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Yang T, Zou Y, Ng HL, Kumar A, Newton SM, Klebba PE. Specificity and mechanism of TonB-dependent ferric catecholate uptake by Fiu. Front Microbiol 2024; 15:1355253. [PMID: 38601941 PMCID: PMC11005823 DOI: 10.3389/fmicb.2024.1355253] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2023] [Accepted: 01/23/2024] [Indexed: 04/12/2024] Open
Abstract
We studied the Escherichia coli outer membrane protein Fiu, a presumed transporter of monomeric ferric catecholates, by introducing Cys residues in its surface loops and modifying them with fluorescein maleimide (FM). Fiu-FM bound iron complexes of the tricatecholate siderophore enterobactin (FeEnt) and glucosylated enterobactin (FeGEnt), their dicatecholate degradation product Fe(DHBS)2 (FeEnt*), the monocatecholates dihydroxybenzoic acid (FeDHBA) and dihydroxybenzoyl serine (FeDHBS), and the siderophore antibiotics cefiderocol (FDC) and MB-1. Unlike high-affinity ligand-gated porins (LGPs), Fiu-FM had only micromolar affinity for iron complexes. Its apparent KD values for FeDHBS, FeDHBA, FeEnt*, FeEnt, FeGEnt, FeFDC, and FeMB-1 were 0.1, 0.7, 0.7, 1.0, 0.3, 0.4, and 4 μM, respectively. Despite its broad binding abilities, the transport repertoires of E. coli Fiu, as well as those of Cir and FepA, were less broad. Fiu only transported FeEnt*. Cir transported FeEnt* and FeDHBS (weakly); FepA transported FeEnt, FeEnt*, and FeDHBA. Both Cir and FepA bound FeGEnt, albeit with lower affinity. Related transporters of Acinetobacter baumannii (PiuA, PirA, BauA) had similarly moderate affinity and broad specificity for di- or monomeric ferric catecholates. Both microbiological and radioisotopic experiments showed Fiu's exclusive transport of FeEnt*, rather than ferric monocatecholate compounds. Molecular docking and molecular dynamics simulations predicted three binding sites for FeEnt*in the external vestibule of Fiu, and a fourth site deeper in its interior. Alanine scanning mutagenesis in the outermost sites (1a, 1b, and 2) decreased FeEnt* binding affinity as much as 20-fold and reduced or eliminated FeEnt* uptake. Finally, the molecular dynamics simulations suggested a pathway of FeEnt* movement through Fiu that may generally describe the process of metal transport by TonB-dependent receptors.
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Affiliation(s)
| | | | | | | | | | - Phillip E. Klebba
- Department of Biochemistry and Molecular Biophysics, Kansas State University, Manhattan, KS, United States
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2
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Campogiani L, Crea AMA, Minardi ML, Ansaldo L, Coppola L, Compagno M, Vitale P, Spalliera I, Malagnino V, Teti E, D’agostini C, Pennacchiotti C, Abate DN, Celeste MG, Andreoni M, Iannetta M, Sarmati L. Real-life Data on Cefiderocol Efficacy and Safety to Treat Multidrug-Resistant Acinetobacter baumannii Infections. Open Forum Infect Dis 2023; 10:ofad627. [PMID: 38156051 PMCID: PMC10753918 DOI: 10.1093/ofid/ofad627] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2023] [Accepted: 12/19/2023] [Indexed: 12/30/2023] Open
Abstract
Background The objective of this study was to expand real-life data on cefiderocol efficacy to treat multidrug-resistant Acinetobacter baumannii infections. Methods This was a retrospective monocentric study including patients hospitalized (>24 hours) at Policlinico Tor Vergata, Rome, Italy, between May 1, 2021, and September 1, 2022, treated with cefiderocol (>48 hours). The primary objective was early clinical improvement at 48-72 hours from cefiderocol start; secondary objectives were clinical success (composite outcome of infection resolution and 14-day survival), breakthrough infection, overall 30-day mortality, and cefiderocol-related adverse events. Results Eleven patients were enrolled; 91% males (10/11), with a median age (interquartile range [IQR]) of 69 (59-71) years, 91% had ≥1 comorbidity, and 72.7% (8/11) were hospitalized in internal medicine wards. Six patients with bloodstream infection (54.5%; 4 primary, 2 central line-associated), 2 with pneumonia (18.2%), 2 with urinary tract infections (18.2%), and 1 with intra-abdominal infection (9.1%) were treated. Four patients (36.3%) presented with septic shock at cefiderocol start. Cefiderocol was used as monotherapy in 3/11 patients (27.3%), was combined with colistin in all the other 8 cases, and was used in triple combination with tigecycline in 2 patients. The median duration of treatment (IQR) was 12 (10-14) days. Early clinical improvement was documented in 8/11 patients (72.7%), clinical success in 8/11 patients (72.7%). Overall 30-day mortality was 27.3% (3/11), with death occurring a median (IQR) of 19 (17.5-20.5) days after the start of therapy. No cefiderocol-related adverse events were documented. Conclusions Cefiderocol seems to be a safe and effective option for multidrug-resistant Acinetobacter baumannii infections.
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Affiliation(s)
- Laura Campogiani
- Infectious Diseases Clinic, Policlinico Tor Vergata, Rome, Italy
- Department of Systems Medicine, Tor Vergata University, Rome, Italy
| | | | | | - Lorenzo Ansaldo
- Department of Systems Medicine, Tor Vergata University, Rome, Italy
| | - Luigi Coppola
- Infectious Diseases Clinic, Policlinico Tor Vergata, Rome, Italy
- Department of Systems Medicine, Tor Vergata University, Rome, Italy
| | - Mirko Compagno
- Infectious Diseases Clinic, Policlinico Tor Vergata, Rome, Italy
- Department of Systems Medicine, Tor Vergata University, Rome, Italy
| | - Pietro Vitale
- Infectious Diseases Clinic, Policlinico Tor Vergata, Rome, Italy
| | - Ilaria Spalliera
- Infectious Diseases Clinic, Policlinico Tor Vergata, Rome, Italy
| | - Vincenzo Malagnino
- Infectious Diseases Clinic, Policlinico Tor Vergata, Rome, Italy
- Department of Systems Medicine, Tor Vergata University, Rome, Italy
| | - Elisabetta Teti
- Infectious Diseases Clinic, Policlinico Tor Vergata, Rome, Italy
| | - C D’agostini
- Laboratory of Clinical Microbiology, Policlinico Tor Vergata, Rome, Italy
- Department of Experimental Medicine, Tor Vergata University, Rome, Italy
| | | | | | | | - Massimo Andreoni
- Infectious Diseases Clinic, Policlinico Tor Vergata, Rome, Italy
- Department of Systems Medicine, Tor Vergata University, Rome, Italy
| | - Marco Iannetta
- Infectious Diseases Clinic, Policlinico Tor Vergata, Rome, Italy
- Department of Systems Medicine, Tor Vergata University, Rome, Italy
| | - Loredana Sarmati
- Infectious Diseases Clinic, Policlinico Tor Vergata, Rome, Italy
- Department of Systems Medicine, Tor Vergata University, Rome, Italy
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3
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Shields RK, Paterson DL, Tamma PD. Navigating Available Treatment Options for Carbapenem-Resistant Acinetobacter baumannii-calcoaceticus Complex Infections. Clin Infect Dis 2023; 76:S179-S193. [PMID: 37125467 PMCID: PMC10150276 DOI: 10.1093/cid/ciad094] [Citation(s) in RCA: 26] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/02/2023] Open
Abstract
Carbapenem-resistant Acinetobacter baumannii-calcoaceticus complex (CRAB) is one of the top-priority pathogens for new antibiotic development. Unlike other antibiotic-resistant threats, none of the available therapies have been shown to consistently reduce mortality or improve patient outcomes in clinical trials. Antibiotic combination therapy is routinely used in clinical practice; however, the preferred combination has not been defined. This narrative review focuses on evidence-based solutions for the treatment of invasive CRAB infections. We dissect the promise and perils of traditional agents used in combination, such as colistin, sulbactam, and the tetracyclines, and offer clinical pearls based on our interpretation of the available data. Next, we investigate the merits of newly developed β-lactam agents like cefiderocol and sulbactam-durlobactam, which have demonstrated contrasting results in recent randomized clinical trials. The review concludes with the authors' perspective on the evolving treatment landscape for CRAB infections, which is complicated by limited clinical data, imperfect treatment options, and a need for future clinical trials. We propose that effective treatment for CRAB infections requires a personalized approach that incorporates host factors, the site of infection, pharmacokinetic-pharmacodynamic principles, local molecular epidemiology of CRAB isolates, and careful interpretation of antibiotic susceptibility testing results. In most clinical scenarios, a dose-optimized, sulbactam-based regimen is recommended with the addition of at least one other in vitro active agent. Should sulbactam-durlobactam receive regulatory approval, recommendations will need to be re-evaluated with the most recent evidence.
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Affiliation(s)
- Ryan K Shields
- Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - David L Paterson
- ADVANCE-ID, Saw Swee Hock School of Public Health, National University of Singapore, Singapore
| | - Pranita D Tamma
- Department of Pediatrics, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
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4
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Ardebili A, Izanloo A, Rastegar M. Polymyxin combination therapy for multidrug-resistant, extensively-drug resistant, and difficult-to-treat drug-resistant gram-negative infections: is it superior to polymyxin monotherapy? Expert Rev Anti Infect Ther 2023; 21:387-429. [PMID: 36820511 DOI: 10.1080/14787210.2023.2184346] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/24/2023]
Abstract
INTRODUCTION The increasing prevalence of infections with multidrug-resistant (MDR), extensively-drug resistant (XDR) or difficult-to-treat drug resistant (DTR) Gram-negative bacilli (GNB), including Pseudomonas aeruginosa, Acinetobacter baumannii, Klebsiella pneumoniae, Enterobacter species, and Escherichia coli poses a severe challenge. AREAS COVERED The rapid growing of multi-resistant GNB as well as the considerable deceleration in development of new anti-infective agents have made polymyxins (e.g. polymyxin B and colistin) a mainstay in clinical practices as either monotherapy or combination therapy. However, whether the polymyxin-based combinations lead to better outcomes remains unknown. This review mainly focuses on the effect of polymyxin combination therapy versus monotherapy on treating GNB-related infections. We also provide several factors in designing studies and their impact on optimizing polymyxin combinations. EXPERT OPINION An abundance of recent in vitro and preclinical in vivo data suggest clinical benefit for polymyxin-drug combination therapies, especially colistin plus meropenem and colistin plus rifampicin, with synergistic killing against MDR, XDR, and DTR P. aeruginosa, K. pneumoniae and A. baumannii. The beneficial effects of polymyxin-drug combinations (e.g. colistin or polymyxin B + carbapenem against carbapenem-resistant K. pneumoniae and carbapenem-resistant A. baumannii, polymyxin B + carbapenem + rifampin against carbapenem-resistant K. pneumoniae, and colistin + ceftolozan/tazobactam + rifampin against PDR-P. aeruginosa) have often been shown in clinical setting by retrospective studies. However, high-certainty evidence from large randomized controlled trials is necessary. These clinical trials should incorporate careful attention to patient's sample size, characteristics of patient's groups, PK/PD relationships and dosing, rapid detection of resistance, MIC determinations, and therapeutic drug monitoring.
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Affiliation(s)
- Abdollah Ardebili
- Infectious Diseases Research Center, Golestan University of Medical Sciences, Gorgan, Iran.,Department of Microbiology, Faculty of Medicine, Golestan University of Medical Sciences, Gorgan, Iran
| | - Ahdieh Izanloo
- Department of Biology, Faculty of Sciences, Golestan University, Gorgan, Iran
| | - Mostafa Rastegar
- Department of Microbiology, Faculty of Medicine, Golestan University of Medical Sciences, Gorgan, Iran
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5
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Marzella N. Treatment for Multidrug Resistant Gram-Negative Infections With Cefiderocol (Fetroja). J Nurse Pract 2023. [DOI: 10.1016/j.nurpra.2022.11.026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
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6
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Choby JE, Ozturk T, Satola SW, Jacob JT, Weiss DS. Does cefiderocol heteroresistance explain the discrepancy between the APEKS-NP and CREDIBLE-CR clinical trial results? THE LANCET. MICROBE 2021; 2:e648-e649. [PMID: 35544102 PMCID: PMC9743357 DOI: 10.1016/s2666-5247(21)00271-8] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 09/23/2021] [Accepted: 09/30/2021] [Indexed: 12/14/2022]
Affiliation(s)
- Jacob E Choby
- Emory Antibiotic Resistance Center, Atlanta, GA 30329, USA; Emory Vaccine Center, Atlanta, GA, USA
| | - Tugba Ozturk
- Emory Antibiotic Resistance Center, Atlanta, GA 30329, USA; Emory Vaccine Center, Atlanta, GA, USA
| | - Sarah W Satola
- Emory Antibiotic Resistance Center, Atlanta, GA 30329, USA; Emory Vaccine Center, Atlanta, GA, USA; Division of Infectious Diseases, Department of Medicine, Emory University School of Medicine, Atlanta, GA, USA; Georgia Emerging Infections Programme, Atlanta, GA, USA
| | - Jesse T Jacob
- Emory Antibiotic Resistance Center, Atlanta, GA 30329, USA; Emory Vaccine Center, Atlanta, GA, USA; Division of Infectious Diseases, Department of Medicine, Emory University School of Medicine, Atlanta, GA, USA; Georgia Emerging Infections Programme, Atlanta, GA, USA
| | - David S Weiss
- Emory Antibiotic Resistance Center, Atlanta, GA 30329, USA; Emory Vaccine Center, Atlanta, GA, USA; Division of Infectious Diseases, Department of Medicine, Emory University School of Medicine, Atlanta, GA, USA.
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McCreary EK, Heil EL, Tamma PD. New Perspectives on Antimicrobial Agents: Cefiderocol. Antimicrob Agents Chemother 2021; 65:e0217120. [PMID: 34031052 PMCID: PMC8373209 DOI: 10.1128/aac.02171-20] [Citation(s) in RCA: 66] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Bacterial resistance to carbapenem agents has reached alarming levels. Accordingly, collaborative efforts between national and international organizations and the pharmaceutical industry have led to an impressive expansion of commercially available β-lactam agents in recent years. No available agent comes close to the broad range of activity afforded by cefiderocol, a novel siderophore-cephalosporin conjugate. The novelty of and need for cefiderocol are clear, but available clinical data are conflicting, leaving infectious diseases specialists puzzled as to when to prescribe this agent in clinical practice. After a brief overview of cefiderocol pharmacokinetics and pharmacodynamics, safety data, cefiderocol susceptibility testing, and putative mechanisms of cefiderocol resistance, this review focuses on determining cefiderocol's role in the management of specific pathogens, including carbapenem-resistant Acinetobacter baumannii complex, carbapenem-resistant Pseudomonas aeruginosa, carbapenem-resistant Enterobacterales, and less commonly identified glucose-nonfermenting organisms such as Stenotrophomonas maltophilia, Burkholderia species, and Achromobacter species. Available preclinical, clinical trial, and postmarketing data are summarized for each organism, and each section concludes with our opinions on where to position cefiderocol as a clinical therapeutic.
