1
|
Jiang F, Wang J, Ren Z, Hu Y, Wang B, Li M, Yu J, Tang J, Guo G, Cheng Y, Han P, Shen H. Targeted Light-Induced Immunomodulatory Strategy for Implant-Associated Infections via Reversing Biofilm-Mediated Immunosuppression. ACS NANO 2024; 18:6990-7010. [PMID: 38385433 DOI: 10.1021/acsnano.3c10172] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/23/2024]
Abstract
The clinical treatment efficacy for implant-associated infections (IAIs), particularly those caused by Methicillin-resistant Staphylococcus aureus (MRSA), remains unsatisfactory, primarily due to the formation of biofilm barriers and the resulting immunosuppressive microenvironment, leading to the chronicity and recurrence of IAIs. To address this challenge, we propose a light-induced immune enhancement strategy, synthesizing BSA@MnO2@Ce6@Van (BMCV). The BMCV exhibits precise targeting and adhesion to the S. aureus biofilm-infected region, coupled with its capacity to catalyze oxygen generation from H2O2 in the hypoxic and acidic biofilm microenvironment (BME), promoting oxygen-dependent photodynamic therapy efficacy while ensuring continuous release of manganese ions. Notably, targeted BMCV can penetrate biofilms, producing ROS that degrade extracellular DNA, disrupting the biofilm structure and impairing its barrier function, making it vulnerable to infiltration and elimination by the immune system. Furthermore, light-induced reactive oxygen species (ROS) around the biofilm can lyse S. aureus, triggering bacterium-like immunogenic cell death (ICD), releasing abundant immune costimulatory factors, facilitating the recognition and maturation of antigen-presenting cells (APCs), and activating adaptive immunity. Additionally, manganese ions in the BME act as immunoadjuvants, further amplifying macrophage-mediated innate and adaptive immune responses and reversing the immunologically cold BME to an immunologically hot BME. We prove that our synthesized BMCV elicits a robust adaptive immune response in vivo, effectively clearing primary IAIs and inducing long-term immune memory to prevent recurrence. Our study introduces a potent light-induced immunomodulatory nanoplatform capable of reversing the biofilm-induced immunosuppressive microenvironment and disrupting biofilm-mediated protective barriers, offering a promising immunotherapeutic strategy for addressing challenging S. aureus IAIs.
Collapse
Affiliation(s)
- Feng Jiang
- Department of Orthopedics, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai 200233, China
| | - Jian Wang
- Department of Interventional Radiology, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai 200233, China
| | - Zun Ren
- Department of Orthopedics, Shanghai General Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200080, China
| | - Yujie Hu
- Department of Orthopedics, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai 200233, China
| | - Boyong Wang
- Department of Orthopedics, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai 200233, China
| | - Mingzhang Li
- Department of Orthopedics, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai 200233, China
| | - Jinlong Yu
- Department of Orthopedics, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai 200233, China
| | - Jin Tang
- Department of Clinical Laboratory, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai 200233, China
| | - Geyong Guo
- Department of Orthopedics, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai 200233, China
| | - Yingsheng Cheng
- Department of Interventional Radiology, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai 200233, China
- Department of Imaging Medicine and Nuclear Medicine, Tongji Hospital, Shanghai 200065, China
| | - Pei Han
- Department of Orthopedics, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai 200233, China
| | - Hao Shen
- Department of Orthopedics, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai 200233, China
| |
Collapse
|
2
|
Jiao F, Bao Y, Li M, Zhang Y, Zhang F, Wang P, Tao J, Tong HHY, Guo J. Unraveling the mechanism of ceftaroline-induced allosteric regulation in penicillin-binding protein 2a: insights for novel antibiotic development against methicillin-resistant Staphylococcus aureus. Antimicrob Agents Chemother 2023; 67:e0089523. [PMID: 37971241 PMCID: PMC10720500 DOI: 10.1128/aac.00895-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2023] [Accepted: 10/11/2023] [Indexed: 11/19/2023] Open
Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) acquires high-level resistance against β-lactam antibiotics by expressing penicillin-binding protein 2a (PBP2a). PBP2a is a cell wall-synthesizing protein whose closed active site exhibits a reduced binding affinity toward β-lactam antibiotics. Ceftaroline (CFT), a fifth-generation cephalosporin, can effectively inhibit the PBP2a activity by binding to an allosteric site to trigger the active site opening, allowing a second CFT to access the active site. However, the essential mechanism behind the allosteric behavior of PBP2a remains unclear. Herein, computational simulations are employed to elucidate how CFT allosterically regulates the conformation and dynamics of the active site of PBP2a. While CFT stabilizes the allosteric domain surrounding it, it simultaneously enhances the dynamics of the catalytic domain. Specifically, the study successfully captured the opening process of the active pocket in the allosteric CFT-bound systems and discovered that CFT alters the potential signal-propagating pathways from the allosteric site to the active site. These findings reveal the implied mechanism of the CFT-mediated allostery in PBP2a and provide new insights into dual-site drug design or combination therapy against MRSA targeting PBP2a.
