1
|
Schäper S, Brito AD, Saraiva BM, Squyres GR, Holmes MJ, Garner EC, Hensel Z, Henriques R, Pinho MG. Cell constriction requires processive septal peptidoglycan synthase movement independent of FtsZ treadmilling in Staphylococcus aureus. Nat Microbiol 2024; 9:1049-1063. [PMID: 38480900 PMCID: PMC10994846 DOI: 10.1038/s41564-024-01629-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Accepted: 02/01/2024] [Indexed: 04/06/2024]
Abstract
Bacterial cell division requires recruitment of peptidoglycan (PG) synthases to the division site by the tubulin homologue, FtsZ. Septal PG synthases promote septum growth. FtsZ treadmilling is proposed to drive the processive movement of septal PG synthases and septal constriction in some bacteria; however, the precise mechanisms spatio-temporally regulating PG synthase movement and activity and FtsZ treadmilling are poorly understood. Here using single-molecule imaging of division proteins in the Gram-positive pathogen Staphylococcus aureus, we showed that the septal PG synthase complex FtsW/PBP1 and its putative activator protein, DivIB, move with similar velocity around the division site. Impairing FtsZ treadmilling did not affect FtsW or DivIB velocities or septum constriction rates. Contrarily, PG synthesis inhibition decelerated or stopped directional movement of FtsW and DivIB, and septum constriction. Our findings suggest that a single population of processively moving FtsW/PBP1 associated with DivIB drives cell constriction independently of FtsZ treadmilling in S. aureus.
Collapse
Affiliation(s)
- Simon Schäper
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade NOVA de Lisboa, Oeiras, Portugal.
| | - António D Brito
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade NOVA de Lisboa, Oeiras, Portugal
- Instituto Gulbenkian de Ciência, Oeiras, Portugal
| | - