1
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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2
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Schäper S, Brito AD, Saraiva BM, Squyres GR, Holmes MJ, Garner EC, Hensel Z, Henriques R, Pinho MG. Cell constriction requires processive septal peptidoglycan synthase movement independent of FtsZ treadmilling in Staphylococcus aureus. Nat Microbiol 2024; 9:1049-1063. [PMID: 38480900 PMCID: PMC10994846 DOI: 10.1038/s41564-024-01629-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Accepted: 02/01/2024] [Indexed: 04/06/2024]
Abstract
Bacterial cell division requires recruitment of peptidoglycan (PG) synthases to the division site by the tubulin homologue, FtsZ. Septal PG synthases promote septum growth. FtsZ treadmilling is proposed to drive the processive movement of septal PG synthases and septal constriction in some bacteria; however, the precise mechanisms spatio-temporally regulating PG synthase movement and activity and FtsZ treadmilling are poorly understood. Here using single-molecule imaging of division proteins in the Gram-positive pathogen Staphylococcus aureus, we showed that the septal PG synthase complex FtsW/PBP1 and its putative activator protein, DivIB, move with similar velocity around the division site. Impairing FtsZ treadmilling did not affect FtsW or DivIB velocities or septum constriction rates. Contrarily, PG synthesis inhibition decelerated or stopped directional movement of FtsW and DivIB, and septum constriction. Our findings suggest that a single population of processively moving FtsW/PBP1 associated with DivIB drives cell constriction independently of FtsZ treadmilling in S. aureus.
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Affiliation(s)
- Simon Schäper
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade NOVA de Lisboa, Oeiras, Portugal.
| | - António D Brito
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade NOVA de Lisboa, Oeiras, Portugal
- Instituto Gulbenkian de Ciência, Oeiras, Portugal
| | - Bruno M Saraiva
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade NOVA de Lisboa, Oeiras, Portugal
- Instituto Gulbenkian de Ciência, Oeiras, Portugal
| | - Georgia R Squyres
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA, USA
| | - Matthew J Holmes
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA, USA
| | - Ethan C Garner
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA, USA
| | - Zach Hensel
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade NOVA de Lisboa, Oeiras, Portugal
| | - Ricardo Henriques
- Instituto Gulbenkian de Ciência, Oeiras, Portugal
- MRC-Laboratory for Molecular Cell Biology, University College London, London, UK
| | - Mariana G Pinho
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade NOVA de Lisboa, Oeiras, Portugal.
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3
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Costa SF, Saraiva BM, Veiga H, Marques LB, Schäper S, Sporniak M, Vega DE, Jorge AM, Duarte AM, Brito AD, Tavares AC, Reed P, Pinho MG. The role of GpsB in Staphylococcus aureus cell morphogenesis. mBio 2024; 15:e0323523. [PMID: 38319093 PMCID: PMC10936418 DOI: 10.1128/mbio.03235-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2023] [Accepted: 12/20/2023] [Indexed: 02/07/2024] Open
Abstract
For decades, cells of the Gram-positive bacterial pathogen Staphylococcus aureus were thought to lack a dedicated elongation machinery. However, S. aureus cells were recently shown to elongate before division, in a process that requires a shape elongation division and sporulation (SEDS)/penicillin-binding protein (PBP) pair for peptidoglycan synthesis, consisting of the glycosyltransferase RodA and the transpeptidase PBP3. In ovococci and rod-shaped bacteria, the elongation machinery, or elongasome, is composed of various proteins besides a dedicated SEDS/PBP pair. To identify proteins required for S. aureus elongation, we screened the Nebraska Transposon Mutant Library, which contains transposon mutants in virtually all non-essential staphylococcal genes, for mutants with modified cell shape. We confirmed the roles of RodA/PBP3 in S. aureus elongation and identified GpsB, SsaA, and RodZ as additional proteins involved in this process. The gpsB mutant showed the strongest phenotype, mediated by the partial delocalization from the division septum of PBP2 and PBP4, two penicillin-binding proteins that synthesize and cross-link peptidoglycan. Increased levels of these PBPs at the cell periphery versus the septum result in higher levels of peptidoglycan insertion/crosslinking throughout the entire cell, possibly overriding the RodA/PBP3-mediated peptidoglycan synthesis at the outer edge of the septum and/or increasing stiffness of the peripheral wall, impairing elongation. Consequently, in the absence of GpsB, S. aureus cells become more spherical. We propose that GpsB has a role in the spatio-temporal regulation of PBP2 and PBP4 at the septum versus cell periphery, contributing to the maintenance of the correct cell morphology in S. aureus. IMPORTANCE Staphylococcus aureus is a Gram-positive clinical pathogen, which is currently the second cause of death by antibiotic-resistant infections worldwide. For decades, S. aureus cells were thought to be spherical and lack the ability to undergo elongation. However, super-resolution microscopy techniques allowed us to observe the minor morphological changes that occur during the cell cycle of this pathogen, including cell elongation. S. aureus elongation is not required for normal growth in laboratory conditions. However, it seems to be essential in the context of some infections, such as osteomyelitis, during which S. aureus cells apparently elongate to invade small channels in the bones. In this work, we uncovered new determinants required for S. aureus cell elongation. In particular, we show that GpsB has an important role in the spatio-temporal regulation of PBP2 and PBP4, two proteins involved in peptidoglycan synthesis, contributing to the maintenance of the correct cell morphology in S. aureus.
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Affiliation(s)
- Sara F. Costa
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade NOVA de Lisboa, Oeiras, Portugal
| | - Bruno M. Saraiva
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade NOVA de Lisboa, Oeiras, Portugal
| | - Helena Veiga
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade NOVA de Lisboa, Oeiras, Portugal
| | - Leonor B. Marques
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade NOVA de Lisboa, Oeiras, Portugal
| | - Simon Schäper
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade NOVA de Lisboa, Oeiras, Portugal
| | - Marta Sporniak
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade NOVA de Lisboa, Oeiras, Portugal
| | - Daniel E. Vega
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade NOVA de Lisboa, Oeiras, Portugal
| | - Ana M. Jorge
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade NOVA de Lisboa, Oeiras, Portugal
| | - Andreia M. Duarte
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade NOVA de Lisboa, Oeiras, Portugal
| | - António D. Brito
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade NOVA de Lisboa, Oeiras, Portugal
| | - Andreia C. Tavares
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade NOVA de Lisboa, Oeiras, Portugal
| | - Patricia Reed
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade NOVA de Lisboa, Oeiras, Portugal
| | - Mariana G. Pinho
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade NOVA de Lisboa, Oeiras, Portugal
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4
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Reed P, Sorg M, Alwardt D, Serra L, Veiga H, Schäper S, Pinho MG. A CRISPRi-based genetic resource to study essential Staphylococcus aureus genes. mBio 2024; 15:e0277323. [PMID: 38054745 PMCID: PMC10870820 DOI: 10.1128/mbio.02773-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2023] [Accepted: 10/19/2023] [Indexed: 12/07/2023] Open
Abstract
IMPORTANCE Staphylococcus aureus is an important clinical pathogen that causes a high number of antibiotic-resistant infections. The study of S. aureus biology, and particularly of the function of essential proteins, is of particular importance to develop new approaches to combat this pathogen. We have optimized a clustered regularly interspaced short palindromic repeat interference (CRISPRi) system that allows efficient targeting of essential S. aureus genes. Furthermore, we have used that system to construct a library comprising 261 strains, which allows the depletion of essential proteins encoded by 200 genes/operons. This library, which we have named Lisbon CRISPRi Mutant Library, should facilitate the study of S. aureus pathogenesis and biology.
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Affiliation(s)
- Patricia Reed
- Bacterial Cell Biology, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Moritz Sorg
- Bacterial Cell Biology, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Dominik Alwardt
- Bacterial Cell Biology, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Lúcia Serra
- Bacterial Cell Biology, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Helena Veiga
- Bacterial Cell Biology, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Simon Schäper
- Bacterial Cell Biology, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Mariana G. Pinho
- Bacterial Cell Biology, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
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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. bioRxiv 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] [What about the content of this article? (0)] [Affiliation(s)] [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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6
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S Mendes S, Sorg M, Luís CM, Fontinha D, Francisco D, Moita D, C Romão C, G Pinho M, Pimentel C, Prudêncio M, M Saraiva L. Conjugated carbon monoxide-releasing molecules have broad-spectrum antimicrobial activity. Future Med Chem 2023; 15:1037-1048. [PMID: 37458074 DOI: 10.4155/fmc-2023-0103] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/18/2023] Open
Abstract
Aim: To test the antimicrobial effect of carbon monoxide-releasing molecules (CORMs) conjugated with azoles on different microorganisms. Methods & results: We used broth microdilution, checkerboard and cytotoxicity assays, as well as imaging, fluorescence and bioluminescence experiments to study [Re(CO)3(2,2'-bipyridyl)(Ctz)]+ (also known as ReBpyCtz). ReBpyCtz exhibits a low minimum inhibitory concentration value, increases the intracellular formation of reactive oxygen species and causes significant alterations on Staphylococcus aureus's membrane. ReBpyCtz is active against fungi, having a more prolonged fungicidal effect on Candida glabrata than clotrimazole and is selectively active on blood-stage malaria parasites, at a concentration that is not toxic to kidney epithelial cells. Conclusion: Conjugated CORMs have the potential to be active against different types of pathogens, thus constituting a promising class of broad-spectrum antimicrobials.
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Affiliation(s)
- Sofia S Mendes
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Avenida da República (EAN), 2780-157, Oeiras, Portugal
| | - Moritz Sorg
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Avenida da República (EAN), 2780-157, Oeiras, Portugal
| | - Cláudia Malta Luís
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Avenida da República (EAN), 2780-157, Oeiras, Portugal
| | - Diana Fontinha
- Instituto de Medicina Molecular João Lobo Antunes, Universidade de Lisboa, Av. Prof. Egas Moniz, 1649-028, Lisboa, Portugal
| | - Denise Francisco
- Instituto de Medicina Molecular João Lobo Antunes, Universidade de Lisboa, Av. Prof. Egas Moniz, 1649-028, Lisboa, Portugal
| | - Diana Moita
- Instituto de Medicina Molecular João Lobo Antunes, Universidade de Lisboa, Av. Prof. Egas Moniz, 1649-028, Lisboa, Portugal
| | - Carlos C Romão
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Avenida da República (EAN), 2780-157, Oeiras, Portugal
| | - Mariana G Pinho
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Avenida da República (EAN), 2780-157, Oeiras, Portugal
| | - Catarina Pimentel
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Avenida da República (EAN), 2780-157, Oeiras, Portugal
| | - Miguel Prudêncio
- Instituto de Medicina Molecular João Lobo Antunes, Universidade de Lisboa, Av. Prof. Egas Moniz, 1649-028, Lisboa, Portugal
| | - Lígia M Saraiva
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Avenida da República (EAN), 2780-157, Oeiras, Portugal
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7
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Veiga H, Jousselin A, Schäper S, Saraiva BM, Marques LB, Reed P, Wilton J, Pereira PM, Filipe SR, Pinho MG. Cell division protein FtsK coordinates bacterial chromosome segregation and daughter cell separation in Staphylococcus aureus. EMBO J 2023:e112140. [PMID: 37038972 DOI: 10.15252/embj.2022112140] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2022] [Revised: 03/15/2023] [Accepted: 03/21/2023] [Indexed: 04/12/2023] Open
Abstract
Unregulated cell cycle progression may have lethal consequences and therefore, bacteria have various mechanisms in place for the precise spatiotemporal control of cell cycle events. We have uncovered a new link between chromosome replication/segregation and splitting of the division septum. We show that the DNA translocase domain-containing divisome protein FtsK regulates cellular levels of a peptidoglycan hydrolase Sle1, which is involved in cell separation in the bacterial pathogen Staphylococcus aureus. FtsK interacts with a chaperone (trigger factor, TF) and establishes a FtsK-dependent TF concentration gradient that is higher in the septal region. Trigger factor binds Sle1 and promotes its preferential export at the septal region, while also preventing Sle1 degradation by the ClpXP proteolytic machinery. Upon conditions that lead to paused septum synthesis, such as DNA damage or impaired DNA replication/segregation, TF gradient is dissipated and Sle1 levels are reduced, thus halting premature septum splitting.
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Affiliation(s)
- Helena Veiga
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Ambre Jousselin
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Simon Schäper
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Bruno M Saraiva
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Leonor B Marques
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Patricia Reed
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Joana Wilton
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Pedro M Pereira
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Sérgio 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
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8
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Sousa FM, Pires P, Barreto A, Refojo PN, Silva MS, Fernandes PB, Carapeto AP, Robalo TT, Rodrigues MS, Pinho MG, Cabrita EJ, Pereira MM. Unveiling the membrane bound dihydroorotate: Quinone oxidoreductase from Staphylococcus aureus. Biochim Biophys Acta Bioenerg 2023; 1864:148948. [PMID: 36481274 DOI: 10.1016/j.bbabio.2022.148948] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Revised: 11/23/2022] [Accepted: 11/28/2022] [Indexed: 12/12/2022]
Abstract
Staphylococcus aureus is an opportunistic pathogen and one of the most frequent causes for community acquired and nosocomial bacterial infections. Even so, its energy metabolism is still under explored and its respiratory enzymes have been vastly overlooked. In this work, we unveil the dihydroorotate:quinone oxidoreductase (DHOQO) from S. aureus, the first example of a DHOQO from a Gram-positive organism. This protein was shown to be a FMN containing menaquinone reducing enzyme, presenting a Michaelis-Menten behaviour towards the two substrates, which was inhibited by Brequinar, Leflunomide, Lapachol, HQNO, Atovaquone and TFFA with different degrees of effectiveness. Deletion of the DHOQO coding gene (Δdhoqo) led to lower bacterial growth rates, and effected in cell morphology and metabolism, most importantly in the pyrimidine biosynthesis, here systematized for S. aureus MW2 for the first time. This work unveils the existence of a functional DHOQO in the respiratory chain of the pathogenic bacterium S. aureus, enlarging the understanding of its energy metabolism.