Collapse
Affiliation(s)
- Fangfang Jiao
- Centre in Artificial Intelligence Driven Drug Discovery, Faculty of Applied Sciences, Macao Polytechnic University, Macao, China
| | - Yiqiong Bao
- College of Life Sciences, Nanjing Agricultural University, Nanjing, China
| | - Mengrong Li
- College of Life Sciences, Nanjing Agricultural University, Nanjing, China
| | - Yan Zhang
- School of Pharmacy, Guizhou University of Traditional Chinese Medicine, Guiyang, China
| | - Feng Zhang
- College of Plant Protection, Nanjing Agricultural University, Nanjing, China
| | - Pinkai Wang
- Department of Orthopedics, Second Affiliated Hospital of Nanchang University, Nanchang, China
| | - Jun Tao
- Department of Orthopedics, Second Affiliated Hospital of Nanchang University, Nanchang, China
| | - Henry H. Y. Tong
- Centre in Artificial Intelligence Driven Drug Discovery, Faculty of Applied Sciences, Macao Polytechnic University, Macao, China
| | - Jingjing Guo
- Centre in Artificial Intelligence Driven Drug Discovery, Faculty of Applied Sciences, Macao Polytechnic University, Macao, China
| |
Collapse
|
3
|
Fisher JF, Mobashery S. β-Lactams against the Fortress of the Gram-Positive Staphylococcus aureus Bacterium. Chem Rev 2021; 121:3412-3463. [PMID: 33373523 PMCID: PMC8653850 DOI: 10.1021/acs.chemrev.0c01010] [Citation(s) in RCA: 41] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The biological diversity of the unicellular bacteria-whether assessed by shape, food, metabolism, or ecological niche-surely rivals (if not exceeds) that of the multicellular eukaryotes. The relationship between bacteria whose ecological niche is the eukaryote, and the eukaryote, is often symbiosis or stasis. Some bacteria, however, seek advantage in this relationship. One of the most successful-to the disadvantage of the eukaryote-is the small (less than 1 μm diameter) and nearly spherical Staphylococcus aureus bacterium. For decades, successful clinical control of its infection has been accomplished using β-lactam antibiotics such as the penicillins and the cephalosporins. Over these same decades S. aureus has perfected resistance mechanisms against these antibiotics, which are then countered by new generations of β-lactam structure. This review addresses the current breadth of biochemical and microbiological efforts to preserve the future of the β-lactam antibiotics through a better understanding of how S. aureus protects the enzyme targets of the β-lactams, the penicillin-binding proteins. The penicillin-binding proteins are essential enzyme catalysts for the biosynthesis of the cell wall, and understanding how this cell wall is integrated into the protective cell envelope of the bacterium may identify new antibacterials and new adjuvants that preserve the efficacy of the β-lactams.
Collapse
Affiliation(s)
- Jed F Fisher
- Department of Chemistry and Biochemistry, McCourtney Hall, University of Notre Dame, Notre Dame Indiana 46556, United States
| | - Shahriar Mobashery
- Department of Chemistry and Biochemistry, McCourtney Hall, University of Notre Dame, Notre Dame Indiana 46556, United States
| |
Collapse
|
4
|
Chang M, Mahasenan KV, Hermoso JA, Mobashery S. Unconventional Antibacterials and Adjuvants. Acc Chem Res 2021; 54:917-929. [PMID: 33512995 DOI: 10.1021/acs.accounts.0c00776] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The need for new classes of antibacterials is genuine in light of the dearth of clinical options for the treatment of bacterial infections. The prodigious discoveries of antibiotics during the 1940s to 1970s, a period wistfully referred to as the Golden Age of Antibiotics, have not kept up in the face of emergence of resistant bacteria in the past few decades. There has been a renewed interest in old drugs, the repurposing of the existing antibiotics and pairing of synergistic antibiotics or of an antibiotic with an adjuvant. Notwithstanding, discoveries of novel classes of these life-saving drugs have become increasingly difficult, calling for new paradigms. We describe, herein, three strategies from our laboratories toward discoveries of new antibacterials and adjuvants using computational and multidisciplinary experimental methods. One approach targets penicillin-binding proteins (PBPs), biosynthetic enzymes of cell-wall peptidoglycan, for discoveries of non-β-lactam inhibitors. Oxadiazoles and quinazolinones emerged as two structural classes out of these efforts. Several hundred analogs of these two classes of antibiotics have been synthesized and fully characterized in our laboratories. A second approach ventures into inhibition of allosteric regulation of cell-wall biosynthesis. The mechanistic details of allosteric regulation of PBP2a of Staphylococcus aureus, discovered in our laboratories, is outlined. The allosteric site in this protein is at 60 Å distance to the active site, whereby ligand binding at the former makes access to the latter by the substrate possible. We have documented that both quinazolinones and ceftaroline, a fifth-generation cephalosporin, bind to the allosteric site in manifestation of the antibacterial activity. Attempts at inhibition of the regulatory phosphorylation events identified three classes of antibacterial adjuvants and one class of antibacterials, the picolinamides. The chemical structures for these hits went through diversification by synthesis of hundreds of analogs. These analogs were characterized in various assays for identification of leads with adjuvant and antibacterial activities. Furthermore, we revisited the mechanism of bulgecins, a class of adjuvants discovered and abandoned in the 1980s. These compounds potentiate the activities of β-lactam antibiotics by the formation of bulges at the sites of septum formation during bacterial replication, which are points of structural weakness in the envelope. These bulges experience rupture, which leads to bacterial death. Bulgecin A inhibits the lytic transglycosylase Slt of Pseudomonas aeruginosa as a likely transition-state mimetic for its turnover of the cell-wall peptidoglycan. Once damage to cell wall is inflicted by a β-lactam antibiotic, the function of Slt is to repair the damage. When Slt is inhibited by bulgecin A, the organism cannot cope with it and would undergo rapid lysis. Bulgecin A is an effective adjuvant of β-lactam antibiotics. These discoveries of small-molecule classes of antibacterials or of adjuvants to antibacterials hold promise in strategies for treatment of bacterial infections.