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Affiliation(s)
- Erin K. McCreary
- Department of Medicine, Division of Infectious Diseases, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Emily L. Heil
- Department of Pharmacy Practice and Science, University of Maryland School of Pharmacy, Baltimore, Maryland, USA
| | - Pranita D. Tamma
- Department of Pediatrics, Division of Pediatric Infectious Diseases, Baltimore, Maryland, USA
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8
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Powers JH. Scientific Evidence, Regulatory Decision Making, and Incentives for Therapeutics in Infectious Diseases: The Example of Cefiderocol. Clin Infect Dis 2021; 72:e1112-e1114. [PMID: 33257939 DOI: 10.1093/cid/ciaa1795] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Accepted: 11/26/2020] [Indexed: 11/12/2022] Open
Affiliation(s)
- John H Powers
- Department of Medicine, George Washington University School of Medicine, Rockville, MD, USA
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9
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Parsels KA, Mastro KA, Steele JM, Thomas SJ, Kufel WD. Cefiderocol: a novel siderophore cephalosporin for multidrug-resistant Gram-negative bacterial infections. J Antimicrob Chemother 2021; 76:1379-1391. [PMID: 33532823 DOI: 10.1093/jac/dkab015] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Cefiderocol is a novel siderophore cephalosporin that forms a complex with extracellular free ferric iron, which leads to transportation across the outer cell membrane to exert its bactericidal activity through cell wall synthesis inhibition. This pharmacological property has rendered cefiderocol active against several clinically relevant MDR Gram-negative bacteria as evidenced by several in vitro and in vivo studies. Cefiderocol was first approved by the US FDA on 14 November 2019 for the treatment of complicated urinary tract infections. On 28 September 2020, cefiderocol was approved for the treatment of hospital-acquired bacterial pneumonia and ventilator-associated bacterial pneumonia. The FDA-approved indications are based on clinical data from the APEKS-cUTI, APEKS-NP and CREDIBLE-CR trials. In APEKS-cUTI, cefiderocol demonstrated non-inferiority to imipenem/cilastatin for the treatment of complicated urinary tract infection caused by MDR Gram-negative bacteria. In APEKS-NP, cefiderocol demonstrated non-inferiority to meropenem for treatment of nosocomial pneumonia. However, in CREDIBLE-CR, higher all-cause mortality was observed with cefiderocol compared with best available therapy for the treatment of severe infections caused by Gram-negative bacteria, primarily in the subset of patients with Acinetobacter spp. infections. Several case reports/series have demonstrated clinical success with cefiderocol for a variety of severe infections. The purpose of this article is to review available data on the mechanism of action, in vitro and in vivo data, pharmacokinetics, pharmacodynamics, susceptibility testing, efficacy and safety of cefiderocol to address its role in therapy.
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Affiliation(s)
- Katie A Parsels
- State University of New York Upstate University Hospital, Syracuse, NY, USA
| | - Keri A Mastro
- Binghamton University School of Pharmacy and Pharmaceutical Sciences, Binghamton, NY, USA
| | - Jeffrey M Steele
- State University of New York Upstate University Hospital, Syracuse, NY, USA
- State University of New York Upstate Medical University, Syracuse, NY, USA
| | - Stephen J Thomas
- State University of New York Upstate University Hospital, Syracuse, NY, USA
- State University of New York Upstate Medical University, Syracuse, NY, USA
| | - Wesley D Kufel
- State University of New York Upstate University Hospital, Syracuse, NY, USA
- Binghamton University School of Pharmacy and Pharmaceutical Sciences, Binghamton, NY, USA
- State University of New York Upstate Medical University, Syracuse, NY, USA
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10
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Klebba PE, Newton SMC, Six DA, Kumar A, Yang T, Nairn BL, Munger C, Chakravorty S. Iron Acquisition Systems of Gram-negative Bacterial Pathogens Define TonB-Dependent Pathways to Novel Antibiotics. Chem Rev 2021; 121:5193-5239. [PMID: 33724814 PMCID: PMC8687107 DOI: 10.1021/acs.chemrev.0c01005] [Citation(s) in RCA: 50] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Iron is an indispensable metabolic cofactor in both pro- and eukaryotes, which engenders a natural competition for the metal between bacterial pathogens and their human or animal hosts. Bacteria secrete siderophores that extract Fe3+ from tissues, fluids, cells, and proteins; the ligand gated porins of the Gram-negative bacterial outer membrane actively acquire the resulting ferric siderophores, as well as other iron-containing molecules like heme. Conversely, eukaryotic hosts combat bacterial iron scavenging by sequestering Fe3+ in binding proteins and ferritin. The variety of iron uptake systems in Gram-negative bacterial pathogens illustrates a range of chemical and biochemical mechanisms that facilitate microbial pathogenesis. This document attempts to summarize and understand these processes, to guide discovery of immunological or chemical interventions that may thwart infectious disease.
