1
|
Burke Ó, Zeden MS, O'Gara JP. The pathogenicity and virulence of the opportunistic pathogen Staphylococcus epidermidis. Virulence 2024; 15:2359483. [PMID: 38868991 DOI: 10.1080/21505594.2024.2359483] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2024] [Accepted: 05/19/2024] [Indexed: 06/14/2024] Open
Abstract
The pervasive presence of Staphylococcus epidermidis and other coagulase-negative staphylococci on the skin and mucous membranes has long underpinned a casual disregard for the infection risk that these organisms pose to vulnerable patients in healthcare settings. Prior to the recognition of biofilm as an important virulence determinant in S. epidermidis, isolation of this microorganism in diagnostic specimens was often overlooked as clinically insignificant with potential delays in diagnosis and onset of appropriate treatment, contributing to the establishment of chronic infection and increased morbidity or mortality. While impressive progress has been made in our understanding of biofilm mechanisms in this important opportunistic pathogen, research into other virulence determinants has lagged S. aureus. In this review, the broader virulence potential of S. epidermidis including biofilm, toxins, proteases, immune evasion strategies and antibiotic resistance mechanisms is surveyed, together with current and future approaches for improved therapeutic interventions.
Collapse
Affiliation(s)
- Órla Burke
- Microbiology, School of Biological and Chemical Sciences, University of Galway, Galway, Ireland
| | | | - James P O'Gara
- Microbiology, School of Biological and Chemical Sciences, University of Galway, Galway, Ireland
| |
Collapse
|
2
|
Mitkowski P, Jagielska E, Sabała I. Engineering of chimeric enzymes with expanded tolerance to ionic strength. Microbiol Spectr 2024; 12:e0354623. [PMID: 38695664 DOI: 10.1128/spectrum.03546-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2023] [Accepted: 03/26/2024] [Indexed: 06/06/2024] Open
Abstract
Antimicrobial resistance poses a significant global threat, reaching dangerously high levels as reported by the World Health Organization. The emergence and rapid spread of new resistance mechanisms, coupled with the absence of effective treatments in recent decades, have led to thousands of deaths annually from infections caused by drug-resistant microorganisms. Consequently, there is an urgent need for the development of new compounds capable of combating antibiotic-resistant bacteria. A promising class of molecules exhibiting potent bactericidal effects is peptidoglycan hydrolases. Previously, we cloned and characterized the biochemical properties of the M23 catalytic domain of the EnpA (EnpACD) protein from Enterococcus faecalis. Unlike other enzymes within the M23 family, EnpACD demonstrates broad specificity. However, its activity is constrained under low ionic strength conditions. In this study, we present the engineering of three chimeric enzymes comprising EnpACD fused with three distinct SH3b cell wall-binding domains. These chimeras exhibit enhanced tolerance to environmental conditions and sustained activity in bovine and human serum. Furthermore, our findings demonstrate that the addition of SH3b domains influences the activity of the chimeric enzymes, thereby expanding their potential applications in combating antimicrobial resistance.IMPORTANCEThese studies demonstrate that the addition of the SH3b-binding domain to the EnpACD results in generation of chimeras with a broader tolerance to ionic strength and pH values, enabling them to remain active over a wider range of conditions. Such approach offers a relatively straightforward method for obtaining antibacterial enzymes with tailored properties and emphasizes the potential for proteins' engineering with enhanced functionality, contributing to the ongoing efforts to address antimicrobial resistance effectively.
Collapse
Affiliation(s)
- Paweł Mitkowski
- International Institute of Molecular and Cell Biology in Warsaw, Warsaw, Poland
- Mossakowski Medical Research Institute Polish Academy of Sciences, Warsaw, Poland
| | - Elżbieta Jagielska
- International Institute of Molecular and Cell Biology in Warsaw, Warsaw, Poland
- Mossakowski Medical Research Institute Polish Academy of Sciences, Warsaw, Poland
| | - Izabela Sabała
- International Institute of Molecular and Cell Biology in Warsaw, Warsaw, Poland
- Mossakowski Medical Research Institute Polish Academy of Sciences, Warsaw, Poland
| |
Collapse
|
3
|
Hoffmann A, Steffens U, Maček B, Franz-Wachtel M, Nieselt K, Harbig TA, Scherlach K, Hertweck C, Sahl HG, Bierbaum G. The unusual mode of action of the polyketide glycoside antibiotic cervimycin C. mSphere 2024; 9:e0076423. [PMID: 38722162 DOI: 10.1128/msphere.00764-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2024] [Accepted: 03/28/2024] [Indexed: 05/30/2024] Open
Abstract
Cervimycins A-D are bis-glycosylated polyketide antibiotics produced by Streptomyces tendae HKI 0179 with bactericidal activity against Gram-positive bacteria. In this study, cervimycin C (CmC) treatment caused a spaghetti-like phenotype in Bacillus subtilis 168, with elongated curved cells, which stayed joined after cell division, and exhibited a chromosome segregation defect, resulting in ghost cells without DNA. Electron microscopy of CmC-treated Staphylococcus aureus (3 × MIC) revealed swollen cells, misshapen septa, cell wall thickening, and a rough cell wall surface. Incorporation tests in B. subtilis indicated an effect on DNA biosynthesis at high cervimycin concentrations. Indeed, artificial downregulation of the DNA gyrase subunit B gene (gyrB) increased the activity of cervimycin in agar diffusion tests, and, in high concentrations (starting at 62.5 × MIC), the antibiotic inhibited S. aureus DNA gyrase supercoiling activity in vitro. To obtain a more global view on the mode of action of CmC, transcriptomics and proteomics of cervimycin treated versus untreated S. aureus cells were performed. Interestingly, 3 × MIC of cervimycin did not induce characteristic responses, which would indicate disturbance of the DNA gyrase activity in vivo. Instead, cervimycin induced the expression of the CtsR/HrcA heat shock operon and the expression of autolysins, exhibiting similarity to the ribosome-targeting antibiotic gentamicin. In summary, we identified the DNA gyrase as a target, but at low concentrations, electron microscopy and omics data revealed a more complex mode of action of cervimycin, which comprised induction of the heat shock response, indicating protein stress in the cell.IMPORTANCEAntibiotic resistance of Gram-positive bacteria is an emerging problem in modern medicine, and new antibiotics with novel modes of action are urgently needed. Secondary metabolites from Streptomyces species are an important source of antibiotics, like the cervimycin complex produced by Streptomyces tendae HKI 0179. The phenotypic response of Bacillus subtilis and Staphylococcus aureus toward cervimycin C indicated a chromosome segregation and septum formation defect. This effect was at first attributed to an interaction between cervimycin C and the DNA gyrase. However, omics data of cervimycin treated versus untreated S. aureus cells indicated a different mode of action, because the stress response did not include the SOS response but resembled the response toward antibiotics that induce mistranslation or premature chain termination and cause protein stress. In summary, these results point toward a possibly novel mechanism that generates protein stress in the cells and subsequently leads to defects in cell and chromosome segregation.
Collapse
Affiliation(s)
- Alina Hoffmann
- University Hospital Bonn, Institute of Medical Microbiology, Immunology and Parasitology, Bonn, Germany
| | - Ursula Steffens
- University Hospital Bonn, Institute of Medical Microbiology, Immunology and Parasitology, Bonn, Germany
| | - Boris Maček
- University of Tübingen, Proteome Center Tübingen, Tübingen, Germany
| | | | - Kay Nieselt
- University of Tübingen, Interfaculty Institute for Bioinformatics and Medical Informatics, Tübingen, Germany
| | - Theresa Anisja Harbig
- University of Tübingen, Interfaculty Institute for Bioinformatics and Medical Informatics, Tübingen, Germany
| | - Kirstin Scherlach
- Leibniz Institute for Natural Product Research and Infection Biology-Hans Knöll Institute (HKI), Jena, Germany
| | - Christian Hertweck
- Leibniz Institute for Natural Product Research and Infection Biology-Hans Knöll Institute (HKI), Jena, Germany
- Friedrich Schiller University Jena, Institute of Microbiology, Faculty of Biological Sciences, Jena, Germany
| | - Hans-Georg Sahl
- University of Bonn, Institute for Pharmaceutical Microbiology, Bonn, Germany
| | - Gabriele Bierbaum
- University Hospital Bonn, Institute of Medical Microbiology, Immunology and Parasitology, Bonn, Germany
| |
Collapse
|
4
|
Alshareef SA. Metabolic analysis of the CAZy class glycosyltransferases in rhizospheric soil fungiome of the plant species Moringa oleifera. Saudi J Biol Sci 2024; 31:103956. [PMID: 38404538 PMCID: PMC10891331 DOI: 10.1016/j.sjbs.2024.103956] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2024] [Revised: 02/03/2024] [Accepted: 02/10/2024] [Indexed: 02/27/2024] Open
Abstract
The target of the present work is to study the most abundant carbohydrate-active enzymes (CAZymes) of glycosyltransferase (GT) class, which are encoded by fungiome genes present in the rhizospheric soil of the plant species Moringa oleifera. The datasets of this CAZy class were recovered using metagenomic whole shotgun genome sequencing approach, and the resultant CAZymes were searched against the KEGG pathway database to identify function. High emphasis was given to the two GT families, GT4 and GT2, which were the highest within GT class in the number and abundance of gene queries in this soil compartment. These two GT families harbor CAZymes playing crucial roles in cell membrane and cell wall processes. These CAZymes are responsible for synthesizing essential structural components such as cellulose and chitin, which contribute to the integrity of cell walls in plants and fungi. The CAZyme beta-1,3-glucan synthase of GT2 family accumulates 1,3-β-glucan, which provides elasticity as well as tensile strength to the fungal cell wall. Other GT CAZymes contribute to the biosynthesis of several compounds crucial for cell membrane and wall integrity, including lipopolysaccharide, e.g., lipopolysaccharide N-acetylglucosaminyltransferase, cell wall teichoic acid, e.g., alpha-glucosyltransferase, and cellulose, e.g., cellulose synthase. These compounds also play pivotal roles in ion homeostasis, organic carbon mineralization, and osmoprotection against abiotic stresses in plants. This study emphasizes the major roles of these two CAZy GT families in connecting the structure and function of cell membranes and cell walls of fungal and plant cells. The study also sheds light on the potential occurrence of tripartite symbiotic relationships involving the plant, rhizospheric bacteriome, and fungiome via the action of CAZymes of GT4 and GT2 families. These findings provide valuable insights towards the generation of innovative agricultural practices to enhance the performance of crop plants in the future.
Collapse
Affiliation(s)
- Sahar A. Alshareef
- Department of Biology, College of Science and Arts at Khulis, University of Jeddah, Jeddah, Saudi Arabia
| |
Collapse
|
5
|
Li FKK, Worrall LJ, Gale RT, Brown ED, Strynadka NCJ. Cryo-EM analysis of S. aureus TarL, a polymerase in wall teichoic acid biogenesis central to virulence and antibiotic resistance. SCIENCE ADVANCES 2024; 10:eadj3864. [PMID: 38416829 PMCID: PMC10901376 DOI: 10.1126/sciadv.adj3864] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2023] [Accepted: 01/23/2024] [Indexed: 03/01/2024]
Abstract
Wall teichoic acid (WTA), a covalent adduct of Gram-positive bacterial cell wall peptidoglycan, contributes directly to virulence and antibiotic resistance in pathogenic species. Polymerization of the Staphylococcus aureus WTA ribitol-phosphate chain is catalyzed by TarL, a member of the largely uncharacterized TagF-like family of membrane-associated enzymes. We report the cryo-electron microscopy structure of TarL, showing a tetramer that forms an extensive membrane-binding platform of monotopic helices. TarL is composed of an amino-terminal immunoglobulin-like domain and a carboxyl-terminal glycosyltransferase-B domain for ribitol-phosphate polymerization. The active site of the latter is complexed to donor substrate cytidine diphosphate-ribitol, providing mechanistic insights into the catalyzed phosphotransfer reaction. Furthermore, the active site is surrounded by electropositive residues that serve to retain the lipid-linked acceptor for polymerization. Our data advance general insight into the architecture and membrane association of the still poorly characterized monotopic membrane protein class and present molecular details of ribitol-phosphate polymerization that may aid in the design of new antimicrobials.
Collapse
Affiliation(s)
- Franco K K Li
- Department of Biochemistry and Molecular Biology, The University of British Columbia, Vancouver, British Columbia, Canada
- Centre for Blood Research, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Liam J Worrall
- Department of Biochemistry and Molecular Biology, The University of British Columbia, Vancouver, British Columbia, Canada
- Centre for Blood Research, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Robert T Gale
- Department of Biochemistry and Biomedical Sciences, Michael G. DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, Ontario, Canada
| | - Eric D Brown
- Department of Biochemistry and Biomedical Sciences, Michael G. DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, Ontario, Canada
| | - Natalie C J Strynadka
- Department of Biochemistry and Molecular Biology, The University of British Columbia, Vancouver, British Columbia, Canada
- Centre for Blood Research, The University of British Columbia, Vancouver, British Columbia, Canada
| |
Collapse
|
6
|
Ibrahim AM, Azam MS, Schneewind O, Missiakas D. Processing of LtaS restricts LTA assembly and YSIRK preprotein trafficking into Staphylococcus aureus cross-walls. mBio 2024; 15:e0285223. [PMID: 38174934 PMCID: PMC10865820 DOI: 10.1128/mbio.02852-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Accepted: 10/31/2023] [Indexed: 01/05/2024] Open
Abstract
Septal membranes of Staphylococcus aureus serve as the site of secretion for precursors endowed with the YSIRK motif. Depletion of ltaS, a gene required for lipoteichoic acid (LTA) synthesis, results in the loss of restricted trafficking of YSIRK precursors to septal membranes. Here, we seek to understand the mechanism that ties LTA assembly and trafficking of YSIRK precursors. We confirm that catalytically inactive lipoteichoic acid synthase (LtaS)T300A does not support YSIRK precursor trafficking to septa. We hypothesize that the enzyme's reactants [gentiobiosyldiacylglycerol (Glc2-DAG) and phosphatidylglycerol (PG)] or products [LTA and diacylglycerol (DAG)], not LtaS, must drive this process. Indeed, we observe that septal secretion of the staphylococcal protein A YSIRK precursor is lost in ypfP and ltaA mutants that produce glycerophosphate polymers [poly(Gro-P)] without the Glc2-DAG lipid anchor. These mutants display longer poly(Gro-P) chains, implying enhanced PG consumption and DAG production. Our experiments also reveal that in the absence of Glc2-DAG, the processing of LtaS to the extracellular catalytic domain, eLtaS, is impaired. Conversely, LTA polymerization is delayed in a strain producing LtaSS218P, a variant processed more slowly than LtaS. We conclude that Glc2-DAG binding to the enzyme couples catalysis by LtaS and the physical release of eLtaS. We propose a model for the temporal and localized assembly of LTA into cross-walls. When LtaS is not processed in a timely manner, eLtaS no longer diffuses upon daughter cell splitting, LTA assembly continues, and the unique septal-lipid pool, PG over DAG ratio, is not established. This results in profound physiological changes in S. aureus cells, including the inability to restrict the secretion of YSIRK precursors at septal membranes.IMPORTANCEIn Staphylococcus aureus, peptidoglycan is assembled at the septum. Dedicated cell division proteins coordinate septal formation and the fission of daughter cells. Lipoteichoic acid (LTA) assembly and trafficking of preproteins with a YSIRK motif also occur at the septum. This begs the question as to whether cell division components also recruit these two pathways. This study shows that the processing of lipoteichoic acid synthase (LtaS) to extracellular LtaS by signal peptidase is regulated by gentiobiosyldiacylglycerol (Glc2-DAG), the priming substrate for LTA assembly. A model is proposed whereby a key substrate controls the temporal and spatial activity of an enzyme. In turn, this mechanism enables the establishment of a unique and transient lipid pool that defines septal membranes as a targeting site for the secretion of YSIRK preproteins.