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Affiliation(s)
- Filipe M Sousa
- Instituto de Tecnologia Química e Biológica - António Xavier, Universidade Nova de Lisboa, Av. da República EAN, 2780-157 Oeiras, Portugal; University of Lisbon, Faculty of Sciences, BioISI - Biosystems & Integrative Sciences Institute, Campo Grande, C8, 1749-016 Lisboa, Portugal
| | - Patrícia Pires
- University of Lisbon, Faculty of Sciences, BioISI - Biosystems & Integrative Sciences Institute, Campo Grande, C8, 1749-016 Lisboa, Portugal
| | - Andreia Barreto
- University of Lisbon, Faculty of Sciences, BioISI - Biosystems & Integrative Sciences Institute, Campo Grande, C8, 1749-016 Lisboa, Portugal
| | - Patrícia N Refojo
- Instituto de Tecnologia Química e Biológica - António Xavier, Universidade Nova de Lisboa, Av. da República EAN, 2780-157 Oeiras, Portugal
| | - Micael S Silva
- UCIBIO, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal
| | - Pedro B Fernandes
- Instituto de Tecnologia Química e Biológica - António Xavier, Universidade Nova de Lisboa, Av. da República EAN, 2780-157 Oeiras, Portugal
| | - Ana P Carapeto
- University of Lisbon, Faculty of Sciences, BioISI - Biosystems & Integrative Sciences Institute, Campo Grande, C8, 1749-016 Lisboa, Portugal; Departamento de Física, Faculdade de Ciências, Universidade de Lisboa, 1749-016 Lisboa, Portugal
| | - Tiago T Robalo
- University of Lisbon, Faculty of Sciences, BioISI - Biosystems & Integrative Sciences Institute, Campo Grande, C8, 1749-016 Lisboa, Portugal; Departamento de Física, Faculdade de Ciências, Universidade de Lisboa, 1749-016 Lisboa, Portugal
| | - Mário S Rodrigues
- University of Lisbon, Faculty of Sciences, BioISI - Biosystems & Integrative Sciences Institute, Campo Grande, C8, 1749-016 Lisboa, Portugal; Departamento de Física, Faculdade de Ciências, Universidade de Lisboa, 1749-016 Lisboa, Portugal
| | - Mariana G Pinho
- Instituto de Tecnologia Química e Biológica - António Xavier, Universidade Nova de Lisboa, Av. da República EAN, 2780-157 Oeiras, Portugal
| | - Eurico J Cabrita
- UCIBIO, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal
| | - Manuela M Pereira
- Instituto de Tecnologia Química e Biológica - António Xavier, Universidade Nova de Lisboa, Av. da República EAN, 2780-157 Oeiras, Portugal; University of Lisbon, Faculty of Sciences, BioISI - Biosystems & Integrative Sciences Institute, Campo Grande, C8, 1749-016 Lisboa, Portugal.
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9
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Schultz JR, Costa SK, Jachak GR, Hegde P, Zimmerman M, Pan Y, Josten M, Ejeh C, Hammerstad T, Sahl HG, Pereira PM, Pinho MG, Dartois V, Cheung A, Aldrich CC. Identification of 5-(Aryl/Heteroaryl)amino-4-quinolones as Potent Membrane-Disrupting Agents to Combat Antibiotic-Resistant Gram-Positive Bacteria. J Med Chem 2022; 65:13910-13934. [PMID: 36219779 PMCID: PMC9826610 DOI: 10.1021/acs.jmedchem.2c01151] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Nosocomial infections caused by resistant Gram-positive organisms are on the rise, presumably due to a combination of factors including prolonged hospital exposure, increased use of invasive procedures, and pervasive antibiotic therapy. Although antibiotic stewardship and infection control measures are helpful, newer agents against multidrug-resistant (MDR) Gram-positive bacteria are urgently needed. Here, we describe our efforts that led to the identification of 5-amino-4-quinolone 111 with exceptionally potent Gram-positive activity with minimum inhibitory concentrations (MICs) ≤0.06 μg/mL against numerous clinical isolates. Preliminary mechanism of action and resistance studies demonstrate that the 5-amino-4-quinolones are bacteriostatic, do not select for resistance, and selectively disrupt bacterial membranes. While the precise molecular mechanism has not been elucidated, the lead compound is nontoxic displaying a therapeutic index greater than 500, is devoid of hemolytic activity, and has attractive physicochemical properties (clog P = 3.8, molecular weight (MW) = 441) that warrant further investigation of this promising antibacterial scaffold for the treatment of Gram-positive infections.
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Affiliation(s)
- John R Schultz
- Department of Medicinal Chemistry, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Stephen K Costa
- Department of Microbiology & Immunology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire 03755, United States
| | - Gorakhnath R Jachak
- Department of Medicinal Chemistry, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Pooja Hegde
- Department of Medicinal Chemistry, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Matthew Zimmerman
- Center for Discovery and Innovation, Hackensack Meridian Health, Nutley, New Jersey 07110, United States
| | - Yan Pan
- Center for Discovery and Innovation, Hackensack Meridian Health, Nutley, New Jersey 07110, United States
| | - Michaele Josten
- Institute for Pharmaceutical Microbiology and Institute for Medical Microbiology, Immunology, and Parasitology, University of Bonn, D-53115 Bonn, Germany
| | - Chinedu Ejeh
- Department of Microbiology & Immunology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire 03755, United States
| | - Travis Hammerstad
- Department of Medicinal Chemistry, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Hans Georg Sahl
- Institute for Pharmaceutical Microbiology and Institute for Medical Microbiology, Immunology, and Parasitology, University of Bonn, D-53115 Bonn, Germany
| | - Pedro M Pereira
- Bacterial Cell Biology Laboratory, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Avenida da República (EAN), 2781-901 Oeiras, Portugal
| | - Mariana G Pinho
- Bacterial Cell Biology Laboratory, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Avenida da República (EAN), 2781-901 Oeiras, Portugal
| | - Véronique Dartois
- Center for Discovery and Innovation, Hackensack Meridian Health, Nutley, New Jersey 07110, United States
| | - Ambrose Cheung
- Department of Microbiology & Immunology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire 03755, United States
| | - Courtney C Aldrich
- Department of Medicinal Chemistry, University of Minnesota, Minneapolis, Minnesota 55455, United States
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10
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Spahn C, Gómez-de-Mariscal E, Laine RF, Pereira PM, von Chamier L, Conduit M, Pinho MG, Jacquemet G, Holden S, Heilemann M, Henriques R. DeepBacs for multi-task bacterial image analysis using open-source deep learning approaches. Commun Biol 2022; 5:688. [PMID: 35810255 PMCID: PMC9271087 DOI: 10.1038/s42003-022-03634-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Accepted: 06/23/2022] [Indexed: 11/09/2022] Open
Abstract
This work demonstrates and guides how to use a range of state-of-the-art artificial neural-networks to analyse bacterial microscopy images using the recently developed ZeroCostDL4Mic platform. We generated a database of image datasets used to train networks for various image analysis tasks and present strategies for data acquisition and curation, as well as model training. We showcase different deep learning (DL) approaches for segmenting bright field and fluorescence images of different bacterial species, use object detection to classify different growth stages in time-lapse imaging data, and carry out DL-assisted phenotypic profiling of antibiotic-treated cells. To also demonstrate the ability of DL to enhance low-phototoxicity live-cell microscopy, we showcase how image denoising can allow researchers to attain high-fidelity data in faster and longer imaging. Finally, artificial labelling of cell membranes and predictions of super-resolution images allow for accurate mapping of cell shape and intracellular targets. Our purposefully-built database of training and testing data aids in novice users' training, enabling them to quickly explore how to analyse their data through DL. We hope this lays a fertile ground for the efficient application of DL in microbiology and fosters the creation of tools for bacterial cell biology and antibiotic research.
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Affiliation(s)
- Christoph Spahn
- Department of Natural Products in Organismic Interaction, Max Planck Institute for Terrestrial Microbiology, Marburg, Germany.
- Institute of Physical and Theoretical Chemistry, Goethe-University Frankfurt, Frankfurt, Germany.
| | | | - Romain F Laine
- MRC-Laboratory for Molecular Cell Biology, University College London, London, UK
- The Francis Crick Institute, London, UK
- Micrographia Bio, Translation and Innovation hub 84 Wood lane, W120BZ, London, UK
| | - Pedro M Pereira
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Lucas von Chamier
- MRC-Laboratory for Molecular Cell Biology, University College London, London, UK
| | - Mia Conduit
- Centre for Bacterial Cell Biology, Newcastle University Biosciences Institute, Faculty of Medical Sciences, Newcastle upon Tyne, NE24AX, United Kingdom
| | - Mariana G Pinho
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Guillaume Jacquemet
- Turku Bioscience Centre, University of Turku and Åbo Akademi University, Turku, Finland
- Faculty of Science and Engineering, Cell Biology, Åbo Akademi University, Turku, Finland
- Turku Bioimaging, University of Turku and Åbo Akademi University, Turku, Finland
| | - Séamus Holden
- Centre for Bacterial Cell Biology, Newcastle University Biosciences Institute, Faculty of Medical Sciences, Newcastle upon Tyne, NE24AX, United Kingdom
| | - Mike Heilemann
- Institute of Physical and Theoretical Chemistry, Goethe-University Frankfurt, Frankfurt, Germany.
| | - Ricardo Henriques
- Instituto Gulbenkian de Ciência, 2780-156, Oeiras, Portugal.
- MRC-Laboratory for Molecular Cell Biology, University College London, London, UK.
- The Francis Crick Institute, London, UK.
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11
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Gouveia A, Pinto D, Veiga H, Antunes W, Pinho MG, São-José C. Synthetic antimicrobial peptides as enhancers of the bacteriolytic action of staphylococcal phage endolysins. Sci Rep 2022; 12:1245. [PMID: 35075218 PMCID: PMC8786859 DOI: 10.1038/s41598-022-05361-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2021] [Accepted: 01/10/2022] [Indexed: 01/09/2023] Open
Abstract
Bacteriophage endolysins degrade the bacterial cell wall and are therefore considered promising antimicrobial alternatives to fight pathogens resistant to conventional antibiotics. Gram-positive bacteria are usually considered easy targets to exogenously added endolysins, since their cell walls are not shielded by an outer membrane. However, in nutrient rich environments these bacteria can also tolerate endolysin attack if they keep an energized cytoplasmic membrane. Hence, we have hypothesized that the membrane depolarizing action of antimicrobial peptides (AMPs), another attractive class of alternative antibacterials, could be explored to overcome bacterial tolerance to endolysins and consequently improve their antibacterial potential. Accordingly, we show that under conditions supporting bacterial growth, Staphylococcus aureus becomes much more susceptible to the bacteriolytic action of endolysins if an AMP is also present. The bactericidal gain resulting from the AMP/endolysin combined action ranged from 1 to 3 logs for different S. aureus strains, which included drug-resistant clinical isolates. In presence of an AMP, as with a reduced content of cell wall teichoic acids, higher endolysin binding to cells is observed. However, our results indicate that this higher endolysin binding alone does not fully explain the higher susceptibility of S. aureus to lysis in these conditions. Other factors possibly contributing to the increased endolysin susceptibility in presence of an AMP are discussed.
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Affiliation(s)
- Ana Gouveia
- Research Institute for Medicines (iMed.ULisboa), Faculdade de Farmácia da Universidade de Lisboa, Av. Prof. Gama Pinto, 1649-003, Lisbon, Portugal
| | - Daniela Pinto
- Research Institute for Medicines (iMed.ULisboa), Faculdade de Farmácia da Universidade de Lisboa, Av. Prof. Gama Pinto, 1649-003, Lisbon, Portugal
| | - Helena Veiga
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Av. da Républica, 2780-157, Oeiras, Portugal
| | - Wilson Antunes
- Unidade Militar Laboratorial de Defesa Biológica e Química (UMLDBQ), Instituto Universitário Militar, Centro de Investigação da Academia Militar (CINAMIL), Av. Dr. Alfredo Bensaúde, 1849-012, Lisbon, Portugal
| | - Mariana G Pinho
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Av. da Républica, 2780-157, Oeiras, Portugal
| | - Carlos São-José
- Research Institute for Medicines (iMed.ULisboa), Faculdade de Farmácia da Universidade de Lisboa, Av. Prof. Gama Pinto, 1649-003, Lisbon, Portugal.
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12
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Saraiva BM, Krippahl L, Filipe SR, Henriques R, Pinho MG. eHooke: A tool for automated image analysis of spherical bacteria based on cell cycle progression. Biol Imaging 2021; 1:e3. [PMID: 35036921 PMCID: PMC8724265 DOI: 10.1017/s2633903x21000027] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/21/2021] [Revised: 08/18/2021] [Accepted: 09/07/2021] [Indexed: 01/18/2023]
Abstract
Fluorescence microscopy is a critical tool for cell biology studies on bacterial cell division and morphogenesis. Because the analysis of fluorescence microscopy images evolved beyond initial qualitative studies, numerous images analysis tools were developed to extract quantitative parameters on cell morphology and organization. To understand cellular processes required for bacterial growth and division, it is particularly important to perform such analysis in the context of cell cycle progression. However, manual assignment of cell cycle stages is laborious and prone to user bias. Although cell elongation can be used as a proxy for cell cycle progression in rod-shaped or ovoid bacteria, that is not the case for cocci, such as Staphylococcus aureus. Here, we describe eHooke, an image analysis framework developed specifically for automated analysis of microscopy images of spherical bacterial cells. eHooke contains a trained artificial neural network to automatically classify the cell cycle phase of individual S. aureus cells. Users can then apply various functions to obtain biologically relevant information on morphological features of individual cells and cellular localization of proteins, in the context of the cell cycle.
