1
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Gardner TM, Grosser MR. A MRSA mystery: how PBP4 and cyclic-di-AMP join forces against β-lactam antibiotics. mBio 2024; 15:e0121024. [PMID: 39028200 PMCID: PMC11323572 DOI: 10.1128/mbio.01210-24] [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] [Indexed: 07/20/2024] Open
Abstract
The high-level resistance to next-generation β-lactams frequently found in Staphylococcus aureus isolates lacking mec, which encodes the transpeptidase PBP2a traditionally associated with methicillin-resistant Staphylococcus aureus (MRSA), has remained incompletely understood for decades. A new study by Lai et al. found that the co-occurrence of mutations in pbp4 and gdpP, which respectively cause increased PBP4-mediated cell wall crosslinking and elevated cyclic-di-AMP levels, produces synergistic β-lactam resistance rivaling that of PBP2a-producing MRSA (L.-Y. Lai, N. Satishkumar, S. Cardozo, V. Hemmadi, et al., mBio 15:e02889-23. 2024, https://doi.org/10.1128/mbio.02889-23). The combined mutations are sufficient to explain the high-level β-lactam resistance of some mec-lacking strains, but the mechanism of synergy remains elusive and an avenue for further research. Importantly, the authors establish that co-occurrence of these mutations leads to antibiotic therapy failure in a Caenorhabditis elegans infection model. These results underscore the need to consider this unique and novel β-lactam resistance mechanism during the clinical diagnosis of MRSA, rather than relying on mec as a diagnostic.
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Affiliation(s)
- Taylor M. Gardner
- Department of Biology, University of North Carolina Asheville, Asheville, North Carolina, USA
| | - Melinda R. Grosser
- Department of Biology, University of North Carolina Asheville, Asheville, North Carolina, USA
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2
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Kanzouai Y, Laghmari M, Yamari I, Bouzammit R, Bahsis L, Benali T, Chtita S, Bakhouch M, Akhazzane M, El Kouali M, Hammani K, Al Houari G. Chromone-isoxazole hybrids molecules: synthesis, spectroscopic, MEDT, ELF, antibacterial, ADME-Tox, molecular docking and MD simulation investigations. J Biomol Struct Dyn 2024; 42:6410-6424. [PMID: 37817499 DOI: 10.1080/07391102.2023.2266022] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2023] [Accepted: 07/01/2023] [Indexed: 10/12/2023]
Abstract
A mechanistic study was performed within the molecular electron density theory at the B3LYP/6-311G (d,p) computational level to explain the regioselectivity observed. An electron localization function analysis was also performed, and the results confirm the zwitterionic-type (zw-type) mechanism of the cycloaddition reactions between nitrile oxide and alkylated 4H-chromene-2-carboxylate derivatives and shed more light on the obtained regioselectivity experimentally. In silico studies on the pharmacokinetics, ADME and toxicity tests of the compounds were also performed, and it was projected that compounds 5a, 5b, 5c and 5d are pharmacokinetic and have favorable ADME profiles. Moreover, docking and molecular dynamics investigations were conducted to evaluate the interactions, orientation and conformation of the target compounds on the active sites of four distinct enzymes. The results of this investigation showed that two compounds, 5a and 5c, interacted effectively with the S. aureus active site while maintaining acceptable binding energy.Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Youssra Kanzouai
- Engineering Laboratory of Organometallic and Molecular Materials and Environment, Department of Chemistry, Faculty of Sciences Dhar El Mahraz, University of Sidi Mohamed Ben Abdellah, Fez, Morocco
| | - Mustapha Laghmari
- Laboratory of Natural Resources and Environment, Department of Biology Polydisciplinary Faculty of Taza, Sidi Mohamed Ben Abdellah University, Taza, Morocco
| | - Imane Yamari
- Laboratory of Analytical and Molecular Chemistry, Department of Chemistry, Faculty of Sciences Ben M'Sik, Hassan II University of Casablanca, Casablanca, Morocco
| | - Rachid Bouzammit
- Engineering Laboratory of Organometallic and Molecular Materials and Environment, Department of Chemistry, Faculty of Sciences Dhar El Mahraz, University of Sidi Mohamed Ben Abdellah, Fez, Morocco
| | - Lahoucine Bahsis
- Laboratoire de Chimie Analytique et Moléculaire, LCAM, Département de Chimie, Faculté Polydisciplinaire de Safi, Université Cadi Ayyad, Safi, Morocco
| | - Taoufiq Benali
- Laboratory of Natural Resources and Environment, Department of Biology Polydisciplinary Faculty of Taza, Sidi Mohamed Ben Abdellah University, Taza, Morocco
- Environment and Health Team, Polydisciplinary Faculty of Safi, Department of Biology, Cadi Ayyad University, Safi, Morocco
| | - Samir Chtita
- Laboratory of Analytical and Molecular Chemistry, Department of Chemistry, Faculty of Sciences Ben M'Sik, Hassan II University of Casablanca, Casablanca, Morocco
| | - Mohamed Bakhouch
- Bioorganic Chemistry Team, Department of Chemistry, Faculty of Sciences, University Chouaïb Doukkali, El Jadida, Morocco
| | - Mohamed Akhazzane
- Cité de l'innovation, Université Sidi Mohamed Ben Abdellah, Fez, Morocco
| | - M'hammed El Kouali
- Laboratory of Analytical and Molecular Chemistry, Department of Chemistry, Faculty of Sciences Ben M'Sik, Hassan II University of Casablanca, Casablanca, Morocco
| | - Khalil Hammani
- Laboratory of Natural Resources and Environment, Department of Biology Polydisciplinary Faculty of Taza, Sidi Mohamed Ben Abdellah University, Taza, Morocco
| | - Ghali Al Houari
- Engineering Laboratory of Organometallic and Molecular Materials and Environment, Department of Chemistry, Faculty of Sciences Dhar El Mahraz, University of Sidi Mohamed Ben Abdellah, Fez, Morocco
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3
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Arzine A, Hadni H, Boujdi K, Chebbac K, Barghady N, Rhazi Y, Chalkha M, Nakkabi A, Chkirate K, Mague JT, Kawsar SMA, Al Houari G, M. Alanazi M, El Yazidi M. Efficient Synthesis, Structural Characterization, Antibacterial Assessment, ADME-Tox Analysis, Molecular Docking and Molecular Dynamics Simulations of New Functionalized Isoxazoles. Molecules 2024; 29:3366. [PMID: 39064944 PMCID: PMC11279828 DOI: 10.3390/molecules29143366] [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: 05/11/2024] [Revised: 06/28/2024] [Accepted: 07/11/2024] [Indexed: 07/28/2024] Open
Abstract
This work describes the synthesis, characterization, and in vitro and in silico evaluation of the biological activity of new functionalized isoxazole derivatives. The structures of all new compounds were analyzed by IR and NMR spectroscopy. The structures of 4c and 4f were further confirmed by single crystal X-ray and their compositions unambiguously determined by mass spectrometry (MS). The antibacterial effect of the isoxazoles was assessed in vitro against Escherichia coli, Bacillus subtilis, and Staphylococcusaureus bacterial strains. Isoxazole 4a showed significant activity against E. coli and B. subtilis compared to the reference antibiotic drugs while 4d and 4f also exhibited some antibacterial effects. The molecular docking results indicate that the synthesized compounds exhibit strong interactions with the target proteins. Specifically, 4a displayed a better affinity for E. coli, S. aureus, and B. subtilis in comparison to the reference drugs. The molecular dynamics simulations performed on 4a strongly support the stability of the ligand-receptor complex when interacting with the active sites of proteins from E. coli, S. aureus, and B. subtilis. Lastly, the results of the Absorption, Distribution, Metabolism, Excretion and Toxicity Analysis (ADME-Tox) reveal that the molecules have promising pharmacokinetic properties, suggesting favorable druglike properties and potential therapeutic agents.
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Affiliation(s)
- Aziz Arzine
- Engineering Laboratory of Organometallic, Molecular Materials and Environment, Faculty of Sciences Dhar EL Mahraz, Sidi Mohamed Ben Abdellah University, P.O. Box 1796, Atlas, Fez 30000, Morocco; (A.A.); (N.B.); (Y.R.); (A.N.); (G.A.H.); (M.E.Y.)
| | - Hanine Hadni
- LIMAS, Faculty of Sciences Dhar El Mahraz, Sidi Mohamed Ben Abdellah University, P.O. Box 1796, Atlas, Fez 30000, Morocco;
- Faculty of Health and Life Sciences, INTI International University, Persiaran Perdana BBN, Putra Nilai, Nilai 71800, Malaysia
| | - Khalid Boujdi
- Faculty of Sciences and Technologies Mohammedia, University Hassan II, B.P. 146, Mohammedia 28800, Morocco;
| | - Khalid Chebbac
- Laboratory of Biotechnology Conservation and Valorisation of Natural Resources, Faculty of Sciences Dhar El Mahraz, Sidi Mohamed Ben Abdallah University, Fez 30000, Morocco;
| | - Najoua Barghady
- Engineering Laboratory of Organometallic, Molecular Materials and Environment, Faculty of Sciences Dhar EL Mahraz, Sidi Mohamed Ben Abdellah University, P.O. Box 1796, Atlas, Fez 30000, Morocco; (A.A.); (N.B.); (Y.R.); (A.N.); (G.A.H.); (M.E.Y.)
| | - Yassine Rhazi
- Engineering Laboratory of Organometallic, Molecular Materials and Environment, Faculty of Sciences Dhar EL Mahraz, Sidi Mohamed Ben Abdellah University, P.O. Box 1796, Atlas, Fez 30000, Morocco; (A.A.); (N.B.); (Y.R.); (A.N.); (G.A.H.); (M.E.Y.)
| | - Mohammed Chalkha
- Engineering Laboratory of Organometallic, Molecular Materials and Environment, Faculty of Sciences Dhar EL Mahraz, Sidi Mohamed Ben Abdellah University, P.O. Box 1796, Atlas, Fez 30000, Morocco; (A.A.); (N.B.); (Y.R.); (A.N.); (G.A.H.); (M.E.Y.)
- Laboratory of Materials Engineering for the Environment and Natural Ressources, Faculty of Sciences and Techniques, University of Moulay Ismail of Meknès, B.P 509, Boutalamine, Errachidia 52000, Morocco
| | - Asmae Nakkabi
- Engineering Laboratory of Organometallic, Molecular Materials and Environment, Faculty of Sciences Dhar EL Mahraz, Sidi Mohamed Ben Abdellah University, P.O. Box 1796, Atlas, Fez 30000, Morocco; (A.A.); (N.B.); (Y.R.); (A.N.); (G.A.H.); (M.E.Y.)
- Laboratory of Materials Engineering for the Environment and Natural Ressources, Faculty of Sciences and Techniques, University of Moulay Ismail of Meknès, B.P 509, Boutalamine, Errachidia 52000, Morocco
| | - Karim Chkirate
- Laboratory of Heterocyclic Organic Chemistry URAC 21, Pharmacochemistry Competence Center, Av. Ibn Battouta, BP 1014, Faculty of Sciences, Mohammed V University in Rabat, Rabat 10010, Morocco;
| | - Joel T. Mague
- Department of Chemistry, Tulane University, New Orleans, LA 70118, USA;
| | - Sarkar M. A. Kawsar
- Laboratory of Carbohydrate and Nucleoside Chemistry (LCNC), Department of Chemistry, Faculty of Science, University of Chittagong, Chittagong 4331, Bangladesh;
| | - Ghali Al Houari
- Engineering Laboratory of Organometallic, Molecular Materials and Environment, Faculty of Sciences Dhar EL Mahraz, Sidi Mohamed Ben Abdellah University, P.O. Box 1796, Atlas, Fez 30000, Morocco; (A.A.); (N.B.); (Y.R.); (A.N.); (G.A.H.); (M.E.Y.)
| | - Mohammed M. Alanazi
- Department of Pharmaceutical Chemistry, College of Pharmacy, King Saud University, Riyadh 11451, Saudi Arabia;
| | - Mohamed El Yazidi
- Engineering Laboratory of Organometallic, Molecular Materials and Environment, Faculty of Sciences Dhar EL Mahraz, Sidi Mohamed Ben Abdellah University, P.O. Box 1796, Atlas, Fez 30000, Morocco; (A.A.); (N.B.); (Y.R.); (A.N.); (G.A.H.); (M.E.Y.)