Collapse
Affiliation(s)
- Mayland Chang
- Department of Chemistry and Biochemistry, University of Notre Dame, McCourtney Hall, Notre Dame Indiana 46556, United States
| | - Kiran V. Mahasenan
- Department of Chemistry and Biochemistry, University of Notre Dame, McCourtney Hall, Notre Dame Indiana 46556, United States
| | - Juan A. Hermoso
- Departamento de Cristalografía y Biología Estructural, Instituto de Química-Física “Rocasolano”, CSIC, Serrano 119, 28006-Madrid Spain
| | - Shahriar Mobashery
- Department of Chemistry and Biochemistry, University of Notre Dame, McCourtney Hall, Notre Dame Indiana 46556, United States
| |
Collapse
|
5
|
Tomlinson JH, Kalverda AP, Calabrese AN. Fusidic acid resistance through changes in the dynamics of the drug target. Proc Natl Acad Sci U S A 2020; 117:25523-25531. [PMID: 32999060 PMCID: PMC7568287 DOI: 10.1073/pnas.2008577117] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Antibiotic resistance in clinically important bacteria can be mediated by target protection mechanisms, whereby a protein binds to the drug target and protects it from the inhibitory effects of the antibiotic. The most prevalent source of clinical resistance to the antibiotic fusidic acid (FA) is expression of the FusB family of proteins that bind to the drug target (Elongation factor G [EF-G]) and promote dissociation of EF-G from FA-stalled ribosome complexes. FusB binding causes changes in both the structure and conformational flexibility of EF-G, but which of these changes drives FA resistance was not understood. We present here detailed characterization of changes in the conformational flexibility of EF-G in response to FusB binding and show that these changes are responsible for conferring FA resistance. Binding of FusB to EF-G causes a significant change in the dynamics of domain III of EF-GC3 that leads to an increase in a minor, more disordered state of EF-G domain III. This is sufficient to overcome the steric block of transmission of conformational changes within EF-G by which FA prevents release of EF-G from the ribosome. This study has identified an antibiotic resistance mechanism mediated by allosteric effects on the dynamics of the drug target.
Collapse
Affiliation(s)
- Jennifer H Tomlinson
- School of Molecular and Cellular Biology, University of Leeds, LS2 9JT Leeds, United Kingdom;
- Astbury Centre for Structural Molecular Biology, Faculty of Biological Sciences, University of Leeds, LS2 9JT Leeds, United Kingdom
| | - Arnout P Kalverda
- School of Molecular and Cellular Biology, University of Leeds, LS2 9JT Leeds, United Kingdom
- Astbury Centre for Structural Molecular Biology, Faculty of Biological Sciences, University of Leeds, LS2 9JT Leeds, United Kingdom
| | - Antonio N Calabrese
- School of Molecular and Cellular Biology, University of Leeds, LS2 9JT Leeds, United Kingdom
- Astbury Centre for Structural Molecular Biology, Faculty of Biological Sciences, University of Leeds, LS2 9JT Leeds, United Kingdom
| |
Collapse
|
6
|
Björn LO. Peptidoglycan in eukaryotes: Unanswered questions. PHYTOCHEMISTRY 2020; 175:112370. [PMID: 32289597 DOI: 10.1016/j.phytochem.2020.112370] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Revised: 03/27/2020] [Accepted: 03/30/2020] [Indexed: 06/11/2023]
Abstract
Peptidoglycan has been retained in chloroplasts that have evolved from cyanobacteria along some evolutionary tracks, but has seemingly been quickly eliminated during evolution of others. It has been eliminated in Rhodophyta, Chlorophyta, Pteridophyta and Spermatophyta, but has been retained in streptophyte algae, Glaukophyta, and Lycophyta. In this article questions emerging from this are raised, and for some of them answers are suggested.
Collapse
Affiliation(s)
- Lars Olof Björn
- Department of Biology, Lund University, Sölvegatan 35, SE-223 62, Lund, Sweden.
| |
Collapse
|
7
|
Qian Y, Allegretta G, Janardhanan J, Peng Z, Mahasenan KV, Lastochkin E, Gozun MMN, Tejera S, Schroeder VA, Wolter WR, Feltzer R, Mobashery S, Chang M. Exploration of the Structural Space in 4(3 H)-Quinazolinone Antibacterials. J Med Chem 2020; 63:5287-5296. [PMID: 32343145 DOI: 10.1021/acs.jmedchem.0c00153] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
We report herein the syntheses of 79 derivatives of the 4(3H)-quinazolinones and their structure-activity relationship (SAR) against methicillin-resistant Staphylococcus aureus (MRSA). Twenty one analogs were further evaluated in in vitro assays. Subsequent investigation of the pharmacokinetic properties singled out compound 73 ((E)-3-(5-carboxy-2-fluorophenyl)-2-(4-cyanostyryl)quinazolin-4(3H)-one) for further study. The compound synergized with piperacillin-tazobactam (TZP) both in vitro and in vivo in a clinically relevant mouse model of MRSA infection. The TZP combination lacks activity against MRSA, yet it synergized with compound 73 to kill MRSA in a bactericidal manner. The synergy is rationalized by the ability of the quinazolinones to bind to the allosteric site of penicillin-binding protein (PBP)2a, resulting in opening of the active site, whereby the β-lactam antibiotic now is enabled to bind to the active site in its mechanism of action. The combination effectively treats MRSA infection, for which many antibiotics (including TZP) have faced clinical obsolescence.