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Affiliation(s)
- Bruno M. Saraiva
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Ludwig Krippahl
- NOVA LINCS, Departamento de Informática, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Caparica, Portugal
| | - Sérgio 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
| | - Ricardo Henriques
- Instituto Gulbenkian de Ciência, Oeiras, Portugal
- MRC Laboratory for Molecular Cell Biology, University College London, London, United Kingdom
| | - Mariana G. Pinho
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
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13
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Do T, Schaefer K, Santiago AG, Coe KA, Fernandes PB, Kahne D, Pinho MG, Walker S. Staphylococcus aureus cell growth and division are regulated by an amidase that trims peptides from uncrosslinked peptidoglycan. Nat Microbiol 2020; 5:291-303. [PMID: 31932712 PMCID: PMC7046134 DOI: 10.1038/s41564-019-0632-1] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2019] [Accepted: 11/05/2019] [Indexed: 12/16/2022]
Abstract
Bacteria are protected by a polymer of peptidoglycan that serves as an exoskeleton1. In Staphylococcus aureus, the peptidoglycan assembly enzymes relocate during the cell cycle from the periphery, where they are active during growth, to the division site where they build the partition between daughter cells2-4. But how peptidoglycan synthesis is regulated throughout the cell cycle is poorly understood5,6. Here, we used a transposon screen to identify a membrane protein complex that spatially regulates S. aureus peptidoglycan synthesis. This complex consists of an amidase that removes stem peptides from uncrosslinked peptidoglycan and a partner protein that controls its activity. Amidases typically hydrolyse crosslinked peptidoglycan between daughter cells so that they can separate7. However, this amidase controls cell growth. In its absence, peptidoglycan synthesis becomes spatially dysregulated, which causes cells to grow so large that cell division is defective. We show that the cell growth and division defects due to loss of this amidase can be mitigated by attenuating the polymerase activity of the major S. aureus peptidoglycan synthase. Our findings lead to a model wherein the amidase complex regulates the density of peptidoglycan assembly sites to control peptidoglycan synthase activity at a given subcellular location. Removal of stem peptides from peptidoglycan at the cell periphery promotes peptidoglycan synthase relocation to midcell during cell division. This mechanism ensures that cell expansion is properly coordinated with cell division.
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Affiliation(s)
- Truc Do
- Department of Microbiology, Harvard Medical School, Boston, MA, USA
| | - Kaitlin Schaefer
- Department of Microbiology, Harvard Medical School, Boston, MA, USA.,Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA
| | | | - Kathryn A Coe
- Department of Microbiology, Harvard Medical School, Boston, MA, USA
| | - Pedro B Fernandes
- Bacterial Cell Biology, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Daniel Kahne
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA
| | - Mariana G Pinho
- Bacterial Cell Biology, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Suzanne Walker
- Department of Microbiology, Harvard Medical School, Boston, MA, USA.
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14
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Jensen C, Bæk KT, Gallay C, Thalsø-Madsen I, Xu L, Jousselin A, Ruiz Torrubia F, Paulander W, Pereira AR, Veening JW, Pinho MG, Frees D. The ClpX chaperone controls autolytic splitting of Staphylococcus aureus daughter cells, but is bypassed by β-lactam antibiotics or inhibitors of WTA biosynthesis. PLoS Pathog 2019; 15:e1008044. [PMID: 31518377 PMCID: PMC6760813 DOI: 10.1371/journal.ppat.1008044] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Revised: 09/25/2019] [Accepted: 08/26/2019] [Indexed: 12/02/2022] Open
Abstract
β-lactam antibiotics interfere with cross-linking of the bacterial cell wall, but the killing mechanism of this important class of antibiotics is not fully understood. Serendipitously we found that sub-lethal doses of β-lactams rescue growth and prevent spontaneous lysis of Staphylococcus aureus mutants lacking the widely conserved chaperone ClpX, and we reasoned that a better understanding of the clpX phenotypes could provide novel insights into the downstream effects of β-lactam binding to the PBP targets. Super-resolution imaging revealed that clpX cells display aberrant septum synthesis, and initiate daughter cell separation prior to septum completion at 30°C, but not at 37°C, demonstrating that ClpX becomes critical for coordinating the S. aureus cell cycle as the temperature decreases. FtsZ localization and dynamics were not affected in the absence of ClpX, suggesting that ClpX affects septum formation and autolytic activation downstream of Z-ring formation. Interestingly, oxacillin antagonized the septum progression defects of clpX cells and prevented lysis of prematurely splitting clpX cells. Strikingly, inhibitors of wall teichoic acid (WTA) biosynthesis that work synergistically with β-lactams to kill MRSA synthesis also rescued growth of the clpX mutant, as did genetic inactivation of the gene encoding the septal autolysin, Sle1. Taken together, our data support a model in which Sle1 causes premature splitting and lysis of clpX daughter cells unless Sle1-dependent lysis is antagonized by β-lactams or by inhibiting an early step in WTA biosynthesis. The finding that β-lactams and inhibitors of WTA biosynthesis specifically prevent lysis of a mutant with dysregulated autolytic activity lends support to the idea that PBPs and WTA biosynthesis play an important role in coordinating cell division with autolytic splitting of daughter cells, and that β-lactams do not kill S. aureus simply by weakening the cell wall. The bacterium Staphylococcus aureus is a major cause of human disease, and the rapid spread of S. aureus strains that are resistant to almost all β-lactam antibiotics has made treatment increasingly difficult. β-lactams interfere with cross-linking of the bacterial cell wall but the killing mechanism of this important class of antibiotics is not fully understood. Here we provide novel insight into this topic by examining a defined S. aureus mutant that has the unusual property of growing markedly better in the presence of β-lactams. Without β-lactams this mutant dies spontaneously at a high frequency due to premature separation of daughter cells during cell division. Cell death of the mutant can, however, be prevented either by exposure to β-lactam antibiotics or by inhibiting synthesis of wall teichoic acid, a major component of the cell wall in Gram-positive bacteria with a conserved role in activation of autolytic splitting of daughter cells. The finding that β-lactam antibiotics can prevent lysis of a mutant with deregulated activity of autolytic enzymes involved in daughter cell splitting, emphasizes the idea that β-lactams interfere with the coordination between cell division and daughter cell splitting, and do not kill S. aureus simply by weakening the cell wall.
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Affiliation(s)
- Camilla Jensen
- Department of Veterinary and Animal Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Kristoffer T. Bæk
- Department of Veterinary and Animal Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Clement Gallay
- Department of Fundamental Microbiology, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland
| | - Ida Thalsø-Madsen
- Department of Veterinary and Animal Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Lijuan Xu
- Department of Veterinary and Animal Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Ambre Jousselin
- Bacterial Cell Biology, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Fernando Ruiz Torrubia
- Department of Veterinary and Animal Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Wilhelm Paulander
- Department of Veterinary and Animal Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Ana R. Pereira
- Bacterial Cell Biology, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Jan-Willem Veening
- Department of Fundamental Microbiology, Faculty of Biology and Medicine, University of Lausanne, Lausanne, Switzerland
| | - Mariana G. Pinho
- Bacterial Cell Biology, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Dorte Frees
- Department of Veterinary and Animal Sciences, University of Copenhagen, Copenhagen, Denmark
- * E-mail:
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15
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Hill MA, Lam AK, Reed P, Harney MC, Wilson BA, Moen EL, Wright SN, Pinho MG, Rice CV. BPEI-Induced Delocalization of PBP4 Potentiates β-Lactams against MRSA. Biochemistry 2019; 58:3813-3822. [PMID: 31429286 PMCID: PMC6941424 DOI: 10.1021/acs.biochem.9b00523] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
With its high morbidity rate and increasing resistance to treatment, methicillin-resistant Staphylococcus aureus (MRSA) is a grave concern in the medical field. In methicillin-susceptible strains, β-lactam antibiotics disable the penicillin binding proteins (PBPs) that cross-link the bacterial cell wall. However, methicillin-resistant strains have PBP2a and PBP4, which continue enzymatic activity in the presence of β-lactam antibiotics. The activity of PBP2a and PBP4 is linked to the presence of wall teichoic acid (WTA); thus, WTA has emerged as a target for antibiotic drug discovery. In this work, we disable WTA in situ using its anionic phosphodiester backbone to attract cationic branched polyethylenimine (BPEI). Data show that BPEI removes β-lactam resistance in common MRSA strains and clinical isolates. Fluorescence microscopy was used to investigate this mechanism of action. The results indicate that BPEI prevents the localization of PBP4 to the cell division septum, thereby changing the cellular morphology and inhibiting cell division. Although PBP4 is not required for septum formation, proper cell division and morphology require WTA; BPEI prevents this essential function. The combination of BPEI and β-lactams is bactericidal and synergistic. Because BPEI allows us to study the role of WTA in the cell wall without genetic mutation or altered translocation of biomolecules and/or their precursors, this approach can help revise existing paradigms regarding the role of WTA in prokaryotic biochemistry at every growth stage.
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Affiliation(s)
- Melissa A. Hill
- Department of Chemistry and Biochemistry, Stephenson Life Sciences Research Center, University of Oklahoma, 101 Stephenson Parkway, Norman, Oklahoma 73019, United States
| | - Anh K. Lam
- Department of Chemistry and Biochemistry, Stephenson Life Sciences Research Center, University of Oklahoma, 101 Stephenson Parkway, Norman, Oklahoma 73019, United States
| | - Patricia Reed
- Laboratory of Bacterial Cell Biology, Instituto de Tecnologia Química e Biologica António Xavier, Universidade NOVA de Lisboa, Av. da Repùblica, 2780-157 Oeiras, Portugal
| | - Madeline C. Harney
- Department of Chemistry and Biochemistry, Stephenson Life Sciences Research Center, University of Oklahoma, 101 Stephenson Parkway, Norman, Oklahoma 73019, United States
| | - Beatrice A. Wilson
- Department of Chemistry and Biochemistry, Stephenson Life Sciences Research Center, University of Oklahoma, 101 Stephenson Parkway, Norman, Oklahoma 73019, United States
| | - Erika L. Moen
- Department of Chemistry and Biochemistry, Stephenson Life Sciences Research Center, University of Oklahoma, 101 Stephenson Parkway, Norman, Oklahoma 73019, United States
| | - Summer N. Wright
- Department of Chemistry and Biochemistry, Stephenson Life Sciences Research Center, University of Oklahoma, 101 Stephenson Parkway, Norman, Oklahoma 73019, United States
| | - Mariana G. Pinho
- Laboratory of Bacterial Cell Biology, Instituto de Tecnologia Química e Biologica António Xavier, Universidade NOVA de Lisboa, Av. da Repùblica, 2780-157 Oeiras, Portugal
| | - Charles V. Rice
- Department of Chemistry and Biochemistry, Stephenson Life Sciences Research Center, University of Oklahoma, 101 Stephenson Parkway, Norman, Oklahoma 73019, United States
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16
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Basuino L, Jousselin A, Alexander JAN, Strynadka NCJ, Pinho MG, Chambers HF, Chatterjee SS. PBP4 activity and its overexpression are necessary for PBP4-mediated high-level β-lactam resistance. J Antimicrob Chemother 2019; 73:1177-1180. [PMID: 29360990 DOI: 10.1093/jac/dkx531] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2017] [Accepted: 12/15/2017] [Indexed: 11/13/2022] Open
Abstract
Background PBP4 is typically considered unimportant for conferring high-level β-lactam resistance in Staphylococcus aureus. Mutations in PBP4 have been associated with β-lactam non-susceptibility among natural strains of S. aureus. We have previously shown that PBP4 can mediate high-level β-lactam resistance in laboratory-generated strains passaged in β-lactam antibiotics. Mutations in the pbp4 promoter that up-regulate its expression and missense mutations that surround PBP4's active site were detected in high frequencies among passaged strains, suggesting PBP4 plays a key role in resistance. How these mutations participate in PBP4's ability to provide high-level β-lactam resistance is unknown. Objectives To determine whether enzymatic activity of PBP4 is required for high-level β-lactam resistance and to investigate how the pbp4-associated mutations provide β-lactam resistance. Methods The catalytic activity of PBP4 was disabled through introduction of a serine to alanine point mutation in its active site (Ser-75→Ala) in a representative and well-studied passaged strain, CRB. pbp4 promoter and missense mutations detected in CRB were reconstituted in a WT strain individually and in combination. β-Lactam resistance of the resultant strains was evaluated by population analysis. Bacterial peptidoglycan composition of the pbp4 mutants was evaluated with and without antibiotic treatment using LC. Results PBP4 inactivation imparted complete β-lactam susceptibility of CRB. Reconstitution of PBP4 missense mutations alone did not impart β-lactam resistance, but did so in synergism with pbp4 promoter mutation. A similar synergistic interaction of pbp4 mutations was observed in enhanced peptidoglycan cross-linking upon antibiotic treatment. Conclusions PBP4's activity and overexpression both contribute to high-level β-lactam resistance.
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Affiliation(s)
- Li Basuino
- Division of HIV/AIDS, Infectious Diseases and Global Health, Department of Medicine, University of California, San Francisco, CA, USA
| | - Ambre Jousselin
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - J Andrew N Alexander
- Department of Biochemistry and Molecular Biology and the Center for Blood Research, University of British Columbia, Vancouver, British Columbia, Canada
| | - Natalie C J Strynadka
- Department of Biochemistry and Molecular Biology and the Center for Blood Research, University of British Columbia, Vancouver, British Columbia, Canada
| | - Mariana G Pinho
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Henry F Chambers
- Division of HIV/AIDS, Infectious Diseases and Global Health, Department of Medicine, University of California, San Francisco, CA, USA
| | - Som S Chatterjee
- Division of HIV/AIDS, Infectious Diseases and Global Health, Department of Medicine, University of California, San Francisco, CA, USA
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17
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Reichmann NT, Tavares AC, Saraiva BM, Jousselin A, Reed P, Pereira AR, Monteiro JM, Sobral RG, VanNieuwenhze MS, Fernandes F, Pinho MG. SEDS-bPBP pairs direct lateral and septal peptidoglycan synthesis in Staphylococcus aureus. Nat Microbiol 2019; 4:1368-1377. [PMID: 31086309 DOI: 10.1038/s41564-019-0437-2] [Citation(s) in RCA: 59] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2018] [Accepted: 03/25/2019] [Indexed: 11/09/2022]
Abstract
Peptidoglycan (PGN) is the major component of the bacterial cell wall, a structure that is essential for the physical integrity and shape of the cell. Bacteria maintain cell shape by directing PGN incorporation to distinct regions of the cell, namely, through the localization of late-stage PGN synthesis proteins. These include two key protein families, SEDS transglycosylases and bPBP transpeptidases, proposed to function in cognate pairs. Rod-shaped bacteria have two SEDS-bPBP pairs, involved in elongation and division. Here, we elucidate why coccoid bacteria, such as Staphylococcus aureus, also possess two SEDS-bPBP pairs. We determined that S. aureus RodA-PBP3 and FtsW-PBP1 probably constitute cognate pairs of interacting proteins. A lack of RodA-PBP3 resulted in more spherical cells due to deficient sidewall PGN synthesis, whereas depletion of FtsW-PBP1 arrested normal septal PGN incorporation. Although PBP1 is an essential protein, a mutant lacking PBP1 transpeptidase activity is viable, showing that this protein has a second function. We propose that the FtsW-PBP1 pair has a role in stabilizing the divisome at midcell. In the absence of these proteins, the divisome appears as multiple rings or arcs that drive lateral PGN incorporation, leading to cell elongation. We conclude that RodA-PBP3 and FtsW-PBP1 mediate sidewall and septal PGN incorporation, respectively, and that their activity must be balanced to maintain coccoid morphology.