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4
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Gondil VS, Butman HS, Young M, Walsh DJ, Narkhede Y, Zeiler MJ, Crow AH, Carpenter ME, Mardikar A, Melander RJ, Wiest O, Dunman PM, Melander C. Development of phenyl-urea-based small molecules that target penicillin-binding protein 4. Chem Biol Drug Des 2024; 103:e14569. [PMID: 38877369 PMCID: PMC11185276 DOI: 10.1111/cbdd.14569] [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: 03/05/2024] [Revised: 05/08/2024] [Accepted: 05/22/2024] [Indexed: 06/16/2024]
Abstract
Staphylococcus aureus has the ability to invade cortical bone osteocyte lacuno-canalicular networks (OLCNs) and cause osteomyelitis. It was recently established that the cell wall transpeptidase, penicillin-binding protein 4 (PBP4), is crucial for this function, with pbp4 deletion strains unable to invade OLCNs and cause bone pathogenesis in a murine model of S. aureus osteomyelitis. Moreover, PBP4 has recently been found to modulate S. aureus resistance to β-lactam antibiotics. As such, small molecule inhibitors of S. aureus PBP4 may represent dual functional antimicrobial agents that limit osteomyelitis and/or reverse antibiotic resistance. A high throughput screen recently revealed that the phenyl-urea 1 targets PBP4. Herein, we describe a structure-activity relationship (SAR) study on 1. Leveraging in silico docking and modeling, a set of analogs was synthesized and assessed for PBP4 inhibitory activities. Results revealed a preliminary SAR and identified lead compounds with enhanced binding to PBP4, more potent antibiotic resistance reversal, and diminished PBP4 cell wall transpeptidase activity in comparison to 1.
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Affiliation(s)
- Vijay S. Gondil
- Department of Microbiology and Immunology, University of Rochester Medical Center, Rochester, New York 14642, United States
| | - Hailey S. Butman
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN, 46556, United States
| | - Mikaeel Young
- Department of Microbiology and Immunology, University of Rochester Medical Center, Rochester, New York 14642, United States
| | - Danica J. Walsh
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN, 46556, United States
| | - Yogesh Narkhede
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN, 46556, United States
| | - Michael J. Zeiler
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN, 46556, United States
| | - Andrew H. Crow
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN, 46556, United States
| | - Morgan E. Carpenter
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN, 46556, United States
| | - Aashay Mardikar
- Department of Microbiology and Immunology, University of Rochester Medical Center, Rochester, New York 14642, United States
| | - Roberta J. Melander
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN, 46556, United States
| | - Olaf Wiest
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN, 46556, United States
| | - Paul M. Dunman
- Department of Microbiology and Immunology, University of Rochester Medical Center, Rochester, New York 14642, United States
| | - Christian Melander
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN, 46556, United States
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5
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Lai LY, Satishkumar N, Cardozo S, Hemmadi V, Marques LB, Huang L, Filipe SR, Pinho MG, Chambers HF, Chatterjee SS. Altered PBP4 and GdpP functions synergistically mediate MRSA-like high-level, broad-spectrum β-lactam resistance in Staphylococcus aureus. mBio 2024; 15:e0288923. [PMID: 38530033 PMCID: PMC11077961 DOI: 10.1128/mbio.02889-23] [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: 10/24/2023] [Accepted: 03/04/2024] [Indexed: 03/27/2024] Open
Abstract
Infections caused by Staphylococcus aureus are a leading cause of mortality worldwide. S. aureus infections caused by methicillin-resistant Staphylococcus aureus (MRSA) are particularly difficult to treat due to their resistance to next-generation β-lactams (NGBs) such as methicillin, nafcillin, and oxacillin. Resistance to NGBs, which is alternatively known as broad-spectrum β-lactam resistance, is classically mediated by PBP2a, a penicillin-binding protein encoded by mecA (or mecC) in MRSA. Thus, presence of mec genes among S. aureus spp. serves as the predictor of resistance to NGBs and facilitates determination of the proper therapeutic strategy for a staphylococcal infection. Although far less appreciated, mecA-deficient S. aureus strains can also exhibit NGB resistance. These strains, which are collectively termed as methicillin-resistant lacking mec (MRLM), are currently being identified in increasing numbers among natural resistant isolates of S. aureus. The mechanism/s through which MRLMs produce resistance to NGBs remains unknown. In this study, we demonstrate that mutations that alter PBP4 and GdpP functions, which are often present among MRLMs, can synergistically mediate resistance to NGBs. Furthermore, our results unravel that this novel mechanism potentially enables MRLMs to produce resistance toward NGBs at levels comparable to those of MRSAs. Our study provides a fresh new perspective about alternative mechanisms of NGB resistance, challenging our current overall understanding of high-level, broad-spectrum β-lactam resistance in S. aureus. It thus suggests reconsideration of the current approach toward diagnosis and treatment of β-lactam-resistant S. aureus infections. IMPORTANCE In Staphylococcus aureus, high-level, broad-spectrum resistance to β-lactams such as methicillin, also referred to as methicillin resistance, is largely attributed to mecA. This study demonstrates that S. aureus strains that lack mecA but contain mutations that functionally alter PBP4 and GdpP can also mediate high-level, broad-spectrum resistance to β-lactams. Resistance brought about by the synergistic action of functionally altered PBP4 and GdpP was phenotypically comparable to that displayed by mecA, as seen by increased bacterial survival in the presence of β-lactams. An analysis of mutations detected in naturally isolated strains of S. aureus revealed that a significant proportion of them had similar pbp4 and GGDEF domain protein containing phosphodiesterase (gdpP) mutations, making this study clinically significant. This study not only identifies important players of non-classical mechanisms of β-lactam resistance but also indicates reconsideration of current clinical diagnosis and treatment protocols of S. aureus infections.
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Affiliation(s)
- Li-Yin Lai
- Department of Microbial Pathogenesis, School of Dentistry, University of Maryland Baltimore, Baltimore, Maryland, USA
- Institute of Marine and Environmental Technology (IMET), Baltimore, Maryland, USA
| | - Nidhi Satishkumar
- Department of Microbial Pathogenesis, School of Dentistry, University of Maryland Baltimore, Baltimore, Maryland, USA
- Institute of Marine and Environmental Technology (IMET), Baltimore, Maryland, USA
| | - Sasha Cardozo
- Department of Microbial Pathogenesis, School of Dentistry, University of Maryland Baltimore, Baltimore, Maryland, USA
- Institute of Marine and Environmental Technology (IMET), Baltimore, Maryland, USA
| | - Vijay Hemmadi
- Department of Microbial Pathogenesis, School of Dentistry, University of Maryland Baltimore, Baltimore, Maryland, USA
- Institute of Marine and Environmental Technology (IMET), Baltimore, Maryland, USA
| | - Leonor B. Marques
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Liusheng Huang
- Department of Clinical Pharmacy, Drug Research Unit, University of California, San Francisco, California, USA
| | - Sergio R. Filipe
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
- UCIBIO-REQUIMTE, Departamento de Ciências da Vida, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Caparica, Portugal
| | - Mariana G. Pinho
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Henry F. Chambers
- Division of Infectious Diseases, School of Medicine, University of California San Francisco, San Francisco, California, USA
| | - Som S. Chatterjee
- Department of Microbial Pathogenesis, School of Dentistry, University of Maryland Baltimore, Baltimore, Maryland, USA
- Institute of Marine and Environmental Technology (IMET), Baltimore, Maryland, USA
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6
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Zhang XL, Báti G, Li C, Guo A, Yeo C, Ding H, Pal KB, Xu Y, Qiao Y, Liu XW. GlcNAc-1,6-anhydro-MurNAc Moiety Affords Unusual Glycosyl Acceptor that Terminates Peptidoglycan Elongation. J Am Chem Soc 2024; 146:7400-7407. [PMID: 38456799 DOI: 10.1021/jacs.3c12526] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/09/2024]
Abstract
Peptidoglycan (PG), an essential exoskeletal polymer in bacteria, is a well-known antibiotic target. PG polymerization requires the action of bacterial transglycosylases (TGases), which couple the incoming glycosyl acceptor to the donor. Interfering with the TGase activity can interrupt the PG assembly. Existing TGase inhibitors like moenomycin and Lipid II analogues always occupy the TGase active sites; other strategies to interfere with proper PG elongation have not been widely exploited. Inspired by the natural 1,6-anhydro-MurNAc termini that mark the ends of PG strands in bacteria, we hypothesized that the incorporation of an anhydromuramyl-containing glycosyl acceptor by TGase into the growing PG may effectively inhibit PG elongation. To explore this possibility, we synthesized 4-O-(N-acetyl-β-d-glucosaminyl)-1,6-anhydro-N-acetyl-β-d-muramyl-l-Ala-γ-d-Glu-l-Lys-d-Ala-d-Ala, 1, within 15 steps, and demonstrated that this anhydromuropeptide and its analogue lacking the peptide, 1-deAA, were both utilized by bacterial TGase as noncanonical anhydro glycosyl acceptors in vitro. The incorporation of an anhydromuramyl moiety into PG strands by TGases afforded efficient termination of glycan chain extension. Moreover, the preliminary in vitro studies of 1-deAA against Staphylococcus aureus showed that 1-deAA served as a reasonable antimicrobial adjunct of vancomycin. These insights imply the potential application of such anhydromuropeptides as novel classes of PG-terminating inhibitors, pointing toward novel strategies in antibacterial agent development.