Collapse
Affiliation(s)
- Yuanyuan Qian
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - Giuseppe Allegretta
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - Jeshina Janardhanan
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - Zhihong Peng
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - Kiran V Mahasenan
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - Elena Lastochkin
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - Melissa Malia N Gozun
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - Sara Tejera
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - Valerie A Schroeder
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - William R Wolter
- Freimann Life Sciences Center, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - Rhona Feltzer
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - Shahriar Mobashery
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, United States
| | - Mayland Chang
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556, United States
| |
Collapse
|
8
|
Shalaby MAW, Dokla EME, Serya RAT, Abouzid KAM. Penicillin binding protein 2a: An overview and a medicinal chemistry perspective. Eur J Med Chem 2020; 199:112312. [PMID: 32442851 DOI: 10.1016/j.ejmech.2020.112312] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2019] [Revised: 03/28/2020] [Accepted: 04/05/2020] [Indexed: 12/17/2022]
Abstract
Antimicrobial resistance is an imminent threat worldwide. Methicillin-resistant Staphylococcus aureus (MRSA) is one of the "superbug" family, manifesting resistance through the production of a penicillin binding protein, PBP2a, an enzyme that provides its transpeptidase activity to allow cell wall biosynthesis. PBP2a's low affinity to most β-lactams, confers resistance to MRSA against numerous members of this class of antibiotics. An Achilles' heel of MRSA, PBP2a represents a substantial target to design novel antibiotics to tackle MRSA threat via inhibition of the bacterial cell wall biosynthesis. In this review we bring into focus the PBP2a enzyme and examine the various aspects related to its role in conferring resistance to MRSA strains. Moreover, we discuss several antibiotics and antimicrobial agents designed to target PBP2a and their therapeutic potential to meet such a grave threat. In conclusion, we consider future perspectives for targeting MRSA infections.
Collapse
Affiliation(s)
- Menna-Allah W Shalaby
- Pharmaceutical Chemistry Department, Faculty of Pharmacy, Ain Shams University, Abbassia, 11566, Cairo, Egypt
| | - Eman M E Dokla
- Pharmaceutical Chemistry Department, Faculty of Pharmacy, Ain Shams University, Abbassia, 11566, Cairo, Egypt.
| | - Rabah A T Serya
- Pharmaceutical Chemistry Department, Faculty of Pharmacy, Ain Shams University, Abbassia, 11566, Cairo, Egypt
| | - Khaled A M Abouzid
- Pharmaceutical Chemistry Department, Faculty of Pharmacy, Ain Shams University, Abbassia, 11566, Cairo, Egypt; Department of Organic and Medicinal Chemistry, Faculty of Pharmacy, University of Sadat City, Sadat City, Egypt.
| |
Collapse
|
9
|
Chiang Y, Wong MTY, Essex JW. Molecular Dynamics Simulations of Antibiotic Ceftaroline at the Allosteric Site of Penicillin‐Binding Protein 2a (PBP2a). Isr J Chem 2020. [DOI: 10.1002/ijch.202000012] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Ying‐Chih Chiang
- School of ChemistryUniversity of Southampton Southampton SO17 1BJ United Kingdom
| | - Mabel T. Y. Wong
- School of ChemistryUniversity of Southampton Southampton SO17 1BJ United Kingdom
| | - Jonathan W. Essex
- School of ChemistryUniversity of Southampton Southampton SO17 1BJ United Kingdom
| |
Collapse
|
10
|
Roch M, Lelong E, Panasenko OO, Sierra R, Renzoni A, Kelley WL. Thermosensitive PBP2a requires extracellular folding factors PrsA and HtrA1 for Staphylococcus aureus MRSA β-lactam resistance. Commun Biol 2019; 2:417. [PMID: 31754647 PMCID: PMC6858329 DOI: 10.1038/s42003-019-0667-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2019] [Accepted: 10/25/2019] [Indexed: 12/21/2022] Open
Abstract
Staphylococcus aureus is a major human pathogen and represents a clinical challenge because of widespread antibiotic resistance. Methicillin resistant Staphylococcus aureus (MRSA) is particularly problematic and originates by the horizontal acquisition of mecA encoding PBP2a, an extracellular membrane anchored transpeptidase, which confers resistance to β-lactam antibiotics by allosteric gating of its active site channel. Herein, we show that dual disruption of PrsA, a lipoprotein chaperone displaying anti-aggregation activity, together with HtrA1, a membrane anchored chaperone/serine protease, resulted in severe and synergistic attenuation of PBP2a folding that restores sensitivity to β-lactams such as oxacillin. Purified PBP2a has a pronounced unfolding transition initiating at physiological temperatures that leads to irreversible precipitation and complete loss of activity. The concordance of genetic and biochemical data highlights the necessity for extracellular protein folding factors governing MRSA β-lactam resistance. Targeting the PBP2a folding pathway represents a particularly attractive adjuvant strategy to combat antibiotic resistance.