Collapse
Affiliation(s)
- Amany M. Ibrahim
- Department of Microbiology, Howard Taylor Ricketts Laboratory, The University of Chicago, Lemont, Illinois, USA
- Department of Microbiology and Immunology, Faculty of Pharmacy, Sinai University, Arish, Egypt
| | - Muhammad S. Azam
- Department of Microbiology, Howard Taylor Ricketts Laboratory, The University of Chicago, Lemont, Illinois, USA
| | - Olaf Schneewind
- Department of Microbiology, Howard Taylor Ricketts Laboratory, The University of Chicago, Lemont, Illinois, USA
| | - Dominique Missiakas
- Department of Microbiology, Howard Taylor Ricketts Laboratory, The University of Chicago, Lemont, Illinois, USA
| |
Collapse
|
7
|
Hammond LR, White ML, Eswara PJ. Probing Bacterial Cell Division and Cell Envelope Biogenesis with Live-Cell Fluorescence Microscopy. Methods Mol Biol 2024; 2727:205-214. [PMID: 37815719 DOI: 10.1007/978-1-0716-3491-2_16] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/11/2023]
Abstract
The development of advanced microscopy techniques has ushered in a new era of research as it helps understand biological processes on a deeper, mechanistic, and molecular level like never before. Live-cell fluorescence microscopy has importantly allowed us to visualize subcellular protein localization and incorporation of various fluorophores compatible with living cells in real time. As such, this technique offers valuable insights at the single-cell level and enables us to monitor phenotypic differences that were easily overlooked at a population level. One area of research that has benefited greatly from these advances is the study of the bacterial cell envelope biogenesis and cell division process. In this report, we provide detailed protocols, optimized in our lab, for imaging these processes in the Gram-positive organisms Bacillus subtilis and Staphylococcus aureus.
Collapse
Affiliation(s)
- Lauren R Hammond
- Department of Molecular Biosciences, University of South Florida, Tampa, FL, USA
| | - Maria L White
- Department of Molecular Biosciences, University of South Florida, Tampa, FL, USA
| | - Prahathees J Eswara
- Department of Molecular Biosciences, University of South Florida, Tampa, FL, USA.
| |
Collapse
|
8
|
Gouveia A, Pinto D, Vítor JMB, São-José C. Cellular and Enzymatic Determinants Impacting the Exolytic Action of an Anti-Staphylococcal Enzybiotic. Int J Mol Sci 2023; 25:523. [PMID: 38203699 PMCID: PMC10778630 DOI: 10.3390/ijms25010523] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2023] [Revised: 12/27/2023] [Accepted: 12/28/2023] [Indexed: 01/12/2024] Open
Abstract
Bacteriophage endolysins are bacteriolytic enzymes that have been explored as potential weapons to fight antibiotic-resistant bacteria. Despite several studies support the application of endolysins as enzybiotics, detailed knowledge on cellular and enzymatic factors affecting their lytic activity is still missing. The bacterial membrane proton motive force (PMF) and certain cell wall glycopolymers of Gram-positive bacteria have been implicated in some tolerance to endolysins. Here, we studied how the anti-staphylococcal endolysin Lys11, a modular enzyme with two catalytic domains (peptidase and amidase) and a cell binding domain (CBD11), responded to changes in the chemical and/or electric gradients of the PMF (ΔpH and Δψ, respectively). We show that simultaneous dissipation of both gradients enhances endolysin binding to cells and lytic activity. The collapse of ΔpH is preponderant in the stimulation of Lys11 lytic action, while the dissipation of Δψ is mainly associated with higher endolysin binding. Interestingly, this binding depends on the amidase domain. The peptidase domain is responsible for most of the Lys11 bacteriolytic activity. Wall teichoic acids (WTAs) are confirmed as major determinants of endolysin tolerance, in part by severely hindering CBD11 binding activity. In conclusion, the PMF and WTA interfere differently with the endolysin functional domains, affecting both the binding and catalytic efficiencies.
Collapse
Affiliation(s)
- Ana Gouveia
- Phage Biology Research and Infection Control (PhaBRIC), Research Institute for Medicines (iMed.ULisboa), Faculdade de Farmácia, Universidade de Lisboa, Av. Prof. Gama Pinto, 1649-003 Lisboa, Portugal; (A.G.); (D.P.)
| | - Daniela Pinto
- Phage Biology Research and Infection Control (PhaBRIC), Research Institute for Medicines (iMed.ULisboa), Faculdade de Farmácia, Universidade de Lisboa, Av. Prof. Gama Pinto, 1649-003 Lisboa, Portugal; (A.G.); (D.P.)
| | - Jorge M. B. Vítor
- Pathogen Genome Bioinformatics and Computational Biology, Research Institute for Medicines (iMed.ULisboa), Faculdade de Farmácia, Universidade de Lisboa, Av. Prof. Gama Pinto, 1649-003 Lisboa, Portugal;
| | - Carlos São-José
- Phage Biology Research and Infection Control (PhaBRIC), Research Institute for Medicines (iMed.ULisboa), Faculdade de Farmácia, Universidade de Lisboa, Av. Prof. Gama Pinto, 1649-003 Lisboa, Portugal; (A.G.); (D.P.)
| |
Collapse
|
9
|
Maisat W, Yuki K. Volatile anesthetic isoflurane exposure facilitates Enterococcus biofilm infection. FASEB J 2023; 37:e23186. [PMID: 37665578 PMCID: PMC10495085 DOI: 10.1096/fj.202301128r] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Revised: 08/21/2023] [Accepted: 08/24/2023] [Indexed: 09/05/2023]
Abstract
Enterococcus faecalis (E. faecalis) is one of the major pathogenic bacteria responsible for surgical site infections. Biofilm infections are major hospital-acquired infections. Previous studies suggested that ions could regulate biofilm formation in microbes. Volatile anesthetics, frequently administered in surgical setting, target ion channels. Here, we investigated the role of ion channels/transporters and volatile anesthetics in the biofilm formation by E. faecalis MMH594 strain and its ion transporter mutants. We found that a chloride transporter mutant significantly reduced biofilm formation compared to the parental strain. Downregulation of teichoic acid biosynthesis in the chloride transporter mutant impaired biofilm matrix formation and cellular adhesion, leading to mitigated biofilm formation. Among anesthetics, isoflurane exposure enhanced biofilm formation in vitro and in vivo. The upregulation of de novo purine biosynthesis pathway by isoflurane exposure potentially enhanced biofilm formation, an essential process for DNA, RNA, and ATP synthesis. We also demonstrated that isoflurane exposure to E. faecalis increased cyclic-di-AMP and extracellular DNA production, consistent with the increased purine biosynthesis. We further showed that isoflurane enhanced the enzymatic activity of phosphoribosyl pyrophosphate synthetase (PRPP-S). With the hypothesis that isoflurane directly bound to PRPP-S, we predicted isoflurane binding site on it using rigid docking. Our study provides a better understanding of the underlying mechanisms of E. faecalis biofilm formation and highlights the potential impact of an ion transporter and volatile anesthetic on this process. These findings may lead to the development of novel strategies for preventing E. faecalis biofilm formation and improving patient outcomes in clinical settings.
Collapse
Affiliation(s)
- Wiriya Maisat
- Department of Anesthesiology, Critical Care and Pain Medicine, Cardiac Anesthesia Division, Boston Children’s Hospital, Boston, MA, USA
- Department of Anaesthesia, Harvard Medical School, Boston, MA, USA
- Department of Immunology, Harvard Medical School, Boston, MA, USA
- Broad Institute of Harvard and MIT, Cambridge, MA, USA
- Department of Anesthesiology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - Koichi Yuki
- Department of Anesthesiology, Critical Care and Pain Medicine, Cardiac Anesthesia Division, Boston Children’s Hospital, Boston, MA, USA
- Department of Anaesthesia, Harvard Medical School, Boston, MA, USA
- Department of Immunology, Harvard Medical School, Boston, MA, USA
- Broad Institute of Harvard and MIT, Cambridge, MA, USA
| |
Collapse
|
10
|
Azara E, Foddai AC, Longheu CM, Addis MF, Tola S. Production of recombinant proteins including the B-cell epitopes of autolysin A of Staphylococcus aureus isolated from clinical sheep mastitis and their potential for vaccine development. Vet Res Commun 2023; 47:1665-1674. [PMID: 37074614 PMCID: PMC10113713 DOI: 10.1007/s11259-023-10121-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2023] [Accepted: 04/10/2023] [Indexed: 04/20/2023]
Abstract
Staphylococcus aureus is the most common clinical mastitis-associated pathogen in sheep which contributes to reduced welfare of affected animals and, therefore, compromises the quality and quantity of milk production. To prevent mastitis and its spread, it is essential to guarantee adequate breeding conditions and animal health, through the adoption of good farm management practices and the application of suitable biosecurity measures. Vaccination can play a strategic role in prevention, control, and eradication of diseases. The identification of secreted and cellular antigens of the predominant sheep-CC130/ST700/t1773 lineage would assist in the design of effective vaccine against mammary infections caused by S. aureus. In the current study, we carried out a 3D structural prediction analysis with the identification of the best B cell epitopes of the whole and secreted portion of S. aureus AtlA. Fragments of atlA, containing the main predicted epitopes, were amplified, cloned, and expressed in Escherichia coli for recombinant protein production. Two selected clones produced recombinant proteins (rAtl4 and rAtl8) showing strong reactivity with a hyperimmune serum against the native AtlA and with blood sera collected from sheep with clinical S. aureus mastitis. These may represent potential candidate protein-based vaccines able to elicit a protective immune response to be evaluated by vaccination and subsequent challenge of the vaccinated sheep.
Collapse
Affiliation(s)
- Elisa Azara
- Istituto Zooprofilattico Sperimentale della Sardegna "G. Pegreffi", Sassari, 07100, Italy
| | | | - Carla Maria Longheu
- Istituto Zooprofilattico Sperimentale della Sardegna "G. Pegreffi", Sassari, 07100, Italy
| | - Maria Filippa Addis
- Dipartimento di Medicina Veterinaria, Università degli Studi di Milano, Lodi, 26900, Italy.
- Laboratorio di Malattie Infettive degli Animali (MiLab), Università degli Studi di Milano, Lodi, 26900, Italy.
| | - Sebastiana Tola
- Istituto Zooprofilattico Sperimentale della Sardegna "G. Pegreffi", Sassari, 07100, Italy.
| |
Collapse
|
11
|
Douglas EJA, Palk N, Brignoli T, Altwiley D, Boura M, Laabei M, Recker M, Cheung GYC, Liu R, Hsieh RC, Otto M, O'Brien E, McLoughlin RM, Massey RC. Extensive remodelling of the cell wall during the development of Staphylococcus aureus bacteraemia. eLife 2023; 12:RP87026. [PMID: 37401629 PMCID: PMC10328498 DOI: 10.7554/elife.87026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/05/2023] Open
Abstract
The bloodstream represents a hostile environment that bacteria must overcome to cause bacteraemia. To understand how the major human pathogen Staphylococcus aureus manages this we have utilised a functional genomics approach to identify a number of new loci that affect the ability of the bacteria to survive exposure to serum, the critical first step in the development of bacteraemia. The expression of one of these genes, tcaA, was found to be induced upon exposure to serum, and we show that it is involved in the elaboration of a critical virulence factor, the wall teichoic acids (WTA), within the cell envelope. The activity of the TcaA protein alters the sensitivity of the bacteria to cell wall attacking agents, including antimicrobial peptides, human defence fatty acids, and several antibiotics. This protein also affects the autolytic activity and lysostaphin sensitivity of the bacteria, suggesting that in addition to changing WTA abundance in the cell envelope, it also plays a role in peptidoglycan crosslinking. With TcaA rendering the bacteria more susceptible to serum killing, while simultaneously increasing the abundance of WTA in the cell envelope, it was unclear what effect this protein may have during infection. To explore this, we examined human data and performed murine experimental infections. Collectively, our data suggests that whilst mutations in tcaA are selected for during bacteraemia, this protein positively contributes to the virulence of S. aureus through its involvement in altering the cell wall architecture of the bacteria, a process that appears to play a key role in the development of bacteraemia.
Collapse
Affiliation(s)
- Edward JA Douglas
- School of Cellular and Molecular Medicine, University of BristolBristolUnited Kingdom
- Department of Life Sciences, University of BathBathUnited Kingdom
| | - Nathanael Palk
- School of Cellular and Molecular Medicine, University of BristolBristolUnited Kingdom
| | - Tarcisio Brignoli
- School of Cellular and Molecular Medicine, University of BristolBristolUnited Kingdom
- Department of Biosciences, Università degli Studi di MilanoMilanItaly
| | - Dina Altwiley
- School of Cellular and Molecular Medicine, University of BristolBristolUnited Kingdom
| | - Marcia Boura
- School of Cellular and Molecular Medicine, University of BristolBristolUnited Kingdom
| | - Maisem Laabei
- Department of Life Sciences, University of BathBathUnited Kingdom
| | - Mario Recker
- Institute of Tropical Medicine, University of TübingenTübingenGermany
- Centre for Ecology and Conservation, University of Exeter, Penryn CampusExeterUnited Kingdom
| | - Gordon YC Cheung
- Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases (NIAID), US National Institutes of Health (NIH)BethesdaUnited States
| | - Ryan Liu
- Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases (NIAID), US National Institutes of Health (NIH)BethesdaUnited States
| | - Roger C Hsieh
- Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases (NIAID), US National Institutes of Health (NIH)BethesdaUnited States
| | - Michael Otto
- Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases (NIAID), US National Institutes of Health (NIH)BethesdaUnited States
| | - Eoin O'Brien
- Host Pathogen Interactions Group, School of Biochemistry and Immunology, Trinity College DublinDublinIreland
| | - Rachel M McLoughlin
- Host Pathogen Interactions Group, School of Biochemistry and Immunology, Trinity College DublinDublinIreland
| | - Ruth C Massey
- School of Cellular and Molecular Medicine, University of BristolBristolUnited Kingdom
- Schools of Microbiology and Medicine, University College Cork, and APC Microbiome IrelandCorkIreland
| |
Collapse
|
12
|
Yao H, Li G, Xiong X, Jin F, Li S, Xie X, Zhong D, Zhang R, Meng F, Yin Y, Jiao X. LygA retention on the surface of Listeria monocytogenes via its interaction with wall teichoic acid modulates bacterial homeostasis and virulence. PLoS Pathog 2023; 19:e1011482. [PMID: 37379353 DOI: 10.1371/journal.ppat.1011482] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2022] [Accepted: 06/13/2023] [Indexed: 06/30/2023] Open
Abstract
Wall teichoic acid (WTA) is the abundant cell wall-associated glycopolymer in Gram-positive bacteria, playing crucial roles in surface proteins retention, bacterial homeostasis, and virulence. Hypervirulent serovar (SV) 4h Listeria monocytogenes is a newly designated serotype with only galactosylated (Gal) type II WTA. Although the surface association of some proteins relies on the WTA glycosylation, the nature and function of the noncovalent interactions between cell wall-associated proteins and WTA are less known. In this study, we found Gal-WTA plays a key role in modulating the novel glycine-tryptophan (GW) domain-containing autolysin protein LygA through direct interactions. An SV 4h strain deficient in WTA galactosylation (XYSNΔgalT) showed a dramatic reduction of LygA on the cell surface, significantly decreasing the autolytic activity, impairing the bacterial colonization in colon and brain. Notably, we demonstrated LygA binds to Gal-WTA with high affinity through the GW domain and that the extent of binding increases with the number of GW domains. Moreover, we confirmed the direct Gal-dependent binding of the GW protein Auto from the type I WTA strain, which has no interaction with l-rhamnosylated WTA, indicating that the complexity of both WTA and GW proteins can affect the coordination patterns. Altogether, our findings suggest that both the glycosylation patterns of WTA and a fixed numbers of GW domains are closely associated with the retention of LygA on the cell surface, which facilitates L. monocytogenes infection by promoting bacteria colonization in intestine and brain.