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Affiliation(s)
- Xiao-Lin Zhang
- School of Chemistry, Chemical Engineering and Biotechnology, Nanyang Technological University, Singapore 637371, Singapore
| | - Gábor Báti
- School of Chemistry, Chemical Engineering and Biotechnology, Nanyang Technological University, Singapore 637371, Singapore
| | - Chenyu Li
- School of Chemistry, Chemical Engineering and Biotechnology, Nanyang Technological University, Singapore 637371, Singapore
| | - Aoxin Guo
- School of Chemistry, Chemical Engineering and Biotechnology, Nanyang Technological University, Singapore 637371, Singapore
| | - Claresta Yeo
- School of Chemistry, Chemical Engineering and Biotechnology, Nanyang Technological University, Singapore 637371, Singapore
| | - Han Ding
- School of Chemistry, Chemical Engineering and Biotechnology, Nanyang Technological University, Singapore 637371, Singapore
| | - Kumar Bhaskar Pal
- School of Chemistry, Chemical Engineering and Biotechnology, Nanyang Technological University, Singapore 637371, Singapore
| | - Yuan Xu
- School of Chemistry, Chemical Engineering and Biotechnology, Nanyang Technological University, Singapore 637371, Singapore
| | - Yuan Qiao
- School of Chemistry, Chemical Engineering and Biotechnology, Nanyang Technological University, Singapore 637371, Singapore
| | - Xue-Wei Liu
- School of Chemistry, Chemical Engineering and Biotechnology, Nanyang Technological University, Singapore 637371, Singapore
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7
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Lai LY, Satishkumar N, Cardozo S, Hemmadi V, Marques LB, Huang L, Filipe SR, Pinho MG, Chambers HF, Chatterjee SS. Altered PBP4 and GdpP functions synergistically mediate MRSA-like high-level, broad-spectrum β-lactam resistance in Staphylococcus aureus. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.10.26.564222. [PMID: 37961375 PMCID: PMC10634853 DOI: 10.1101/2023.10.26.564222] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
Infections caused by Staphylococcus aureus are a leading cause of mortality worldwide. S. aureus infections caused by Methicillin-Resistant Staphylococcus aureus (MRSA) are particularly difficult to treat due to their resistance to Next Generation β-lactams (NGB) such as Methicillin, Nafcillin, Oxacillin etc. Resistance to NGBs, which is alternatively known as broad-spectrum β-lactam resistance is classically mediated by PBP2a, a Penicillin-Binding Protein encoded by mecA (or mecC) in MRSA. Thus, presence of mec genes among S. aureus serves as the predictor of resistance to NGBs and facilitates determination of the proper therapeutic strategy for a staphylococcal infection. Although far less appreciated, mecA deficient S. aureus strains can also exhibit NGB resistance. These strains, which are collectively termed as Methicillin-Resistant Lacking mec (MRLM) are currently being identified in increasing numbers among natural resistant isolates of S. aureus. The mechanism/s through which MRLMs produce resistance to NGBs remains unknown. In this study, we demonstrate that mutations that alter PBP4 and GdpP functions, which are often present among MRLMs can synergistically mediate resistance to NGBs. Furthermore, our results unravel that this novel mechanism potentially enables MRLMs to produce resistance towards NGBs at levels comparable to that of MRSAs. Our study, provides a fresh new perspective about alternative mechanisms of NGBs resistance, challenging our current overall understanding of high-level, broad-spectrum β-lactam resistance in S. aureus. It thus suggests reconsideration of the current approach towards diagnosis and treatment of β-lactam resistant S. aureus infections.
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Affiliation(s)
- Li-Yin Lai
- Department of Microbial Pathogenesis, School of Dentistry, University of Maryland Baltimore, USA
- Institute of Marine and Environmental Technology (IMET), Baltimore, USA
| | - Nidhi Satishkumar
- Department of Microbial Pathogenesis, School of Dentistry, University of Maryland Baltimore, USA
- Institute of Marine and Environmental Technology (IMET), Baltimore, USA
| | - Sasha Cardozo
- Department of Microbial Pathogenesis, School of Dentistry, University of Maryland Baltimore, USA
- Institute of Marine and Environmental Technology (IMET), Baltimore, USA
| | - Vijay Hemmadi
- Department of Microbial Pathogenesis, School of Dentistry, University of Maryland Baltimore, USA
- Institute of Marine and Environmental Technology (IMET), Baltimore, USA
| | - Leonor B. Marques
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Liusheng Huang
- Drug Research Unit, Department of Clinical Pharmacy, University of California, San Francisco, San Francisco, CA, USA
| | - Sergio R. Filipe
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
- UCIBIO-REQUIMTE, Departamento de Ciências da Vida, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Caparica, Portugal
| | - Mariana G. Pinho
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Henry F. Chambers
- Division of Infectious Diseases, School of Medicine, University of California San Francisco, San Francisco, CA, USA
| | - Som S. Chatterjee
- Department of Microbial Pathogenesis, School of Dentistry, University of Maryland Baltimore, USA
- Institute of Marine and Environmental Technology (IMET), Baltimore, USA
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8
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Lade H, Kim JS. Molecular Determinants of β-Lactam Resistance in Methicillin-Resistant Staphylococcus aureus (MRSA): An Updated Review. Antibiotics (Basel) 2023; 12:1362. [PMID: 37760659 PMCID: PMC10525618 DOI: 10.3390/antibiotics12091362] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Revised: 08/21/2023] [Accepted: 08/24/2023] [Indexed: 09/29/2023] Open
Abstract
The development of antibiotic resistance in Staphylococcus aureus, particularly in methicillin-resistant S. aureus (MRSA), has become a significant health concern worldwide. The acquired mecA gene encodes penicillin-binding protein 2a (PBP2a), which takes over the activities of endogenous PBPs and, due to its low affinity for β-lactam antibiotics, is the main determinant of MRSA. In addition to PBP2a, other genetic factors that regulate cell wall synthesis, cell signaling pathways, and metabolism are required to develop high-level β-lactam resistance in MRSA. Although several genetic factors that modulate β-lactam resistance have been identified, it remains unclear how they alter PBP2a expression and affect antibiotic resistance. This review describes the molecular determinants of β-lactam resistance in MRSA, with a focus on recent developments in our understanding of the role of mecA-encoded PBP2a and on other genetic factors that modulate the level of β-lactam resistance. Understanding the molecular determinants of β-lactam resistance can aid in developing novel strategies to combat MRSA.
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Affiliation(s)
| | - Jae-Seok Kim
- Department of Laboratory Medicine, Hallym University College of Medicine, Kangdong Sacred Heart Hospital, Seoul 05355, Republic of Korea;
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9
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Shahzadi I, Aqeel M, Haider A, Naz S, Imran M, Nabgan W, Al-Shanini A, Shahzadi A, Alshahrani T, Ikram M. Hydrothermal Synthesis of Fe-Doped Cadmium Oxide Showed Bactericidal Behavior and Highly Efficient Visible Light Photocatalysis. ACS OMEGA 2023; 8:30681-30693. [PMID: 37636921 PMCID: PMC10448685 DOI: 10.1021/acsomega.3c04543] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/26/2023] [Accepted: 07/28/2023] [Indexed: 08/29/2023]
Abstract
Cationic dyes present in industrial effluents significantly reduce the effectiveness of remediation operations. Considering the terrible impact of these pollutants on environment and biodiversity, investigating strategies to remove potentially harmful compounds from water is becoming an increasingly intriguing issue. In this work, we employed a simple hydrothermal technique to synthesize Fe-doped CdO (2, 4, and 6 wt %) nanostructures and assessed their efficacy in degrading methylene blue (MB) dye and inhibiting the growth of Staphylococcus aureus and Escherichia coli, respectively. Structural, morphological, and optical characterization of produced nanomaterials was also performed using X-ray diffraction, TEM, and UV absorption spectra. The photocatalytic decomposition of MB was significantly enhanced (58.8%) by using Fe (6 wt %)-doped CdO catalysts for 80 min under irradiation. In addition, 2.05-5.05 mm inhibitory zones were seen against Gram-positive bacteria (S. aureus), whereas the range for Gram-negative bacteria (E. coli) was 1.65-2.75 mm. These nanostructures were shown to be very effective inhibitors of beta-lactamase, d-alanine-d-alanine ligase B, and fatty acid synthase inhibitor by in silico molecular docking investigations.
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Affiliation(s)
- Iram Shahzadi
- Punjab
University College of Pharmacy, Allama Iqbal Campus, University of the Punjab, Lahore 54000, Punjab, Pakistan
| | - Muhammad Aqeel
- Department
of Physics, The University of Gothenburg, Box 100 405 30 Gothenburg, Sweden
| | - Ali Haider
- Department
of Clinical Sciences, Faculty of Veterinary and Animal Sciences, Muhammad Nawaz Shareef University of Agriculture, Multan, 66000 Punjab, Pakistan
| | - Sadia Naz
- Tianjin
Institute of Industrial Biotechnology, Chinese
Academy of Sciences, Tianjin 300308, China
| | - Muhammad Imran
- Department
of Chemistry, Government College University
Faisalabad, Pakpattan
Road, Sahiwal, Punjab 57000, Pakistan
| | - Walid Nabgan
- Departament
d’Enginyeria Química, Universitat
Rovira I Virgili, Av Països Catalans 26,, Tarragona 43007, Spain
| | - Ali Al-Shanini
- College
of Petroleum and Engineering, Hadhramout
University, Hadhramout,
P.O. Box 50511, Mukalla 50511, Yemen
| | - Anum Shahzadi
- Faculty
of Pharmacy, The University of Lahore, Lahore, Punjab 54000, Pakistan
| | - Thamraa Alshahrani
- Department
of Physics, College of Sciences, Princess
Nourah bint Abdulrahman University (PNU), P.O. Box 84428, Riyadh 11671, Saudi Arabia
| | - Muhammad Ikram
- Solar
Cell Applications Research Lab, Department of Physics, Government College University Lahore, Lahore, Punjab 54000, Pakistan
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10
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Design, Synthesis, Antimicrobial Evaluation, Antioxidant Studies, and Molecular Docking of Some New 1
H
‐Benzimidazole Derivatives. ChemistrySelect 2023. [DOI: 10.1002/slct.202203651] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
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11
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Flanders PL, Contreras-Martel C, Brown NW, Shirley JD, Martins A, Nauta KN, Dessen A, Carlson EE, Ambrose EA. Combined Structural Analysis and Molecular Dynamics Reveal Penicillin-Binding Protein Inhibition Mode with β-Lactones. ACS Chem Biol 2022; 17:3110-3120. [PMID: 36173746 PMCID: PMC10057605 DOI: 10.1021/acschembio.2c00503] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
β-Lactam antibiotics comprise one of the most widely used therapeutic classes to combat bacterial infections. This general scaffold has long been known to inhibit bacterial cell wall biosynthesis by inactivating penicillin-binding proteins (PBPs); however, bacterial resistance to β-lactams is now widespread, and new strategies are urgently needed to target PBPs and other proteins involved in bacterial cell wall formation. A key requirement in the identification of strategies to overcome resistance is a deeper understanding of the roles of the PBPs and their associated proteins during cell growth and division, such as can be obtained with the use of selective chemical probes. Probe development has typically depended upon known PBP inhibitors, which have historically been thought to require a negatively charged moiety that mimics the C-terminus of the PBP natural peptidoglycan substrate, d-Ala-d-Ala. However, we have identified a new class of β-lactone-containing molecules that interact with PBPs, often in an isoform-specific manner, and do not incorporate this C-terminal mimetic. Here, we report a series of structural biology experiments and molecular dynamics simulations that we utilized to evaluate specific binding modes of this novel PBP inhibitor class. In this work, we obtained <2 Å resolution X-ray structures of four β-lactone probes bound to PBP1b from Streptococcus pneumoniae. Despite their diverging recognition modes beyond the site of covalent modification, these four probes all efficiently labeled PBP1b, as well as other PBPs from S. pneumoniae. From these structures, we analyzed protein-ligand interactions and characterized the β-lactone-bound active sites using in silico mutagenesis and molecular dynamics. Our approach has clarified the dynamic interaction profile in this series of ligands, expanding the understanding of PBP inhibitor binding.