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Affiliation(s)
- Nathalie T Reichmann
- Bacterial Cell Biology, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Andreia C Tavares
- Bacterial Cell Biology, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Bruno M Saraiva
- Bacterial Cell Biology, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Ambre Jousselin
- Bacterial Cell Biology, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Patricia Reed
- Bacterial Cell Biology, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Ana R Pereira
- Bacterial Cell Biology, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - João M Monteiro
- Bacterial Cell Biology, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Rita G Sobral
- Bacterial Cell Biology, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal.,Departamento de Ciências da Vida e UCIBIO-REQUIMTE, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Caparica, Portugal
| | | | - Fábio Fernandes
- Centro de Química-Física Molecular and Institute of Nanoscience and Nanotechnology, Instituto Superior Técnico, University of Lisbon, Lisbon, Portugal.,Institute for Bioengineering and Biosciences, Department of Bioengineering, Instituto Superior Técnico, University of Lisbon, Lisbon, Portugal
| | - Mariana G Pinho
- Bacterial Cell Biology, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal.
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18
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Monteiro JM, Covas G, Rausch D, Filipe SR, Schneider T, Sahl HG, Pinho MG. The pentaglycine bridges of Staphylococcus aureus peptidoglycan are essential for cell integrity. Sci Rep 2019; 9:5010. [PMID: 30899062 PMCID: PMC6428869 DOI: 10.1038/s41598-019-41461-1] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2018] [Accepted: 03/07/2019] [Indexed: 02/04/2023] Open
Abstract
Bacterial cells are surrounded by cell wall, whose main component is peptidoglycan (PG), a macromolecule that withstands the internal turgor of the cell. PG composition can vary considerably between species. The Gram-positive pathogen Staphylococcus aureus possesses highly crosslinked PG due to the presence of cross bridges containing five glycines, which are synthesised by the FemXAB protein family. FemX adds the first glycine of the cross bridge, while FemA and FemB add the second and the third, and the fourth and the fifth glycines, respectively. Of these, FemX was reported to be essential. To investigate the essentiality of FemAB, we constructed a conditional S. aureus mutant of the femAB operon. Depletion of femAB was lethal, with cells appearing as pseudomulticellular forms that eventually lyse due to extensive membrane rupture. This deleterious effect was mitigated by drastically increasing the osmolarity of the medium, indicating that pentaglycine crosslinks are required for S. aureus cells to withstand internal turgor. Despite the absence of canonical membrane targeting domains, FemA has been shown to localise at the membrane. To study its mechanism of localisation, we constructed mutants in key residues present in the putative transferase pocket and the α6 helix of FemA, possibly involved in tRNA binding. Mutations in the α6 helix led to a sharp decrease in protein activity in vivo and in vitro but did not impair correct membrane localisation, indicating that FemA activity is not required for localisation. Our data indicates that, contrarily to what was previously thought, S. aureus cells do not survive in the absence of a pentaglycine cross bridge.
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Affiliation(s)
- João M Monteiro
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Gonçalo Covas
- 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
| | - Daniela Rausch
- Institute of Pharmaceutical Microbiology, University of Bonn, 53115, Bonn, Germany
| | - Sérgio 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
| | - Tanja Schneider
- Institute of Pharmaceutical Microbiology, University of Bonn, 53115, Bonn, Germany
| | - Hans-Georg Sahl
- Institute of Pharmaceutical Microbiology, University of Bonn, 53115, Bonn, Germany
| | - Mariana G Pinho
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal.
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19
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Catteau L, Reichmann NT, Olson J, Pinho MG, Nizet V, Van Bambeke F, Quetin-Leclercq J. Synergy between Ursolic and Oleanolic Acids from Vitellaria paradoxa Leaf Extract and β-Lactams against Methicillin-Resistant Staphylococcus aureus: In Vitro and In Vivo Activity and Underlying Mechanisms. Molecules 2017; 22:E2245. [PMID: 29258194 PMCID: PMC6149719 DOI: 10.3390/molecules22122245] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2017] [Revised: 12/08/2017] [Accepted: 12/12/2017] [Indexed: 02/06/2023] Open
Abstract
Combining antibiotics with resistance reversing agents is a key strategy to overcome bacterial resistance. Upon screening antimicrobial activities of plants used in traditional medicine, we found that a leaf dichloromethane extract from the shea butter tree (Vitellaria paradoxa) had antimicrobial activity against methicillin-resistant Staphylococcus aureus (MRSA) with further evidence of synergy when combined with β-lactams. Using HPLC-MS, we identified ursolic (UA) and oleanolic acids (OA) in leaves and twigs of this species, and quantified them by HPLC-UV as the major constituents in leaf extracts (21% and 6% respectively). Both pure triterpenic acids showed antimicrobial activity against reference and clinical strains of MRSA, with MICs ranging from 8-16 mg/L for UA to 32-128 mg/L for OA. They were highly synergistic with β-lactams (ampicillin and oxacillin) at subMIC concentrations. Reversion of MRSA phenotype was attributed to their capacity to delocalize PBP2 from the septal division site, as observed by fluorescence microscopy, and to disturb thereby peptidoglycan synthesis. Moreover, both compounds also inhibited β-lactamases activity of living bacteria (as assessed by inhibition of nitrocefin hydrolysis), but not in bacterial lysates, suggesting an indirect mechanism for this inhibition. In a murine model of subcutaneous MRSA infection, local administration of UA was synergistic with nafcillin to reduce lesion size and inflammatory cytokine (IL-1β) production. Thus, these data highlight the potential interest of triterpenic acids as resistance reversing agents in combination with β-lactams against MRSA.
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Affiliation(s)
- Lucy Catteau
- Pharmacognosy Research Group, Louvain Drug Research Institute, Université catholique de Louvain, 1200 Brussels, Belgium.
- Cellular and Molecular Pharmacology Research Group, Louvain Drug Research Institute, Université catholique de Louvain, 1200 Brussels, Belgium.
| | - Nathalie T Reichmann
- Bacterial Cell Biology Laboratory, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, 2780-157 Oeiras, Portugal.
| | - Joshua Olson
- Department of Pediatrics, University of California, San Diego, La Jolla, CA 92093-0760, USA.
| | - Mariana G Pinho
- Bacterial Cell Biology Laboratory, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, 2780-157 Oeiras, Portugal.
| | - Victor Nizet
- Department of Pediatrics, University of California, San Diego, La Jolla, CA 92093-0760, USA.
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, CA 92093-0760, USA.
| | - Françoise Van Bambeke
- Cellular and Molecular Pharmacology Research Group, Louvain Drug Research Institute, Université catholique de Louvain, 1200 Brussels, Belgium.
| | - Joëlle Quetin-Leclercq
- Pharmacognosy Research Group, Louvain Drug Research Institute, Université catholique de Louvain, 1200 Brussels, Belgium.
- MASSMET Platform, Louvain Drug Research Institute, Université catholique de Louvain, 1200 Brussels, Belgium.
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20
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Stahlhut SG, Alqarzaee AA, Jensen C, Fisker NS, Pereira AR, Pinho MG, Thomas VC, Frees D. The ClpXP protease is dispensable for degradation of unfolded proteins in Staphylococcus aureus. Sci Rep 2017; 7:11739. [PMID: 28924169 PMCID: PMC5603545 DOI: 10.1038/s41598-017-12122-y] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2017] [Accepted: 09/04/2017] [Indexed: 01/01/2023] Open
Abstract
In living cells intracellular proteolysis is crucial for protein homeostasis, and ClpP proteases are conserved between eubacteria and the organelles of eukaryotic cells. In Staphylococcus aureus, ClpP associates to the substrate specificity factors, ClpX and ClpC forming two ClpP proteases, ClpXP and ClpCP. To address how individual ClpP proteases impact cell physiology, we constructed a S. aureus mutant expressing ClpX with an I265E substitution in the ClpP recognition tripeptide of ClpX. This mutant cannot degrade established ClpXP substrates confirming that the introduced amino acid substitution abolishes ClpXP activity. Phenotypic characterization of this mutant showed that ClpXP activity controls cell size and is required for growth at low temperature. Cells expressing the ClpXI265E variant, in contrast to cells lacking ClpP, are not sensitive to heat-stress and do not accumulate protein aggregates showing that ClpXP is dispensable for degradation of unfolded proteins in S. aureus. Consistent with this finding, transcriptomic profiling revealed strong induction of genes responding to protein folding stress in cells devoid of ClpP, but not in cells lacking only ClpXP. In the latter cells, highly upregulated loci include the urease operon, the pyrimidine biosynthesis operon, the betA-betB operon, and the pathogenicity island, SaPI5, while virulence genes were dramatically down-regulated.
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Affiliation(s)
- Steen G Stahlhut
- Department of Veterinary Disease Biology, University of Copenhagen, 1870, Frederiksberg C, Denmark
| | - Abdulelah A Alqarzaee
- Center for Staphylococcal Research, Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, Nebraska, 68198, USA
| | - Camilla Jensen
- Department of Veterinary Disease Biology, University of Copenhagen, 1870, Frederiksberg C, Denmark
| | - Niclas S Fisker
- Department of Veterinary Disease Biology, University of Copenhagen, 1870, Frederiksberg C, Denmark
| | - Ana R Pereira
- Bacterial Cell Biology, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Mariana G Pinho
- Bacterial Cell Biology, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Vinai Chittezham Thomas
- Center for Staphylococcal Research, Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, Nebraska, 68198, USA
| | - Dorte Frees
- Department of Veterinary Disease Biology, University of Copenhagen, 1870, Frederiksberg C, Denmark.
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21
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Reichmann NT, Pinho MG. Role of SCCmec type in resistance to the synergistic activity of oxacillin and cefoxitin in MRSA. Sci Rep 2017; 7:6154. [PMID: 28733674 PMCID: PMC5522475 DOI: 10.1038/s41598-017-06329-2] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2017] [Accepted: 06/12/2017] [Indexed: 11/09/2022] Open
Abstract
β-lactam antibiotics target penicillin-binding proteins (PBPs) preventing peptidoglycan synthesis and this inhibition is circumvented in methicillin resistant Staphylococcus aureus (MRSA) strains through the expression of an additional PBP, named PBP2A. This enzyme is encoded by the mecA gene located within the Staphylococcal Chromosome Cassette mec (SCCmec) mobile genetic element, of which there are 12 types described to date. Previous investigations aimed at analysing the synergistic activity of two β-lactams, oxacillin and cefoxitin, found that SCCmec type IV community-acquired MRSA strains exhibited increased susceptibility to oxacillin in the presence of cefoxitin, while hospital-acquired MRSA strains were unaffected. However, it is not clear if these differences in β-lactam resistance are indeed a consequence of the presence of the different SCCmec types. To address this question, we have exchanged the SCCmec type I in COL (HA-MRSA) for the SCCmec type IV from MW2 (CA-MRSA). This exchange did not decrease the resistance of COL against oxacillin and cefoxitin, as observed in MW2, indicating that genetic features residing outside of the SCCmec element are likely to be responsible for the discrepancy in oxacillin and cefoxitin synergy against these MRSA strains.
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Affiliation(s)
- Nathalie T Reichmann
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Mariana G Pinho
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal.
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22
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Veiga H, G Pinho M. Staphylococcus aureus requires at least one FtsK/SpoIIIE protein for correct chromosome segregation. Mol Microbiol 2016; 103:504-517. [PMID: 27886417 DOI: 10.1111/mmi.13572] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/02/2016] [Indexed: 11/30/2022]
Abstract
Faithful coordination between bacterial cell division and chromosome segregation in rod-shaped bacteria, such as Escherichia coli and Bacillus subtilis, is dependent on the DNA translocase activity of FtsK/SpoIIIE proteins, which move DNA away from the division site before cytokinesis is completed. However, the role of these proteins in chromosome partitioning has not been well studied in spherical bacteria. Here, it was shown that the two Staphylococcus aureus FtsK/SpoIIIE homologues, SpoIIIE and FtsK, operate in independent pathways to ensure correct chromosome management during cell division. SpoIIIE forms foci at the centre of the closing septum in at least 50% of the cells that are close to complete septum synthesis. FtsK is a multifunctional septal protein with a C-terminal DNA translocase domain that is not required for correct chromosome management in the presence of SpoIIIE. However, lack of both SpoIIIE and FtsK causes severe nucleoid segregation and morphological defects, showing that the two proteins have partially redundant roles in S. aureus.