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Affiliation(s)
- Phillip E Klebba
- Department of Biochemistry and Molecular Biophysics, Kansas State University, Manhattan, Kansas 66506, United States
| | - Salete M C Newton
- Department of Biochemistry and Molecular Biophysics, Kansas State University, Manhattan, Kansas 66506, United States
| | - David A Six
- Venatorx Pharmaceuticals, Inc., 30 Spring Mill Drive, Malvern, Pennsylvania 19355, United States
| | - Ashish Kumar
- Department of Biochemistry and Molecular Biophysics, Kansas State University, Manhattan, Kansas 66506, United States
| | - Taihao Yang
- Department of Biochemistry and Molecular Biophysics, Kansas State University, Manhattan, Kansas 66506, United States
| | - Brittany L Nairn
- Department of Biological Sciences, Bethel University, 3900 Bethel Drive, St. Paul, Minnesota 55112, United States
| | - Colton Munger
- Department of Biochemistry and Molecular Biophysics, Kansas State University, Manhattan, Kansas 66506, United States
| | - Somnath Chakravorty
- Jacobs School of Medicine and Biomedical Sciences, SUNY Buffalo, Buffalo, New York 14203, United States
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11
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Sargun A, Johnstone TC, Zhi H, Raffatellu M, Nolan EM. Enterobactin- and salmochelin-β-lactam conjugates induce cell morphologies consistent with inhibition of penicillin-binding proteins in uropathogenic Escherichia coli CFT073. Chem Sci 2021; 12:4041-4056. [PMID: 34163675 PMCID: PMC8179508 DOI: 10.1039/d0sc04337k] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Accepted: 12/31/2020] [Indexed: 12/15/2022] Open
Abstract
The design and synthesis of narrow-spectrum antibiotics that target a specific bacterial strain, species, or group of species is a promising strategy for treating bacterial infections when the causative agent is known. In this work, we report the synthesis and evaluation of four new siderophore-β-lactam conjugates where the broad-spectrum β-lactam antibiotics cephalexin (Lex) and meropenem (Mem) are covalently attached to either enterobactin (Ent) or diglucosylated Ent (DGE) via a stable polyethylene glycol (PEG3) linker. These siderophore-β-lactam conjugates showed enhanced minimum inhibitory concentrations against Escherichia coli compared to the parent antibiotics. Uptake studies with uropathogenic E. coli CFT073 demonstrated that the DGE-β-lactams target the pathogen-associated catecholate siderophore receptor IroN. A comparative analysis of siderophore-β-lactams harboring ampicillin (Amp), Lex and Mem indicated that the DGE-Mem conjugate is advantageous because it targets IroN and exhibits low minimum inhibitory concentrations, fast time-kill kinetics, and enhanced stability to serine β-lactamases. Phase-contrast and fluorescence imaging of E. coli treated with the siderophore-β-lactam conjugates revealed cellular morphologies consistent with the inhibition of penicillin-binding proteins PBP3 (Ent/DGE-Amp/Lex) and PBP2 (Ent/DGE-Mem). Overall, this work illuminates the uptake and cell-killing activity of Ent- and DGE-β-lactam conjugates against E. coli and supports that native siderophore scaffolds provide the opportunity for narrowing the activity spectrum of antibiotics in clinical use and targeting pathogenicity.