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Affiliation(s)
- Parker L Flanders
- Department of Medicinal Chemistry, University of Minnesota, 208 Harvard Street SE, Minneapolis, Minnesota 55454, United States
| | - Carlos Contreras-Martel
- Université Grenoble Alpes, CNRS, CEA, Institut de Biologie Structurale (IBS), F-38044 Grenoble, France
| | - Nathaniel W Brown
- Department of Chemistry, University of Minnesota, 207 Pleasant Street SE, Minneapolis, Minnesota 55455, United States
| | - Joshua D Shirley
- Department of Medicinal Chemistry, University of Minnesota, 208 Harvard Street SE, Minneapolis, Minnesota 55454, United States
| | - Alexandre Martins
- Université Grenoble Alpes, CNRS, CEA, Institut de Biologie Structurale (IBS), F-38044 Grenoble, France
| | - Kelsie N Nauta
- Department of Chemistry, University of Minnesota, 207 Pleasant Street SE, Minneapolis, Minnesota 55455, United States
| | - Andréa Dessen
- Université Grenoble Alpes, CNRS, CEA, Institut de Biologie Structurale (IBS), F-38044 Grenoble, France.,Brazilian Biosciences National Laboratory (LNBio), CNPEM, Campinas 13084-971, São Paulo, Brazil
| | - Erin E Carlson
- Department of Medicinal Chemistry, University of Minnesota, 208 Harvard Street SE, Minneapolis, Minnesota 55454, United States.,Department of Chemistry, University of Minnesota, 207 Pleasant Street SE, Minneapolis, Minnesota 55455, United States.,Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, 321 Church Street SE, Minneapolis, Minnesota 55454, United States.,Department of Pharmacology, University of Minnesota, 321 Church Street SE, Minneapolis, Minnesota 55454, United States
| | - Elizabeth A Ambrose
- Department of Medicinal Chemistry, University of Minnesota, 208 Harvard Street SE, Minneapolis, Minnesota 55454, United States.,Minnesota Supercomputing Institute for Advanced Computational Research, University of Minnesota, Minneapolis, Minnesota 55455, United States
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12
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Antimicrobial Activity of Rhenium Di- and Tricarbonyl Diimine Complexes: Insights on Membrane-Bound S. aureus Protein Binding. Pharmaceuticals (Basel) 2022; 15:ph15091107. [PMID: 36145328 PMCID: PMC9501577 DOI: 10.3390/ph15091107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Revised: 08/31/2022] [Accepted: 08/31/2022] [Indexed: 11/16/2022] Open
Abstract
Antimicrobial resistance is one of the major human health threats, with significant impacts on the global economy. Antibiotics are becoming increasingly ineffective as drug-resistance spreads, imposing an urgent need for new and innovative antimicrobial agents. Metal complexes are an untapped source of antimicrobial potential. Rhenium complexes, amongst others, are particularly attractive due to their low in vivo toxicity and high antimicrobial activity, but little is known about their targets and mechanism of action. In this study, a series of rhenium di- and tricarbonyl diimine complexes were prepared and evaluated for their antimicrobial potential against eight different microorganisms comprising Gram-negative and -positive bacteria. Our data showed that none of the Re dicarbonyl or neutral tricarbonyl species have either bactericidal or bacteriostatic potential. In order to identify possible targets of the molecules, and thus possibly understand the observed differences in the antimicrobial efficacy of the molecules, we computationally evaluated the binding affinity of active and inactive complexes against structurally characterized membrane-bound S. aureus proteins. The computational analysis indicates two possible major targets for this class of compounds, namely lipoteichoic acids flippase (LtaA) and lipoprotein signal peptidase II (LspA). Our results, consistent with the published in vitro studies, will be useful for the future design of rhenium tricarbonyl diimine-based antibiotics.
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13
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Saqallah FG, Hamed WM, Talib WH, Dianita R, Wahab HA. Antimicrobial activity and molecular docking screening of bioactive components of Antirrhinum majus (snapdragon) aerial parts. Heliyon 2022; 8:e10391. [PMID: 36072262 PMCID: PMC9441312 DOI: 10.1016/j.heliyon.2022.e10391] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Revised: 05/19/2022] [Accepted: 08/15/2022] [Indexed: 11/28/2022] Open
Abstract
Background Antirrhinum majus (Snapdragon) is a perennial Mediterranean-native plant that is commonly used for mass display. Few reports acknowledged the traditional use of A. majus for its medicinal and therapeutic effects. Herein, we assess the impact of A. majus’s sample preparation and extraction methods on the plant-aerial parts’ phytochemical contents and antimicrobial activity. Furthermore, the microbial targets of the extracts’ secondary metabolites are inspected using molecular docking simulations. Methods The leaves and flowers of A. majus were prepared as fresh and air-dried samples, then extracted using cold maceration and hot reflux, respectively. Extracts with the best phytochemical profiles were selected to test their antimicrobial activities against Bacillus subtilis, Staphylococcus aureus, Enterobacter aerogenes, Escherichia coli and Candida albicans. Besides, molecular docking of 66 reported isolated compounds was conducted against various microbial targets. Results The dried-refluxed samples revealed a massive deterioration in their phytochemical profiles, whereas the macerated flowers extract exhibited the highest total phenolic content and antimicrobial activity against all tested bacterial strains. However, both flowers and leaves extracts showed similar minimum inhibitory and lethal concentrations against C. albicans. Molecular docking studies revealed that chlorogenic acid, chalcononaringenin 4’-glucoside, 3,4,2’,4’,6’-pentahydroxy-chalcone 4’-glucoside, apigenin-7-glucuronide, and luteolin-7-glucuronide were the lead compounds in expressing the antimicrobial activity. Yet, A. majus’s compounds could neither inhibit the 30S ribosomal subunit nor muramyl ligase E. Conclusion Our results suggest that cold maceration of A. majus fresh aerial parts gave higher flavonoid and phenolic content contributing to its antimicrobial properties. These flavonoids and phenolic compounds are predicted to have a crucial role in inhibiting fungal sterol 14-demethylase, and bacterial dihydropteroate synthase and gyrase B subunit proteins. Air-drying of A. majus’s aerial parts deteriorates its phytochemical composition, affecting its antimicrobial activity. A. majus’s fresh-flowers macerate exhibited the highest total phenolic content and antibacterial activity. The antimycotic activity of A. majus was the same for flowers and leaves macerates. In-silico results showed that some phenolics, chalcones, and flavonoids are responsible for the antimicrobial activity. A.majus’s components act on fungal sterol 14-demethylase, and bacterial dihydropteroate synthase and gyrase B enzymes.
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Affiliation(s)
- Fadi G. Saqallah
- Discipline of Pharmaceutical Chemistry, School of Pharmaceutical Sciences, Universiti Sains Malaysia, 11800 Minden, Penang, Malaysia
- Faculty of Pharmacy, Applied Science Private University, 11931, Amman, Jordan
| | - Wafaa M. Hamed
- Pharmacy Department, Al-Noor University College, 41019, Mosul, Iraq
- Corresponding author.
| | - Wamidh H. Talib
- Faculty of Pharmacy, Applied Science Private University, 11931, Amman, Jordan
| | - Roza Dianita
- Discipline of Pharmaceutical Chemistry, School of Pharmaceutical Sciences, Universiti Sains Malaysia, 11800 Minden, Penang, Malaysia
| | - Habibah A. Wahab
- Discipline of Pharmaceutical Technology, School of Pharmaceutical Sciences, Universiti Sains Malaysia, 11800 Minden, Penang, Malaysia
- Corresponding author.
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14
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In Vitro and In Silico Antistaphylococcal Activity of Indole Alkaloids Isolated from Tabernaemontana cymosa Jacq (Apocynaceae). Sci Pharm 2022. [DOI: 10.3390/scipharm90020038] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The species of the genus Tabernaemontana have a long tradition of use in different pathologies of infectious origins; the antibacterial, antifungal, and antiviral effects related to the control of the pathologies where the species of this genus are used, have been attributed to the indole monoterpene alkaloids, mainly those of the iboga type. There are more than 1000 alkaloids isolated from different species of Tabernaemontana and other genera of the Apocynaceae family, several of which lack studies related to antibacterial activity. In the present study, four monoterpene indole alkaloids were isolated from the seeds of the species Tabernaemontana cymosa Jacq, namely voacangine (1), voacangine-7-hydroxyindolenine (2), 3-oxovoacangine (3), and rupicoline (4), which were tested in an in vitro antibacterial activity study against the bacteria S. aureus, sensitive and resistant to methicillin, and classified by the World Health Organization as critical for the investigation of new antibiotics. Of the four alkaloids tested, only voacangine was active against S. aureus, with an MIC of 50 µg/mL. In addition, an in silico study was carried out between the four isolated alkaloids and some proteins of this bacterium, finding that voacangine also showed binding to proteins involved in cell wall synthesis, mainly PBP2 and PBP2a.
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15
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Thaker TM, Mishra S, Zhou W, Mohan M, Tang Q, Faraldo-Goméz JD, Mchaourab HS, Tomasiak TM. Asymmetric drug binding in an ATP-loaded inward-facing state of an ABC transporter. Nat Chem Biol 2022; 18:226-235. [PMID: 34931066 PMCID: PMC9242650 DOI: 10.1038/s41589-021-00936-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Accepted: 10/26/2021] [Indexed: 12/24/2022]
Abstract
Substrate efflux by ATP-binding cassette (ABC) transporters, which play a major role in multidrug resistance, entails the ATP-powered interconversion between transporter intermediates. Despite recent progress in structure elucidation, a number of intermediates have yet to be visualized and mechanistically interpreted. Here, we combine cryogenic-electron microscopy (cryo-EM), double electron-electron resonance spectroscopy and molecular dynamics simulations to profile a previously unobserved intermediate of BmrCD, a heterodimeric multidrug ABC exporter from Bacillus subtilis. In our cryo-EM structure, ATP-bound BmrCD adopts an inward-facing architecture featuring two molecules of the substrate Hoechst-33342 in a striking asymmetric head-to-tail arrangement. Deletion of the extracellular domain capping the substrate-binding chamber or mutation of Hoechst-coordinating residues abrogates cooperative stimulation of ATP hydrolysis. Together, our findings support a mechanistic role for symmetry mismatch between the nucleotide binding and the transmembrane domains in the conformational cycle of ABC transporters and is of notable importance for rational design of molecules for targeted ABC transporter inhibition.
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Affiliation(s)
- Tarjani M Thaker
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, AZ, USA
| | - Smriti Mishra
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, USA
- St Jude Children's Research Hospital, Memphis, TN, USA
| | - Wenchang Zhou
- Theoretical Molecular Biophysics Laboratory, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, USA
| | - Michael Mohan
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, USA
| | - Qingyu Tang
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, USA
| | - José D Faraldo-Goméz
- Theoretical Molecular Biophysics Laboratory, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, USA
| | - Hassane S Mchaourab
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, USA.
| | - Thomas M Tomasiak
- Department of Chemistry and Biochemistry, University of Arizona, Tucson, AZ, USA.
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16
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Dietrich A, Steffens U, Sass P, Bierbaum G. The hypersusceptible antibiotic screening strain Staphylococcus aureus SG511-Berlin harbors multiple mutations in regulatory genes. Int J Med Microbiol 2021; 311:151545. [PMID: 34896903 DOI: 10.1016/j.ijmm.2021.151545] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2021] [Revised: 12/01/2021] [Accepted: 12/05/2021] [Indexed: 10/19/2022] Open
Abstract
The genetic plasticity of Staphylococcus aureus has facilitated the evolution of many virulent and drug-resistant strains. Here we present the sequence of the 2.74 Mbp genome of S. aureus SG511-Berlin, which is frequently used for antibiotic screening. Although S. aureus SG511 and the related methicillin-resistant S. aureus MRSA252 share a high similarity in their core genomes, indicated by an average nucleotide identity (ANI) of 99.83%, the accessory genomes of these strains differed, as nearly no mobile elements and resistance determinants were identified in the genome of S. aureus SG511. Susceptibility testing showed that S. aureus SG511 was susceptible to most of the tested antibiotics of different classes. Intriguingly, and in contrast to the standard laboratory strain S. aureus HG001, S. aureus SG511 was even hyper-susceptible towards cell wall and membrane targeting agents, with the exception of the MurA-inhibitor fosfomycin. In depth comparative genome analysis revealed that, in addition to the loss of function mutation in the antibiotic sensor histidine kinase gene graS, further mutations had occurred in the lysyltransferase gene mprF, the structural giant protein gene ebh, and the regulator genes codY and saeR, which might contribute to antibiotic susceptibility. In addition, an insertion element in agrC abolishes Agr-activity in S. aureus SG511, and the spa and sarS genes, which encode the surface protein SpA and its transcriptional regulator, were deleted. Thus, the lack of mobile resistance genes together with multiple mutations affecting cell envelope morphology may render S. aureus SG511 hyper-susceptible towards most cell wall targeting agents.