Collapse
Affiliation(s)
- Mélanie Roch
- Department of Microbiology and Molecular Medicine, University Hospital and Medical School of Geneva, 1 rue Michel-Servet, Geneva, CH-1211 Switzerland
| | - Emmanuelle Lelong
- Service of Infectious Diseases and Department of Medical Specialties, University Hospital and Medical School of Geneva, 4 rue Gabrielle-Perret-Gentil, Geneva, CH-1206 Switzerland
| | - Olesya O. Panasenko
- Department of Microbiology and Molecular Medicine, University Hospital and Medical School of Geneva, 1 rue Michel-Servet, Geneva, CH-1211 Switzerland
- Service of Infectious Diseases and Department of Medical Specialties, University Hospital and Medical School of Geneva, 4 rue Gabrielle-Perret-Gentil, Geneva, CH-1206 Switzerland
| | - Roberto Sierra
- Department of Microbiology and Molecular Medicine, University Hospital and Medical School of Geneva, 1 rue Michel-Servet, Geneva, CH-1211 Switzerland
| | - Adriana Renzoni
- Service of Infectious Diseases and Department of Medical Specialties, University Hospital and Medical School of Geneva, 4 rue Gabrielle-Perret-Gentil, Geneva, CH-1206 Switzerland
| | - William L. Kelley
- Department of Microbiology and Molecular Medicine, University Hospital and Medical School of Geneva, 1 rue Michel-Servet, Geneva, CH-1211 Switzerland
| |
Collapse
|
11
|
Hill MA, Lam AK, Reed P, Harney MC, Wilson BA, Moen EL, Wright SN, Pinho MG, Rice CV. BPEI-Induced Delocalization of PBP4 Potentiates β-Lactams against MRSA. Biochemistry 2019; 58:3813-3822. [PMID: 31429286 PMCID: PMC6941424 DOI: 10.1021/acs.biochem.9b00523] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
With its high morbidity rate and increasing resistance to treatment, methicillin-resistant Staphylococcus aureus (MRSA) is a grave concern in the medical field. In methicillin-susceptible strains, β-lactam antibiotics disable the penicillin binding proteins (PBPs) that cross-link the bacterial cell wall. However, methicillin-resistant strains have PBP2a and PBP4, which continue enzymatic activity in the presence of β-lactam antibiotics. The activity of PBP2a and PBP4 is linked to the presence of wall teichoic acid (WTA); thus, WTA has emerged as a target for antibiotic drug discovery. In this work, we disable WTA in situ using its anionic phosphodiester backbone to attract cationic branched polyethylenimine (BPEI). Data show that BPEI removes β-lactam resistance in common MRSA strains and clinical isolates. Fluorescence microscopy was used to investigate this mechanism of action. The results indicate that BPEI prevents the localization of PBP4 to the cell division septum, thereby changing the cellular morphology and inhibiting cell division. Although PBP4 is not required for septum formation, proper cell division and morphology require WTA; BPEI prevents this essential function. The combination of BPEI and β-lactams is bactericidal and synergistic. Because BPEI allows us to study the role of WTA in the cell wall without genetic mutation or altered translocation of biomolecules and/or their precursors, this approach can help revise existing paradigms regarding the role of WTA in prokaryotic biochemistry at every growth stage.
Collapse
Affiliation(s)
- Melissa A. Hill
- Department of Chemistry and Biochemistry, Stephenson Life Sciences Research Center, University of Oklahoma, 101 Stephenson Parkway, Norman, Oklahoma 73019, United States
| | - Anh K. Lam
- Department of Chemistry and Biochemistry, Stephenson Life Sciences Research Center, University of Oklahoma, 101 Stephenson Parkway, Norman, Oklahoma 73019, United States
| | - Patricia Reed
- Laboratory of Bacterial Cell Biology, Instituto de Tecnologia Química e Biologica António Xavier, Universidade NOVA de Lisboa, Av. da Repùblica, 2780-157 Oeiras, Portugal
| | - Madeline C. Harney
- Department of Chemistry and Biochemistry, Stephenson Life Sciences Research Center, University of Oklahoma, 101 Stephenson Parkway, Norman, Oklahoma 73019, United States
| | - Beatrice A. Wilson
- Department of Chemistry and Biochemistry, Stephenson Life Sciences Research Center, University of Oklahoma, 101 Stephenson Parkway, Norman, Oklahoma 73019, United States
| | - Erika L. Moen
- Department of Chemistry and Biochemistry, Stephenson Life Sciences Research Center, University of Oklahoma, 101 Stephenson Parkway, Norman, Oklahoma 73019, United States
| | - Summer N. Wright
- Department of Chemistry and Biochemistry, Stephenson Life Sciences Research Center, University of Oklahoma, 101 Stephenson Parkway, Norman, Oklahoma 73019, United States
| | - Mariana G. Pinho
- Laboratory of Bacterial Cell Biology, Instituto de Tecnologia Química e Biologica António Xavier, Universidade NOVA de Lisboa, Av. da Repùblica, 2780-157 Oeiras, Portugal
| | - Charles V. Rice
- Department of Chemistry and Biochemistry, Stephenson Life Sciences Research Center, University of Oklahoma, 101 Stephenson Parkway, Norman, Oklahoma 73019, United States
| |
Collapse
|
12
|
Decuyper L, Jukič M, Sosič I, Žula A, D'hooghe M, Gobec S. Antibacterial and β-Lactamase Inhibitory Activity of Monocyclic β-Lactams. Med Res Rev 2017; 38:426-503. [DOI: 10.1002/med.21443] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2016] [Revised: 01/16/2017] [Accepted: 02/08/2017] [Indexed: 01/06/2023]
Affiliation(s)
- Lena Decuyper
- SynBioC Research Group, Department of Sustainable Organic Chemistry and Technology, Faculty of Bioscience Engineering; Ghent University; Ghent Belgium
| | - Marko Jukič
- Faculty of Pharmacy; University of Ljubljana; Ljubljana Slovenia
| | - Izidor Sosič
- Faculty of Pharmacy; University of Ljubljana; Ljubljana Slovenia
| | - Aleš Žula
- Faculty of Pharmacy; University of Ljubljana; Ljubljana Slovenia
| | - Matthias D'hooghe
- SynBioC Research Group, Department of Sustainable Organic Chemistry and Technology, Faculty of Bioscience Engineering; Ghent University; Ghent Belgium
| | - Stanislav Gobec
- Faculty of Pharmacy; University of Ljubljana; Ljubljana Slovenia
| |
Collapse
|
13
|
Srisuknimit V, Qiao Y, Schaefer K, Kahne D, Walker S. Peptidoglycan Cross-Linking Preferences of Staphylococcus aureus Penicillin-Binding Proteins Have Implications for Treating MRSA Infections. J Am Chem Soc 2017; 139:9791-9794. [PMID: 28691491 PMCID: PMC5613940 DOI: 10.1021/jacs.7b04881] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) infections are a global public health problem. MRSA strains have acquired a non-native penicillin-binding protein called PBP2a that cross-links peptidoglycan when the native S. aureus PBPs are inhibited by β-lactams. It has been proposed that the native S. aureus PBPs can use cell wall precursors having different glycine branch lengths (penta-, tri-, or monoglycine), while PBP2a can only cross-link peptidoglycan strands bearing a complete pentaglycine branch. This hypothesis has never been tested because the necessary substrates have not been available. Here, we compared the ability of PBP2a and two native S. aureus transpeptidases to cross-link peptidoglycan strands bearing different glycine branches. We show that purified PBP2a can cross-link glycan strands bearing penta- and triglycine, but not monoglycine, and experiments in cells provide support for these findings. Because PBP2a cannot cross-link peptidoglycan containing monoglycine, this study implicates the enzyme (FemA) that extends the monoglycine branch to triglycine on Lipid II as an ideal target for small molecules that restore sensitivity of MRSA to β-lactams.