Collapse
Affiliation(s)
- Hao Yao
- Jiangsu Key Laboratory of Zoonosis, Yangzhou University, Yangzhou, China
- Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agrifood Safety and Quality, MOA of China, Yangzhou, Jiangsu Province, China
- Joint International Research Laboratory of Agriculture and Agri-product Safety of the Ministry of Education, Yangzhou, Jiangsu Province, China
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Disease and Zoonoses, Yangzhou, Jiangsu Province, China
| | - Guo Li
- Jiangsu Key Laboratory of Zoonosis, Yangzhou University, Yangzhou, China
- Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agrifood Safety and Quality, MOA of China, Yangzhou, Jiangsu Province, China
- Joint International Research Laboratory of Agriculture and Agri-product Safety of the Ministry of Education, Yangzhou, Jiangsu Province, China
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Disease and Zoonoses, Yangzhou, Jiangsu Province, China
| | - Xianglian Xiong
- Jiangsu Key Laboratory of Zoonosis, Yangzhou University, Yangzhou, China
- Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agrifood Safety and Quality, MOA of China, Yangzhou, Jiangsu Province, China
- Joint International Research Laboratory of Agriculture and Agri-product Safety of the Ministry of Education, Yangzhou, Jiangsu Province, China
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Disease and Zoonoses, Yangzhou, Jiangsu Province, China
| | - Fanxin Jin
- Jiangsu Key Laboratory of Zoonosis, Yangzhou University, Yangzhou, China
- Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agrifood Safety and Quality, MOA of China, Yangzhou, Jiangsu Province, China
- Joint International Research Laboratory of Agriculture and Agri-product Safety of the Ministry of Education, Yangzhou, Jiangsu Province, China
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Disease and Zoonoses, Yangzhou, Jiangsu Province, China
| | - Sirui Li
- Jiangsu Key Laboratory of Zoonosis, Yangzhou University, Yangzhou, China
- Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agrifood Safety and Quality, MOA of China, Yangzhou, Jiangsu Province, China
- Joint International Research Laboratory of Agriculture and Agri-product Safety of the Ministry of Education, Yangzhou, Jiangsu Province, China
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Disease and Zoonoses, Yangzhou, Jiangsu Province, China
| | - Xinyu Xie
- Jiangsu Key Laboratory of Zoonosis, Yangzhou University, Yangzhou, China
- Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agrifood Safety and Quality, MOA of China, Yangzhou, Jiangsu Province, China
- Joint International Research Laboratory of Agriculture and Agri-product Safety of the Ministry of Education, Yangzhou, Jiangsu Province, China
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Disease and Zoonoses, Yangzhou, Jiangsu Province, China
| | - Dan Zhong
- Jiangsu Key Laboratory of Zoonosis, Yangzhou University, Yangzhou, China
- Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agrifood Safety and Quality, MOA of China, Yangzhou, Jiangsu Province, China
- Joint International Research Laboratory of Agriculture and Agri-product Safety of the Ministry of Education, Yangzhou, Jiangsu Province, China
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Disease and Zoonoses, Yangzhou, Jiangsu Province, China
| | - Renling Zhang
- Jiangsu Key Laboratory of Zoonosis, Yangzhou University, Yangzhou, China
- Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agrifood Safety and Quality, MOA of China, Yangzhou, Jiangsu Province, China
- Joint International Research Laboratory of Agriculture and Agri-product Safety of the Ministry of Education, Yangzhou, Jiangsu Province, China
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Disease and Zoonoses, Yangzhou, Jiangsu Province, China
| | - Fanzeng Meng
- Jiangsu Key Laboratory of Zoonosis, Yangzhou University, Yangzhou, China
- Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agrifood Safety and Quality, MOA of China, Yangzhou, Jiangsu Province, China
- Joint International Research Laboratory of Agriculture and Agri-product Safety of the Ministry of Education, Yangzhou, Jiangsu Province, China
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Disease and Zoonoses, Yangzhou, Jiangsu Province, China
| | - Yuelan Yin
- Jiangsu Key Laboratory of Zoonosis, Yangzhou University, Yangzhou, China
- Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agrifood Safety and Quality, MOA of China, Yangzhou, Jiangsu Province, China
- Joint International Research Laboratory of Agriculture and Agri-product Safety of the Ministry of Education, Yangzhou, Jiangsu Province, China
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Disease and Zoonoses, Yangzhou, Jiangsu Province, China
| | - Xin'an Jiao
- Jiangsu Key Laboratory of Zoonosis, Yangzhou University, Yangzhou, China
- Key Laboratory of Prevention and Control of Biological Hazard Factors (Animal Origin) for Agrifood Safety and Quality, MOA of China, Yangzhou, Jiangsu Province, China
- Joint International Research Laboratory of Agriculture and Agri-product Safety of the Ministry of Education, Yangzhou, Jiangsu Province, China
- Jiangsu Co-Innovation Center for Prevention and Control of Important Animal Infectious Disease and Zoonoses, Yangzhou, Jiangsu Province, China
| |
Collapse
|
13
|
Salamaga B, Turner RD, Elsarmane F, Galley NF, Kulakauskas S, Mesnage S. A moonlighting role for LysM peptidoglycan binding domains underpins Enterococcus faecalis daughter cell separation. Commun Biol 2023; 6:428. [PMID: 37072531 PMCID: PMC10113225 DOI: 10.1038/s42003-023-04808-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2022] [Accepted: 04/04/2023] [Indexed: 04/20/2023] Open
Abstract
Control of cell size and morphology is of paramount importance for bacterial fitness. In the opportunistic pathogen Enterococcus faecalis, the formation of diplococci and short cell chains facilitates innate immune evasion and dissemination in the host. Minimisation of cell chain size relies on the activity of a peptidoglycan hydrolase called AtlA, dedicated to septum cleavage. To prevent autolysis, AtlA activity is tightly controlled, both temporally and spatially. Here, we show that the restricted localization of AtlA at the septum occurs via an unexpected mechanism. We demonstrate that the C-terminal LysM domain that allows the enzyme to bind peptidoglycan is essential to target this enzyme to the septum inside the cell before its translocation across the membrane. We identify a membrane-bound cytoplasmic protein partner (called AdmA) involved in the recruitment of AtlA via its LysM domains. This work reveals a moonlighting role for LysM domains, and a mechanism evolved to restrict the subcellular localization of a potentially lethal autolysin to its site of action.
Collapse
Affiliation(s)
| | - Robert D Turner
- School of Biosciences, University of Sheffield, Sheffield, UK
| | - Fathe Elsarmane
- School of Biosciences, University of Sheffield, Sheffield, UK
| | - Nicola F Galley
- School of Biosciences, University of Sheffield, Sheffield, UK
| | - Saulius Kulakauskas
- Université Paris-Saclay, INRAE, AgroParisTech, Micalis Institute, 78350, Jouy-en-Josas, France
| | | |
Collapse
|
14
|
Brogan AP, Rudner DZ. Regulation of peptidoglycan hydrolases: localization, abundance, and activity. Curr Opin Microbiol 2023; 72:102279. [PMID: 36812681 PMCID: PMC10031507 DOI: 10.1016/j.mib.2023.102279] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2022] [Revised: 01/17/2023] [Accepted: 01/18/2023] [Indexed: 02/22/2023]
Abstract
Most bacteria are surrounded by a cell wall composed of peptidoglycan (PG) that specifies shape and protects the cell from osmotic rupture. Growth, division, and morphogenesis are intimately linked to the synthesis of this exoskeleton but also its hydrolysis. The enzymes that cleave the PG meshwork require careful control to prevent aberrant hydrolysis and loss of envelope integrity. Bacteria employ diverse mechanisms to control the activity, localization, and abundance of these potentially autolytic enzymes. Here, we discuss four examples of how cells integrate these control mechanisms to finely tune cell wall hydrolysis. We highlight recent advances and exciting avenues for future investigation.
Collapse
Affiliation(s)
- Anna P Brogan
- Department of Microbiology, Harvard Medical School, Boston, MA 02115, USA
| | - David Z Rudner
- Department of Microbiology, Harvard Medical School, Boston, MA 02115, USA.
| |
Collapse
|
15
|
Weaver A, Taguchi A, Dörr T. Masters of Misdirection: Peptidoglycan Glycosidases in Bacterial Growth. J Bacteriol 2023; 205:e0042822. [PMID: 36757204 PMCID: PMC10029718 DOI: 10.1128/jb.00428-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/10/2023] Open
Abstract
The dynamic composition of the peptidoglycan cell wall has been the subject of intense research for decades, yet how bacteria coordinate the synthesis of new peptidoglycan with the turnover and remodeling of existing peptidoglycan remains elusive. Diversity and redundancy within peptidoglycan synthases and peptidoglycan autolysins, enzymes that degrade peptidoglycan, have often made it challenging to assign physiological roles to individual enzymes and determine how those activities are regulated. For these reasons, peptidoglycan glycosidases, which cleave within the glycan strands of peptidoglycan, have proven veritable masters of misdirection over the years. Unlike many of the broadly conserved peptidoglycan synthetic complexes, diverse bacteria can employ unrelated glycosidases to achieve the same physiological outcome. Additionally, although the mechanisms of action for many individual enzymes have been characterized, apparent conserved homologs in other organisms can exhibit an entirely different biochemistry. This flexibility has been recently demonstrated in the context of three functions critical to vegetative growth: (i) release of newly synthesized peptidoglycan strands from their membrane anchors, (ii) processing of peptidoglycan turned over during cell wall expansion, and (iii) removal of peptidoglycan fragments that interfere with daughter cell separation during cell division. Finally, the regulation of glycosidase activity during these cell processes may be a cumulation of many factors, including protein-protein interactions, intrinsic substrate preferences, substrate availability, and subcellular localization. Understanding the true scope of peptidoglycan glycosidase activity will require the exploration of enzymes from diverse organisms with equally diverse growth and division strategies.
Collapse
Affiliation(s)
- Anna Weaver
- Department of Microbiology, Blavatnik Institute, Harvard Medical School, Boston, Massachusetts, USA
| | - Atsushi Taguchi
- SANKEN (The Institute of Scientific and Industrial Research), Osaka University, Ibaraki, Osaka, Japan
| | - Tobias Dörr
- Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, New York, USA
- Department of Microbiology, Cornell University, Ithaca, New York, USA
- Cornell Institute of Host-Microbe Interactions and Disease, Cornell University, Ithaca, New York, USA
| |
Collapse
|
16
|
Malet-Villemagne J, Yucheng L, Evanno L, Denis-Quanquin S, Hugonnet JE, Arthur M, Janoir C, Candela T. Polysaccharide II Surface Anchoring, the Achilles' Heel of Clostridioides difficile. Microbiol Spectr 2023; 11:e0422722. [PMID: 36815772 PMCID: PMC10100865 DOI: 10.1128/spectrum.04227-22] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Accepted: 01/25/2023] [Indexed: 02/24/2023] Open
Abstract
Cell wall glycopolymers (CWPGs) in Gram-positive bacteria have been reported to be involved in several bacterial processes. These polymers, pillars for proteins and S-layer, are essential for the bacterial surface setup, could be essential for growth, and, in pathogens, participate most often in virulence. CWGPs are covalently anchored to peptidoglycan by proteins that belong to the LytR-CpsA-PSr (LCP) family. This anchoring, important for growth, was reported as essential for some bacteria such as Bacillus subtilis, but the reason why CWGP anchoring is essential remains unknown. We studied LcpA and LcpB of Clostridioides difficile and showed that they have a redundant activity. To delete both lcp genes, we set up the first conditional-lethal mutant method in C. difficile and showed that polysaccharide II (PSII) anchoring at the bacterial surface is essential for C. difficile survival. In the conditional-lethal mutant, C. difficile morphology was impaired, suggesting that peptidoglycan synthesis was affected. Because Lcp proteins are transferring CWPGs from the C55-undecaprenyl phosphate (also needed in the peptidoglycan synthesis process), we assumed that there was competition between PSII and peptidoglycan synthesis pathways. We confirmed that UDP-MurNAc-pentapeptide precursor was accumulated, showing that peptidoglycan synthesis was blocked. Our results provide an explanation for the essentiality of PSII anchoring in C. difficile and suggest that the essentiality of the anchoring of CWPGs in other bacteria can also be explained by the blocking of peptidoglycan synthesis. To conclude, our results suggest that Lcps are potential new targets to combat C. difficile infection. IMPORTANCE Cell wall glycopolymers (CWGPs) in Gram-positive bacteria have been reported to be involved in several bacterial processes. CWGP anchoring to peptidoglycan is important for growth and virulence. We set up the first conditional-lethal mutant method in Clostridioides difficile to study LcpA and LcpB involved in the anchoring of CWPGs to peptidoglycan. This study offers new tools to reveal the role of essential genes in C. difficile. LcpA and LcpB activity was shown to be essential, suggesting that they are potential new targets to combat C. difficile infection. In this study, we also showed that there is competition between the polysaccharide II synthesis pathway and peptidoglycan synthesis that probably exists in other Gram-positive bacteria. A better understanding of these mechanisms allows us to define the Lcp proteins as a therapeutic target for potential design of novel antibiotics against pathogenic Gram-positive bacteria.