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Affiliation(s)
- Alina Dietrich
- Institute of Medical Microbiology, Immunology and Parasitology, University Hospital Bonn, Medical Faculty, 53127 Bonn, Germany.
| | - Ursula Steffens
- Institute of Medical Microbiology, Immunology and Parasitology, University Hospital Bonn, Medical Faculty, 53127 Bonn, Germany.
| | - Peter Sass
- Institute of Medical Microbiology, Immunology and Parasitology, University Hospital Bonn, Medical Faculty, 53127 Bonn, Germany.
| | - Gabriele Bierbaum
- Institute of Medical Microbiology, Immunology and Parasitology, University Hospital Bonn, Medical Faculty, 53127 Bonn, Germany.
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17
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Loch JI, Imiolczyk B, Sliwiak J, Wantuch A, Bejger M, Gilski M, Jaskolski M. Crystal structures of the elusive Rhizobium etli L-asparaginase reveal a peculiar active site. Nat Commun 2021; 12:6717. [PMID: 34795296 PMCID: PMC8602277 DOI: 10.1038/s41467-021-27105-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Accepted: 11/01/2021] [Indexed: 12/04/2022] Open
Abstract
Rhizobium etli, a nitrogen-fixing bacterial symbiont of legume plants, encodes an essential L-asparaginase (ReAV) with no sequence homology to known enzymes with this activity. High-resolution crystal structures of ReAV show indeed a structurally distinct, dimeric enzyme, with some resemblance to glutaminases and β-lactamases. However, ReAV has no glutaminase or lactamase activity, and at pH 9 its allosteric asparaginase activity is relatively high, with Km for L-Asn at 4.2 mM and kcat of 438 s-1. The active site of ReAV, deduced from structural comparisons and confirmed by mutagenesis experiments, contains a highly specific Zn2+ binding site without a catalytic role. The extensive active site includes residues with unusual chemical properties. There are two Ser-Lys tandems, all connected through a network of H-bonds to the Zn center, and three tightly bound water molecules near Ser48, which clearly indicate the catalytic nucleophile.
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Affiliation(s)
- Joanna I Loch
- Department of Crystal Chemistry and Crystal Physics, Faculty of Chemistry, Jagiellonian University, Krakow, Poland
| | - Barbara Imiolczyk
- Institute of Bioorganic Chemistry, Polish Academy of Sciences, Poznan, Poland
| | - Joanna Sliwiak
- Institute of Bioorganic Chemistry, Polish Academy of Sciences, Poznan, Poland
| | - Anna Wantuch
- Department of Crystal Chemistry and Crystal Physics, Faculty of Chemistry, Jagiellonian University, Krakow, Poland
| | - Magdalena Bejger
- Institute of Bioorganic Chemistry, Polish Academy of Sciences, Poznan, Poland
| | - Miroslaw Gilski
- Institute of Bioorganic Chemistry, Polish Academy of Sciences, Poznan, Poland
- Department of Crystallography, Faculty of Chemistry, A. Mickiewicz University, Poznan, Poland
| | - Mariusz Jaskolski
- Institute of Bioorganic Chemistry, Polish Academy of Sciences, Poznan, Poland.
- Department of Crystallography, Faculty of Chemistry, A. Mickiewicz University, Poznan, Poland.
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18
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Martínez-Caballero S, Mahasenan KV, Kim C, Molina R, Feltzer R, Lee M, Bouley R, Hesek D, Fisher JF, Muñoz IG, Chang M, Mobashery S, Hermoso JA. Integrative structural biology of the penicillin-binding protein-1 from Staphylococcus aureus, an essential component of the divisome machinery. Comput Struct Biotechnol J 2021; 19:5392-5405. [PMID: 34667534 PMCID: PMC8493512 DOI: 10.1016/j.csbj.2021.09.018] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Revised: 09/13/2021] [Accepted: 09/15/2021] [Indexed: 12/18/2022] Open
Abstract
The penicillin-binding proteins are the enzyme catalysts of the critical transpeptidation crosslinking polymerization reaction of bacterial peptidoglycan synthesis and the molecular targets of the penicillin antibiotics. Here, we report a combined crystallographic, small-angle X-ray scattering (SAXS) in-solution structure, computational and biophysical analysis of PBP1 of Staphylococcus aureus (saPBP1), providing mechanistic clues about its function and regulation during cell division. The structure reveals the pedestal domain, the transpeptidase domain, and most of the linker connecting to the "penicillin-binding protein and serine/threonine kinase associated" (PASTA) domains, but not its two PASTA domains, despite their presence in the construct. To address this absence, the structure of the PASTA domains was determined at 1.5 Å resolution. Extensive molecular-dynamics simulations interpret the PASTA domains of saPBP1 as conformationally mobile and separated from the transpeptidase domain. This conclusion was confirmed by SAXS experiments on the full-length protein in solution. A series of crystallographic complexes with β-lactam antibiotics (as inhibitors) and penta-Gly (as a substrate mimetic) allowed the molecular characterization of both inhibition by antibiotics and binding for the donor and acceptor peptidoglycan strands. Mass-spectrometry experiments with synthetic peptidoglycan fragments revealed binding by PASTA domains in coordination with the remaining domains. The observed mobility of the PASTA domain in saPBP1 could play a crucial role for in vivo interaction with its glycosyltransferase partner in the membrane or with other components of the divisome machinery, as well as for coordination of transpeptidation and polymerization processes in the bacterial divisome.
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Affiliation(s)
- Siseth Martínez-Caballero
- Department of Crystallography and Structural Biology, Institute of Physical Chemistry "Rocasolano", CSIC, 28006 Madrid, Spain
| | - Kiran V Mahasenan
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556, USA
| | - Choon Kim
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556, USA
| | - Rafael Molina
- Department of Crystallography and Structural Biology, Institute of Physical Chemistry "Rocasolano", CSIC, 28006 Madrid, Spain
| | - Rhona Feltzer
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556, USA
| | - Mijoon Lee
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556, USA
| | - Renee Bouley
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556, USA
| | - Dusan Hesek
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556, USA
| | - Jed F Fisher
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556, USA
| | - Inés G Muñoz
- Structural Biology Programme, Spanish National Cancer Research Center (CNIO), 28029 Madrid, Spain
| | - Mayland Chang
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556, USA
| | - Shahriar Mobashery
- Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556, USA
| | - Juan A Hermoso
- Department of Crystallography and Structural Biology, Institute of Physical Chemistry "Rocasolano", CSIC, 28006 Madrid, Spain
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19
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Rahman S, Das AK. Integrated Multi-omics, Virtual Screening and Molecular Docking Analysis of Methicillin-Resistant Staphylococcus aureus USA300 for the Identification of Potential Therapeutic Targets: An In-Silico Approach. Int J Pept Res Ther 2021; 27:2735-2755. [PMID: 34548853 PMCID: PMC8446483 DOI: 10.1007/s10989-021-10287-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/10/2021] [Indexed: 11/28/2022]
Abstract
Staphylococcus aureus infection is a leading cause of mortality and morbidity in community, hospital and live-stock sectors, especially with the widespread emergence of methicillin-resistant S. aureus (MRSA) strains. To identify new drug molecules to treat MRSA patients, we have undertaken to search essential proteins that are indispensable for their survival but non-homologous to human host proteins. The current study utilizes a subtractive genome and proteome approach to screen the possible therapeutic targets against S. aureus USA300. Bacterial essential genes are obtained from the DEG database and are compared to avoid cross-reactivity with human host genes. In silico analysis shows 198 proteins that may be considered as therapeutic candidates. Depending on their sub-cellular localization, proteins are grouped as either vaccine or drug targets or both. Extracellular proteins such as cell division proteins (Q2FZ91, Q2FZ95), penicillin-binding proteins (Q2FZ94, Q2FYI0) of the bacterial cell wall, phosphoglucomutase (Q2FE11) and lipoteichoic acid synthase (Q2FIS2) are considered as vaccine targets, and their epitopes have been mapped. Altogether, 53 drug targets are identified, which have shown similarity with the drug targets available in the DrugBank database. Predicted drug targets belong to the common metabolic pathways of MRSA, such as fatty acid biosynthesis, folate biosynthesis, peptidoglycan biosynthesis, ribosome, etc. Protein-protein interaction analysis emphasizing peptidoglycan biosynthesis reveals the connection between penicillin-binding proteins, mur-family proteins and FemXAB proteins. In this study, staphylococcal FemA protein (P0A0A5) is subjected to structure-based virtual screening for the drug repurposing approach. There are 20 residues missing in the crystal structure of FemA, and 12 of these residues are located at the catalytic site. The missing residues are modelled, and stereochemistry is checked. FDA approved drugs available in the DrugBank database have been used in virtual screening with FemA in search of potential repurposed molecules. This approach provides us with 10 drugs that may be used in the treatment of methicillin-resistant staphylococcal mediated diseases. AutoDock 4.2 is used for in silico screening and shows a comparable inhibition constant (Ki) for all 10 FDA-approved drugs towards FemA. Most of these drugs are used in the treatment of various cancers, migraines and leukaemia. Protein-drug interaction analysis shows that the drugs mostly interact with hydrophobic residues of FemA. Moreover, Tyr328 and Lys383 contribute largely to hydrogen bondings during interactions. All interacting amino acids that bind to the drugs are part of the active site cavity of FemA. Supplementary Information The online version contains supplementary material available at 10.1007/s10989-021-10287-9.
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Affiliation(s)
- Shakilur Rahman
- Department of Biotechnology, Indian Institute of Technology Kharagpur, Kharagpur, West Bengal 721302 India
| | - Amit Kumar Das
- Department of Biotechnology, Indian Institute of Technology Kharagpur, Kharagpur, West Bengal 721302 India
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Liu P, Hao Z, Liu M, Niu M, Sun P, Yan S, Zhao L, Zhao X. Genetic mutations in adaptive evolution of growth-independent vancomycin-tolerant Staphylococcus aureus. J Antimicrob Chemother 2021; 76:2765-2773. [PMID: 34302174 DOI: 10.1093/jac/dkab260] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Accepted: 06/29/2021] [Indexed: 01/31/2023] Open
Abstract
BACKGROUND Antibiotic tolerance allows bacteria to overcome antibiotic treatment transiently and potentially accelerates the emergence of resistance. However, our understanding of antibiotic tolerance at the genetic level during adaptive evolution of Staphylococcus aureus remains incomplete. We sought to identify the mutated genes and verify the role of these genes in the formation of vancomycin tolerance in S. aureus. METHODS Vancomycin-susceptible S. aureus strain Newman was used to induce vancomycin-tolerant isolates in vitro by cyclic exposure under a high concentration of vancomycin (20× MIC). WGS and Sanger sequencing were performed to identify the genetic mutations. The function of mutated genes in vancomycin-tolerant isolates were verified by gene complementation. Other phenotypes of vancomycin-tolerant isolates were also determined, including mutation frequency, autolysis, lysostaphin susceptibility, cell wall thickness and cross-tolerance. RESULTS A series of vancomycin-tolerant S. aureus (VTSA) strains were isolated and 18 mutated genes were identified by WGS. Among these genes, pbp4, htrA, stp1, pth and NWMN_1068 were confirmed to play roles in VTSA formation. Mutation of mutL promoted the emergence of VTSA. All VTSA showed no changes in growth phenotype. Instead, they exhibited reduced autolysis, decreased lysostaphin susceptibility and thickened cell walls. In addition, all VTSA strains were cross-tolerant to antibiotics targeting cell wall synthesis but not to quinolones and lipopeptides. CONCLUSIONS Our results demonstrate that genetic mutations are responsible for emergence of phenotypic tolerance and formation of vancomycin tolerance may lie in cell wall changes in S. aureus.