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Affiliation(s)
- Helena Veiga
- Laboratory of Bacterial Cell Biology, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Mariana G Pinho
- Laboratory of Bacterial Cell Biology, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
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23
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Mann PA, Müller A, Wolff KA, Fischmann T, Wang H, Reed P, Hou Y, Li W, Müller CE, Xiao J, Murgolo N, Sher X, Mayhood T, Sheth PR, Mirza A, Labroli M, Xiao L, McCoy M, Gill CJ, Pinho MG, Schneider T, Roemer T. Chemical Genetic Analysis and Functional Characterization of Staphylococcal Wall Teichoic Acid 2-Epimerases Reveals Unconventional Antibiotic Drug Targets. PLoS Pathog 2016; 12:e1005585. [PMID: 27144276 PMCID: PMC4856313 DOI: 10.1371/journal.ppat.1005585] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2015] [Accepted: 03/29/2016] [Indexed: 11/18/2022] Open
Abstract
Here we describe a chemical biology strategy performed in Staphylococcus aureus and Staphylococcus epidermidis to identify MnaA, a 2-epimerase that we demonstrate interconverts UDP-GlcNAc and UDP-ManNAc to modulate substrate levels of TarO and TarA wall teichoic acid (WTA) biosynthesis enzymes. Genetic inactivation of mnaA results in complete loss of WTA and dramatic in vitro β-lactam hypersensitivity in methicillin-resistant S. aureus (MRSA) and S. epidermidis (MRSE). Likewise, the β-lactam antibiotic imipenem exhibits restored bactericidal activity against mnaA mutants in vitro and concomitant efficacy against 2-epimerase defective strains in a mouse thigh model of MRSA and MRSE infection. Interestingly, whereas MnaA serves as the sole 2-epimerase required for WTA biosynthesis in S. epidermidis, MnaA and Cap5P provide compensatory WTA functional roles in S. aureus. We also demonstrate that MnaA and other enzymes of WTA biosynthesis are required for biofilm formation in MRSA and MRSE. We further determine the 1.9Å crystal structure of S. aureus MnaA and identify critical residues for enzymatic dimerization, stability, and substrate binding. Finally, the natural product antibiotic tunicamycin is shown to physically bind MnaA and Cap5P and inhibit 2-epimerase activity, demonstrating that it inhibits a previously unanticipated step in WTA biosynthesis. In summary, MnaA serves as a new Staphylococcal antibiotic target with cognate inhibitors predicted to possess dual therapeutic benefit: as combination agents to restore β-lactam efficacy against MRSA and MRSE and as non-bioactive prophylactic agents to prevent Staphylococcal biofilm formation. Staphylococcus aureus and Staphylococcus epidermidis cause life-threatening infections that are commonly acquired in hospitals as well as the community and remain difficult to treat with current antibiotics. In part, this is due to the emergence of methicillin-resistant S. aureus and S. epidermidis (MRSA and MRSE), which exhibit broad resistance to β-lactams such as penicillin and other members of this important founding class of antibiotics. Compounding this problem, Staphylococci commonly colonize the surface of catheters and other medical devices, forming bacterial communities that are intrinsically resistant to antibiotics. Here we functionally characterize a family of 2-epimerases, named MnaA and Cap5P, that we demonstrate by genetic, biochemical, and X-ray crystallography means are essential for wall teichoic acid biosynthesis and that upon their genetic inactivation render methicillin-resistant Staphylococci unable to form biofilms as well as broadly hypersusceptible to β-lactam antibiotics both in vitro and in a host infection setting. WTA 2-epimerases therefore constitute a novel class of methicillin-resistant Staphylococcal drug targets.
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Affiliation(s)
- Paul A. Mann
- Merck Research Laboratories, Kenilworth New Jersey, United States of America
| | - Anna Müller
- Institute for Pharmaceutical Microbiology, University of Bonn, Bonn, Germany
- German Centre for Infection Research (DZIF), partner site Bonn-Cologne, Bonn, Germany
| | - Kerstin A. Wolff
- Merck Research Laboratories, Kenilworth New Jersey, United States of America
| | - Thierry Fischmann
- Merck Research Laboratories, Kenilworth New Jersey, United States of America
| | - Hao Wang
- Merck Research Laboratories, Kenilworth New Jersey, United States of America
| | - Patricia Reed
- Laboratory of Bacterial Cell Biology, Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Yan Hou
- Merck Research Laboratories, Kenilworth New Jersey, United States of America
| | - Wenjin Li
- PharmaCenter Bonn, Pharmaceutical Institute, Pharmaceutical Chemistry, University of Bonn, Bonn, Germany
| | - Christa E. Müller
- PharmaCenter Bonn, Pharmaceutical Institute, Pharmaceutical Chemistry, University of Bonn, Bonn, Germany
| | - Jianying Xiao
- Merck Research Laboratories, Kenilworth New Jersey, United States of America
| | - Nicholas Murgolo
- Merck Research Laboratories, Kenilworth New Jersey, United States of America
| | - Xinwei Sher
- Merck Research Laboratories, Kenilworth New Jersey, United States of America
| | - Todd Mayhood
- Merck Research Laboratories, Kenilworth New Jersey, United States of America
| | - Payal R. Sheth
- Merck Research Laboratories, Kenilworth New Jersey, United States of America
| | - Asra Mirza
- Merck Research Laboratories, Kenilworth New Jersey, United States of America
| | - Marc Labroli
- Merck Research Laboratories, Kenilworth New Jersey, United States of America
| | - Li Xiao
- Merck Research Laboratories, Kenilworth New Jersey, United States of America
| | - Mark McCoy
- Merck Research Laboratories, Kenilworth New Jersey, United States of America
| | - Charles J. Gill
- Merck Research Laboratories, Kenilworth New Jersey, United States of America
| | - Mariana G. Pinho
- Laboratory of Bacterial Cell Biology, Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Tanja Schneider
- Institute for Pharmaceutical Microbiology, University of Bonn, Bonn, Germany
- German Centre for Infection Research (DZIF), partner site Bonn-Cologne, Bonn, Germany
| | - Terry Roemer
- Merck Research Laboratories, Kenilworth New Jersey, United States of America
- * E-mail:
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24
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Abstract
Most bacterial cells are surrounded by a surface composed mainly of peptidoglycan (PGN), a glycopolymer responsible for ensuring the bacterial shape and a telltale molecule that betrays the presence of bacteria to the host immune system. In Staphylococcus aureus, as in most gram-positive bacteria, peptidoglycan is concealed by covalently linked molecules of wall teichoic acids (WTA)-phosphate rich molecules made of glycerol and ribitol phosphates which may be tailored by different amino acids and sugars.In order to analyze and compare the composition of WTA produced by different S. aureus strains, we describe methods to: (1) quantify the total amount of WTA present at the bacterial cell surface, through the determination of the inorganic phosphate present in phosphodiester linkages of WTA; (2) identify which sugar constituents are present in the assembled WTA molecules, by detecting the monosaccharides, released by acid hydrolysis, through an high-performance anion exchange chromatography analysis coupled with pulsed amperometric detection (HPAEC-PAD) and (3) compare the polymerization degree of WTA found at the cell surface of different S. aureus strains, through their different migration in a polyacrylamide gel electrophoresis (PAGE).
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Affiliation(s)
- Gonçalo Covas
- Laboratory of Bacterial Cell Surfaces and Pathogenesis, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Avenida da República, Apartado 127, 2781-901, Oeiras, Portugal
| | - Filipa Vaz
- Laboratory of Bacterial Cell Surfaces and Pathogenesis, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Avenida da República, Apartado 127, 2781-901, Oeiras, Portugal
| | - Gabriela Henriques
- Laboratory of Bacterial Cell Biology, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Mariana G Pinho
- Laboratory of Bacterial Cell Biology, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Sérgio R Filipe
- Laboratory of Bacterial Cell Surfaces and Pathogenesis, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Avenida da República, Apartado 127, 2781-901, Oeiras, Portugal. .,UCIBIO@REQUIMTE, Departamento de Ciências da Vida/ Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Campus da Caparica, 2829-516, Caparica, Portugal.
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25
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Correia VG, Ferraria AM, Pinho MG, Aguiar-Ricardo A. Antimicrobial Contact-Active Oligo(2-oxazoline)s-Grafted Surfaces for Fast Water Disinfection at the Point-of-Use. Biomacromolecules 2015; 16:3904-15. [DOI: 10.1021/acs.biomac.5b01243] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Affiliation(s)
- Vanessa G. Correia
- LAQV-REQUIMTE,
Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Campus de Caparica, 2829-516 Caparica, Portugal
- Bacterial
Cell Biology Laboratory, Instituto de Tecnologia Química e Biológica António Xavier, Av. da República (EAN) 2780-157 Oeiras, Portugal
| | - Ana M. Ferraria
- Centro
de Química-Física Molecular (CQFM) and Institute of
Nanoscience and Nanotechnology (IN), Instituto Superior Técnico, Universidade de Lisboa, 1049-001 Lisboa, Portugal
| | - Mariana G. Pinho
- Bacterial
Cell Biology Laboratory, Instituto de Tecnologia Química e Biológica António Xavier, Av. da República (EAN) 2780-157 Oeiras, Portugal
| | - Ana Aguiar-Ricardo
- LAQV-REQUIMTE,
Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Campus de Caparica, 2829-516 Caparica, Portugal
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26
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Tavares AC, Fernandes PB, Carballido-López R, Pinho MG. MreC and MreD Proteins Are Not Required for Growth of Staphylococcus aureus. PLoS One 2015; 10:e0140523. [PMID: 26470021 PMCID: PMC4607420 DOI: 10.1371/journal.pone.0140523] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2015] [Accepted: 09/28/2015] [Indexed: 12/31/2022] Open
Abstract
The transmembrane proteins MreC and MreD are present in a wide variety of bacteria and are thought to be involved in cell shape determination. Together with the actin homologue MreB and other morphological elements, they play an essential role in the synthesis of the lateral cell wall in rod-shaped bacteria. In ovococcus, which lack MreB homologues, mreCD are also essential and have been implicated in peripheral cell wall synthesis. In this work we addressed the possible roles of MreC and MreD in the spherical pathogen Staphylococcus aureus. We show that MreC and MreD are not essential for cell viability and do not seem to affect cell morphology, cell volume or cell cycle control. MreC and MreD localize preferentially to the division septa, but do not appear to influence peptidoglycan composition, nor the susceptibility to different antibiotics and to oxidative and osmotic stress agents. Our results suggest that the function of MreCD in S. aureus is not critical for cell division and cell shape determination.
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Affiliation(s)
- Andreia C. Tavares
- Laboratory of Bacterial Cell Biology, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Pedro B. Fernandes
- Laboratory of Bacterial Cell Biology, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Rut Carballido-López
- INRA, UMR 1319 Micalis, F-78350, Jouy-en-Josas, France
- AgroParisTech, UMR Micalis, F-78350, Jouy-en-Josas, France
| | - Mariana G. Pinho
- Laboratory of Bacterial Cell Biology, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
- * E-mail:
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27
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Loskill P, Pereira PM, Jung P, Bischoff M, Herrmann M, Pinho MG, Jacobs K. Reduction of the peptidoglycan crosslinking causes a decrease in stiffness of the Staphylococcus aureus cell envelope. Biophys J 2015; 107:1082-1089. [PMID: 25185544 DOI: 10.1016/j.bpj.2014.07.029] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2014] [Revised: 06/30/2014] [Accepted: 07/15/2014] [Indexed: 11/28/2022] Open
Abstract
We have used atomic-force microscopy (AFM) to probe the effect of peptidoglycan crosslinking reduction on the elasticity of the Staphylococcus aureus cell wall, which is of particular interest as a target for antimicrobial chemotherapy. Penicillin-binding protein 4 (PBP4) is a nonessential transpeptidase, required for the high levels of peptidoglycan crosslinking characteristic of S. aureus. Importantly, this protein is essential for β-lactam resistance in community-acquired, methicillin-resistant S. aureus (MRSA) strains but not in hospital-acquired MRSA strains. Using AFM in a new mode for recording force/distance curves, we observed that the absence of PBP4, and the concomitant reduction of the peptidoglycan crosslinking, resulted in a reduction in stiffness of the S. aureus cell wall. Importantly, the reduction in cell wall stiffness in the absence of PBP4 was observed both in community-acquired and hospital-acquired MRSA strains, indicating that high levels of peptidoglycan crosslinking modulate the overall structure and mechanical properties of the S. aureus cell envelope in both types of clinically relevant strains. Additionally, we were able to show that the applied method enables the separation of cell wall properties and turgor pressure.
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Affiliation(s)
- Peter Loskill
- Experimental Physics, Saarland University, Saarbrücken, Germany
| | - Pedro M Pereira
- Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Philipp Jung
- Institute of Medical Microbiology and Hygiene, Saarland University, Homburg/Saar, Germany
| | - Markus Bischoff
- Institute of Medical Microbiology and Hygiene, Saarland University, Homburg/Saar, Germany
| | - Mathias Herrmann
- Institute of Medical Microbiology and Hygiene, Saarland University, Homburg/Saar, Germany
| | - Mariana G Pinho
- Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Oeiras, Portugal.
| | - Karin Jacobs
- Experimental Physics, Saarland University, Saarbrücken, Germany.
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28
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Gautam S, Kim T, Shoda T, Sen S, Deep D, Luthra R, Ferreira MT, Pinho MG, Spiegel DA. An Activity-Based Probe for Studying Crosslinking in Live Bacteria. Angew Chem Int Ed Engl 2015. [DOI: 10.1002/ange.201503869] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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29
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Monteiro JM, Fernandes PB, Vaz F, Pereira AR, Tavares AC, Ferreira MT, Pereira PM, Veiga H, Kuru E, VanNieuwenhze MS, Brun YV, Filipe SR, Pinho MG. Cell shape dynamics during the staphylococcal cell cycle. Nat Commun 2015; 6:8055. [PMID: 26278781 PMCID: PMC4557339 DOI: 10.1038/ncomms9055] [Citation(s) in RCA: 148] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2015] [Accepted: 07/13/2015] [Indexed: 12/04/2022] Open
Abstract
Staphylococcus aureus is an aggressive pathogen and a model organism to study cell division in sequential orthogonal planes in spherical bacteria. However, the small size of staphylococcal cells has impaired analysis of changes in morphology during the cell cycle. Here we use super-resolution microscopy and determine that S. aureus cells are not spherical throughout the cell cycle, but elongate during specific time windows, through peptidoglycan synthesis and remodelling. Both peptidoglycan hydrolysis and turgor pressure are required during division for reshaping the flat division septum into a curved surface. In this process, the septum generates less than one hemisphere of each daughter cell, a trait we show is common to other cocci. Therefore, cell surface scars of previous divisions do not divide the cells in quadrants, generating asymmetry in the daughter cells. Our results introduce a need to reassess the models for division plane selection in cocci. Staphylococci are spherical bacteria that divide in sequential orthogonal planes. Here, the authors use super-resolution microscopy to show that staphylococcal cells elongate before dividing, and that the division septum generates less than one hemisphere of each daughter cell, generating asymmetry.