Collapse
Affiliation(s)
| | - Liang Yucheng
- INSERM UMR-S 1138, Centre de Recherche des Cordeliers, Sorbonne Université, Université Paris Cité, Paris, France
| | - Laurent Evanno
- Biomolécules: Conception, Isolement et Synthèse (BioCIS), Université Paris-Saclay, CNRS, Orsay, France
| | | | - Jean-Emmanuel Hugonnet
- INSERM UMR-S 1138, Centre de Recherche des Cordeliers, Sorbonne Université, Université Paris Cité, Paris, France
| | - Michel Arthur
- INSERM UMR-S 1138, Centre de Recherche des Cordeliers, Sorbonne Université, Université Paris Cité, Paris, France
| | - Claire Janoir
- Micalis Institute, Université Paris-Saclay, INRAE, AgroParisTech, Jouy-en-Josas, France
| | - Thomas Candela
- Micalis Institute, Université Paris-Saclay, INRAE, AgroParisTech, Jouy-en-Josas, France
| |
Collapse
|
17
|
Douglas EJA, Palk N, Brignoli T, Altwiley D, Boura M, Laabei M, Recker M, Cheung GYC, Liu R, Hsieh RC, Otto M, Oâ Brien E, McLoughlin RM, Massey RC. Extensive re-modelling of the cell wall during the development of Staphylococcus aureus bacteraemia. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.02.23.529713. [PMID: 36865143 PMCID: PMC9980097 DOI: 10.1101/2023.02.23.529713] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/25/2023]
Abstract
The bloodstream represents a hostile environment that bacteria must overcome to cause bacteraemia. To understand how the major human pathogen Staphylococcus aureus manages this we have utilised a functional genomics approach to identify a number of new loci that affect the ability of the bacteria to survive exposure to serum, the critical first step in the development of bacteraemia. The expression of one of these genes, tcaA , was found to be induced upon exposure to serum, and we show that it is involved in the elaboration of a critical virulence factor, the wall teichoic acids (WTA), within the cell envelope. The activity of this protein alters the sensitivity of the bacteria to cell wall attacking agents, including antimicrobial peptides, human defence fatty acids, and several antibiotics. This protein also affects the autolytic activity and lysostaphin sensitivity of the bacteria, suggesting that in addition to changing WTA abundance in the cell envelope, it also plays a role in peptidoglycan crosslinking. With TcaA rendering the bacteria more susceptible to serum killing, while simultaneously increasing the abundance of WTA in the cell envelope, it was unclear what effect this protein may have during infection. To explore this, we examined human data and performed murine experimental infections. Collectively, our data suggests that whilst mutations in tcaA are selected for during bacteraemia, this protein positively contributes to the virulence of S. aureus through its involvement in altering the cell wall architecture of the bacteria, a process that appears to play a key role in the development of bacteraemia.
Collapse
|
18
|
Ersoy SC, Gonçalves B, Cavaco G, Manna AC, Sobral RG, Nast CC, Proctor RA, Chambers HF, Cheung A, Bayer AS. Influence of Sodium Bicarbonate on Wall Teichoic Acid Synthesis and β-Lactam Sensitization in NaHCO 3-Responsive and Nonresponsive Methicillin-Resistant Staphylococcus aureus. Microbiol Spectr 2022; 10:e0342222. [PMID: 36377886 PMCID: PMC9769754 DOI: 10.1128/spectrum.03422-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Accepted: 10/13/2022] [Indexed: 11/16/2022] Open
Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) strains pose major treatment challenges due to their innate resistance to most β-lactams under standard in vitro antimicrobial susceptibility testing conditions. A novel phenotype among MRSA, termed "NaHCO3 responsiveness," where certain strains display increased susceptibility to β-lactams in the presence of NaHCO3, has been identified among a relatively large proportion of MRSA isolates. One underlying mechanism of NaHCO3 responsiveness appears to be related to decreased expression and altered functionality of several genes and proteins involved in cell wall synthesis and maturation. Here, we studied the impact of NaHCO3 on wall teichoic acid (WTA) synthesis, a process intimately linked to peptidoglycan (PG) synthesis and functionality, in NaHCO3-responsive versus -nonresponsive MRSA isolates. NaHCO3 sensitized responsive MRSA strains to cefuroxime, a specific penicillin-binding protein 2 (PBP2)-inhibitory β-lactam known to synergize with early WTA synthesis inhibitors (e.g., ticlopidine). Combining cefuroxime with ticlopidine with or without NaHCO3 suggested that these latter two agents target the same step in WTA synthesis. Further, NaHCO3 decreased the abundance and molecular weight of WTA only in responsive strains. Additionally, NaHCO3 stimulated increased autolysis and aberrant cell division in responsive strains, two phenotypes associated with disruption of WTA synthesis. Of note, studies of key genes involved in the WTA biosynthetic pathway (e.g., tarO, tarG, dltA, and fmtA) indicated that the inhibitory impact of NaHCO3 on WTA biosynthesis in responsive strains likely occurred posttranslationally. IMPORTANCE MRSA is generally viewed as resistant to standard β-lactam antibiotics. However, a NaHCO3-responsive phenotype is observed in a substantial proportion of clinical MRSA strains in vitro, i.e., isolates which demonstrate enhanced susceptibility to standard β-lactam antibiotics (e.g., oxacillin) in the presence of NaHCO3. This phenotype correlates with increased MRSA clearance in vivo by standard β-lactam antibiotics, suggesting that patients with infections caused by such MRSA strains might be amenable to treatment with β-lactams. The mechanism(s) behind this phenotype is not fully understood but appears to involve mecA-PBP2a production and maturation axes. Our study adds significantly to this body of knowledge in terms of additional mechanistic targets of NaHCO3 in selected MRSA strains. This investigation demonstrates that NaHCO3 has direct impacts on S. aureus wall teichoic acid biosynthesis in NaHCO3-responsive MRSA. These findings provide an additional target for new agents being designed to synergistically kill MRSA using β-lactam antibiotics.
Collapse
Affiliation(s)
| | - Barbara Gonçalves
- Laboratory of Molecular Microbiology of Bacterial Pathogens, UCIBIO, Applied Molecular Biosciences Unit, Department of Life Sciences, Nova School of Science and Technology, Universidade Nova de Lisboa, Caparica, Portugal
- Associate Laboratory i4HB, Institute for Health and Bioeconomy, Nova School of Science and Technology, Universidade Nova de Lisboa, Caparica, Portugal
| | - Gonçalo Cavaco
- Laboratory of Molecular Microbiology of Bacterial Pathogens, UCIBIO, Applied Molecular Biosciences Unit, Department of Life Sciences, Nova School of Science and Technology, Universidade Nova de Lisboa, Caparica, Portugal
- Associate Laboratory i4HB, Institute for Health and Bioeconomy, Nova School of Science and Technology, Universidade Nova de Lisboa, Caparica, Portugal
| | - Adhar C. Manna
- Department of Microbiology & Immunology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA
| | - Rita G. Sobral
- Laboratory of Molecular Microbiology of Bacterial Pathogens, UCIBIO, Applied Molecular Biosciences Unit, Department of Life Sciences, Nova School of Science and Technology, Universidade Nova de Lisboa, Caparica, Portugal
- Associate Laboratory i4HB, Institute for Health and Bioeconomy, Nova School of Science and Technology, Universidade Nova de Lisboa, Caparica, Portugal
| | - Cynthia C. Nast
- Cedars-Sinai Medical Center, Los Angeles, California, USA
- Geffen School of Medicine at UCLA, Los Angeles, California, USA
| | - Richard A. Proctor
- Department of Medicine, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, USA
- Department of Medical Microbiology/Immunology, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, USA
| | | | - Ambrose Cheung
- Department of Microbiology & Immunology, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA
| | - Arnold S. Bayer
- The Lundquist Institute, Torrance, California, USA
- Geffen School of Medicine at UCLA, Los Angeles, California, USA
| |
Collapse
|
19
|
Barbuti MD, Myrbråten IS, Morales Angeles D, Kjos M. The cell cycle of Staphylococcus aureus: An updated review. Microbiologyopen 2022; 12:e1338. [PMID: 36825883 PMCID: PMC9733580 DOI: 10.1002/mbo3.1338] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Revised: 11/29/2022] [Accepted: 11/29/2022] [Indexed: 12/13/2022] Open
Abstract
As bacteria proliferate, DNA replication, chromosome segregation, cell wall synthesis, and cytokinesis occur concomitantly and need to be tightly regulated and coordinated. Although these cell cycle processes have been studied for decades, several mechanisms remain elusive, specifically in coccus-shaped cells such as Staphylococcus aureus. In recent years, major progress has been made in our understanding of how staphylococci divide, including new, fundamental insights into the mechanisms of cell wall synthesis and division site selection. Furthermore, several novel proteins and mechanisms involved in the regulation of replication initiation or progression of the cell cycle have been identified and partially characterized. In this review, we will summarize our current understanding of the cell cycle processes in the spheroid model bacterium S. aureus, with a focus on recent advances in the understanding of how these processes are regulated.
Collapse
Affiliation(s)
- Maria D. Barbuti
- Faculty of Chemistry, Biotechnology and Food ScienceNorwegian University of Life Sciences (NMBU)ÅsNorway
| | - Ine S. Myrbråten
- Faculty of Chemistry, Biotechnology and Food ScienceNorwegian University of Life Sciences (NMBU)ÅsNorway
| | - Danae Morales Angeles
- Faculty of Chemistry, Biotechnology and Food ScienceNorwegian University of Life Sciences (NMBU)ÅsNorway
| | - Morten Kjos
- Faculty of Chemistry, Biotechnology and Food ScienceNorwegian University of Life Sciences (NMBU)ÅsNorway
| |
Collapse
|
20
|
The Staphylococcus aureus cell division protein, DivIC, interacts with the cell wall and controls its biosynthesis. Commun Biol 2022; 5:1228. [DOI: 10.1038/s42003-022-04161-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Accepted: 10/24/2022] [Indexed: 11/13/2022] Open
Abstract
AbstractBacterial cell division is a complex, dynamic process that requires multiple protein components to orchestrate its progression. Many division proteins are highly conserved across bacterial species alluding to a common, basic mechanism. Central to division is a transmembrane trimeric complex involving DivIB, DivIC and FtsL in Gram-positives. Here, we show a distinct, essential role for DivIC in division and survival of Staphylococcus aureus. DivIC spatially regulates peptidoglycan synthesis, and consequently cell wall architecture, by influencing the recruitment to the division septum of the major peptidoglycan synthetases PBP2 and FtsW. Both the function of DivIC and its recruitment to the division site depend on its extracellular domain, which interacts with the cell wall via binding to wall teichoic acids. DivIC facilitates the spatial and temporal coordination of peptidoglycan synthesis with the developing architecture of the septum during cell division. A better understanding of the cell division mechanisms in S. aureus and other pathogenic microorganisms can provide possibilities for the development of new, more effective treatments for bacterial infections.
Collapse
|
21
|
Zhou J, Cai Y, Liu Y, An H, Deng K, Ashraf MA, Zou L, Wang J. Breaking down the cell wall: Still an attractive antibacterial strategy. Front Microbiol 2022; 13:952633. [PMID: 36212892 PMCID: PMC9544107 DOI: 10.3389/fmicb.2022.952633] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Accepted: 08/18/2022] [Indexed: 11/17/2022] Open
Abstract
Since the advent of penicillin, humans have known about and explored the phenomenon of bacterial inhibition via antibiotics. However, with changes in the global environment and the abuse of antibiotics, resistance mechanisms have been selected in bacteria, presenting huge threats and challenges to the global medical and health system. Thus, the study and development of new antimicrobials is of unprecedented urgency and difficulty. Bacteria surround themselves with a cell wall to maintain cell rigidity and protect against environmental insults. Humans have taken advantage of antibiotics to target the bacterial cell wall, yielding some of the most widely used antibiotics to date. The cell wall is essential for bacterial growth and virulence but is absent from humans, remaining a high-priority target for antibiotic screening throughout the antibiotic era. Here, we review the extensively studied targets, i.e., MurA, MurB, MurC, MurD, MurE, MurF, Alr, Ddl, MurI, MurG, lipid A, and BamA in the cell wall, starting from the very beginning to the latest developments to elucidate antimicrobial screening. Furthermore, recent advances, including MraY and MsbA in peptidoglycan and lipopolysaccharide, and tagO, LtaS, LspA, Lgt, Lnt, Tol-Pal, MntC, and OspA in teichoic acid and lipoprotein, have also been profoundly discussed. The review further highlights that the application of new methods such as macromolecular labeling, compound libraries construction, and structure-based drug design will inspire researchers to screen ideal antibiotics.
Collapse
Affiliation(s)
- Jingxuan Zhou
- The People’s Hospital of China Three Gorges University, Yichang, Hubei, China
- Hubei Key Laboratory of Tumor Microenvironment and Immunotherapy, College of Basic Medical Sciences, China Three Gorges University, Yichang, Hubei, China
- The Institute of Infection and Inflammation, College of Basic Medical Sciences, China Three Gorges University, Yichang, Hubei, China
| | - Yi Cai
- Hubei Key Laboratory of Tumor Microenvironment and Immunotherapy, College of Basic Medical Sciences, China Three Gorges University, Yichang, Hubei, China
- The Institute of Infection and Inflammation, College of Basic Medical Sciences, China Three Gorges University, Yichang, Hubei, China
| | - Ying Liu
- Hubei Key Laboratory of Tumor Microenvironment and Immunotherapy, College of Basic Medical Sciences, China Three Gorges University, Yichang, Hubei, China
- The Institute of Infection and Inflammation, College of Basic Medical Sciences, China Three Gorges University, Yichang, Hubei, China
| | - Haoyue An
- Hubei Key Laboratory of Tumor Microenvironment and Immunotherapy, College of Basic Medical Sciences, China Three Gorges University, Yichang, Hubei, China
- The Institute of Infection and Inflammation, College of Basic Medical Sciences, China Three Gorges University, Yichang, Hubei, China
| | - Kaihong Deng
- Hubei Key Laboratory of Tumor Microenvironment and Immunotherapy, College of Basic Medical Sciences, China Three Gorges University, Yichang, Hubei, China
- The Institute of Infection and Inflammation, College of Basic Medical Sciences, China Three Gorges University, Yichang, Hubei, China
| | - Muhammad Awais Ashraf
- Department of Microbiology, Government College University Faisalabad, Faisalabad, Pakistan
| | - Lili Zou
- Hubei Key Laboratory of Tumor Microenvironment and Immunotherapy, College of Basic Medical Sciences, China Three Gorges University, Yichang, Hubei, China
- The Institute of Infection and Inflammation, College of Basic Medical Sciences, China Three Gorges University, Yichang, Hubei, China
| | - Jun Wang
- The People’s Hospital of China Three Gorges University, Yichang, Hubei, China
- *Correspondence: Jun Wang,
| |
Collapse
|
22
|
Wall Teichoic Acids Facilitate the Release of Toxins from the Surface of Staphylococcus aureus. Microbiol Spectr 2022; 10:e0101122. [PMID: 35863033 PMCID: PMC9430763 DOI: 10.1128/spectrum.01011-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A major feature of the pathogenicity of Staphylococcus aureus is its ability to secrete cytolytic toxins. This process involves the translocation of the toxins from the cytoplasm through the bacterial membrane and the cell wall to the external environment. The process of their movement through the membrane is relatively well defined, involving both general and toxin-specific secretory systems. Movement of the toxins through the cell wall was considered to involve the passive diffusion of the proteins through the porous cell wall structures; however, recent work suggests that this is more complex, and here we demonstrate a role for the wall teichoic acids (WTA) in this process. Utilizing a genome-wide association approach, we identified a polymorphism in the locus encoding the WTA biosynthetic machinery as associated with the cytolytic activity of the bacteria. We verified this association using an isogenic mutant set and found that WTA are required for the release of several cytolytic toxins from the bacterial cells. We show that this effect is mediated by a change in the electrostatic charge across the cell envelope that results from the loss of WTA. As a major target for the development of novel therapeutics, it is important that we fully understand the entire process of cytolytic toxin production and release. These findings open up a new aspect to the process of toxin release by a major human pathogen while also demonstrating that clinical isolates can utilize WTA production to vary their cytotoxicity, thereby altering their pathogenic capabilities. IMPORTANCE The production and release of cytolytic toxins is a critical aspect for the pathogenicity of many bacterial pathogens. In this study, we demonstrate a role for wall teichoic acids, molecules that are anchored to the peptidoglycan of the bacterial cell wall, in the release of toxins from S. aureus cells into the extracellular environment. Our findings suggest that this effect is mediated by a gradient of electrostatic charge which the presence of the negatively charged WTA molecules create across the cell envelope. This work brings an entirely new aspect to our understanding of the cytotoxicity of S. aureus and demonstrates a further means by which this major human pathogen can adapt its pathogenic capabilities.