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Affiliation(s)
- Pilong Liu
- College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, People's Republic of China.,Key Laboratory of Animal Genetics, Breeding and Reproduction of Shaanxi Province, Northwest A&F University, Yangling, Shaanxi, People's Republic of China
| | - Zehua Hao
- College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, People's Republic of China
| | - Miaomiao Liu
- College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, People's Republic of China
| | - Mingze Niu
- College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, People's Republic of China
| | - Peng Sun
- College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, People's Republic of China
| | - Shunhua Yan
- College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, People's Republic of China
| | - Lixiu Zhao
- College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, People's Republic of China
| | - Xin Zhao
- Department of Animal Science, McGill University, Ste. Anne de Bellevue, Quebec, Canada
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Qumar U, Hassan J, Naz S, Haider A, Raza A, Ul-Hamid A, Haider J, Shahzadi I, Ahmad I, Ikram M. Silver decorated 2D nanosheets of GO and MoS 2serve as nanocatalyst for water treatment and antimicrobial applications as ascertained with molecular docking evaluation. NANOTECHNOLOGY 2021; 32:255704. [PMID: 33556921 DOI: 10.1088/1361-6528/abe43c] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2020] [Accepted: 02/08/2021] [Indexed: 06/12/2023]
Abstract
In this work, synthesis of graphene oxide (GO) and reduced graphene oxide (rGO) was realized through a modified Hummers route. Different concentrations (5 and 10 wt%) of Ag were doped in MoS2and rGO using a hydrothermal technique. Synthesized Ag-MoS2and Ag-rGO were evaluated through XRD that confirmed the hexagonal structure of MoS2along with the transformation of GO to Ag-rGO as indicated by a shift in XRD peaks while Mo-O bonding and S=O functional groups were confirmed with FTIR. Morphological information of GO and formation of MoS2nanopetals as well as interlayer spacing were verified through FESEM and HRTEM respectively. Raman analysis was employed to probe any evidence regarding defect densities of GO. Optical properties of GO, MoS2, Ag-rGO, and Ag-MoS2were visualized through UV-vis and PL spectroscopy. Prepared products were employed as nanocatalysts to purify industrial wastewater. Experimental results revealed that Ag-rGO and Ag-MoS2showed 99% and 80% response in photocatalytic activity. Besides, the nanocatalyst (Ag-MoS2and Ag-rGO) exhibited 6.05 mm inhibition zones againstS. aureusgram positive (G+) and 3.05 mm forE. coligram negative (G-) in antibacterial activity. To rationalize biocidal mechanism of Ag-doped MoS2NPs and Ag-rGO,in silicomolecular docking study was employed for two enzymes i.e.β-lactamase and D-alanine-D-alanine ligase B (ddlB) from cell wall biosynthetic pathway and enoyl-[acylcarrier-protein] reductase (FabI) from fatty acid biosynthetic pathway belonging toS. aureus. The present study provides evidence for the development of cost-effective, environment friendly and viable candidate for photocatalytic and antimicrobial applications.
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Affiliation(s)
- U Qumar
- Department of Physics, Riphah Institute of Computing and Applied Sciences (RICAS), Riphah International University, 14 Ali Road, Lahore, Pakistan
| | - J Hassan
- Department of Physics, Riphah Institute of Computing and Applied Sciences (RICAS), Riphah International University, 14 Ali Road, Lahore, Pakistan
| | - S Naz
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, People's Republic of China
| | - A Haider
- Department of Clinical Medicine and Surgery, University of Veterinary and Animal Sciences, Lahore 54000, Punjab, Pakistan
| | - A Raza
- Department of Physics, Riphah Institute of Computing and Applied Sciences (RICAS), Riphah International University, 14 Ali Road, Lahore, Pakistan
| | - A Ul-Hamid
- Center for Engineering Research, Research Institute, King Fahd University of Petroleum & Minerals, Dhahran, 31261, Saudi Arabia
| | - J Haider
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, People's Republic of China
| | - I Shahzadi
- College of Pharmacy, University of the Punjab, Lahore, 54000, Pakistan
| | - I Ahmad
- Department of Chemistry, Allama Iqbal Open University, Islamabad 44000, Pakistan
| | - M Ikram
- Solar Cell Applications Research Lab, Department of Physics, Government College University Lahore, 54000, Punjab, Pakistan
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Gómez P, Ruiz-Ripa L, Fernández-Fernández R, Gharsa H, Ben Slama K, Höfle U, Zarazaga M, Holmes MA, Torres C. Genomic Analysis of Staphylococcus aureus of the Lineage CC130, Including mecC-Carrying MRSA and MSSA Isolates Recovered of Animal, Human, and Environmental Origins. Front Microbiol 2021; 12:655994. [PMID: 33841383 PMCID: PMC8027229 DOI: 10.3389/fmicb.2021.655994] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Accepted: 03/03/2021] [Indexed: 02/02/2023] Open
Abstract
Most methicillin resistant Staphylococcus aureus (MRSA) isolates harboring mecC gene belong to clonal complex CC130. This lineage has traditionally been regarded as animal-associated as it lacks the human specific immune evasion cluster (IEC), and has been recovered from a broad range of animal hosts. Nevertheless, sporadic mecC-MRSA human infections have been reported, with evidence of zoonotic transmission in some cases. The objective of this study was to investigate the whole-genome sequences of 18 S. aureus CC130 isolates [13 methicillin-resistant (mecC-MRSA) and five methicillin-susceptible (MSSA)] from different sequences types, obtained from a variety of host species and origins (human, livestock, wild birds and mammals, and water), and from different geographic locations, in order to identify characteristic markers and genomic features. Antibiotic resistance genes found among MRSA-CC130 were those associated with the SSCmecXI element. Most MRSA-CC130 strains carried a similar virulence gene profile. Additionally, six MRSA-CC130 possessed scn-sak and one MSSA-ST130 had lukMF'. The MSSA-ST700 strains were most divergent in their resistance and virulence genes. The pan-genome analysis showed that 29 genes were present solely in MRSA-CC130 (associated with SCCmecXI) and 21 among MSSA-CC130 isolates (associated with phages). The SCCmecXI, PBP3, GdpP, and AcrB were identical at the amino acid level in all strains, but some differences were found in PBP1, PBP2, PBP4, and YjbH proteins. An examination of the host markers showed that the 3' region of the bacteriophage φ3 was nearly identical to the reference sequence. Truncated hlb gene was also found in scn-negative strains (two of them carrying sak-type gene). The dtlB gene of wild rabbit isolates included novel mutations. The vwbp gene was found in the three MSSA-ST700 strains from small ruminants and in one MSSA-ST130 from a red deer; these strains also carried a scn-type gene, different from the human and equine variants. Finally, a phylogenetic analysis showed that the three MSSA-ST700 strains and the two MSSA-ST130 strains cluster separately from the remaining MRSA-CC130 strains with the etD2 gene as marker for the main lineage. The presence of the human IEC cluster in some mecC-MRSA-CC130 strains suggests that these isolates may have had a human origin.
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Affiliation(s)
- Paula Gómez
- Area of Biochemistry and Molecular Biology, OneHealth-UR Research Group, University of La Rioja, Logroño, Spain
| | - Laura Ruiz-Ripa
- Area of Biochemistry and Molecular Biology, OneHealth-UR Research Group, University of La Rioja, Logroño, Spain
| | - Rosa Fernández-Fernández
- Area of Biochemistry and Molecular Biology, OneHealth-UR Research Group, University of La Rioja, Logroño, Spain
| | - Haythem Gharsa
- Laboratoire des Microorganismes et Biomolécules Actives, Faculté des Sciences de Tunis, Université de Tunis El Manar, Tunis, Tunisia
| | - Karim Ben Slama
- Laboratoire des Microorganismes et Biomolécules Actives, Faculté des Sciences de Tunis, Université de Tunis El Manar, Tunis, Tunisia
| | - Ursula Höfle
- Health and Biotechnology SaBio Research Group, Instituto de Investigación en Recursos Cinegéticos IREC (CSIC-UCLM-JCCM), Ciudad Real, Spain
| | - Myriam Zarazaga
- Area of Biochemistry and Molecular Biology, OneHealth-UR Research Group, University of La Rioja, Logroño, Spain
| | - Mark A. Holmes
- Department of Veterinary Medicine, University of Cambridge, Cambridge, United Kingdom
| | - Carmen Torres
- Area of Biochemistry and Molecular Biology, OneHealth-UR Research Group, University of La Rioja, Logroño, Spain
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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: 52] [Impact Index Per Article: 17.3] [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.
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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
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24
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Laser-Irradiated Chlorpromazine as a Potent Anti-Biofilm Agent for Coating of Biomedical Devices. COATINGS 2020. [DOI: 10.3390/coatings10121230] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Nowadays, antibiotic resistance has become increasingly common, triggering a global health crisis, immediately needing alternative, including repurposed drugs with potent bactericidal effects. We demonstrated that chlorpromazine aqueous solutions exposed to laser radiation exhibited visible activity against various microorganisms. The aim of this study was to investigate the quantitative antimicrobial activity of chlorpromazine in non-irradiated and 4-h laser irradiated form. Also, we examined the effect of both solutions impregnated on a cotton patch, cannula, and urinary catheter against Gram-positive Staphylococcus aureus and Gram-negative Pseudomonas aeruginosa and Escherichia coli. In all experimental versions, the chlorpromazine antimicrobial activity was enhanced by laser exposure. Besides the experimental results, the in silico analyses using molecular docking proved that the improved antimicrobial activity of the irradiated compound was a result of the combined action of the photoproducts on the biological target (s). Our results show that laser radiation could alter the molecular structure of various drugs and their effects, proving to be a promising strategy to halt antibiotic resistance, by repurposing current medicines for new antimicrobial strategies, thereby decreasing the costs and time for the development of more efficient drugs.
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Gao Y, Chen Y, Cao Y, Mo A, Peng Q. Potentials of nanotechnology in treatment of methicillin-resistant Staphylococcus aureus. Eur J Med Chem 2020; 213:113056. [PMID: 33280899 DOI: 10.1016/j.ejmech.2020.113056] [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: 09/15/2020] [Revised: 11/24/2020] [Accepted: 11/24/2020] [Indexed: 02/05/2023]
Abstract
Abuse of antibiotics has led to the emergence of drug-resistant pathogens. Methicillin-resistant Staphylococcus aureus (MRSA) was reported just two years after the clinical use of methicillin, which can cause severe infections with high morbidity and mortality in both community and hospital. The treatment of MRSA infection is greatly challenging since it has developed the resistance to almost all types of antibiotics. As such, it is of great significance and importance to develop novel therapeutic approaches. The fast development of nanotechnology provides a promising solution to this dilemma. Functional nanomaterials and nanoparticles can act either as drug carriers or as antibacterial agents for antibacterial therapy. Herein, we aim to provide a comprehensive understanding of the drug resistance mechanisms of MRSA and discuss the potential applications of some functionalized nanomaterials in anti-MRSA therapy. Also, the concerns and possible solutions for the nanomaterials-based anti-MRSA therapy are discussed.