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Affiliation(s)
- João M Monteiro
- Laboratory of Bacterial Cell Biology, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, 2780-157 Oeiras, Portugal
| | - Pedro B Fernandes
- Laboratory of Bacterial Cell Biology, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, 2780-157 Oeiras, Portugal
| | - Filipa Vaz
- Laboratory of Bacterial Cell Surfaces and Pathogenesis, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, 2780-157 Oeiras, Portugal
| | - Ana R Pereira
- Laboratory of Bacterial Cell Biology, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, 2780-157 Oeiras, Portugal
| | - Andreia C Tavares
- Laboratory of Bacterial Cell Biology, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, 2780-157 Oeiras, Portugal
| | - Maria T Ferreira
- Laboratory of Bacterial Cell Biology, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, 2780-157 Oeiras, Portugal
| | - Pedro M Pereira
- Laboratory of Bacterial Cell Biology, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, 2780-157 Oeiras, Portugal
| | - Helena Veiga
- Laboratory of Bacterial Cell Biology, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, 2780-157 Oeiras, Portugal
| | - Erkin Kuru
- 1] Department of Chemistry, Indiana University Bloomington, Bloomington, Indiana 47405, USA [2] Department of Biology, Indiana University Bloomington, Bloomington, Indiana 47405, USA
| | | | - Yves V Brun
- Department of Biology, Indiana University Bloomington, Bloomington, Indiana 47405, USA
| | - Sérgio R Filipe
- Laboratory of Bacterial Cell Surfaces and Pathogenesis, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, 2780-157 Oeiras, Portugal
| | - Mariana G Pinho
- Laboratory of Bacterial Cell Biology, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, 2780-157 Oeiras, Portugal
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30
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Gautam S, Kim T, Shoda T, Sen S, Deep D, Luthra R, Ferreira MT, Pinho MG, Spiegel DA. An Activity-Based Probe for Studying Crosslinking in Live Bacteria. Angew Chem Int Ed Engl 2015. [PMID: 26204841 DOI: 10.1002/anie.201503869] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Penicillin-binding proteins (PBPs) catalyze the crosslinking of peptidoglycan (PG), an essential process for bacterial growth and survival, and a common antibiotic target. Yet, despite its importance, little is known about the spatiotemporal aspects of crosslinking—largely because of a lack of experimental tools for studying the reaction in live bacteria. Here we introduce such a tool: an activity-based probe that enables visualization and relative quantitation of crosslinking in vivo. In Staphylococcus aureus, we show that fluorescent mimics of the natural substrate of PBPs (PG stem peptide) are covalently incorporated into the cell wall, installing fluorophores in place of natural crosslinks. These fluorescent stem peptide mimics (FSPMs) are selectively recognized by a single PBP in S. aureus: PBP4. Thus, we were able to use FSPM pulse-labeling to localize PBP4 activity in live cells, showing that it is recruited to the septum in a manner dependent on wall teichoic acid.
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Affiliation(s)
- Samir Gautam
- Department of Cell Biology, Yale School of Medicine, 333 Cedar Street, New Haven, CT 06520 (USA).,Department of Chemistry, Yale University, 225 Prospect Street, New Haven, CT 06511 (USA)
| | - Taehan Kim
- Department of Chemistry, Yale University, 225 Prospect Street, New Haven, CT 06511 (USA)
| | - Takuji Shoda
- Department of Chemistry, Yale University, 225 Prospect Street, New Haven, CT 06511 (USA).,National Institute of Health Sciences, 1-18-1 Kamiyoga, Setagaya-ku, Tokyo, 158-8501 (Japan)
| | - Sounok Sen
- Department of Chemistry, Yale University, 225 Prospect Street, New Haven, CT 06511 (USA).,Department of Medicine, Massachusetts General Hospital and Harvard Medical School, 55 Fruit Street, Boston, MA 02114 (USA)
| | - Deeksha Deep
- Department of Chemistry, Yale University, 225 Prospect Street, New Haven, CT 06511 (USA)
| | - Ragini Luthra
- Department of Chemistry, Yale University, 225 Prospect Street, New Haven, CT 06511 (USA)
| | - Maria Teresa Ferreira
- Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Av. da República, 2780-157 Oeiras (Portugal)
| | - Mariana G Pinho
- Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Av. da República, 2780-157 Oeiras (Portugal)
| | - David A Spiegel
- Department of Chemistry, Yale University, 225 Prospect Street, New Haven, CT 06511 (USA). .,Department of Pharmacology, Yale School of Medicine, 333 Cedar Street, New Haven, CT 06520 (USA).
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31
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Reed P, Atilano ML, Alves R, Hoiczyk E, Sher X, Reichmann NT, Pereira PM, Roemer T, Filipe SR, Pereira-Leal JB, Ligoxygakis P, Pinho MG. Staphylococcus aureus Survives with a Minimal Peptidoglycan Synthesis Machine but Sacrifices Virulence and Antibiotic Resistance. PLoS Pathog 2015; 11:e1004891. [PMID: 25951442 PMCID: PMC4423922 DOI: 10.1371/journal.ppat.1004891] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2014] [Accepted: 04/17/2015] [Indexed: 11/19/2022] Open
Abstract
Many important cellular processes are performed by molecular machines, composed of multiple proteins that physically interact to execute biological functions. An example is the bacterial peptidoglycan (PG) synthesis machine, responsible for the synthesis of the main component of the cell wall and the target of many contemporary antibiotics. One approach for the identification of essential components of a cellular machine involves the determination of its minimal protein composition. Staphylococcus aureus is a Gram-positive pathogen, renowned for its resistance to many commonly used antibiotics and prevalence in hospitals. Its genome encodes a low number of proteins with PG synthesis activity (9 proteins), when compared to other model organisms, and is therefore a good model for the study of a minimal PG synthesis machine. We deleted seven of the nine genes encoding PG synthesis enzymes from the S. aureus genome without affecting normal growth or cell morphology, generating a strain capable of PG biosynthesis catalyzed only by two penicillin-binding proteins, PBP1 and the bi-functional PBP2. However, multiple PBPs are important in clinically relevant environments, as bacteria with a minimal PG synthesis machinery became highly susceptible to cell wall-targeting antibiotics, host lytic enzymes and displayed impaired virulence in a Drosophila infection model which is dependent on the presence of specific peptidoglycan receptor proteins, namely PGRP-SA. The fact that S. aureus can grow and divide with only two active PG synthesizing enzymes shows that most of these enzymes are redundant in vitro and identifies the minimal PG synthesis machinery of S. aureus. However a complex molecular machine is important in environments other than in vitro growth as the expendable PG synthesis enzymes play an important role in the pathogenicity and antibiotic resistance of S. aureus. Peptidoglycan forms the stress-bearing sacculus that prevents lysis of bacteria due to turgor pressure. The integrity of peptidoglycan is therefore essential for bacterial survival and its synthesis is the target of many important antibiotics, such as penicillin. The final steps of peptidoglycan synthesis are catalyzed by penicillin-binding proteins, enzymes that are proposed to work in multi-enzyme complexes. We show that seven of the nine genes encoding peptidoglycan synthesis enzymes can be deleted from the Staphylococcus aureus genome without affecting normal growth and cell morphology in vitro, identifying the minimal peptidoglycan synthesis machinery of this organism. Identification of minimal machineries is key for synthetic biology efforts towards the design of systems with reduced complexity. However, the non-essential peptidoglycan synthetic proteins are important for survival of S. aureus in more challenging environments, such as in the presence of antibiotics that target cell wall synthesis or within the host, as shown by the inability of the mutant strain to establish a successful infection and kill Drosophila flies.
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Affiliation(s)
- Patricia Reed
- Laboratory of Bacterial Cell Biology, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Magda L. Atilano
- Laboratory of Bacterial Cell Surface and Pathogenesis, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
- Laboratory of Genes and Development, Department of Biochemistry, University of Oxford, Oxford, United Kingdom
| | - Renato Alves
- Instituto Gulbenkian de Ciência, Oeiras, Portugal
| | - Egbert Hoiczyk
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, United States of America
- The University of Sheffield, Department of Molecular Biology and Biotechnology, Western Bank, Sheffield, United Kingdom
| | - Xinwei Sher
- Merck Research Laboratories IT, Boston, Massachusetts, United States of America
| | - Nathalie T. Reichmann
- Laboratory of Bacterial Cell Biology, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Pedro M. Pereira
- Laboratory of Bacterial Cell Biology, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Terry Roemer
- Infectious Disease Research, Merck Research Laboratories, Kenilworth, New Jersey, United States of America
| | - Sérgio R. Filipe
- Laboratory of Bacterial Cell Surface and Pathogenesis, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | | | - Petros Ligoxygakis
- Laboratory of Genes and Development, Department of Biochemistry, University of Oxford, Oxford, United Kingdom
| | - Mariana G. Pinho
- Laboratory of Bacterial Cell Biology, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
- * E-mail:
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32
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Reichmann NT, Piçarra Cassona C, Monteiro JM, Bottomley AL, Corrigan RM, Foster SJ, Pinho MG, Gründling A. Differential localization of LTA synthesis proteins and their interaction with the cell division machinery in Staphylococcus aureus. Mol Microbiol 2014; 92:273-86. [PMID: 24533796 PMCID: PMC4065355 DOI: 10.1111/mmi.12551] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/12/2014] [Indexed: 11/28/2022]
Abstract
Lipoteichoic acid (LTA) is an important cell wall component of Gram-positive bacteria. In Staphylococcus aureus it consists of a polyglycerolphosphate-chain that is retained within the membrane via a glycolipid. Using an immunofluorescence approach, we show here that the LTA polymer is not surface exposed in S. aureus, as it can only be detected after digestion of the peptidoglycan layer. S. aureus mutants lacking LTA are enlarged and show aberrant positioning of septa, suggesting a link between LTA synthesis and the cell division process. Using a bacterial two-hybrid approach, we show that the three key LTA synthesis proteins, YpfP and LtaA, involved in glycolipid production, and LtaS, required for LTA backbone synthesis, interact with one another. All three proteins also interacted with numerous cell division and peptidoglycan synthesis proteins, suggesting the formation of a multi-enzyme complex and providing further evidence for the co-ordination of these processes. When assessed by fluorescence microscopy, YpfP and LtaA fluorescent protein fusions localized to the membrane while the LtaS enzyme accumulated at the cell division site. These data support a model whereby LTA backbone synthesis proceeds in S. aureus at the division site in co-ordination with cell division, while glycolipid synthesis takes place throughout the membrane.
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Affiliation(s)
- Nathalie T Reichmann
- Section of Microbiology and MRC Centre for Molecular Bacteriology and Infection, Imperial College LondonLondon, SW7 2AZ, UK
| | - Carolina Piçarra Cassona
- Section of Microbiology and MRC Centre for Molecular Bacteriology and Infection, Imperial College LondonLondon, SW7 2AZ, UK
| | - João M Monteiro
- Instituto de Technologia Química e Biológica, Universidade Nova de LisboaOeiras, Portugal
| | - Amy L Bottomley
- The Krebs Institute, Department of Molecular Biology and Biotechnology, University of SheffieldSheffield, UK
| | - Rebecca M Corrigan
- Section of Microbiology and MRC Centre for Molecular Bacteriology and Infection, Imperial College LondonLondon, SW7 2AZ, UK
| | - Simon J Foster
- The Krebs Institute, Department of Molecular Biology and Biotechnology, University of SheffieldSheffield, UK
| | - Mariana G Pinho
- Instituto de Technologia Química e Biológica, Universidade Nova de LisboaOeiras, Portugal
| | - Angelika Gründling
- Section of Microbiology and MRC Centre for Molecular Bacteriology and Infection, Imperial College LondonLondon, SW7 2AZ, UK
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33
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Mann PA, Müller A, Xiao L, Pereira PM, Yang C, Ho Lee S, Wang H, Trzeciak J, Schneeweis J, dos Santos MM, Murgolo N, She X, Gill C, Balibar CJ, Labroli M, Su J, Flattery A, Sherborne B, Maier R, Tan CM, Black T, Önder K, Kargman S, Monsma FJ, Pinho MG, Schneider T, Roemer T. Murgocil is a highly bioactive staphylococcal-specific inhibitor of the peptidoglycan glycosyltransferase enzyme MurG. ACS Chem Biol 2013; 8:2442-51. [PMID: 23957438 DOI: 10.1021/cb400487f] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Modern medicine is founded on the discovery of penicillin and subsequent small molecules that inhibit bacterial peptidoglycan (PG) and cell wall synthesis. However, the discovery of new chemically and mechanistically distinct classes of PG inhibitors has become exceedingly rare, prompting speculation that intracellular enzymes involved in PG precursor synthesis are not 'druggable' targets. Here, we describe a β-lactam potentiation screen to identify small molecules that augment the activity of β-lactams against methicillin-resistant Staphylococcus aureus (MRSA) and mechanistically characterize a compound resulting from this screen, which we have named murgocil. We provide extensive genetic, biochemical, and structural modeling data demonstrating both in vitro and in whole cells that murgocil specifically inhibits the intracellular membrane-associated glycosyltransferase, MurG, which synthesizes the lipid II PG substrate that penicillin binding proteins (PBPs) polymerize and cross-link into the cell wall. Further, we demonstrate that the chemical synergy and cidality achieved between murgocil and the β-lactam imipenem is mediated through MurG dependent localization of PBP2 to the division septum. Collectively, these data validate our approach to rationally identify new target-specific bioactive β-lactam potentiation agents and demonstrate that murgocil now serves as a highly selective and potent chemical probe to assist our understanding of PG biosynthesis and cell wall biogenesis across Staphylococcal species.