Collapse
|
23
|
Hammond LR, Sacco MD, Khan SJ, Spanoudis C, Hough-Neidig A, Chen Y, Eswara PJ. GpsB Coordinates Cell Division and Cell Surface Decoration by Wall Teichoic Acids in Staphylococcus aureus. Microbiol Spectr 2022; 10:e0141322. [PMID: 35647874 PMCID: PMC9241681 DOI: 10.1128/spectrum.01413-22] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Accepted: 05/12/2022] [Indexed: 11/20/2022] Open
Abstract
Bacterial cell division is a complex and highly regulated process requiring the coordination of many different proteins. Despite substantial work in model organisms, our understanding of the systems regulating cell division in noncanonical organisms, including critical human pathogens, is far from complete. One such organism is Staphylococcus aureus, a spherical bacterium that lacks known cell division regulatory proteins. Recent studies on GpsB, a protein conserved within the Firmicutes phylum, have provided insight into cell division regulation in S. aureus and other related organisms. It has been revealed that GpsB coordinates cell division and cell wall synthesis in multiple species. In S. aureus, we have previously shown that GpsB directly regulates FtsZ polymerization. In this study, using Bacillus subtilis as a tool, we isolated spontaneous suppressors that abrogate the lethality of S. aureus GpsB overproduction in B. subtilis. Through characterization, we identified several residues important for the function of GpsB. Furthermore, we discovered an additional role for GpsB in wall teichoic acid (WTA) biosynthesis in S. aureus. Specifically, we show that GpsB directly interacts with the WTA export protein TarG. We also identified a region in GpsB that is crucial for this interaction. Analysis of TarG localization in S. aureus suggests that WTA machinery is part of the divisome complex. Taken together, this research illustrates how GpsB performs an essential function in S. aureus by directly linking the tightly regulated cell cycle processes of cell division and WTA-mediated cell surface decoration. IMPORTANCE Cytokinesis in bacteria involves an intricate orchestration of several key cell division proteins and other factors involved in building a robust cell envelope. Presence of teichoic acids is a signature characteristic of the Gram-positive cell wall. By characterizing the role of Staphylococcus aureus GpsB, an essential cell division protein in this organism, we have uncovered an additional role for GpsB in wall teichoic acid (WTA) biosynthesis. We show that GpsB directly interacts with TarG of the WTA export complex. We also show that this function of GpsB may be conserved in other GpsB homologs as GpsB and the WTA exporter complex follow similar localization patterns. It has been suggested that WTA acts as a molecular signal to control the activity of autolytic enzymes, especially during the separation of conjoined daughter cells. Thus, our results reveal that GpsB, in addition to playing a role in cell division, may also help coordinate WTA biogenesis.
Collapse
Affiliation(s)
- Lauren R. Hammond
- Department of Cell Biology, Microbiology, and Molecular Biology, University of South Florida, Tampa, Florida, USA
| | - Michael D. Sacco
- Department of Molecular Medicine, University of South Florida, Tampa, Florida, USA
| | - Sebastian J. Khan
- Department of Cell Biology, Microbiology, and Molecular Biology, University of South Florida, Tampa, Florida, USA
| | - Catherine Spanoudis
- Department of Cell Biology, Microbiology, and Molecular Biology, University of South Florida, Tampa, Florida, USA
| | - Abigail Hough-Neidig
- Department of Cell Biology, Microbiology, and Molecular Biology, University of South Florida, Tampa, Florida, USA
| | - Yu Chen
- Department of Molecular Medicine, University of South Florida, Tampa, Florida, USA
| | - Prahathees J. Eswara
- Department of Cell Biology, Microbiology, and Molecular Biology, University of South Florida, Tampa, Florida, USA
| |
Collapse
|
24
|
Wysocka A, Łężniak Ł, Jagielska E, Sabała I. Electrostatic Interaction with the Bacterial Cell Envelope Tunes the Lytic Activity of Two Novel Peptidoglycan Hydrolases. Microbiol Spectr 2022; 10:e0045522. [PMID: 35467396 PMCID: PMC9241647 DOI: 10.1128/spectrum.00455-22] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Accepted: 04/04/2022] [Indexed: 12/14/2022] Open
Abstract
Peptidoglycan (PG) hydrolases, due to their crucial role in the metabolism of the bacterial cell wall (CW), are increasingly being considered suitable targets for therapies, and a potent alternative to conventional antibiotics. In the light of contradictory data reported, detailed mechanism of regulation of enzymes activity based on electrostatic interactions between hydrolase molecule and bacterial CW surface remains unknown. Here, we report a comprehensive study on this phenomenon using as a model two novel PG hydrolases, SpM23_A, and SpM23_B, which although share the same bacterial host, similarities in sequence conservation, domain architecture, and structure, display surprisingly distinct net charges (in 2D electrophoresis, pI 6.8, and pI 9.7, respectively). We demonstrate a strong correlation between hydrolases surface net charge and the enzymes activity by modulating the charge of both, enzyme molecule and bacterial cell surface. Teichoic acids, anionic polymers present in the bacterial CW, are shown to be involved in the mechanism of enzymes activity regulation by the electrostatics-based interplay between charged bacterial envelope and PG hydrolases. These data serve as a hint for the future development of chimeric PG hydrolases of desired antimicrobial specificity. IMPORTANCE This study shows direct relationship between the surface charge of two recently described enzymes, SpM23_A and SpM23_B, and bacterial cell walls. We demonstrate that by (i) surface charge probing of bacterial strains collection, (ii) reduction of the net charge of the positively charged enzyme, and (iii) altering the net charge of the bacterial surface by modifying the content and composition of teichoic acids. In all cases, we observed that lytic activity and binding strength of SpM23 enzymes, are regulated by electrostatic interactions with the bacterial cell envelope and that this interaction contributes to the determination of the spectrum of susceptible bacterial species. Moreover, we revealed the regulatory role of charged cell wall components, namely, teichoic and lipoteichoic acids, over the SpM23 enzymes. We believe that our findings make an important contribution to understand the means of hydrolases activity regulation in the complex environment of the bacterial cell wall.
Collapse
Affiliation(s)
- Alicja Wysocka
- International Institute of Molecular and Cell Biology in Warsaw, Warsaw, Poland
| | - Łukasz Łężniak
- International Institute of Molecular and Cell Biology in Warsaw, Warsaw, Poland
| | - Elżbieta Jagielska
- International Institute of Molecular and Cell Biology in Warsaw, Warsaw, Poland
- Mossakowski Medical Research Institute Polish Academy of Sciences, Warsaw, Poland
| | - Izabela Sabała
- International Institute of Molecular and Cell Biology in Warsaw, Warsaw, Poland
- Mossakowski Medical Research Institute Polish Academy of Sciences, Warsaw, Poland
| |
Collapse
|
25
|
Targeting the Holy Triangle of Quorum Sensing, Biofilm Formation, and Antibiotic Resistance in Pathogenic Bacteria. Microorganisms 2022; 10:microorganisms10061239. [PMID: 35744757 PMCID: PMC9228545 DOI: 10.3390/microorganisms10061239] [Citation(s) in RCA: 43] [Impact Index Per Article: 21.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2022] [Revised: 06/12/2022] [Accepted: 06/14/2022] [Indexed: 12/12/2022] Open
Abstract
Chronic and recurrent bacterial infections are frequently associated with the formation of biofilms on biotic or abiotic materials that are composed of mono- or multi-species cultures of bacteria/fungi embedded in an extracellular matrix produced by the microorganisms. Biofilm formation is, among others, regulated by quorum sensing (QS) which is an interbacterial communication system usually composed of two-component systems (TCSs) of secreted autoinducer compounds that activate signal transduction pathways through interaction with their respective receptors. Embedded in the biofilms, the bacteria are protected from environmental stress stimuli, and they often show reduced responses to antibiotics, making it difficult to eradicate the bacterial infection. Besides reduced penetration of antibiotics through the intricate structure of the biofilms, the sessile biofilm-embedded bacteria show reduced metabolic activity making them intrinsically less sensitive to antibiotics. Moreover, they frequently express elevated levels of efflux pumps that extrude antibiotics, thereby reducing their intracellular levels. Some efflux pumps are involved in the secretion of QS compounds and biofilm-related materials, besides being important for removing toxic substances from the bacteria. Some efflux pump inhibitors (EPIs) have been shown to both prevent biofilm formation and sensitize the bacteria to antibiotics, suggesting a relationship between these processes. Additionally, QS inhibitors or quenchers may affect antibiotic susceptibility. Thus, targeting elements that regulate QS and biofilm formation might be a promising approach to combat antibiotic-resistant biofilm-related bacterial infections.
Collapse
|
26
|
Penicillin-Binding Protein 1 (PBP1) of Staphylococcus aureus Has Multiple Essential Functions in Cell Division. mBio 2022; 13:e0066922. [PMID: 35703435 PMCID: PMC9426605 DOI: 10.1128/mbio.00669-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Bacterial cell division is a complex process requiring the coordination of multiple components to allow the appropriate spatial and temporal control of septum formation and cell scission. Peptidoglycan (PG) is the major structural component of the septum, and our recent studies in the human pathogen Staphylococcus aureus have revealed a complex, multistage PG architecture that develops during septation. Penicillin-binding proteins (PBPs) are essential for the final steps of PG biosynthesis; their transpeptidase activity links the peptide side chains of nascent glycan strands. PBP1 is required for cell division in S. aureus, and here, we demonstrate that it has multiple essential functions associated with its enzymatic activity and as a regulator of division. Loss of PBP1, or just its C-terminal PASTA domains, results in cessation of division at the point of septal plate formation. The PASTA domains can bind PG and thereby potentially coordinate the cell division process. The transpeptidase activity of PBP1 is also essential, but its loss leads to a strikingly different phenotype of thickened and aberrant septa, which is phenocopied by the morphological effects of adding the PBP1-specific β-lactam, meropenem. Together, these results lead to a model for septal PG synthesis where PBP1 enzyme activity is required for the characteristic architecture of the septum and PBP1 protein molecules enable the formation of the septal plate.
Collapse
|
27
|
Berry KA, Verhoef MTA, Leonard AC, Cox G. Staphylococcus aureus adhesion to the host. Ann N Y Acad Sci 2022; 1515:75-96. [PMID: 35705378 DOI: 10.1111/nyas.14807] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Staphylococcus aureus is a pathobiont capable of colonizing and infecting most tissues within the human body, resulting in a multitude of different clinical outcomes. Adhesion of S. aureus to the host is crucial for both host colonization and the establishment of infections. Underlying the pathogen's success is a complex and diverse arsenal of adhesins. In this review, we discuss the different classes of adhesins, including a consideration of the various adhesion sites throughout the body and the clinical outcomes of each infection type. The development of therapeutics targeting the S. aureus host-pathogen interaction is a relatively understudied area. Due to the increasing global threat of antimicrobial resistance, it is crucial that innovative and alternative approaches are considered. Neutralizing virulence factors, through the development of antivirulence agents, could reduce bacterial pathogenicity and the ever-increasing burden of S. aureus infections. This review provides insight into potentially efficacious adhesion-associated targets for the development of novel decolonizing and antivirulence strategies.
Collapse
Affiliation(s)
- Kirsten A Berry
- Department of Molecular and Cellular Biology, College of Biological Sciences, University of Guelph, Guelph, Ontario, Canada
| | - Mackenzie T A Verhoef
- Department of Molecular and Cellular Biology, College of Biological Sciences, University of Guelph, Guelph, Ontario, Canada
| | - Allison C Leonard
- Department of Molecular and Cellular Biology, College of Biological Sciences, University of Guelph, Guelph, Ontario, Canada
| | - Georgina Cox
- Department of Molecular and Cellular Biology, College of Biological Sciences, University of Guelph, Guelph, Ontario, Canada
| |
Collapse
|
28
|
Wang M, Buist G, van Dijl JM. Staphylococcus aureus cell wall maintenance - the multifaceted roles of peptidoglycan hydrolases in bacterial growth, fitness, and virulence. FEMS Microbiol Rev 2022; 46:6604383. [PMID: 35675307 PMCID: PMC9616470 DOI: 10.1093/femsre/fuac025] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Revised: 04/22/2022] [Accepted: 05/25/2022] [Indexed: 01/07/2023] Open
Abstract
Staphylococcus aureus is an important human and livestock pathogen that is well-protected against environmental insults by a thick cell wall. Accordingly, the wall is a major target of present-day antimicrobial therapy. Unfortunately, S. aureus has mastered the art of antimicrobial resistance, as underscored by the global spread of methicillin-resistant S. aureus (MRSA). The major cell wall component is peptidoglycan. Importantly, the peptidoglycan network is not only vital for cell wall function, but it also represents a bacterial Achilles' heel. In particular, this network is continuously opened by no less than 18 different peptidoglycan hydrolases (PGHs) encoded by the S. aureus core genome, which facilitate bacterial growth and division. This focuses attention on the specific functions executed by these enzymes, their subcellular localization, their control at the transcriptional and post-transcriptional levels, their contributions to staphylococcal virulence and their overall importance in bacterial homeostasis. As highlighted in the present review, our understanding of the different aspects of PGH function in S. aureus has been substantially increased over recent years. This is important because it opens up new possibilities to exploit PGHs as innovative targets for next-generation antimicrobials, passive or active immunization strategies, or even to engineer them into effective antimicrobial agents.
Collapse
Affiliation(s)
- Min Wang
- Department of Medical Microbiology, University of Groningen, University Medical Center Groningen, Hanzeplein 1, PO Box 30001, 9700 RB Groningen, the Netherlands
| | | | - Jan Maarten van Dijl
- Corresponding author: Department of Medical Microbiology, University of Groningen, University Medical Center Groningen, Hanzeplein 1, P.O. box 30001, HPC EB80, 9700 RB Groningen, the Netherlands, Tel. +31-50-3615187; Fax. +31-50-3619105; E-mail:
| |
Collapse
|
29
|
Flores-Kim J, Dobihal GS, Bernhardt TG, Rudner DZ. WhyD tailors surface polymers to prevent premature bacteriolysis and direct cell elongation in Streptococcus pneumoniae. eLife 2022; 11:76392. [PMID: 35593695 PMCID: PMC9208761 DOI: 10.7554/elife.76392] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Accepted: 05/19/2022] [Indexed: 11/30/2022] Open
Abstract
Penicillin and related antibiotics disrupt cell wall synthesis in bacteria causing the downstream misactivation of cell wall hydrolases called autolysins to induce cell lysis. Despite the clinical importance of this phenomenon, little is known about the factors that control autolysins and how penicillins subvert this regulation to kill cells. In the pathogen Streptococcus pneumoniae (Sp), LytA is the major autolysin responsible for penicillin-induced bacteriolysis. We recently discovered that penicillin treatment of Sp causes a dramatic shift in surface polymer biogenesis in which cell wall-anchored teichoic acids (WTAs) increase in abundance at the expense of lipid-linked teichoic acids (LTAs). Because LytA binds to both species of teichoic acids, this change recruits the enzyme to its substrate where it cleaves the cell wall and elicits lysis. In this report, we identify WhyD (SPD_0880) as a new factor that controls the level of WTAs in Sp cells to prevent LytA misactivation and lysis during exponential growth . We show that WhyD is a WTA hydrolase that restricts the WTA content of the wall to areas adjacent to active peptidoglycan (PG) synthesis. Our results support a model in which the WTA tailoring activity of WhyD during exponential growth directs PG remodeling activity required for proper cell elongation in addition to preventing autolysis by LytA.