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Affiliation(s)
- Yujie Gao
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, 610041, China; Department of Oral Implantology, West China Hospital of Stomatology, Sichuan University, Chengdu, 610041, China
| | - Yuan Chen
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, 610041, China; Department of Oral Implantology, West China Hospital of Stomatology, Sichuan University, Chengdu, 610041, China
| | - Yubin Cao
- Department of Oral and Maxillofacial Surgery, West China Hospital of Stomatology, Sichuan University, Chengdu, 610041, China
| | - Anchun Mo
- Department of Oral Implantology, West China Hospital of Stomatology, Sichuan University, Chengdu, 610041, China.
| | - Qiang Peng
- State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, 610041, China.
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26
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Masters EA, de Mesy Bentley KL, Gill AL, Hao SP, Galloway CA, Salminen AT, Guy DR, McGrath JL, Awad HA, Gill SR, Schwarz EM. Identification of Penicillin Binding Protein 4 (PBP4) as a critical factor for Staphylococcus aureus bone invasion during osteomyelitis in mice. PLoS Pathog 2020; 16:e1008988. [PMID: 33091079 PMCID: PMC7608983 DOI: 10.1371/journal.ppat.1008988] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2020] [Revised: 11/03/2020] [Accepted: 09/17/2020] [Indexed: 12/03/2022] Open
Abstract
Staphylococcus aureus infection of bone is challenging to treat because it colonizes the osteocyte lacuno-canalicular network (OLCN) of cortical bone. To elucidate factors involved in OLCN invasion and identify novel drug targets, we completed a hypothesis-driven screen of 24 S. aureus transposon insertion mutant strains for their ability to propagate through 0.5 μm-sized pores in the Microfluidic Silicon Membrane Canalicular Arrays (μSiM-CA), developed to model S. aureus invasion of the OLCN. This screen identified the uncanonical S. aureus transpeptidase, penicillin binding protein 4 (PBP4), as a necessary gene for S. aureus deformation and propagation through nanopores. In vivo studies revealed that Δpbp4 infected tibiae treated with vancomycin showed a significant 12-fold reduction in bacterial load compared to WT infected tibiae treated with vancomycin (p<0.05). Additionally, Δpbp4 infected tibiae displayed a remarkable decrease in pathogenic bone-loss at the implant site with and without vancomycin therapy. Most importantly, Δpbp4 S. aureus failed to invade and colonize the OLCN despite high bacterial loads on the implant and in adjacent tissues. Together, these results demonstrate that PBP4 is required for S. aureus colonization of the OLCN and suggest that inhibitors may be synergistic with standard of care antibiotics ineffective against bacteria within the OLCN. Staphylococcus aureus is the most prevalent pathogen in osteomyelitis, and its infection of bone is difficult to cure. S. aureus colonization of the osteocyte lacuno-canalicular network (OLCN) of cortical bone has been identified as a novel pathogenetic mechanism in chronic osteomyelitis. To elucidate factors involved in OLCN invasion, we conducted an in vitro genetic screen that identified pbp4 as a critical gene for S. aureus cell deformation and propagation through nanopores and demonstrated that PBP4 is critical for OLCN colonization in murine osteomyelitis. Thus, PBP4 inhibitors may be novel drugs to treat osteomyelitis in combination with standard of care antibiotics.
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Affiliation(s)
- Elysia A. Masters
- Center for Musculoskeletal Research, University of Rochester Medical Center, Rochester, NY, United States of America
- Department of Biomedical Engineering, University of Rochester Medical Center, Rochester, NY, United States of America
| | - Karen L. de Mesy Bentley
- Center for Musculoskeletal Research, University of Rochester Medical Center, Rochester, NY, United States of America
- Department of Pathology and Laboratory Medicine, University of Rochester Medical Center, Rochester, NY, United States of America
- Department of Orthopaedics, University of Rochester Medical Center, Rochester, NY, United States of America
| | - Ann Lindley Gill
- Department of Microbiology and Immunology, University of Rochester Medical Center, Rochester, NY, United States of America
| | - Stephanie P. Hao
- Center for Musculoskeletal Research, University of Rochester Medical Center, Rochester, NY, United States of America
| | - Chad A. Galloway
- Center for Musculoskeletal Research, University of Rochester Medical Center, Rochester, NY, United States of America
- Department of Pathology and Laboratory Medicine, University of Rochester Medical Center, Rochester, NY, United States of America
| | - Alec T. Salminen
- Department of Biomedical Engineering, University of Rochester Medical Center, Rochester, NY, United States of America
| | - Diamond R. Guy
- Center for Musculoskeletal Research, University of Rochester Medical Center, Rochester, NY, United States of America
| | - James L. McGrath
- Department of Biomedical Engineering, University of Rochester Medical Center, Rochester, NY, United States of America
| | - Hani A. Awad
- Center for Musculoskeletal Research, University of Rochester Medical Center, Rochester, NY, United States of America
- Department of Biomedical Engineering, University of Rochester Medical Center, Rochester, NY, United States of America
| | - Steven R. Gill
- Department of Microbiology and Immunology, University of Rochester Medical Center, Rochester, NY, United States of America
| | - Edward M. Schwarz
- Center for Musculoskeletal Research, University of Rochester Medical Center, Rochester, NY, United States of America
- Department of Biomedical Engineering, University of Rochester Medical Center, Rochester, NY, United States of America
- Department of Orthopaedics, University of Rochester Medical Center, Rochester, NY, United States of America
- * E-mail:
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Structural Insights into Ceftobiprole Inhibition of Pseudomonas aeruginosa Penicillin-Binding Protein 3. Antimicrob Agents Chemother 2020; 64:AAC.00106-20. [PMID: 32152075 DOI: 10.1128/aac.00106-20] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Accepted: 02/28/2020] [Indexed: 02/08/2023] Open
Abstract
Ceftobiprole is an advanced-generation broad-spectrum cephalosporin antibiotic with potent and rapid bactericidal activity against Gram-positive pathogens, including methicillin-resistant Staphylococcus aureus, as well as susceptible Gram-negative pathogens, including Pseudomonas sp. pathogens. In the case of Pseudomonas aeruginosa, ceftobiprole acts by inhibiting P. aeruginosa penicillin-binding protein 3 (PBP3). Structural studies were pursued to elucidate the molecular details of this PBP inhibition. The crystal structure of the His-tagged PBP3-ceftobiprole complex revealed a covalent bond between the ligand and the catalytic residue S294. Ceftobiprole binding leads to large active site changes near binding sites for the pyrrolidinone and pyrrolidine rings. The S528 to L536 region adopts a conformation previously not observed in PBP3, including partial unwinding of the α11 helix. These molecular insights can lead to a deeper understanding of β-lactam-PBP interactions that result in major changes in protein structure, as well as suggesting how to fine-tune current inhibitors and to develop novel inhibitors of this PBP.
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Fisher JF, Mobashery S. Constructing and deconstructing the bacterial cell wall. Protein Sci 2020; 29:629-646. [PMID: 31747090 PMCID: PMC7021008 DOI: 10.1002/pro.3737] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2019] [Revised: 09/17/2019] [Accepted: 09/18/2019] [Indexed: 12/11/2022]
Abstract
The history of modern medicine cannot be written apart from the history of the antibiotics. Antibiotics are cytotoxic secondary metabolites that are isolated from Nature. The antibacterial antibiotics disproportionately target bacterial protein structure that is distinct from eukaryotic protein structure, notably within the ribosome and within the pathways for bacterial cell-wall biosynthesis (for which there is not a eukaryotic counterpart). This review focuses on a pre-eminent class of antibiotics-the β-lactams, exemplified by the penicillins and cephalosporins-from the perspective of the evolving mechanisms for bacterial resistance. The mechanism of action of the β-lactams is bacterial cell-wall destruction. In the monoderm (single membrane, Gram-positive staining) pathogen Staphylococcus aureus the dominant resistance mechanism is expression of a β-lactam-unreactive transpeptidase enzyme that functions in cell-wall construction. In the diderm (dual membrane, Gram-negative staining) pathogen Pseudomonas aeruginosa a dominant resistance mechanism (among several) is expression of a hydrolytic enzyme that destroys the critical β-lactam ring of the antibiotic. The key sensing mechanism used by P. aeruginosa is monitoring the molecular difference between cell-wall construction and cell-wall deconstruction. In both bacteria, the resistance pathways are manifested only when the bacteria detect the presence of β-lactams. This review summarizes how the β-lactams are sensed and how the resistance mechanisms are manifested, with the expectation that preventing these processes will be critical to future chemotherapeutic control of multidrug resistant bacteria.
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Affiliation(s)
- Jed F. Fisher
- Department of Chemistry and BiochemistryUniversity of Notre DameSouth BendIndiana
| | - Shahriar Mobashery
- Department of Chemistry and BiochemistryUniversity of Notre DameSouth BendIndiana
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Gostev V, Sopova J, Kalinogorskaya O, Tsvetkova I, Lobzin Y, Klotchenko S, Sidorenko S. In Vitro Ceftaroline Resistance Selection of Methicillin-Resistant Staphylococcus aureus Involves Different Genetic Pathways. Microb Drug Resist 2019; 25:1401-1409. [PMID: 31329022 DOI: 10.1089/mdr.2019.0130] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
The pathways in the development of ceftaroline resistance of methicillin-resistant Staphylococcus aureus (MRSA) isolates belonging to the ST8, ST239, and ST228 were evaluated. Ceftaroline-resistant derivatives were isolated through selection during 40 passages. Ceftaroline MIC measurements and whole-genome sequencing were performed after 5, 20, and 40 passages. In two ST8 derivative isolates, ceftaroline MIC increased up to 128 mg/L. Mutations were acquired in gdpP and graS in one isolate after 20 passages and in gdpP in another after 40 passages. MIC for two ST239 derivatives increased to 128 mg/L. Substitutions in Pbp4 and polymorphisms in the upstream region of pbp4 were identified in both derivatives after 40 passages. In one isolate, additional mutation in gdpP and deletion in graR were detected. In an ST228 derivative, MIC increased to 32 mg/L with one mutation in penicillin-binding protein 2a (Y446N) detected after five passages and a second (E447K) after 20 passages. Three pathways in the development of ceftaroline resistance were identified. For ST8 and ST239 derivatives mutations were detected in gdpP and pbp4, respectively, whereas in ST228 - in mecA. Most derivatives harbored additional mutations whose potential role in the development of resistance has not been determined.
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Affiliation(s)
- Vladimir Gostev
- Department of Medical Microbiology and Molecular Epidemiology, Pediatric Research and Clinical Center for Infectious Diseases, Saint Petersburg, Russia
- Department of Medical Microbiology, North-Western State Medical University named after I.I. Mechnikov, Saint Petersburg, Russia
| | - Julia Sopova
- Laboratory of Genetic Models of Human Diseases, Saint Petersburg Branch of Vavilov Institute of General Genetics, Saint Petersburg, Russia
- Department of Genetics and Biotechnology, Saint Petersburg State University, Saint Petersburg, Russia
| | - Olga Kalinogorskaya
- Department of Medical Microbiology and Molecular Epidemiology, Pediatric Research and Clinical Center for Infectious Diseases, Saint Petersburg, Russia
| | - Irina Tsvetkova
- Department of Medical Microbiology and Molecular Epidemiology, Pediatric Research and Clinical Center for Infectious Diseases, Saint Petersburg, Russia
| | - Yuri Lobzin
- Department of Medical Microbiology and Molecular Epidemiology, Pediatric Research and Clinical Center for Infectious Diseases, Saint Petersburg, Russia
- Department of Medical Microbiology, North-Western State Medical University named after I.I. Mechnikov, Saint Petersburg, Russia
| | - Sergey Klotchenko
- Division of Viral Molecular Biology, Smorodintsev Research Institute of Influenza, Saint Petersburg, Russia
| | - Sergey Sidorenko
- Department of Medical Microbiology and Molecular Epidemiology, Pediatric Research and Clinical Center for Infectious Diseases, Saint Petersburg, Russia
- Department of Medical Microbiology, North-Western State Medical University named after I.I. Mechnikov, Saint Petersburg, Russia
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30
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Antimicrobial resistance in methicillin-resistant Staphylococcus aureus to newer antimicrobial agents. Antimicrob Agents Chemother 2019:AAC.01216-19. [PMID: 31527033 DOI: 10.1128/aac.01216-19] [Citation(s) in RCA: 65] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Infections caused by methicillin-resistant Staphylococcus aureus (MRSA) result in significant morbidity and mortality for patients in both community and health care settings. This is primarily due to the difficulty in treating MRSA, which is often resistant to multiple classes of antibiotics. Understanding the mechanisms of antimicrobial resistance (AMR) in MRSA provides insight into the optimal use of antimicrobial agents in clinical practice and also underpins critical aspects of antimicrobial stewardship programs. In this review we delineate the mechanisms, prevalence, and clinical importance of resistance to antibiotics licensed in the past 20 years that target MRSA, as well as new drugs in the pipeline which are likely to be licensed soon. Current gaps in scientific knowledge about MRSA resistance mechanisms are discussed, and topics in the epidemiology of AMR in S. aureus that require further investigation are highlighted.