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Affiliation(s)
- Paul A. Mann
- Infectious
Disease Research, Merck Research Laboratories, Kenilworth, New Jersey 07033, United States
| | - Anna Müller
- Institute
of Medical Microbiology, Immunology and Parasitology—Pharmaceutical
Microbiology Section, University of Bonn, Bonn, Germany
| | - Li Xiao
- Computational
Chemistry, Global Structure Chemistry, Merck Research Laboratories, Kenilworth, New Jersey 07033, United States
| | - Pedro M. Pereira
- Laboratory
of Bacterial Cell Biology, Instituto de Tecnologia Química
e Biológica, Universidade Nova de Lisboa, Avenida da República, 2781-901 Oeiras, Portugal
| | - Christine Yang
- Medicinal
Chemistry, Merck Research Laboratories, Kenilworth, New Jersey 07033, United States
| | - Sang Ho Lee
- Infectious
Disease Research, Merck Research Laboratories, Kenilworth, New Jersey 07033, United States
| | - Hao Wang
- Infectious
Disease Research, Merck Research Laboratories, Kenilworth, New Jersey 07033, United States
| | - Joanna Trzeciak
- Infectious
Disease Research, Merck Research Laboratories, Kenilworth, New Jersey 07033, United States
| | - Jonathan Schneeweis
- In Vitro Pharmacology, Merck Research Laboratories, Kenilworth, New Jersey 07033, United States
| | - Margarida Moreira dos Santos
- Laboratory
of Bacterial Cell Biology, Instituto de Tecnologia Química
e Biológica, Universidade Nova de Lisboa, Avenida da República, 2781-901 Oeiras, Portugal
| | - Nicholas Murgolo
- Research
Solutions, Bioinformatics, Merck Research Laboratories, Kenilworth, New Jersey 07033, United States
| | - Xinwei She
- Informatics
IT, Merck Inc., Boston, Massachusetts 02110, United States
| | - Charles Gill
- In Vivo Pharmacology, Merck Research Laboratories, Kenilworth, New Jersey 07033, United States
| | - Carl J. Balibar
- Infectious
Disease Research, Merck Research Laboratories, Kenilworth, New Jersey 07033, United States
| | - Marc Labroli
- Medicinal
Chemistry, Merck Research Laboratories, Kenilworth, New Jersey 07033, United States
| | - Jing Su
- Medicinal
Chemistry, Merck Research Laboratories, Kenilworth, New Jersey 07033, United States
| | - Amy Flattery
- In Vivo Pharmacology, Merck Research Laboratories, Kenilworth, New Jersey 07033, United States
| | - Brad Sherborne
- Computational
Chemistry, Global Structure Chemistry, Merck Research Laboratories, Kenilworth, New Jersey 07033, United States
| | - Richard Maier
- Procomcure Biotech GmbH, Krems a.d. Donau, Austria
- Division of Molecular
Dermatology, Department of Dermatology, Paracelsus Medical University, Salzburg, Austria
| | - Christopher M. Tan
- Infectious
Disease Research, Merck Research Laboratories, Kenilworth, New Jersey 07033, United States
| | - Todd Black
- Infectious
Disease Research, Merck Research Laboratories, Kenilworth, New Jersey 07033, United States
| | - Kamil Önder
- Procomcure Biotech GmbH, Krems a.d. Donau, Austria
- Division of Molecular
Dermatology, Department of Dermatology, Paracelsus Medical University, Salzburg, Austria
| | - Stacia Kargman
- In Vitro Pharmacology, Merck Research Laboratories, Kenilworth, New Jersey 07033, United States
| | - Frederick J Monsma
- In Vitro Pharmacology, Merck Research Laboratories, Kenilworth, New Jersey 07033, United States
| | - Mariana G. Pinho
- Laboratory
of Bacterial Cell Biology, Instituto de Tecnologia Química
e Biológica, Universidade Nova de Lisboa, Avenida da República, 2781-901 Oeiras, Portugal
| | - Tanja Schneider
- Institute
of Medical Microbiology, Immunology and Parasitology—Pharmaceutical
Microbiology Section, University of Bonn, Bonn, Germany
- German Centre for Infection Research (DZIF), partner site
Bonn-Cologne, Bonn, Germany
| | - Terry Roemer
- Infectious
Disease Research, Merck Research Laboratories, Kenilworth, New Jersey 07033, United States
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Roemer T, Schneider T, Pinho MG. Auxiliary factors: a chink in the armor of MRSA resistance to β-lactam antibiotics. Curr Opin Microbiol 2013; 16:538-48. [PMID: 23895826 DOI: 10.1016/j.mib.2013.06.012] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2013] [Revised: 06/28/2013] [Accepted: 06/28/2013] [Indexed: 12/20/2022]
Abstract
Combination agents provide an important orthogonal approach to treat infectious diseases, particularly those caused by drug resistant pathogens. Indeed, applying a biologically 'rational' and systems-level paradigm to discover potent, selective, and synergistic agents would augment current (and arguably overly relied upon) empirical and serendipitous approaches to such discovery efforts. Here, we review the cellular mechanisms of β-lactam drug resistance and tolerance achieved amongst methicillin-resistant Staphylococcus aureus (MRSA) as well as their molecular targets and strategies to identify cognate inhibitors as potential combination agents to restore β-lactam efficacy against MRSA.
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Affiliation(s)
- Terry Roemer
- Infectious Disease Research, Merck Research Laboratories, Kenilworth, NJ 07033, USA.
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35
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Ferreira MT, Manso AS, Gaspar P, Pinho MG, Neves AR. Effect of oxygen on glucose metabolism: utilization of lactate in Staphylococcus aureus as revealed by in vivo NMR studies. PLoS One 2013; 8:e58277. [PMID: 23472168 PMCID: PMC3589339 DOI: 10.1371/journal.pone.0058277] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2012] [Accepted: 02/01/2013] [Indexed: 01/25/2023] Open
Abstract
The ability to successfully adapt to changing host conditions is crucial for full virulence of bacterial pathogens. Staphylococcus aureus has to cope with fluctuating oxygen concentrations during the course of infection. Hence, we studied the effect of oxygen on glucose metabolism in non-growing S. aureus COL-S cells by in vivo13C-NMR. Glucose catabolism was probed at different oxygen concentrations in suspensions of cells grown aerobically (direct effects on metabolism) or anaerobically (transcriptional adjustment to oxygen deprivation). In aerobically-grown cells, the rate of glucose consumption diminished progressively with decreasing oxygen concentrations. Additionally, oxygen deprivation resulted in biphasic glucose consumption, with the second phase presenting a higher rate. The fructose-1,6-bisphosphate pool peaked while glucose was still abundant, but the transient maximum varied with the oxygen concentration. As oxygen became limiting mannitol/mannitol-1-phosphate were detected as products of glucose catabolism. Under anoxic conditions, accumulation of mannitol-1-phosphate ceased with the switch to higher glucose consumption rates, which implies the activation of a more efficient means by which NAD+ can be regenerated. The distribution of end-products deriving from glucose catabolism was dramatically affected by oxygen: acetate increased and lactate decreased with the oxygen concentration; ethanol was formed only anaerobically. Moreover, oxygen promoted the energetically favourable conversion of lactate into acetate, which was particularly noticeable under fully oxygenated conditions. Interestingly, under aerobiosis growing S. aureus cells also converted lactate to acetate, used simultaneously glucose and lactate as substrates for growth, and grew considerably well on lactate-medium. We propose that the efficient lactate catabolism may endow S. aureus with a metabolic advantage in its ecological niche.
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Affiliation(s)
- Maria Teresa Ferreira
- Laboratory of Lactic Acid Bacteria & in vivo NMR, Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Oeiras, Portugal
- Laboratory of Bacterial Cell Biology, Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Ana S. Manso
- Laboratory of Lactic Acid Bacteria & in vivo NMR, Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Oeiras, Portugal
- Laboratory of Bacterial Cell Biology, Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Paula Gaspar
- Laboratory of Lactic Acid Bacteria & in vivo NMR, Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Mariana G. Pinho
- Laboratory of Bacterial Cell Biology, Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Ana Rute Neves
- Laboratory of Lactic Acid Bacteria & in vivo NMR, Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Oeiras, Portugal
- * E-mail:
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36
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Pereira AR, Reed P, Veiga H, Pinho MG. The Holliday junction resolvase RecU is required for chromosome segregation and DNA damage repair in Staphylococcus aureus. BMC Microbiol 2013; 13:18. [PMID: 23356868 PMCID: PMC3584850 DOI: 10.1186/1471-2180-13-18] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2012] [Accepted: 01/17/2013] [Indexed: 11/24/2022] Open
Abstract
Background The Staphylococcus aureus RecU protein is homologous to a Bacillus subtilis Holliday junction resolvase. Interestingly, RecU is encoded in the same operon as PBP2, a penicillin-binding protein required for cell wall synthesis and essential for the full expression of resistance in Methicillin Resistant S. aureus strains. In this work we have studied the role of RecU in the clinical pathogen S. aureus. Results Depletion of RecU in S. aureus results in the appearance of cells with compact nucleoids, septa formed over the DNA and anucleate cells. RecU-depleted cells also show increased septal recruitment of the DNA translocase SpoIIIE, presumably to resolve chromosome segregation defects. Additionally cells are more sensitive to DNA damaging agents such as mitomycin C or UV radiation. Expression of RecU from the ectopic chromosomal spa locus showed that co-expression of RecU and PBP2 was not necessary to ensure correct cell division, a process that requires tight coordination between chromosome segregation and septal cell wall synthesis. Conclusions RecU is required for correct chromosome segregation and DNA damage repair in S. aureus. Co-expression of recU and pbp2 from the same operon is not required for normal cell division.
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Affiliation(s)
- Ana R Pereira
- Laboratory of Bacterial Cell Biology, Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Av, da República, Oeiras 2780-157, Portugal
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Farha MA, Leung A, Sewell EW, D’Elia MA, Allison SE, Ejim L, Pereira PM, Pinho MG, Wright GD, Brown ED. Inhibition of WTA synthesis blocks the cooperative action of PBPs and sensitizes MRSA to β-lactams. ACS Chem Biol 2013; 8:226-33. [PMID: 23062620 PMCID: PMC3552485 DOI: 10.1021/cb300413m] [Citation(s) in RCA: 160] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
![]()
Rising drug resistance is limiting treatment options
for infections
by methicillin-resistant Staphylococcus aureus (MRSA).
Herein we provide new evidence that wall teichoic acid (WTA) biogenesis
is a remarkable antibacterial target with the capacity to destabilize
the cooperative action of penicillin-binding proteins (PBPs) that
underlie β-lactam resistance in MRSA. Deletion of gene tarO, encoding the first step of WTA synthesis, resulted
in the restoration of sensitivity of MRSA to a unique profile of β-lactam
antibiotics with a known selectivity for penicillin binding protein
2 (PBP2). Of these, cefuroxime was used as a probe to screen for previously
approved drugs with a cryptic capacity to potentiate its activity
against MRSA. Ticlopidine, the antiplatelet drug Ticlid, strongly
potentiated cefuroxime, and this synergy was abolished in strains
lacking tarO. The combination was also effective
in a Galleria mellonella model of infection. Using
both genetic and biochemical strategies, we determined the molecular
target of ticlopidine as the N-acetylglucosamine-1-phosphate
transferase encoded in gene tarO and provide evidence
that WTA biogenesis represents an Achilles heel supporting the cooperative
function of PBP2 and PBP4 in creating highly cross-linked muropeptides
in the peptidoglycan of S. aureus. This approach
represents a new paradigm to tackle MRSA infection.
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Affiliation(s)
- Maya A. Farha
- M. G. DeGroote
Institute for
Infectious Disease Research and Department of Biochemistry and Biomedical
Sciences, McMaster University, Hamilton,
Ontario, Canada L8N 3Z5
| | - Alexander Leung
- M. G. DeGroote
Institute for
Infectious Disease Research and Department of Biochemistry and Biomedical
Sciences, McMaster University, Hamilton,
Ontario, Canada L8N 3Z5
| | - Edward W. Sewell
- M. G. DeGroote
Institute for
Infectious Disease Research and Department of Biochemistry and Biomedical
Sciences, McMaster University, Hamilton,
Ontario, Canada L8N 3Z5
| | - Michael A. D’Elia
- M. G. DeGroote
Institute for
Infectious Disease Research and Department of Biochemistry and Biomedical
Sciences, McMaster University, Hamilton,
Ontario, Canada L8N 3Z5
| | - Sarah E. Allison
- M. G. DeGroote
Institute for
Infectious Disease Research and Department of Biochemistry and Biomedical
Sciences, McMaster University, Hamilton,
Ontario, Canada L8N 3Z5
| | - Linda Ejim
- M. G. DeGroote
Institute for
Infectious Disease Research and Department of Biochemistry and Biomedical
Sciences, McMaster University, Hamilton,
Ontario, Canada L8N 3Z5
| | - Pedro M. Pereira
- Laboratory of Bacterial Cell
Biology, Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, 2781-901 Oeiras, Portugal
| | - Mariana G. Pinho
- Laboratory of Bacterial Cell
Biology, Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, 2781-901 Oeiras, Portugal
| | - Gerard D. Wright
- M. G. DeGroote
Institute for
Infectious Disease Research and Department of Biochemistry and Biomedical
Sciences, McMaster University, Hamilton,
Ontario, Canada L8N 3Z5
| | - Eric D. Brown
- M. G. DeGroote
Institute for
Infectious Disease Research and Department of Biochemistry and Biomedical
Sciences, McMaster University, Hamilton,
Ontario, Canada L8N 3Z5
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38
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Correia VG, Coelho M, Barroso T, Raje VP, Bonifácio VDB, Casimiro T, Pinho MG, Aguiar-Ricardo A. Anti-biofouling 3D porous systems: the blend effect of oxazoline-based oligomers on chitosan scaffolds. Biofouling 2013; 29:273-282. [PMID: 23458129 DOI: 10.1080/08927014.2013.766172] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
The production, characterization and anti-biofouling activity of 3D porous scaffolds combining different blends of chitosan and oxazoline-based antimicrobial oligomers is reported. The incorporation of ammonium quaternized oligo(2-oxazoline)s into the composition of the scaffold enhances the stability of the chitosan scaffold under physiological conditions as well as its ability to repel protein adsorption. The blended scaffolds showed mean pore sizes in the range of 18-32 μm, a good pore interconnectivity and high porosity, as well as a large surface area, ultimate key features for anti-biofouling applications. Bovine serum albumin (BSA) adhesion profiles showed that the composition of the scaffolds plays a critical role in the chitosan-oligooxazoline system. Oligobisoxazoline-enriched scaffolds (20% w/w, CB8020) decreased protein adsorption (BSA) by up to 70%. Moreover, 1 mg of CB8020 was able to kill 99.9% of Escherichia coli cells upon contact, demonstrating its potential as promising material for production of tailored non-fouling 3D structures to be used in the construction of novel devices with applications in the biomedical field and water treatment processes.