Collapse
Affiliation(s)
- Josué Flores-Kim
- Department of Microbiology, Harvard Medical School, Boston, United States
| | | | - Thomas G Bernhardt
- Department of Microbiology, Howard Hughes Medical Institute, Harvard Medical School, Boston, United States
| | - David Z Rudner
- Department of Microbiology, Harvard Medical School, Boston, United States
| |
Collapse
|
30
|
Harden MM, Anderson ME, Grossman AD. A
CRISPR
interference screen reveals a role for cell wall teichoic acids in conjugation in
Bacillus subtilis. Mol Microbiol 2022; 117:1366-1383. [PMID: 35490406 PMCID: PMC9324163 DOI: 10.1111/mmi.14914] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Revised: 04/19/2022] [Accepted: 04/27/2022] [Indexed: 11/30/2022]
Abstract
Conjugative elements are widespread in bacteria and include plasmids and integrative and conjugative elements (ICEs). They transfer from donor to recipient cells via an element‐encoded type IV secretion system. These elements interact with and utilize host functions for their lifecycles. We sought to identify essential host genes involved in the lifecycle of the integrative and conjugative element ICEBs1 of Bacillus subtilis. We constructed a library of strains for inducible knockdown of essential B. subtilis genes using CRISPR interference. Each strain expressed one guide RNA in ICEBs1. We induced partial interference of essential genes and identified those that caused an acute defect in acquisition of ICEBs1 by recipient cells. This screen revealed that reducing expression of genes needed for synthesis of cell wall teichoic acids caused a decrease in conjugation. Using three different ways to reduce their synthesis, we found that wall teichoic acids were necessary in both donors and recipients for efficient conjugative transfer of ICEBs1. Further, we found that depletion of wall teichoic acids caused cells involved in ICEBs1 conjugation to die, most likely from damage to the cell envelope. Our results indicate that wall teichoic acids help protect against envelope stress caused by active conjugation machines.
Collapse
Affiliation(s)
- M. Michael Harden
- Department of Biology Massachusetts Institute of Technology Cambridge, MA 02139
| | - Mary E. Anderson
- Department of Biology Massachusetts Institute of Technology Cambridge, MA 02139
| | - Alan D. Grossman
- Department of Biology Massachusetts Institute of Technology Cambridge, MA 02139
| |
Collapse
|
31
|
Ledger EVK, Mesnage S, Edwards AM. Human serum triggers antibiotic tolerance in Staphylococcus aureus. Nat Commun 2022; 13:2041. [PMID: 35440121 PMCID: PMC9018823 DOI: 10.1038/s41467-022-29717-3] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Accepted: 03/30/2022] [Indexed: 12/13/2022] Open
Abstract
Staphylococcus aureus frequently causes infections that are challenging to treat, leading to high rates of persistent and relapsing infection. Here, to understand how the host environment influences treatment outcomes, we study the impact of human serum on staphylococcal antibiotic susceptibility. We show that serum triggers a high degree of tolerance to the lipopeptide antibiotic daptomycin and several other classes of antibiotic. Serum-induced daptomycin tolerance is due to two independent mechanisms. Firstly, the host defence peptide LL-37 induces tolerance by triggering the staphylococcal GraRS two-component system, leading to increased peptidoglycan accumulation. Secondly, GraRS-independent increases in membrane cardiolipin abundance are required for full tolerance. When both mechanisms are blocked, S. aureus incubated in serum is as susceptible to daptomycin as when grown in laboratory media. Our work demonstrates that host factors can significantly modulate antibiotic susceptibility via diverse mechanisms, and combination therapy may provide a way to mitigate this.
Collapse
Affiliation(s)
- Elizabeth V K Ledger
- MRC Centre for Molecular Bacteriology and Infection, Imperial College London, Armstrong Rd, London, SW7 2AZ, UK
| | - Stéphane Mesnage
- School of Biosciences, University of Sheffield, Sheffield, S10 2TN, UK
| | - Andrew M Edwards
- MRC Centre for Molecular Bacteriology and Infection, Imperial College London, Armstrong Rd, London, SW7 2AZ, UK.
| |
Collapse
|
32
|
The Major Autolysin Atl Regulates the Virulence of Staphylococcus aureus by Controlling the Sorting of LukAB. Infect Immun 2022; 90:e0005622. [PMID: 35258336 PMCID: PMC9022505 DOI: 10.1128/iai.00056-22] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Infections caused by the Gram-positive bacterium Staphylococcus aureus remain a significant health threat globally. The production of bicomponent pore-forming leukocidins plays an important role in S. aureus pathogenesis. Transcriptionally, these toxins are primarily regulated by the Sae and Agr regulatory systems. However, the posttranslational regulation of these toxins is largely unexplored. In particular, one of the leukocidins, LukAB, has been shown to be both secreted into the extracellular milieu and associated with the bacterial cell envelope. Here, we report that a major cell wall hydrolase, autolysin (Atl), controls the sorting of LukAB from the cell envelope to the extracellular milieu, an effect independent of transcriptional regulation. By influencing the sorting of LukAB, Atl modulates S. aureus cytotoxicity toward primary human neutrophils. Mechanistically, we found that the reduction in peptidoglycan cleavage and increased LukAB secretion in the atl mutant can be reversed through the supplementation of exogenous mutanolysin. Altogether, our study revealed that the cell wall hydrolase activity of Atl and the cleavage of peptidoglycan play an important role in controlling the sorting of S. aureus toxins during secretion.
Collapse
|
33
|
Elasnin Effectively Eradicates Daptomycin-Resistant Methicillin-Resistant Staphylococcus aureus Biofilms. Microbiol Spectr 2022; 10:e0232021. [PMID: 35196789 PMCID: PMC8865424 DOI: 10.1128/spectrum.02320-21] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Elasnin is a recently reported antibiofilm agent that is effective against Gram-positive bacteria including methicillin-resistant Staphylococcus aureus (MRSA). Remarkably, we observed that elasnin has a superior activity in eradicating daptomycin-resistant MRSA strain biofilm, with a lower minimum biofilm eradication concentration (MBEC) value of 0.625 μg/mL, compared to 2.5 μg/mL for the wild type. Confocal microscopy further confirmed the higher biofilm eradication on the daptomycin-resistant strain, displaying ∼53% decrease in cell density upon elasnin treatment, while the wild-type strain was only decreased by ∼15%. Quantitative proteomics revealed that the daptomycin-resistant strain has a lower expression of the membrane, cell wall, and extracellular proteins, and also proteins involved in the arginine biosynthesis, pathogenesis, and cell adhesion compared to the wild type, which may result in weaker biofilm development. This study highlights the potential clinical application of elasnin through its superior biofilm eradication activity against a daptomycin-resistant MRSA strain, and revealed the associated processes governing this superior activity through proteomics analysis. IMPORTANCE Due to the increased use of daptomycin for the treatment of MRSA infections, the emergence of daptomycin-resistant strains has become prevalent in recent years. In this study, we discovered that elasnin, a newly reported antibiofilm compound, has a superior activity in eradicating daptomycin-resistant MRSA strain biofilms compared to the wild type. Follow-up analysis revealed the reason behind this superior activity, which is the lower expression of key proteins that play a role in pathogenesis and cell adhesion in the daptomycin-resistant strain, leading to weaker biofilm development. This showcases the potential use of elasnin in clinical settings where daptomycin-resistant strains and biofilm formation are prevalent. Altogether, our study provides new insights into the mechanism of elasnin in MRSA biofilm cells and identified its superior biofilm eradicating activity in the daptomycin-resistant strain.
Collapse
|
34
|
Species-Scale Genomic Analysis of Staphylococcus aureus Genes Influencing Phage Host Range and Their Relationships to Virulence and Antibiotic Resistance Genes. mSystems 2022; 7:e0108321. [PMID: 35040700 PMCID: PMC8765062 DOI: 10.1128/msystems.01083-21] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Phage therapy has been proposed as a possible alternative treatment for infections caused by the ubiquitous bacterial pathogen Staphylococcus aureus. However, successful therapy requires understanding the genetic basis of host range—the subset of strains in a species that could be killed by a particular phage. We searched diverse sets of S. aureus public genome sequences against a database of genes suggested from prior studies to influence host range to look for patterns of variation across the species. We found that genes encoding biosynthesis of molecules that were targets of S. aureus phage adsorption to the outer surface of the cell were the most conserved in the pangenome. Putative phage resistance genes that were core components of the pangenome genes had similar nucleotide diversity, ratio of nonsynonymous to synonymous substitutions, and functionality (measured by delta-bitscore) to other core genes. However, phage resistance genes that were not part of the core genome were significantly less consistent with the core genome phylogeny than all noncore genes in this set, suggesting more frequent movement between strains by horizontal gene transfer. Only superinfection immunity genes encoded by temperate phages inserted in the genome correlated with experimentally determined temperate phage resistance. Taken together, these results suggested that, while phage adsorption genes are heavily conserved in the S. aureus species, HGT may play a significant role in strain-specific evolution of host range patterns. IMPORTANCEStaphylococcus aureus is a widespread, hospital- and community-acquired pathogen that is commonly antibiotic resistant. It causes diverse diseases affecting both the skin and internal organs. Its ubiquity, antibiotic resistance, and disease burden make new therapies urgent, such as phage therapy, in which viruses specific to infecting bacteria clear infection. S. aureus phage host range not only determines whether phage therapy will be successful by killing bacteria but also horizontal gene transfer through transduction of host genetic material by phages. In this work, we comprehensively reviewed existing literature to build a list of S. aureus phage resistance genes and searched our database of almost 43,000 S. aureus genomes for these genes to understand their patterns of evolution, finding that prophages’ superinfection immunity correlates best with phage resistance and HGT. These findings improved our understanding of the relationship between known phage resistance genes and phage host range in the species.
Collapse
|
35
|
Wassmann CS, Rolsted AP, Lyngsie MC, Puig ST, Kronborg T, Vestergaard M, Ingmer H, Pontoppidan SP, Klitgaard JK. The menaquinone pathway is important for susceptibility of Staphylococcus aureus to the antibiotic adjuvant, cannabidiol. Microbiol Res 2022; 257:126974. [DOI: 10.1016/j.micres.2022.126974] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Revised: 01/14/2022] [Accepted: 01/17/2022] [Indexed: 01/12/2023]
|
36
|
THCz: Small molecules with antimicrobial activity that block cell wall lipid intermediates. Proc Natl Acad Sci U S A 2021; 118:2108244118. [PMID: 34785593 PMCID: PMC8617507 DOI: 10.1073/pnas.2108244118] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/05/2021] [Indexed: 11/18/2022] Open
Abstract
Considering the alarming emergence of resistance to most antibiotics and the need for new antibiotics, the finding here of a small-molecule class, THCz, that displayed bactericidal activity against gram-positive and selected gram-negative bacteria, is of the greatest importance. We found that THCz target the cell envelope synthesis and can easily be synthesized and modified, and resistance did not readily develop in vitro. Thus, THCz are promising scaffolds for development of bacterial cell wall inhibitors. Emerging antibiotic resistance demands identification of novel antibacterial compound classes. A bacterial whole-cell screen based on pneumococcal autolysin-mediated lysis induction was developed to identify potential bacterial cell wall synthesis inhibitors. A hit class comprising a 1-amino substituted tetrahydrocarbazole (THCz) scaffold, containing two essential amine groups, displayed bactericidal activity against a broad range of gram-positive and selected gram-negative pathogens in the low micromolar range. Mode of action studies revealed that THCz inhibit cell envelope synthesis by targeting undecaprenyl pyrophosphate–containing lipid intermediates and thus simultaneously inhibit peptidoglycan, teichoic acid, and polysaccharide capsule biosynthesis. Resistance did not readily develop in vitro, and the ease of synthesizing and modifying these small molecules, as compared to natural lipid II–binding antibiotics, makes THCz promising scaffolds for development of cell wall–targeting antimicrobials.
Collapse
|
37
|
Spengler C, Nolle F, Thewes N, Wieland B, Jung P, Bischoff M, Jacobs K. Using Knock-Out Mutants to Investigate the Adhesion of Staphylococcus aureus to Abiotic Surfaces. Int J Mol Sci 2021; 22:11952. [PMID: 34769382 PMCID: PMC8584566 DOI: 10.3390/ijms222111952] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2021] [Revised: 10/29/2021] [Accepted: 10/30/2021] [Indexed: 12/19/2022] Open
Abstract
The adhesion of Staphylococcus aureus to abiotic surfaces is crucial for establishing device-related infections. With a high number of single-cell force spectroscopy measurements with genetically modified S. aureus cells, this study provides insights into the adhesion process of the pathogen to abiotic surfaces of different wettability. Our results show that S. aureus utilizes different cell wall molecules and interaction mechanisms when binding to hydrophobic and hydrophilic surfaces. We found that covalently bound cell wall proteins strongly interact with hydrophobic substrates, while their contribution to the overall adhesion force is smaller on hydrophilic substrates. Teichoic acids promote adhesion to hydrophobic surfaces as well as to hydrophilic surfaces. This, however, is to a lesser extent. An interplay of electrostatic effects of charges and protein composition on bacterial surfaces is predominant on hydrophilic surfaces, while it is overshadowed on hydrophobic surfaces by the influence of the high number of binding proteins. Our results can help to design new models of bacterial adhesion and may be used to interpret the adhesion of other microorganisms with similar surface properties.
Collapse
Affiliation(s)
- Christian Spengler
- Experimental Physics and Center for Biophysics, Saarland University, 66123 Saarbrücken, Germany; (C.S.); (F.N.); (N.T.)
| | - Friederike Nolle
- Experimental Physics and Center for Biophysics, Saarland University, 66123 Saarbrücken, Germany; (C.S.); (F.N.); (N.T.)
| | - Nicolas Thewes
- Experimental Physics and Center for Biophysics, Saarland University, 66123 Saarbrücken, Germany; (C.S.); (F.N.); (N.T.)
| | - Ben Wieland
- Institute of Medical Microbiology and Hygiene and Center for Biophysics, Saarland University, 66421 Homburg, Germany; (B.W.); (P.J.); (M.B.)
| | - Philipp Jung
- Institute of Medical Microbiology and Hygiene and Center for Biophysics, Saarland University, 66421 Homburg, Germany; (B.W.); (P.J.); (M.B.)
| | - Markus Bischoff
- Institute of Medical Microbiology and Hygiene and Center for Biophysics, Saarland University, 66421 Homburg, Germany; (B.W.); (P.J.); (M.B.)
| | - Karin Jacobs
- Experimental Physics and Center for Biophysics, Saarland University, 66123 Saarbrücken, Germany; (C.S.); (F.N.); (N.T.)