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Affiliation(s)
- Artur Sargun
- Department of Chemistry, Massachusetts Institute of Technology Cambridge MA 02139 USA +1-617-452-2495
| | - Timothy C Johnstone
- Department of Chemistry, Massachusetts Institute of Technology Cambridge MA 02139 USA +1-617-452-2495
| | - Hui Zhi
- Division of Host-Microbe Systems and Therapeutics, Department of Pediatrics, University of California San Diego La Jolla CA 92093 USA
| | - Manuela Raffatellu
- Division of Host-Microbe Systems and Therapeutics, Department of Pediatrics, University of California San Diego La Jolla CA 92093 USA
- Center for Microbiome Innovation, University of California San Diego La Jolla CA 92093 USA
- Chiba University-UC San Diego Center for Mucosal Immunology, Allergy, and Vaccines La Jolla CA 92093 USA
| | - Elizabeth M Nolan
- Department of Chemistry, Massachusetts Institute of Technology Cambridge MA 02139 USA +1-617-452-2495
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12
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Sargun A, Gerner RR, Raffatellu M, Nolan EM. Harnessing Iron Acquisition Machinery to Target Enterobacteriaceae. J Infect Dis 2020; 223:S307-S313. [PMID: 33330928 DOI: 10.1093/infdis/jiaa440] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Infections caused by Gram-negative bacteria can be challenging to treat due to the outer membrane permeability barrier and the increasing emergence of antibiotic resistance. During infection, Gram-negative pathogens must acquire iron, an essential nutrient, in the host. Many Gram-negative bacteria utilize sophisticated iron acquisition machineries based on siderophores, small molecules that bind iron with high affinity. In this review, we provide an overview of siderophore-mediated iron acquisition in Enterobacteriaceae and show how these systems provide a foundation for the conceptualization and development of approaches to prevent and/or treat bacterial infections. Differences between the siderophore-based iron uptake machineries of pathogenic Enterobacteriaceae and commensal microbes may lead to the development of selective "Trojan-horse" antimicrobials and immunization strategies that will not harm the host microbiota.
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Affiliation(s)
- Artur Sargun
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Romana R Gerner
- Division of Host-Microbe Systems and Therapeutics, Department of Pediatrics, University of California San Diego, La Jolla, California, USA
| | - Manuela Raffatellu
- Division of Host-Microbe Systems and Therapeutics, Department of Pediatrics, University of California San Diego, La Jolla, California, USA.,Center for Microbiome Innovation, University of California San Diego, La Jolla, California, USA.,Chiba University-UC San Diego Center for Mucosal Immunology, Allergy, and Vaccines, La Jolla, California, USA
| | - Elizabeth M Nolan
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
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13
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Is it time to move away from polymyxins?: evidence and alternatives. Eur J Clin Microbiol Infect Dis 2020; 40:461-475. [PMID: 33009595 DOI: 10.1007/s10096-020-04053-w] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Accepted: 09/25/2020] [Indexed: 12/17/2022]
Abstract
Increasing burden of carbapenem resistance and resultant difficult-to-treat infections are of particular concern due to the lack of effective and safe treatment options. More recently, several new agents with activity against certain multidrug-resistant (MDR) and extensive drug-resistant (XDR) Gram-negative pathogens have been approved for clinical use. These include ceftazidime-avibactam, meropenem-vaborbactam, imipenem-cilastatin-relebactam, plazomicin, and cefiderocol. For the management of MBL infections, clinically used triple combination comprising ceftazidime-avibactam and aztreonam is hindered due to non-availability of antimicrobial susceptibility testing methods and lack of information on potential drug-drug interaction leading to PK changes impacting its safety and efficacy. Moreover, in several countries including Indian subcontinent and developing countries, these new agents are yet to be made available. Under these circumstances, polymyxins are the only last resort for the treatment of carbapenem-resistant infections. With the recent evidence of suboptimal PK/PD particularly in lung environment, limited efficacy and increased nephrotoxicity associated with polymyxin use, the Clinical and Laboratory Standards Institute (CLSI) has revised both colistin and polymyxin B breakpoints. Thus, polymyxins 'intermediate' breakpoint for Enterobacterales, P. aeruginosa, and Acinetobacter spp. are now set at ≤ 2 mg/L, implying limited clinical efficacy even for isolates with the MIC value 2 mg/L. This change has questioned the dependency on polymyxins in treating XDR infections. In this context, recently approved cefiderocol and phase 3 stage combination drug cefepime-zidebactam assume greater significance due to their potential to act as polymyxin-supplanting therapies.