Collapse
Affiliation(s)
- Veerasak Srisuknimit
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts, 02138, United States
| | - Yuan Qiao
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts, 02138, United States
- Department of Microbiology and Immunology, Harvard Medical School, Boston, Massachusetts, 02138, United States
| | - Kaitlin Schaefer
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts, 02138, United States
- Department of Microbiology and Immunology, Harvard Medical School, Boston, Massachusetts, 02138, United States
| | - Daniel Kahne
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts, 02138, United States
| | - Suzanne Walker
- Department of Microbiology and Immunology, Harvard Medical School, Boston, Massachusetts, 02138, United States
| |
Collapse
|
14
|
Andrey DO, François P, Manzano C, Bonetti EJ, Harbarth S, Schrenzel J, Kelley WL, Renzoni A. Antimicrobial activity of ceftaroline against methicillin-resistant Staphylococcus aureus (MRSA) isolates collected in 2013-2014 at the Geneva University Hospitals. Eur J Clin Microbiol Infect Dis 2017; 36:343-350. [PMID: 27744604 PMCID: PMC5253141 DOI: 10.1007/s10096-016-2807-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2016] [Accepted: 09/27/2016] [Indexed: 11/30/2022]
Abstract
Ceftaroline is a broad-spectrum antibiotic with activity against methicillin-resistant Staphylococcus aureus (MRSA) strains. Ceftaroline susceptibility of an MRSA set archived between 1994 and 2003 in the Geneva University Hospitals detected a high percentage (66 %) of ceftaroline resistance in clonotypes ST228 and ST247 and correlated with mutations in PBP2a. The ceftaroline mechanism of action is based on the inhibition of PBP2a; thus, the identification of PBP2a mutations of recently circulating clonotypes in our institution was investigated. We analyzed ceftaroline susceptibility in MRSA isolates (2013 and 2014) and established that resistant strains correlated with PBP2a mutations and specific clonotypes. Ninety-six MRSA strains were analyzed from independent patients and were isolated from blood cultures (23 %), deep infections (38.5 %), and superficial (skin or wound) infections (38.5 %). This sample showed a ceftaroline minimum inhibitory concentration (MIC) range between 0.25 and 2 μg/ml and disk diameters ranging from 10 to 30 mm, with a majority of strains showing diameters ≥20 mm. Based on the European Committee on Antimicrobial Susceptibility Testing (EUCAST) breakpoints, 76 % (73/96) of isolates showed susceptibility to ceftaroline. Nevertheless, we still observed 24 % (23/96) of resistant isolates (MIC = 2 μg/ml). All resistant isolates were assigned to clonotype ST228 and carried the N146K mutation in PBP2a. Only two ST228 isolates showed ceftaroline susceptibility. The decreasing percentage of ceftaroline-resistant isolates in our hospital can be explained by the decline of ST228 clonotype circulating in our hospital since 2008. We present evidence that ceftaroline is active against recent MRSA strains from our hospital; however, the presence of PBP2a variants in particular clonotypes may affect ceftaroline efficacy.
Collapse
Affiliation(s)
- D O Andrey
- Service of Infectious Diseases, Department of Medical Specialties, Geneva University Hospitals and Medical School, Geneva, Switzerland
| | - P François
- Genomic Research Laboratory, Service of Infectious Diseases, Department of Medical Specialties, Geneva University Hospitals and Medical School, Geneva, Switzerland
| | - C Manzano
- Service of Infectious Diseases, Department of Medical Specialties, Geneva University Hospitals and Medical School, Geneva, Switzerland
| | - E J Bonetti
- Genomic Research Laboratory, Service of Infectious Diseases, Department of Medical Specialties, Geneva University Hospitals and Medical School, Geneva, Switzerland
| | - S Harbarth
- Service of Infectious Diseases, Department of Medical Specialties, Geneva University Hospitals and Medical School, Geneva, Switzerland
- Infection Control Program, Geneva University Hospitals and Medical School, Geneva, Switzerland
| | - J Schrenzel
- Service of Infectious Diseases, Department of Medical Specialties, Geneva University Hospitals and Medical School, Geneva, Switzerland
- Genomic Research Laboratory, Service of Infectious Diseases, Department of Medical Specialties, Geneva University Hospitals and Medical School, Geneva, Switzerland
- Bacteriology Laboratory, Department of Laboratories and Genetic Medicine, Geneva University Hospitals, Geneva, Switzerland
| | - W L Kelley
- Department of Microbiology and Molecular Medicine, Faculty of Medicine, Geneva University, Geneva, Switzerland
| | - A Renzoni
- Service of Infectious Diseases, Department of Medical Specialties, Geneva University Hospitals and Medical School, Geneva, Switzerland.