- Max Planck School Matter to Life, Jahnstraße 29, 69120 Heidelberg, Germany
| |
Collapse
|
38
|
Demonstration of the role of cell wall homeostasis in Staphylococcus aureus growth and the action of bactericidal antibiotics. Proc Natl Acad Sci U S A 2021; 118:2106022118. [PMID: 34716264 PMCID: PMC8612353 DOI: 10.1073/pnas.2106022118] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Accepted: 09/02/2021] [Indexed: 12/29/2022] Open
Abstract
Bacterial cell wall peptidoglycan is essential, maintaining both cellular integrity and morphology, in the face of internal turgor pressure. Peptidoglycan synthesis is important, as it is targeted by cell wall antibiotics, including methicillin and vancomycin. Here, we have used the major human pathogen Staphylococcus aureus to elucidate both the cell wall dynamic processes essential for growth (life) and the bactericidal effects of cell wall antibiotics (death) based on the principle of coordinated peptidoglycan synthesis and hydrolysis. The death of S. aureus due to depletion of the essential, two-component and positive regulatory system for peptidoglycan hydrolase activity (WalKR) is prevented by addition of otherwise bactericidal cell wall antibiotics, resulting in stasis. In contrast, cell wall antibiotics kill via the activity of peptidoglycan hydrolases in the absence of concomitant synthesis. Both methicillin and vancomycin treatment lead to the appearance of perforating holes throughout the cell wall due to peptidoglycan hydrolases. Methicillin alone also results in plasmolysis and misshapen septa with the involvement of the major peptidoglycan hydrolase Atl, a process that is inhibited by vancomycin. The bactericidal effect of vancomycin involves the peptidoglycan hydrolase SagB. In the presence of cell wall antibiotics, the inhibition of peptidoglycan hydrolase activity using the inhibitor complestatin results in reduced killing, while, conversely, the deregulation of hydrolase activity via loss of wall teichoic acids increases the death rate. For S. aureus, the independent regulation of cell wall synthesis and hydrolysis can lead to cell growth, death, or stasis, with implications for the development of new control regimes for this important pathogen.
Collapse
|
39
|
Hort M, Bertsche U, Nozinovic S, Dietrich A, Schrötter AS, Mildenberger L, Axtmann K, Berscheid A, Bierbaum G. The Role of β-Glycosylated Wall Teichoic Acids in the Reduction of Vancomycin Susceptibility in Vancomycin-Intermediate Staphylococcus aureus. Microbiol Spectr 2021; 9:e0052821. [PMID: 34668723 PMCID: PMC8528128 DOI: 10.1128/spectrum.00528-21] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Accepted: 09/12/2021] [Indexed: 11/20/2022] Open
Abstract
Staphylococcus aureus is an opportunistic pathogen that causes a wide range of infections. Due to the rapid evolution of antibiotic resistance that leads to treatment failure, it is important to understand the underlying mechanisms. Here, the cell wall structures of several laboratory vancomycin-intermediate S. aureus (VISA) strains were analyzed. Among the VISA strains were S. aureus VC40, which accumulated 79 mutations, including most importantly 2 exchanges in the histidine-kinase VraS, and developed full resistance against vancomycin (MIC, 64 μg/ml); a revertant S. aureus VC40R, which has an additional mutation in vraR (MIC, 4 μg/ml); and S. aureus VraS(VC40), in which the 2 vraS mutations were reconstituted into a susceptible background (MIC, 4 μg/ml). A ultraperformance liquid chromatography (UPLC) analysis showed that S. aureus VC40 had a significantly decreased cross-linking of the peptidoglycan. Both S. aureus VC40 and S. aureus VraS(VC40) displayed reduced autolysis and an altered autolysin profile in a zymogram. Most striking was the significant increase in d-alanine and N-acetyl-d-glucosamine (GlcNAc) substitution of the wall teichoic acids (WTAs) in S. aureus VC40. Nuclear magnetic resonance (NMR) analysis revealed that this strain had mostly β-glycosylated WTAs in contrast to the other strains, which showed only the α-glycosylation peak. Salt stress induced the incorporation of β-GlcNAc anomers and drastically increased the vancomycin MIC for S. aureus VC40R. In addition, β-glycosylated WTAs decreased the binding affinity of AtlA, the major autolysin of S. aureus, to the cell wall, compared with α-glycosylated WTAs. In conclusion, there is a novel connection between wall teichoic acids, autolysis, and vancomycin susceptibility in S. aureus. IMPORTANCE Infections with methicillin-resistant Staphylococcus aureus are commonly treated with vancomycin. This antibiotic inhibits cell wall biosynthesis by binding to the cell wall building block lipid II. We set out to characterize the mechanisms leading to decreased vancomycin susceptibility in a laboratory-generated strain, S. aureus VC40. This strain has an altered cell wall architecture with a thick cell wall with low cross-linking, which provides decoy binding sites for vancomycin. The low cross-linking, necessary for this resistance mechanism, decreases the stability of the cell wall against lytic enzymes, which separate the daughter cells. Protection against these enzymes is provided by another cell wall polymer, the teichoic acids, which contain an unusually high substitution with sugars in the β-conformation. By experimentally increasing the proportion of β-N-acetyl-d-glucosamine in a closely related isolate through the induction of salt stress, we could show that the β-conformation of the sugars plays a vital role in the resistance of S. aureus VC40.
Collapse
Affiliation(s)
- Michael Hort
- Institute of Medical Microbiology, Immunology and Parasitology, University Clinics of Bonn, Bonn, Germany
| | - Ute Bertsche
- Department of Infection Biology, University of Tuebingen, Tuebingen, Germany
| | | | - Alina Dietrich
- Institute of Medical Microbiology, Immunology and Parasitology, University Clinics of Bonn, Bonn, Germany
| | - Anne Sophie Schrötter
- Institute of Medical Microbiology, Immunology and Parasitology, University Clinics of Bonn, Bonn, Germany
| | - Laura Mildenberger
- Institute of Medical Microbiology, Immunology and Parasitology, University Clinics of Bonn, Bonn, Germany
| | - Katharina Axtmann
- Institute of Medical Microbiology, Immunology and Parasitology, University Clinics of Bonn, Bonn, Germany
| | - Anne Berscheid
- Institute of Medical Microbiology, Immunology and Parasitology, University Clinics of Bonn, Bonn, Germany
| | - Gabriele Bierbaum
- Institute of Medical Microbiology, Immunology and Parasitology, University Clinics of Bonn, Bonn, Germany
| |
Collapse
|
40
|
The cell envelope of Staphylococcus aureus selectively controls the sorting of virulence factors. Nat Commun 2021; 12:6193. [PMID: 34702812 PMCID: PMC8548510 DOI: 10.1038/s41467-021-26517-z] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Accepted: 10/05/2021] [Indexed: 11/08/2022] Open
Abstract
Staphylococcus aureus bi-component pore-forming leukocidins are secreted toxins that directly target and lyse immune cells. Intriguingly, one of the leukocidins, Leukocidin AB (LukAB), is found associated with the bacterial cell envelope in addition to secreted into the extracellular milieu. Here, we report that retention of LukAB on the bacterial cells provides S. aureus with a pre-synthesized active toxin that kills immune cells. On the bacteria, LukAB is distributed as discrete foci in two distinct compartments: membrane-proximal and surface-exposed. Through genetic screens, we show that a membrane lipid, lysyl-phosphatidylglycerol (LPG), and lipoteichoic acid (LTA) contribute to LukAB deposition and release. Furthermore, by studying non-covalently surface-bound proteins we discovered that the sorting of additional exoproteins, such as IsaB, Hel, ScaH, and Geh, are also controlled by LPG and LTA. Collectively, our study reveals a multistep secretion system that controls exoprotein storage and protein translocation across the S. aureus cell wall.
Collapse
|
41
|
Wysocka A, Jagielska E, Łężniak Ł, Sabała I. Two New M23 Peptidoglycan Hydrolases With Distinct Net Charge. Front Microbiol 2021; 12:719689. [PMID: 34630350 PMCID: PMC8498115 DOI: 10.3389/fmicb.2021.719689] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Accepted: 08/16/2021] [Indexed: 11/13/2022] Open
Abstract
Bacterial peptidoglycan hydrolases play an essential role in cell wall metabolism during bacterial growth, division, and elongation (autolysins) or in the elimination of closely related species from the same ecological niche (bacteriocins). Most studies concerning the peptidoglycan hydrolases present in Gram-positive bacteria have focused on clinically relevant Staphylococcus aureus or the model organism Bacillus subtilis, while knowledge relating to other species remains limited. Here, we report two new peptidoglycan hydrolases from the M23 family of metallopeptidases derived from the same staphylococcal species, Staphylococcus pettenkoferi. They share modular architecture, significant sequence identity (60%), catalytic and binding residue conservation, and similar modes of activation, but differ in gene distribution, putative biological role, and, strikingly, in their isoelectric points (pIs). One of the peptides has a high pI, similar to that reported for all M23 peptidases evaluated to date, whereas the other displays a low pI, a unique feature among M23 peptidases. Consequently, we named them SpM23_B (Staphylococcus pettenkoferi M23 "Basic") and SpM23_A (Staphylococcus pettenkoferi M23 "Acidic"). Using genetic and biochemical approaches, we have characterized these two novel lytic enzymes, both in vitro and in their physiological context. Our study presents a detailed characterization of two novel and clearly distinct peptidoglycan hydrolases to understand their role in bacterial physiology.
Collapse
Affiliation(s)
- Alicja Wysocka
- International Institute of Molecular and Cell Biology in Warsaw, Warsaw, Poland
| | - Elżbieta Jagielska
- International Institute of Molecular and Cell Biology in Warsaw, Warsaw, Poland
| | - Łukasz Łężniak
- International Institute of Molecular and Cell Biology in Warsaw, Warsaw, Poland
| | - Izabela Sabała
- International Institute of Molecular and Cell Biology in Warsaw, Warsaw, Poland
| |
Collapse
|
42
|
Suresh MK, Vasudevan AK, Biswas L, Biswas R. Protective efficacy of Alum adjuvanted Amidase protein vaccine against Staphylococcus aureus infection in multiple mouse models. J Appl Microbiol 2021; 132:1422-1434. [PMID: 34487603 DOI: 10.1111/jam.15291] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2021] [Revised: 08/05/2021] [Accepted: 08/23/2021] [Indexed: 12/20/2022]
Abstract
AIMS Staphylococcus aureus is an opportunistic pathogen of humans. No commercial vaccine is available to combat S. aureus infections. In this study, we have investigated the protective immune response generated by S. aureus non-covalently associated cell wall surface protein N-acetylmuramoyl-L-alanine amidase (AM) in combination with Alum (Al) and heat-killed S. aureus (hkSA) using murine models. METHODS AND RESULTS BALB/c mice were immunized with increasing concentrations of AM antigen or hkSA to determine their optimum concentration for vaccination. Fifty micrograms of AM and hkSA each were found to generate maximum anti-AM IgG antibody production. BALB/c mice were immunized next with 50 µg of AM, 50 µg of hKSA and 1 mg Al vaccine formulation. Vaccine efficacy was validated by challenging immunized BALB/c mice with S. aureus Newman and three clinical methicillin-resistant S. aureus strains. AM-hkSA-Al-immunized mice generated high anti-AM IgG antibody response with IgG1 and IgG2b as the predominant immunoglobulin subtypes. Increased survival (60%-90%) with decreased clinical disease symptoms was observed in the vaccinated BALB/c mice group. A significantly lower bacterial load and decreased kidney abscess formation was observed following the challenge with S. aureus in the vaccinated BALB/c mice group. Furthermore, the efficacy of AM-hkSA-Al vaccine was also validated using C57 BL/6 and Swiss albino mice. CONCLUSIONS Using murine infection models, we have demonstrated that AM-hkSA-Al vaccine would be effective in preventing S. aureus infections. SIGNIFICANCE AND IMPACT OF STUDY AM-hkSA-Al vaccine elicited strong immune response and may be considered for future vaccine design against S. aureus infections.
Collapse
Affiliation(s)
- Maneesha K Suresh
- Center for Nanosciences and Molecular Medicine, Amrita Vishwa Vidyapeetham, Kochi, India
| | - Anil Kumar Vasudevan
- Department of Microbiology, Amrita Institute of Medical Sciences and Research Center, Amrita Vishwa Vidyapeetham, AIMS - Ponekkara, Cochin, India
| | - Lalitha Biswas
- Center for Nanosciences and Molecular Medicine, Amrita Vishwa Vidyapeetham, Kochi, India
| | - Raja Biswas
- Center for Nanosciences and Molecular Medicine, Amrita Vishwa Vidyapeetham, Kochi, India
| |
Collapse
|
43
|
Wang M, Li Z, Zhang Y, Li Y, Li N, Huang D, Xu B. Interaction with teichoic acids contributes to highly effective antibacterial activity of graphene oxide on Gram-positive bacteria. JOURNAL OF HAZARDOUS MATERIALS 2021; 412:125333. [PMID: 33951879 DOI: 10.1016/j.jhazmat.2021.125333] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Revised: 02/02/2021] [Accepted: 02/03/2021] [Indexed: 05/20/2023]
Abstract
Graphene oxide (GO) has high-efficient antibacterial activity to diverse pathogenic bacteria. However, the detailed antibacterial mechanism of GO is not fully clear. Herein the antibacterial properties of GO against model Gram-positive (Gram+) (Staphylococcus aureus and Staphylococcus epidermidis) and Gram-negative (Gram-) bacteria (Pseudomonas aeruginosa and Escherichia coli) were compared by plate count method. Results showed that 4 mg/L of GO induced the mortality of Gram+ and Gram- bacteria by > 99% and < 25%, respectively. GO had greater adsorption affinity to teichoic acids, the unique components existing in the cell wall of Gram+ bacteria, mainly via π-π interaction. The adsorption efficiency of teichoic acids was 27 times higher than that of peptidoglycan when they were simultaneously exposed to 100 mg/L GO. The superior adsorption of teichoic acids onto GO increased one order of magnitude of atlA expression, the autolysin related gene. As a result, these accelerated bacterial death by hydrolyzing peptidoglycan in cell walls. Exogenous addition of 50 mg/L teichoic acids could impair 4-5 fold of antibacterial activity of GO against S. aureus. These new findings illuminate the antibacterial mechanism of GO against Gram+ bacteria, which paves the way for the further application of graphene-based materials in water disinfection and pathogen control.