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Treatment options for K. pneumoniae, P. aeruginosa and A. baumannii co-resistant to carbapenems, aminoglycosides, polymyxins and tigecycline: an approach based on the mechanisms of resistance to carbapenems. Infection 2020; 48:835-851. [PMID: 32875545 PMCID: PMC7461763 DOI: 10.1007/s15010-020-01520-6] [Citation(s) in RCA: 82] [Impact Index Per Article: 20.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Accepted: 08/26/2020] [Indexed: 02/07/2023]
Abstract
The management of carbapenem-resistant infections is often based on polymyxins, tigecycline, aminoglycosides and their combinations. However, in a recent systematic review, we found that Gram-negative bacteria (GNB) co-resistant to carbapanems, aminoglycosides, polymyxins and tigecycline (CAPT-resistant) are increasingly being reported worldwide. Clinical data to guide the treatment of CAPT-resistant GNB are scarce and based exclusively on few case reports and small case series, but seem to indicate that appropriate (in vitro active) antimicrobial regimens, including newer antibiotics and synergistic combinations, may be associated with lower mortality. In this review, we consolidate the available literature to inform clinicians dealing with CAPT-resistant GNB about treatment options by considering the mechanisms of resistance to carbapenems. In combination with rapid diagnostic methods that allow fast detection of carbapenemase production, the approach proposed in this review may guide a timely and targeted treatment of patients with infections by CAPT-resistant GNB. Specifically, we focus on the three most problematic species, namely Klebsiella pneumoniae, Pseudomonas aeruginosa and Acinetobacter baumannii. Several treatment options are currently available for CAPT-resistant K. pneumonia. Newer β-lactam-β-lactamase combinations, including the combination of ceftazidime/avibactam with aztreonam against metallo-β-lactamase-producing isolates, appear to be more effective compared to combinations of older agents. Options for P. aeruginosa (especially metallo-β-lactamase-producing strains) and A. baumannii remain limited. Synergistic combination of older agents (e.g., polymyxin- or fosfomycin-based synergistic combinations) may represent a last resort option, but their use against CAPT-resistant GNB requires further study.
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Kufel WD, Steele JM, Riddell SW, Jones Z, Shakeraneh P, Endy TP. Cefiderocol for treatment of an empyema due to extensively drug-resistant Pseudomonas aeruginosa: Clinical observations and susceptibility testing considerations. IDCases 2020; 21:e00863. [PMID: 32577400 PMCID: PMC7300106 DOI: 10.1016/j.idcr.2020.e00863] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Revised: 06/01/2020] [Accepted: 06/01/2020] [Indexed: 12/15/2022] Open
Abstract
Cefiderocol is a novel siderophore cephalosporin antibacterial with activity against carbapenem-resistant Gram-negative bacteria including Pseudomonas aeruginosa. We report a medically complex patient treated with compassionate use cefiderocol for an empyema caused by extensively drug-resistant P. aeruginosa as well as clinical considerations for cefiderocol use based on our findings. We observed a potential discordance in cefiderocol susceptibility testing results depending if disk diffusion or iron-depleted cation-adjusted Mueller Hinton Broth dilution is used. Furthermore, interpretative criteria differ between the Clinical Laboratory Standards Institute and United States Food and Drug Administration for P. aeruginosa, which makes cefiderocol interpretation potentially challenging for clinicians. We may have also observed selective pressure from prior cefiderocol exposure given the respective increases and decreases in MIC values and zone diameters for P. aeruginosa isolates following cefiderocol treatment. Additional data are needed to further describe cefiderocol use, susceptibility testing, and resistance development as real-world clinical use expands.
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Affiliation(s)
- Wesley D Kufel
- Binghamton University School of Pharmacy and Pharmaceutical Sciences, Binghamton, NY, USA.,State University of New York Upstate Medical University, Syracuse, NY, USA.,State University of New York Upstate University Hospital, Syracuse, NY, USA
| | - Jeffrey M Steele
- State University of New York Upstate Medical University, Syracuse, NY, USA.,State University of New York Upstate University Hospital, Syracuse, NY, USA
| | - Scott W Riddell
- State University of New York Upstate Medical University, Syracuse, NY, USA.,State University of New York Upstate University Hospital, Syracuse, NY, USA
| | - Zachary Jones
- United Health Services Hospitals, Binghamton, NY, USA
| | - Pegah Shakeraneh
- State University of New York Upstate University Hospital, Syracuse, NY, USA
| | - Timothy P Endy
- State University of New York Upstate Medical University, Syracuse, NY, USA.,State University of New York Upstate University Hospital, Syracuse, NY, USA
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