- Service of Infectious Diseases, Geneva University Hospital and Medical School, 4 Rue Gabrielle Perret Gentil, Geneva, Switzerland.
| |
Collapse
|
15
|
Mahasenan KV, Molina R, Bouley R, Batuecas MT, Fisher JF, Hermoso JA, Chang M, Mobashery S. Conformational Dynamics in Penicillin-Binding Protein 2a of Methicillin-Resistant Staphylococcus aureus, Allosteric Communication Network and Enablement of Catalysis. J Am Chem Soc 2017; 139:2102-2110. [PMID: 28099001 DOI: 10.1021/jacs.6b12565] [Citation(s) in RCA: 56] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The mechanism of the β-lactam antibacterials is the functionally irreversible acylation of the enzymes that catalyze the cross-linking steps in the biosynthesis of their peptidoglycan cell wall. The Gram-positive pathogen Staphylococcus aureus uses one primary resistance mechanism. An enzyme, called penicillin-binding protein 2a (PBP2a), is brought into this biosynthetic pathway to complete the cross-linking. PBP2a effectively discriminates against the β-lactam antibiotics as potential inhibitors, and in favor of the peptidoglycan substrate. The basis for this discrimination is an allosteric site, distal from the active site, that when properly occupied concomitantly opens the gatekeeper residues within the active site and realigns the conformation of key residues to permit catalysis. We address the molecular basis of this regulation using crystallographic studies augmented by computational analyses. The crystal structures of three β-lactams (oxacillin, cefepime, ceftazidime) complexes with PBP2a-each with the β-lactam in the allosteric site-defined (with preceding PBP2a structures) as the "open" or "partially open" PBP2a states. A particular loop motion adjacent to the active site is identified as the driving force for the active-site conformational change that accompanies active-site opening. Correlation of this loop motion to effector binding at the allosteric site, in order to identify the signaling pathway, was accomplished computationally in reference to the known "closed" apo-PBP2a X-ray crystal structure state. This correlation enabled the computational simulation of the structures coinciding with initial peptidoglycan substrate binding to PBP2a, acyl enzyme formation, and acyl transfer to a second peptidoglycan substrate to attain cross-linking. These studies offer important insights into the structural bases for allosteric site-to-active site communication and for β-lactam mimicry of the peptidoglycan substrates, as foundational to the mechanistic understanding of emerging PBP2a resistance mutations.
Collapse
Affiliation(s)
- Kiran V Mahasenan
- Department of Chemistry and Biochemistry, University of Notre Dame , Notre Dame, Indiana 46556, United States
| | - Rafael Molina
- Department of Crystallography and Structural Biology, Institute of Physical Chemistry "Rocasolano", CSIC , 28006 Madrid, Spain
| | - Renee Bouley
- Department of Chemistry and Biochemistry, University of Notre Dame , Notre Dame, Indiana 46556, United States
| | - María T Batuecas
- Department of Crystallography and Structural Biology, Institute of Physical Chemistry "Rocasolano", CSIC , 28006 Madrid, Spain
| | - Jed F Fisher
- Department of Chemistry and Biochemistry, University of Notre Dame , Notre Dame, Indiana 46556, United States
| | - Juan A Hermoso
- Department of Crystallography and Structural Biology, Institute of Physical Chemistry "Rocasolano", CSIC , 28006 Madrid, Spain
| | - Mayland Chang
- Department of Chemistry and Biochemistry, University of Notre Dame , Notre Dame, Indiana 46556, United States
| | - Shahriar Mobashery
- Department of Chemistry and Biochemistry, University of Notre Dame , Notre Dame, Indiana 46556, United States
| |
Collapse
|
16
|
Abstract
β-Lactamases, the enzymes that hydrolyze β-lactam antibiotics, remain the greatest threat to the usage of these agents. In this review, the mechanism of hydrolysis is discussed for both those enzymes that use serine at the active site and those that require divalent zinc ions for hydrolysis. The β-lactamases now include >2000 unique, naturally occurring amino acid sequences. Some of the clinically most important of these are the class A penicillinases, the extended-spectrum β-lactamases (ESBLs), the AmpC cephalosporinases, and the carbapenem-hydrolyzing enzymes in both the serine and metalloenzyme groups. Because of the versatility of these enzymes to evolve as new β-lactams are used therapeutically, new approaches to antimicrobial therapy may be required.