Collapse
Affiliation(s)
- Meizhen Wang
- School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou 310012, China; Zhejiang Provincial Key Laboratory of Solid Waste Treatment and Recycling, Hangzhou 310012, China
| | - Zhangqiang Li
- School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou 310012, China; Zhejiang Provincial Key Laboratory of Solid Waste Treatment and Recycling, Hangzhou 310012, China
| | - Yunyun Zhang
- School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou 310012, China
| | - Yue Li
- School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou 310012, China
| | - Na Li
- School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou 310012, China
| | - Dan Huang
- School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou 310012, China; Zhejiang Provincial Key Laboratory of Solid Waste Treatment and Recycling, Hangzhou 310012, China.
| | - Baile Xu
- Institut für Biologie, Freie Universität Berlin, Berlin D-14195, Germany
| |
Collapse
|
44
|
Bæk KT, Jensen C, Farha MA, Nielsen TK, Paknejadi E, Mebus VH, Vestergaard M, Brown ED, Frees D. A Staphylococcus aureus clpX Mutant Used as a Unique Screening Tool to Identify Cell Wall Synthesis Inhibitors that Reverse β-Lactam Resistance in MRSA. Front Mol Biosci 2021; 8:691569. [PMID: 34150853 PMCID: PMC8212132 DOI: 10.3389/fmolb.2021.691569] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Accepted: 05/14/2021] [Indexed: 11/17/2022] Open
Abstract
Staphylococcus aureus is a leading cause of bacterial infections world-wide. Staphylococcal infections are preferentially treated with β-lactam antibiotics, however, methicillin-resistant S. aureus (MRSA) strains have acquired resistance to this superior class of antibiotics. We have developed a growth-based, high-throughput screening approach that directly identifies cell wall synthesis inhibitors capable of reversing β-lactam resistance in MRSA. The screen is based on the finding that S. aureus mutants lacking the ClpX chaperone grow very poorly at 30°C unless specific steps in teichoic acid synthesis or penicillin binding protein (PBP) activity are inhibited. This property allowed us to exploit the S. aureus clpX mutant as a unique screening tool to rapidly identify biologically active compounds that target cell wall synthesis. We tested a library of ∼50,000 small chemical compounds and searched for compounds that inhibited growth of the wild type while stimulating growth of the clpX mutant. Fifty-eight compounds met these screening criteria, and preliminary tests of 10 compounds identified seven compounds that reverse β-lactam resistance of MRSA as expected for inhibitors of teichoic acid synthesis. The hit compounds are therefore promising candidates for further development as novel combination agents to restore β-lactam efficacy against MRSA.
Collapse
Affiliation(s)
- Kristoffer T Bæk
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Camilla Jensen
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Maya A Farha
- Department of Biochemistry and Biomedical Sciences, Michael G. DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, ON, Canada
| | - Tobias K Nielsen
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Ervin Paknejadi
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Viktor H Mebus
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Martin Vestergaard
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Eric D Brown
- Department of Biochemistry and Biomedical Sciences, Michael G. DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, ON, Canada
| | - Dorte Frees
- Department of Veterinary and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| |
Collapse
|
45
|
Zamakhaeva S, Chaton CT, Rush JS, Ajay Castro S, Kenner CW, Yarawsky AE, Herr AB, van Sorge NM, Dorfmueller HC, Frolenkov GI, Korotkov KV, Korotkova N. Modification of cell wall polysaccharide guides cell division in Streptococcus mutans. Nat Chem Biol 2021; 17:878-887. [PMID: 34045745 DOI: 10.1038/s41589-021-00803-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2020] [Accepted: 04/21/2021] [Indexed: 02/07/2023]
Abstract
In ovoid-shaped, Gram-positive bacteria, MapZ guides FtsZ-ring positioning at cell equators. The cell wall of the ovococcus Streptococcus mutans contains peptidoglycan decorated with serotype c carbohydrates (SCCs). In the present study, we identify the major cell separation autolysin AtlA as an SCC-binding protein. AtlA binding to SCC is attenuated by the glycerol phosphate (GroP) modification. Using fluorescently labeled AtlA constructs, we mapped SCC distribution on the streptococcal surface, revealing enrichment of GroP-deficient immature SCCs at the cell poles and equators. The immature SCCs co-localize with MapZ at the equatorial rings throughout the cell cycle. In GroP-deficient mutants, AtlA is mislocalized, resulting in dysregulated cellular autolysis. These mutants display morphological abnormalities associated with MapZ mislocalization, leading to FtsZ-ring misplacement. Altogether, our data support a model in which maturation of a cell wall polysaccharide provides the molecular cues for the recruitment of cell division machinery, ensuring proper daughter cell separation and FtsZ-ring positioning.
Collapse
Affiliation(s)
- Svetlana Zamakhaeva
- Department of Microbiology, Immunology and Molecular Genetics, University of Kentucky, Lexington, KY, USA
| | - Catherine T Chaton
- Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, KY, USA
| | - Jeffrey S Rush
- Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, KY, USA
| | - Sowmya Ajay Castro
- Division of Molecular Microbiology, School of Life Sciences, University of Dundee, Dundee, UK
| | - Cameron W Kenner
- Department of Microbiology, Immunology and Molecular Genetics, University of Kentucky, Lexington, KY, USA
| | - Alexander E Yarawsky
- Divisions of Immunobiology and Infectious Diseases, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
| | - Andrew B Herr
- Divisions of Immunobiology and Infectious Diseases, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
| | - Nina M van Sorge
- Department of Medical Microbiology and Infection Prevention, Amsterdam University Medical Center, University of Amsterdam, Amsterdam, The Netherlands.,Netherlands Reference Laboratory for Bacterial Meningitis, Amsterdam University Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - Helge C Dorfmueller
- Division of Molecular Microbiology, School of Life Sciences, University of Dundee, Dundee, UK
| | | | - Konstantin V Korotkov
- Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, KY, USA
| | - Natalia Korotkova
- Department of Microbiology, Immunology and Molecular Genetics, University of Kentucky, Lexington, KY, USA. .,Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, KY, USA.
| |
Collapse
|
46
|
Zhang R, Shebes MA, Kho K, Scaffidi SJ, Meredith TC, Yu W. Spatial regulation of protein A in Staphylococcus aureus. Mol Microbiol 2021; 116:589-605. [PMID: 33949015 DOI: 10.1111/mmi.14734] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Revised: 04/29/2021] [Accepted: 04/30/2021] [Indexed: 12/31/2022]
Abstract
Surface proteins of Staphylococcus aureus play vital roles in bacterial physiology and pathogenesis. Recent work suggests that surface proteins are spatially regulated by a YSIRK/GXXS signal peptide that promotes cross-wall targeting at the mid-cell, though the mechanisms remain unclear. We previously showed that protein A (SpA), a YSIRK/GXXS protein and key staphylococcal virulence factor, mis-localizes in a ltaS mutant deficient in lipoteichoic acid (LTA) production. Here, we identified that SpA contains another cross-wall targeting signal, the LysM domain, which, in addition to the YSIRK/GXXS signal peptide, significantly enhances SpA cross-wall targeting. We show that LTA synthesis, but not LtaS, is required for SpA septal anchoring and cross-wall deposition. Interestingly, LTA is predominantly found at the peripheral cell membrane and is diminished at the septum of dividing staphylococcal cells, suggesting a restriction mechanism for SpA septal localization. Finally, we show that D-alanylation of LTA abolishes SpA cross-wall deposition by disrupting SpA distribution in the peptidoglycan layer without altering SpA septal anchoring. Our study reveals that multiple factors contribute to the spatial regulation and cross-wall targeting of SpA via different mechanisms, which coordinately ensures efficient incorporation of surface proteins into the growing peptidoglycan during the cell cycle.
Collapse
Affiliation(s)
- Ran Zhang
- Department of Cell Biology, Microbiology and Molecular Biology (CMMB), University of South Florida, Tampa, FL, USA
| | - Mac A Shebes
- Department of Cell Biology, Microbiology and Molecular Biology (CMMB), University of South Florida, Tampa, FL, USA
| | - Kelvin Kho
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA, USA
| | - Salvatore J Scaffidi
- Department of Cell Biology, Microbiology and Molecular Biology (CMMB), University of South Florida, Tampa, FL, USA
| | - Timothy C Meredith
- Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA, USA
| | - Wenqi Yu
- Department of Cell Biology, Microbiology and Molecular Biology (CMMB), University of South Florida, Tampa, FL, USA
| |
Collapse
|
47
|
Lade H, Kim JS. Bacterial Targets of Antibiotics in Methicillin-Resistant Staphylococcus aureus. Antibiotics (Basel) 2021; 10:398. [PMID: 33917043 PMCID: PMC8067735 DOI: 10.3390/antibiotics10040398] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Revised: 04/02/2021] [Accepted: 04/05/2021] [Indexed: 12/17/2022] Open
Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) is one of the most prevalent bacterial pathogens and continues to be a leading cause of morbidity and mortality worldwide. MRSA is a commensal bacterium in humans and is transmitted in both community and healthcare settings. Successful treatment remains a challenge, and a search for new targets of antibiotics is required to ensure that MRSA infections can be effectively treated in the future. Most antibiotics in clinical use selectively target one or more biochemical processes essential for S. aureus viability, e.g., cell wall synthesis, protein synthesis (translation), DNA replication, RNA synthesis (transcription), or metabolic processes, such as folic acid synthesis. In this review, we briefly describe the mechanism of action of antibiotics from different classes and discuss insights into the well-established primary targets in S. aureus. Further, several components of bacterial cellular processes, such as teichoic acid, aminoacyl-tRNA synthetases, the lipid II cycle, auxiliary factors of β-lactam resistance, two-component systems, and the accessory gene regulator quorum sensing system, are discussed as promising targets for novel antibiotics. A greater molecular understanding of the bacterial targets of antibiotics has the potential to reveal novel therapeutic strategies or identify agents against antibiotic-resistant pathogens.
Collapse
Affiliation(s)
| | - Jae-Seok Kim
- Department of Laboratory Medicine, Kangdong Sacred Heart Hospital, Hallym University College of Medicine, Seoul 05355, Korea;
| |
Collapse
|
48
|
Li FKK, Gale RT, Petrotchenko EV, Borchers CH, Brown ED, Strynadka NCJ. Crystallographic analysis of TarI and TarJ, a cytidylyltransferase and reductase pair for CDP-ribitol synthesis in Staphylococcus aureus wall teichoic acid biogenesis. J Struct Biol 2021; 213:107733. [PMID: 33819634 DOI: 10.1016/j.jsb.2021.107733] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Revised: 03/29/2021] [Accepted: 03/30/2021] [Indexed: 11/18/2022]
Abstract
The cell wall of many pathogenic Gram-positive bacteria contains ribitol-phosphate wall teichoic acid (WTA), a polymer that is linked to virulence and regulation of essential physiological processes including cell division. CDP-ribitol, the activated precursor for ribitol-phosphate polymerization, is synthesized by a cytidylyltransferase and reductase pair known as TarI and TarJ, respectively. In this study, we present crystal structures of Staphylococcus aureus TarI and TarJ in their apo forms and in complex with substrates and products. The TarI structures illustrate the mechanism of CDP-ribitol synthesis from CTP and ribitol-phosphate and reveal structural changes required for substrate binding and catalysis. Insights into the upstream step of ribulose-phosphate reduction to ribitol-phosphate is provided by the structures of TarJ. Furthermore, we propose a general topology of the enzymes in a heterotetrameric form built using restraints from crosslinking mass spectrometry analysis. Together, our data present molecular details of CDP-ribitol production that may aid in the design of inhibitors against WTA biosynthesis.
Collapse
Affiliation(s)
- Franco K K Li
- Department of Biochemistry and Molecular Biology and Centre for Blood Research, The University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada
| | - Robert T Gale
- Department of Biochemistry and Biomedical Sciences, Michael G. DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, Ontario L8N 3ZS, Canada
| | - Evgeniy V Petrotchenko
- Segal Cancer Proteomics Centre, Lady Davis Institute, Jewish General Hospital, McGill University, Montreal, Quebec H3T 1E2, Canada; Center for Computational and Data-Intensive Science and Engineering, Skolkovo Institute of Science and Technology, Moscow 121205, Russia
| | - Christoph H Borchers
- Segal Cancer Proteomics Centre, Lady Davis Institute, Jewish General Hospital, McGill University, Montreal, Quebec H3T 1E2, Canada; Center for Computational and Data-Intensive Science and Engineering, Skolkovo Institute of Science and Technology, Moscow 121205, Russia; Gerald Bronfman Department of Oncology, Jewish General Hospital, McGill University, Montreal, Quebec H3T 1E2, Canada
| | - Eric D Brown
- Department of Biochemistry and Biomedical Sciences, Michael G. DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, Ontario L8N 3ZS, Canada
| | - Natalie C J Strynadka
- Department of Biochemistry and Molecular Biology and Centre for Blood Research, The University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada.
| |
Collapse
|
49
|
Fisher JF, Mobashery S. β-Lactams against the Fortress of the Gram-Positive Staphylococcus aureus Bacterium. Chem Rev 2021; 121:3412-3463. [PMID: 33373523 PMCID: PMC8653850 DOI: 10.1021/acs.chemrev.0c01010] [Citation(s) in RCA: 41] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The biological diversity of the unicellular bacteria-whether assessed by shape, food, metabolism, or ecological niche-surely rivals (if not exceeds) that of the multicellular eukaryotes. The relationship between bacteria whose ecological niche is the eukaryote, and the eukaryote, is often symbiosis or stasis. Some bacteria, however, seek advantage in this relationship. One of the most successful-to the disadvantage of the eukaryote-is the small (less than 1 μm diameter) and nearly spherical Staphylococcus aureus bacterium. For decades, successful clinical control of its infection has been accomplished using β-lactam antibiotics such as the penicillins and the cephalosporins. Over these same decades S. aureus has perfected resistance mechanisms against these antibiotics, which are then countered by new generations of β-lactam structure. This review addresses the current breadth of biochemical and microbiological efforts to preserve the future of the β-lactam antibiotics through a better understanding of how S. aureus protects the enzyme targets of the β-lactams, the penicillin-binding proteins. The penicillin-binding proteins are essential enzyme catalysts for the biosynthesis of the cell wall, and understanding how this cell wall is integrated into the protective cell envelope of the bacterium may identify new antibacterials and new adjuvants that preserve the efficacy of the β-lactams.
Collapse
Affiliation(s)
- Jed F Fisher
- Department of Chemistry and Biochemistry, McCourtney Hall, University of Notre Dame, Notre Dame Indiana 46556, United States
| | - Shahriar Mobashery
- Department of Chemistry and Biochemistry, McCourtney Hall, University of Notre Dame, Notre Dame Indiana 46556, United States
| |
Collapse
|
50
|
Dörr T. Understanding tolerance to cell wall-active antibiotics. Ann N Y Acad Sci 2020; 1496:35-58. [PMID: 33274447 PMCID: PMC8359209 DOI: 10.1111/nyas.14541] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Revised: 11/02/2020] [Accepted: 11/04/2020] [Indexed: 12/19/2022]
Abstract
Antibiotic tolerance-the ability of bacteria to survive for an extended time in the presence of bactericidal antibiotics-is an understudied contributor to antibiotic treatment failure. Herein, I review the manifestations, mechanisms, and clinical relevance of tolerance to cell wall-active (CWA) antibiotics, one of the most important groups of antibiotics at the forefront of clinical use. I discuss definitions of tolerance and assays for tolerance detection, comprehensively discuss the mechanism of action of β-lactams and other CWA antibiotics, and then provide an overview of how cells mitigate the potentially lethal effects of CWA antibiotic-induced cell damage to become tolerant. Lastly, I discuss evidence for a role of CWA antibiotic tolerance in clinical antibiotic treatment failure.
Collapse
Affiliation(s)
- Tobias Dörr
- Weill Institute for Cell and Molecular Biology, Department of Microbiology, and Cornell Institute of Host-Pathogen Interactions and Disease, Cornell University, Ithaca, New York
| |
Collapse
|