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31
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Structural insight into YcbB-mediated beta-lactam resistance in Escherichia coli. Nat Commun 2019; 10:1849. [PMID: 31015395 PMCID: PMC6478713 DOI: 10.1038/s41467-019-09507-0] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2018] [Accepted: 03/13/2019] [Indexed: 12/03/2022] Open
Abstract
The bacterial cell wall plays a crucial role in viability and is an important drug target. In Escherichia coli, the peptidoglycan crosslinking reaction to form the cell wall is primarily carried out by penicillin-binding proteins that catalyse D,D-transpeptidase activity. However, an alternate crosslinking mechanism involving the L,D-transpeptidase YcbB can lead to bypass of D,D-transpeptidation and beta-lactam resistance. Here, we show that the crystallographic structure of YcbB consists of a conserved L,D-transpeptidase catalytic domain decorated with a subdomain on the dynamic substrate capping loop, peptidoglycan-binding and large scaffolding domains. Meropenem acylation of YcbB gives insight into the mode of inhibition by carbapenems, the singular antibiotic class with significant activity against L,D-transpeptidases. We also report the structure of PBP5-meropenem to compare interactions mediating inhibition. Additionally, we probe the interaction network of this pathway and assay beta-lactam resistance in vivo. Our results provide structural insights into the mechanism of action and the inhibition of L,D-transpeptidation, and into YcbB-mediated antibiotic resistance. In E. coli, alternate peptidoglycan crosslinking reactions carried out by the L,D-transpeptidase YcbB can lead to beta-lactam resistance. Here, Caveney et al. solve the crystal structure of YcbB and shed light into its mechanism of action and into YcbB-mediated antibiotic resistance.
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Boudjemaa R, Steenkeste K, Canette A, Briandet R, Fontaine-Aupart MP, Marlière C. Direct observation of the cell-wall remodeling in adhering Staphylococcus aureus 27217: An AFM study supported by SEM and TEM. Cell Surf 2019; 5:100018. [PMID: 32743135 PMCID: PMC7389151 DOI: 10.1016/j.tcsw.2019.100018] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2018] [Revised: 12/19/2018] [Accepted: 01/24/2019] [Indexed: 01/28/2023] Open
Abstract
We took benefit from Atomic Force Microscopy (AFM) in the force spectroscopy mode to describe the time evolution – over 24 h – of the surface nanotopography and mechanical properties of the strain Staphylococcus aureus 27217 from bacterial adhesion to the first stage of biofilm genesis. In addition, Transmission Electron Microscopy (TEM) and Scanning Electron Microscopy (SEM) experiments allowed identifying two types of self-adhering subpopulations (the so-called “bald” and “hairy” cells) and revealed changes in their relative populations with the bacterial culture age and the protocol of preparation. We indeed observed a dramatic evanescing of the “hairy” subpopulation for samples that underwent centrifugation and resuspension processes. When examined by AFM, the “hairy” cell surface resembled to a herringbone structure characterized by upper structural units with lateral dimensions of ∼70 nm and a high Young modulus value (∼2.3 MPa), a mean depth of the trough between them of ∼15 nm and a resulting roughness of ∼5 nm. By contrast, the “bald” cells appeared much softer (∼0.35 MPa) with a roughness one order of magnitude lower. We observed too the gradual detachment of the herringbone patterns from the “hairy” bacterial envelope of cell harvested from a 16 h old culture and their progressive accumulation between the bacteria in the form of globular clusters. The secretion of a soft extracellular polymeric substance was also identified that, in addition to the globular clusters, may contribute to the initiation of the biofilm spatial organization.
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Affiliation(s)
- Rym Boudjemaa
- Institut des Sciences Moléculaires d'Orsay (ISMO), CNRS, Université Paris-Sud, Université Paris-Saclay, Orsay, France
| | - Karine Steenkeste
- Institut des Sciences Moléculaires d'Orsay (ISMO), CNRS, Université Paris-Sud, Université Paris-Saclay, Orsay, France
| | - Alexis Canette
- Micalis Institute, INRA, AgroParisTech, Université Paris-Saclay, Jouy-en-Josas, France.,Institut de Biologie Paris-Seine (FR 3631), Unité Mixte de Service (UMS 30) d'Imagerie et de Cytométrie (LUMIC), Sorbonne Université, CNRS, Paris, France
| | - Romain Briandet
- Micalis Institute, INRA, AgroParisTech, Université Paris-Saclay, Jouy-en-Josas, France
| | - Marie-Pierre Fontaine-Aupart
- Institut des Sciences Moléculaires d'Orsay (ISMO), CNRS, Université Paris-Sud, Université Paris-Saclay, Orsay, France
| | - Christian Marlière
- Institut des Sciences Moléculaires d'Orsay (ISMO), CNRS, Université Paris-Sud, Université Paris-Saclay, Orsay, France
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Maya-Martinez R, Alexander JAN, Otten CF, Ayala I, Vollmer D, Gray J, Bougault CM, Burt A, Laguri C, Fonvielle M, Arthur M, Strynadka NCJ, Vollmer W, Simorre JP. Recognition of Peptidoglycan Fragments by the Transpeptidase PBP4 From Staphylococcus aureus. Front Microbiol 2019; 9:3223. [PMID: 30713527 PMCID: PMC6346638 DOI: 10.3389/fmicb.2018.03223] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2018] [Accepted: 12/11/2018] [Indexed: 11/13/2022] Open
Abstract
Peptidoglycan (PG) is an essential component of the cell envelope, maintaining bacterial cell shape and protecting it from bursting due to turgor pressure. The monoderm bacterium Staphylococcus aureus has a highly cross-linked PG, with ~90% of peptide stems participating in DD-cross-links and up to 15 peptide stems connected with each other. These cross-links are formed in transpeptidation reactions catalyzed by penicillin-binding proteins (PBPs) of classes A and B. Most S. aureus strains have three housekeeping PBPs with this function (PBP1, PBP2, and PBP3) but MRSA strains have acquired a third class B PBP, PBP2a, which is encoded by the mecA gene and required for the expression of high-level resistance to β-lactams. Another housekeeping PBP of S. aureus is PBP4, which belongs to the class C PBPs, and hence would be expected to have PG hydrolase (DD-carboxypeptidase or DD-endopeptidase) activity. However, previous works showed that, unexpectedly, PBP4 has transpeptidase activity that significantly contributes to both the high level of cross-linking in the PG of S. aureus and to the low level of β-lactam resistance in the absence of PBP2a. To gain insights into this unusual activity of PBP4, we studied by NMR spectroscopy its interaction in vitro with different substrates, including intact peptidoglycan, synthetic peptide stems, muropeptides, and long glycan chains with uncross-linked peptide stems. PBP4 showed no affinity for the complex, intact peptidoglycan or the smallest isolated peptide stems. Transpeptidase activity of PBP4 was verified with the disaccharide peptide subunits (muropeptides) in vitro, producing cyclic dimer and multimer products; these assays also showed a designed PBP4(S75C) nucleophile mutant to be inactive. Using this inactive but structurally highly similar variant, liquid-state NMR identified two interaction surfaces in close proximity to the central nucleophile position that can accommodate the potential donor and acceptor stems for the transpeptidation reaction. A PBP4:muropeptide model structure was built from these experimental restraints, which provides new mechanistic insights into mecA independent resistance to β-lactams in S. aureus.
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Affiliation(s)
| | - J Andrew N Alexander
- Department of Biochemistry and Molecular Biology and Centre for Blood Research, The University of British Columbia, Vancouver, BC, Canada
| | - Christian F Otten
- Centre for Bacterial Cell Biology, Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Isabel Ayala
- University Grenoble Alpes, CNRS, CEA, IBS, Grenoble, France
| | - Daniela Vollmer
- Centre for Bacterial Cell Biology, Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Joe Gray
- Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle upon Tyne, United Kingdom
| | | | - Alister Burt
- University Grenoble Alpes, CNRS, CEA, IBS, Grenoble, France
| | - Cédric Laguri
- University Grenoble Alpes, CNRS, CEA, IBS, Grenoble, France
| | - Matthieu Fonvielle
- Centre de Recherche des Cordeliers, LRMA, Equipe 12, Université Sorbone-Paris, Paris, France
| | - Michel Arthur
- Centre de Recherche des Cordeliers, LRMA, Equipe 12, Université Sorbone-Paris, Paris, France
| | - Natalie C J Strynadka
- Department of Biochemistry and Molecular Biology and Centre for Blood Research, The University of British Columbia, Vancouver, BC, Canada
| | - Waldemar Vollmer
- Centre for Bacterial Cell Biology, Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle upon Tyne, United Kingdom
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Miyachiro MM, Contreras-Martel C, Dessen A. Penicillin-Binding Proteins (PBPs) and Bacterial Cell Wall Elongation Complexes. Subcell Biochem 2019; 93:273-289. [PMID: 31939154 DOI: 10.1007/978-3-030-28151-9_8] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The bacterial cell wall is the validated target of mainstream antimicrobials such as penicillin and vancomycin. Penicillin and other β-lactams act by targeting Penicillin-Binding Proteins (PBPs), enzymes that play key roles in the biosynthesis of the main component of the cell wall, the peptidoglycan. Despite the spread of resistance towards these drugs, the bacterial cell wall continues to be a major Achilles' heel for microbial survival, and the exploration of the cell wall formation machinery is a vast field of work that can lead to the development of novel exciting therapies. The sheer complexity of the cell wall formation process, however, has created a significant challenge for the study of the macromolecular interactions that regulate peptidoglycan biosynthesis. New developments in genetic and biochemical screens, as well as different aspects of structural biology, have shed new light on the importance of complexes formed by PBPs, notably within the cell wall elongation machinery. This chapter summarizes structural and functional details of PBP complexes involved in the periplasmic and membrane steps of peptidoglycan biosynthesis with a focus on cell wall elongation. These assemblies could represent interesting new targets for the eventual development of original antibacterials.
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Affiliation(s)
- Mayara M Miyachiro
- Brazilian Biosciences National Laboratory (LNBio), CNPEM, Campinas, Brazil
| | - Carlos Contreras-Martel
- Univ Grenoble Alpes, CNRS, CEA, Institut de Biologie Structurale (IBS), Bacterial Pathogenesis Group, Grenoble, France
| | - Andréa Dessen
- Brazilian Biosciences National Laboratory (LNBio), CNPEM, Campinas, Brazil. .,Univ Grenoble Alpes, CNRS, CEA, Institut de Biologie Structurale (IBS), Bacterial Pathogenesis Group, Grenoble, France.
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