefepime-taniborbactam; MEM, meropenem; MVB, meropenem-vaborbactam; TGC, tigecycline. * The breakpoint for CST is intermediate, as no susceptible breakpoint is available. ** The susceptible-dose-dependent breakpoint for FEP alone was provisionally applied to FTB, where taniborbactam was fixed at 4 μg/mL. Breakpoints from CLSI M100, 31st ed, 2021. Conclusion The addition of taniborbactam restored susceptibility to FEP in 99.0% of CRACKLE isolates studied, comparable to CZA and MVB. Taniborbactam also restored FEP activity against some MVB- and CZA-resistant strains. FTB may provide a promising therapy for CRK infections. Disclosures Robin Patel, MD, 1928 Diagnostics (Consultant)BioFire Diagnostics (Grant/Research Support)ContraFect Corporation (Grant/Research Support)Curetis (Consultant)Hylomorph AG (Grant/Research Support)IDSA (Other Financial or Material Support, Editor’s Stipend)Infectious Diseases Board Review Course (Other Financial or Material Support, Honoraria)Mammoth Biosciences (Consultant)NBME (Other Financial or Material Support, Honoraria)Netflix (Consultant)Next Gen Diagnostics (Consultant)PathoQuest (Consultant)PhAST (Consultant)Qvella (Consultant)Samsung (Other Financial or Material Support, Patent Royalties)Selux Diagnostics (Consultant)Shionogi & Co., Ltd. (Grant/Research Support)Specific Technologies (Consultant)TenNor Therapeutics Limited (Grant/Research Support)Torus Biosystems (Consultant)Up-to-Date (Other Financial or Material Support, Honoraria) Robin Patel, MD, BioFire (Individual(s) Involved: Self): Grant/Research Support; Contrafect (Individual(s) Involved: Self): Grant/Research Support; IDSA (Individual(s) Involved: Self): Editor’s stipend; NBME, Up-to-Date and the Infectious Diseases Board Review Course (Individual(s) Involved: Self): Honoraria; Netflix (Individual(s) Involved: Self): Consultant; TenNor Therapeutics Limited (Individual(s) Involved: Self): Grant/Research Support; to Curetis, Specific Technologies, Next Gen Diagnostics, PathoQuest, Selux Diagnostics, 1928 Diagnostics, PhAST, Torus Biosystems, Mammoth Biosciences and Qvella (Individual(s) Involved: Self): Consultant David van Duin, MD, PhD, Entasis (Advisor or Review Panel member)genentech (Advisor or Review Panel member)Karius (Advisor or Review Panel member)Merck (Grant/Research Support, Advisor or Review Panel member)Pfizer (Consultant, Advisor or Review Panel member)Qpex (Advisor or Review Panel member)Shionogi (Grant/Research Support, Scientific Research Study Investigator, Advisor or Review Panel member)Utility (Advisor or Review Panel member) Vance G. Fowler, Jr., MD, MHS, Achaogen (Consultant)Advanced Liquid Logics (Grant/Research Support)Affinergy (Consultant, Grant/Research Support)Affinium (Consultant)Akagera (Consultant)Allergan (Grant/Research Support)Amphliphi Biosciences (Consultant)Aridis (Consultant)Armata (Consultant)Basilea (Consultant, Grant/Research Support)Bayer (Consultant)C3J (Consultant)Cerexa (Consultant, Other Financial or Material Support, Educational fees)Contrafect (Consultant, Grant/Research Support)Debiopharm (Consultant, Other Financial or Material Support, Educational fees)Destiny (Consultant)Durata (Consultant, Other Financial or Material Support, educational fees)Genentech (Consultant, Grant/Research Support)Green Cross (Other Financial or Material Support, Educational fees)Integrated Biotherapeutics (Consultant)Janssen (Consultant, Grant/Research Support)Karius (Grant/Research Support)Locus (Grant/Research Support)Medical Biosurfaces (Grant/Research Support)Medicines Co. (Consultant)MedImmune (Consultant, Grant/Research Support)Merck (Grant/Research Support)NIH (Grant/Research Support)Novadigm (Consultant)Novartis (Consultant, Grant/Research Support)Pfizer (Grant/Research Support)Regeneron (Consultant, Grant/Research Support)sepsis diagnostics (Other Financial or Material Support, Pending