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Affiliation(s)
- Vanessa G Correia
- REQUIMTE, Departamento de Química, Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, Caparica, Portugal
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Tan CM, Therien AG, Lu J, Lee SH, Caron A, Gill CJ, Lebeau-Jacob C, Benton-Perdomo L, Monteiro JM, Pereira PM, Elsen NL, Wu J, Deschamps K, Petcu M, Wong S, Daigneault E, Kramer S, Liang L, Maxwell E, Claveau D, Vaillancourt J, Skorey K, Tam J, Wang H, Meredith TC, Sillaots S, Wang-Jarantow L, Ramtohul Y, Langlois E, Landry F, Reid JC, Parthasarathy G, Sharma S, Baryshnikova A, Lumb KJ, Pinho MG, Soisson SM, Roemer T. Restoring methicillin-resistant Staphylococcus aureus susceptibility to β-lactam antibiotics. Sci Transl Med 2012; 4:126ra35. [PMID: 22440737 DOI: 10.1126/scitranslmed.3003592] [Citation(s) in RCA: 162] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Despite the need for new antibiotics to treat drug-resistant bacteria, current clinical combinations are largely restricted to β-lactam antibiotics paired with β-lactamase inhibitors. We have adapted a Staphylococcus aureus antisense knockdown strategy to genetically identify the cell division Z ring components-FtsA, FtsZ, and FtsW-as β-lactam susceptibility determinants of methicillin-resistant S. aureus (MRSA). We demonstrate that the FtsZ-specific inhibitor PC190723 acts synergistically with β-lactam antibiotics in vitro and in vivo and that this combination is efficacious in a murine model of MRSA infection. Fluorescence microscopy localization studies reveal that synergy between these agents is likely to be elicited by the concomitant delocalization of their cognate drug targets (FtsZ and PBP2) in MRSA treated with PC190723. A 2.0 Å crystal structure of S. aureus FtsZ in complex with PC190723 identifies the compound binding site, which corresponds to the predominant location of mutations conferring resistance to PC190723 (PC190723(R)). Although structural studies suggested that these drug resistance mutations may be difficult to combat through chemical modification of PC190723, combining PC190723 with the β-lactam antibiotic imipenem markedly reduced the spontaneous frequency of PC190723(R) mutants. Multiple MRSA PC190723(R) FtsZ mutants also displayed attenuated virulence and restored susceptibility to β-lactam antibiotics in vitro and in a mouse model of imipenem efficacy. Collectively, these data support a target-based approach to rationally develop synergistic combination agents that mitigate drug resistance and effectively treat MRSA infections.
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Affiliation(s)
- Christopher M Tan
- Infectious Diseases, Merck Research Laboratories, Kenilworth, NJ 07033, USA
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Jorge AM, Hoiczyk E, Gomes JP, Pinho MG. EzrA contributes to the regulation of cell size in Staphylococcus aureus. PLoS One 2011; 6:e27542. [PMID: 22110668 PMCID: PMC3215724 DOI: 10.1371/journal.pone.0027542] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2011] [Accepted: 10/19/2011] [Indexed: 01/02/2023] Open
Abstract
EzrA is a negative regulator of FtsZ in Bacillus subtilis, involved in the coordination between cell growth and cell division and in the control of the cell elongation–division cycle. We have now studied the role of the Staphylococcus aureus homologue of the B. subtilis EzrA protein and shown that it is not essential for cell viability. EzrA conditional and null mutants have an overall increase of the average cell size, compared to wild type strains. In the larger ezrA mutant S. aureus cells, cell division protein FtsZ and the cell wall synthesizing Penicillin Binding Proteins (PBPs) are not properly localized. This suggests that there may be a maximum cell diameter that allows formation of a Z-ring capable of recruiting the other components of the divisome and of driving cytokinesis. We propose that the major role of EzrA in S. aureus is in cell size homeostasis.
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Affiliation(s)
- Ana M Jorge
- Laboratory of Bacterial Cell Biology, Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Oeiras, Portugal
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41
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Correia VG, Bonifácio VD, Raje VP, Casimiro T, Moutinho G, da Silva CL, Pinho MG, Aguiar-Ricardo A. Macromol. Biosci. 8/2011. Macromol Biosci 2011. [DOI: 10.1002/mabi.201190023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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42
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Correia VG, Bonifácio VDB, Raje VP, Casimiro T, Moutinho G, da Silva CL, Pinho MG, Aguiar-Ricardo A. Oxazoline-based antimicrobial oligomers: synthesis by CROP using supercritical CO2. Macromol Biosci 2011; 11:1128-37. [PMID: 21674806 DOI: 10.1002/mabi.201100126] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2011] [Indexed: 01/21/2023]
Abstract
A method using supercritical CO(2) to obtain biocompatible 2-oxazoline-based oligomers quaternized with different amines is described. The synthesized oligo(2-oxazoline)s display partial carbamic-acid insertion at one end. The syntheses of quaternary oligo(2-bisoxazoline)s and linear oligoethylenimine hydrochlorides are reported. Oligo(2-methyl-2-oxazoline) and oligo(2-bisoxazoline) quaternized with N,N-dimethyldodecylamine are the most efficient biocidal agents showing fast killing rates against Staphylococcus aureus and Escherichia coli. Linear oligoethylenimine hydrochloride shows the lowest MIC values but higher killing times against both bacteria. Based on the antimicrobial activity studies, a cooperative action of carbamic acid with the ammonium end group is proposed.
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Affiliation(s)
- Vanessa G Correia
- REQUIMTE, Faculdade de Ciências e Tecnologia, Departamento de Química, Universidade Nova de Lisboa, Caparica, Portugal
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43
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Veiga H, Jorge AM, Pinho MG. Absence of nucleoid occlusion effector Noc impairs formation of orthogonal FtsZ rings during Staphylococcus aureus cell division. Mol Microbiol 2011; 80:1366-80. [DOI: 10.1111/j.1365-2958.2011.07651.x] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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44
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Bernal P, Lemaire S, Pinho MG, Mobashery S, Hinds J, Taylor PW. Insertion of epicatechin gallate into the cytoplasmic membrane of methicillin-resistant Staphylococcus aureus disrupts penicillin-binding protein (PBP) 2a-mediated beta-lactam resistance by delocalizing PBP2. J Biol Chem 2010; 285:24055-65. [PMID: 20516078 PMCID: PMC2911331 DOI: 10.1074/jbc.m110.114793] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Epicatechin gallate (ECg) sensitizes methicillin-resistant Staphylococcus aureus (MRSA) to oxacillin and other beta-lactam agents; it also reduces the secretion of virulence-associated proteins, prevents biofilm formation, and induces gross morphological changes in MRSA cells without compromising the growth rate. MRSA is resistant to oxacillin because of the presence of penicillin-binding protein 2a (PBP2a), which allows peptidoglycan synthesis to continue after oxacillin-mediated acylation of native PBPs. We show that ECg binds predominantly to the cytoplasmic membrane (CM), initially decreasing the fluidity of the bilayer, and induces changes in gene expression indicative of an attempt to preserve and repair a compromised cell wall. On further incubation, the CM is reorganized; the amount of lysylphosphatidylglycerol is markedly reduced, with a concomitant increase in phosphatidylglycerol, and the proportion of branched chain fatty acids increases, resulting in a more fluid structure. We found no evidence that ECg modulates the enzymatic activity of PBP2a through direct binding to the protein but determined that PBP2 is delocalized from the FtsZ-anchored cell wall biosynthetic machinery at the septal division site following intercalation into the CM. We argue that many features of the ECg-induced phenotype can be explained by changes in the fluid dynamics of the CM.
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Affiliation(s)
- Patricia Bernal
- School of Pharmacy, University of London, London WC1N 1AX, United Kingdom
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45
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Pereira SFF, Henriques AO, Pinho MG, de Lencastre H, Tomasz A. Evidence for a dual role of PBP1 in the cell division and cell separation of Staphylococcus aureus. Mol Microbiol 2009; 72:895-904. [PMID: 19400776 DOI: 10.1111/j.1365-2958.2009.06687.x] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Penicillin-binding proteins (PBPs) catalyse the synthesis of cell wall peptidoglycan. PBP1 of Staphylococcus aureus is a high-molecular-weight monofunctional transpeptidase (TPase) and previous studies with a conditional mutant showed that this protein was essential for bacterial growth and survival: cells in which PBP1 was depleted stopped dividing but continued to enlarge in size, accompanied by rapid loss of viability. Also, cell walls produced under PBP1 depletion appeared to have normal composition. We describe here construction of a second PBP1 mutant in which the active site of the TPase domain was inactivated. Cells in which the wild-type PBP1 was replaced by the mutant protein were able to initiate and complete septa and undergo at least one or two cell divisions after which growth stopped accompanied by inhibition of cell separation, downregulation in the transcription of the autolytic system and production of cell walls with increased proportion of monomeric and dimeric muropeptides and decrease in oligomeric muropeptides. PBP1 seems to perform a dual role in the cell cycle of S. aureus: as a protein required for septation and also as a transpeptidase that generates a critical signal for cell separation at the end of cell division.
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Affiliation(s)
- Sandro F F Pereira
- Laboratory of Molecular Genetics, Instituto de Tecnologia Química e Biológica (ITQB) da Universidade Nova de Lisboa (UNL), 2780 Oeiras, Portugal
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46
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47
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Pereira PM, Filipe SR, Tomasz A, Pinho MG. Fluorescence ratio imaging microscopy shows decreased access of vancomycin to cell wall synthetic sites in vancomycin-resistant Staphylococcus aureus. Antimicrob Agents Chemother 2007; 51:3627-33. [PMID: 17646417 PMCID: PMC2043281 DOI: 10.1128/aac.00431-07] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A new method of fluorescence ratio imaging microscopy was used to compare the in vivo binding capacity and the access of a fluorescent derivative of vancomycin to the cell wall synthetic sites in isogenic pairs of vancomycin-susceptible and -resistant laboratory mutants and vancomycin-intermediate and -susceptible clinical isolates of Staphylococcus aureus. Live cells of resistant strains were found to bind approximately 1.5 times more antibiotic, but there was no correlation between the increased binding capacity and the MICs of the strains. In both susceptible and resistant bacteria, the subcellular sites of wall synthesis were localized to the division septa, but the rate of diffusion of drug molecules to these sites was reduced in resistant cells. The findings allow a reinterpretation of the mechanism of vancomycin resistance in which the path of vancomycin to its lethal target (lipid II) is considered to be through the division septum and therefore is dependent on the stage of the staphylococcal cell cycle.
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Affiliation(s)
- Pedro M Pereira
- Laboratory of Bacterial Cell Biology, Instituto de Tecnologia Química e Biológica, Av da Republica, 2781-901, Oeiras, Portugal
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48
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Abstract
We constructed a conditional mutant of pbpA in which transcription of the gene was placed under the control of an IPTG (isopropyl-beta-D-thiogalactopyranoside)-inducible promoter in order to explore the role of PBP1 in growth, cell wall structure, and cell division. A methicillin-resistant strain and an isogenic methicillin-susceptible strain, each carrying the pbpA mutation, were unable to grow in the absence of the inducer. Conditional mutants of pbpA transferred into IPTG-free medium underwent a four- to fivefold increase in cell mass, which was not accompanied by a proportional increase in viable titer. Examination of thin sections of such cells by transmission electron microscopy or fluorescence microscopy of intact cells with Nile red-stained membranes showed a morphologically heterogeneous population of bacteria with abnormally increased sizes, distorted axial ratios, and a deficit in the number of cells with completed septa. Immunofluorescence with an antibody specific for PBP1 localized the protein to sites of cell division. No alteration in the composition of peptidoglycan was detectable in pbpA conditional mutants grown in the presence of a suboptimal concentration of IPTG, which severely restricted the rate of growth, and the essential function of PBP1 could not be replaced by PBP2A present in methicillin-resistant cells. These observations suggest that PBP1 is not a major contributor to the cross-linking of peptidoglycan and that its essential function must be intimately integrated into the mechanism of cell division.
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Affiliation(s)
- S F F Pereira
- Laboratory of Molecular Genetics, Instituto de Tecnologia Química e Biológica da Universidade Nova de Lisboa, Oeiras, Portugal
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49
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Abstract
In order to maintain shape and withstand intracellular pressure, most bacteria are surrounded by a cell wall that consists mainly of the cross-linked polymer peptidoglycan (PG). The importance of PG for the maintenance of bacterial cell shape is underscored by the fact that, for various bacteria, several mutations affecting PG synthesis are associated with cell shape defects. In recent years, the application of fluorescence microscopy to the field of PG synthesis has led to an enormous increase in data on the relationship between cell wall synthesis and bacterial cell shape. First, a novel staining method enabled the visualization of PG precursor incorporation in live cells. Second, penicillin-binding proteins (PBPs), which mediate the final stages of PG synthesis, have been localized in various model organisms by means of immunofluorescence microscopy or green fluorescent protein fusions. In this review, we integrate the knowledge on the last stages of PG synthesis obtained in previous studies with the new data available on localization of PG synthesis and PBPs, in both rod-shaped and coccoid cells. We discuss a model in which, at least for a subset of PBPs, the presence of substrate is a major factor in determining PBP localization.
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Affiliation(s)
- Dirk-Jan Scheffers
- Department of Molecular Microbiology, Institute of Molecular Cell Biology, Vrije Universiteit, De Boelelaan 1085, 1081 HV Amsterdam, The Netherlands.
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50
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Pinho MG, Errington J. A divIVA null mutant of Staphylococcus aureus undergoes normal cell division. FEMS Microbiol Lett 2005; 240:145-9. [PMID: 15522501 DOI: 10.1016/j.femsle.2004.09.038] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2004] [Revised: 09/15/2004] [Accepted: 09/19/2004] [Indexed: 11/25/2022] Open
Abstract
DivIVA is involved in placement of the division septum and chromosome segregation in Bacillus subtilis and it plays important roles in cell division or morphogenesis in diverse Gram-positive bacteria. In Staphylococcus aureus, DivIVA is localized at the division septum, but it does not colocalize with the chromosomal origin of replication, as labeled with SpoOJ protein. Unexpectedly, a divIVA null mutant is not impaired in growth, nor is it affected in chromosome segregation or cell morphology.
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Affiliation(s)
- Mariana G Pinho
- Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, UK
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