Collapse
Affiliation(s)
- Robert A Bonomo
- Department of Medicine, Case Western Reserve University School of Medicine, Louis Stokes Cleveland Department of Veterans Affairs Medical Center, Cleveland, Ohio 44120.,Departments of Pharmacology, Molecular Biology and Microbiology, Biochemistry, and Proteomics and Bioinformatics, Case Western Reserve University School of Medicine, Cleveland, Ohio 44120
| |
Collapse
|
17
|
Lahiri SD, Alm RA. Identification of non-PBP2a resistance mechanisms in Staphylococcus aureus after serial passage with ceftaroline: involvement of other PBPs. J Antimicrob Chemother 2016; 71:3050-3057. [PMID: 27494915 DOI: 10.1093/jac/dkw282] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2016] [Revised: 05/12/2016] [Accepted: 06/11/2016] [Indexed: 12/16/2023] Open
Abstract
OBJECTIVES Ceftaroline (the active metabolite of ceftaroline fosamil) is a cephalosporin that possesses activity against MRSA due to its differentiating high affinity for PBP2a. It is known that PBP2a sequence variations, including some outside of the transpeptidase-binding pocket, impact ceftaroline susceptibility and recent evidence suggests involvement of non-PBP2a mechanisms in ceftaroline resistance. This study evaluated the potential of ceftaroline to select for resistant Staphylococcus aureus clones during serial passage. METHODS Selection experiments were performed by up to 20 daily passages of three S. aureus isolates (two MRSA and one MSSA) in broth with increasing selective pressure. Mutants that emerged were tested for changes in ceftaroline susceptibility and genetically characterized. RESULTS The MSSA isolate developed mutations in PBP2 and PBP3 that increased the ceftaroline MIC by 16-fold and increased the MICs of other β-lactams. A Glu447Lys substitution in the PBP2a transpeptidase pocket in one MRSA isolate elevated the ceftaroline MIC to 8 mg/L. Selective pressure in a ceftaroline-resistant MRSA isolate generated mutations in LytD, as well as changes in the pbp4 promoter previously shown to result in PBP4 overexpression, the one PBP not inhibited by ceftaroline. Elevated ceftaroline MIC was reversed when tested in combination with extremely low levels of methicillin or meropenem that could inhibit the function of PBP4. CONCLUSIONS These studies demonstrate that resistance to ceftaroline can be manifested through numerous mechanisms. Further, they support a hypothesis where PBP4 can functionally provide the essential transpeptidase activity required for MRSA cell wall biogenesis when PBP2a is inhibited.
Collapse
Affiliation(s)
- Sushmita D Lahiri
- Infection Innovative Medicines Unit, AstraZeneca R&D Boston, Waltham, MA, USA
| | - Richard A Alm
- Infection Innovative Medicines Unit, AstraZeneca R&D Boston, Waltham, MA, USA
| |
Collapse
|
18
|
Wang DY, Abboud MI, Markoulides MS, Brem J, Schofield CJ. The road to avibactam: the first clinically useful non-β-lactam working somewhat like a β-lactam. Future Med Chem 2016; 8:1063-84. [PMID: 27327972 DOI: 10.4155/fmc-2016-0078] [Citation(s) in RCA: 85] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2023] Open
Abstract
Avibactam, which is the first non-β-lactam β-lactamase inhibitor to be introduced for clinical use, is a broad-spectrum serine β-lactamase inhibitor with activity against class A, class C, and, some, class D β-lactamases. We provide an overview of efforts, which extend to the period soon after the discovery of the penicillins, to develop clinically useful non-β-lactam compounds as antibacterials, and, subsequently, penicillin-binding protein and β-lactamase inhibitors. Like the β-lactam inhibitors, avibactam works via a mechanism involving covalent modification of a catalytically important nucleophilic serine residue. However, unlike the β-lactam inhibitors, avibactam reacts reversibly with its β-lactamase targets. We discuss chemical factors that may account for the apparently special nature of β-lactams and related compounds as antibacterials and β-lactamase inhibitors, including with respect to resistance. Avenues for future research including non-β-lactam antibacterials acting similarly to β-lactams are discussed.
Collapse
Affiliation(s)
| | | | | | - Jürgen Brem
- Department of Chemistry, University of Oxford, UK
| | | |
Collapse
|
19
|
Fisher JF, Mobashery S. β-Lactam Resistance Mechanisms: Gram-Positive Bacteria and Mycobacterium tuberculosis. Cold Spring Harb Perspect Med 2016; 6:cshperspect.a025221. [PMID: 27091943 DOI: 10.1101/cshperspect.a025221] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The value of the β-lactam antibiotics for the control of bacterial infection has eroded with time. Three Gram-positive human pathogens that were once routinely susceptible to β-lactam chemotherapy-Streptococcus pneumoniae, Enterococcus faecium, and Staphylococcus aureus-now are not. Although a fourth bacterium, the acid-fast (but not Gram-positive-staining) Mycobacterium tuberculosis, has intrinsic resistance to earlier β-lactams, the emergence of strains of this bacterium resistant to virtually all other antibiotics has compelled the evaluation of newer β-lactam combinations as possible contributors to the multidrug chemotherapy required to control tubercular infection. The emerging molecular-level understanding of these resistance mechanisms used by these four bacteria provides the conceptual framework for bringing forward new β-lactams, and new β-lactam strategies, for the future control of their infections.
Collapse
Affiliation(s)
- Jed F Fisher
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556-5670
| | - Shahriar Mobashery
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, Indiana 46556-5670
| |
Collapse
|
20
|
Shapiro AB. Investigation of β-lactam antibacterial drugs, β-lactamases, and penicillin-binding proteins with fluorescence polarization and anisotropy: a review. Methods Appl Fluoresc 2016; 4:024002. [DOI: 10.1088/2050-6120/4/2/024002] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
21
|
Abstract
The practice of medicine was profoundly transformed by the introduction of the antibiotics (compounds isolated from Nature) and the antibacterials (compounds prepared by synthesis) for the control of bacterial infection. As a result of the extraordinary success of these compounds over decades of time, a timeless biological activity for these compounds has been presumed. This presumption is no longer. The inexorable acquisition of resistance mechanisms by bacteria is retransforming medical practice. Credible answers to this dilemma are far better recognized than they are being implemented. In this perspective we examine (and in key respects, reiterate) the chemical and biological strategies being used to address the challenge of bacterial resistance.
Collapse
Affiliation(s)
- Jed F. Fisher
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame IN 46556–5670, USA
| | - Shahriar Mobashery
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame IN 46556–5670, USA
| |
Collapse
|
22
|
References. Antibiotics (Basel) 2015. [DOI: 10.1128/9781555819316.refs] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
|