patent for host gene expression signature diagnostic for sepsis.)Tetraphase (Consultant)Theravance (Consultant, Grant/Research Support, Other Financial or Material Support, Educational fees)Trius (Consultant)UpToDate (Other Financial or Material Support, Royalties)Valanbio (Consultant, Other Financial or Material Support, Stock options)xBiotech (Consultant) Daniel D. Rhoads, MD, Becton, Dickinson and Company (Grant/Research Support) Michael Jacobs, MBBS, Venatorx Pharmaceuticals, Inc. (Grant/Research Support) Focco van den Akker, PhD, Venatorx Pharmaceuticals, Inc. (Grant/Research Support) David A. Six, PhD, Venatorx Pharmaceuticals, Inc. (Employee) Greg Moeck, PhD, Venatorx Pharmaceuticals, Inc. (Employee) Krisztina M. Papp-Wallace, Ph.D., Merck & Co., Inc. (Grant/Research Support)Spero Therapeutics, Inc. (Grant/Research Support)Venatorx Pharmaceuticals, Inc. (Grant/Research Support)Wockhardt Ltd. (Other Financial or Material Support, Research Collaborator) Robert A. Bonomo, MD, entasis (Research Grant or Support)Merck (Grant/Research Support)NIH (Grant/Research Support)VA Merit Award (Grant/Research Support)VenatoRx (Grant/Research Support)
Clinical and Infection Prevention Applications of Severe Acute Respiratory Syndrome Coronavirus 2 Genotyping: an Infectious Diseases Society of America/American Society for Microbiology Consensus Review Document
Greninger, Alexander L. , Bard, Jennifer Dien , Colgrove, Robert C. , Graf, Erin H. , Hanson, Kimberly E. , Hayden, Mary K. , Humphries, Romney M. , Lowe, Christopher F. , Pillai, Dylan R. , Rhoads, Daniel D. , Yao, Joseph D. , Lee, Francesca M, Dien Bard, Jennifer , Humphries, Romney , Hanson, Kimberly , Rhoads, Daniel D , Greninger, Alexander L , Graf, Erin H , Miller, Melissa B.
Journal of Clinical Microbiology | November 3, 2021 | Volume: 60 | Issue: 1 | Pages: No page available
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) emerged into a world of maturing pathogen genomics, with more than 2 million genomes sequenced at the time of writing. The rise of more transmissible variants of concern that impact vaccine and therapeutic effectiveness has led to widespread interest in SARS-CoV-2 evolution.
Clinical and Infection Prevention Applications of Severe Acute Respiratory Syndrome Coronavirus 2 Genotyping: An Infectious Diseases Society of America/American Society for Microbiology Consensus Review Document
Greninger, Alexander L. , Bard, Jennifer Dien , Colgrove, Robert C. , Hayden, Mary K. , Humphries, Romney M. , Lowe, Christopher F. , Pillai, Dylan R. , Rhoads, Daniel D. , Yao, Joseph D. , Lee, Francesca M, Graf, Erin H. , Humphries, Romney , Rhoads, Daniel D , Greninger, Alexander L , Hanson, Kimberly E. , Miller, Melissa B.
Clinical Infectious Diseases | September 8, 2021 | Volume: 74 | Issue: 8 | Pages: 1496-1502
Abstract Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) emerged into a world of maturing pathogen genomics, with >2 million genomes sequenced at this writing. The rise of more transmissible variants of concern that affect vaccine and therapeutic effectiveness has led to widespread interest in SARS-CoV-2 evolution. Clinicians are also eager to take advantage of the information provided by SARS-CoV-2 genotyping beyond surveillance purposes. Here, we review the potential role of SARS-CoV-2 genotyping in clinical care. The review covers clinical use cases for SARS-CoV-2 genotyping, methods of SARS-CoV-2 genotyping, assay validation and regulatory requirements, clinical reporting for laboratories, and emerging issues in clinical SARS-CoV-2 sequencing. While clinical uses of SARS-CoV-2 genotyping are currently limited, rapid technological change along with a growing ability to interpret variants in real time foretell a growing role for SARS-CoV-2 genotyping in clinical care as continuing data emerge on vaccine and therapeutic efficacy.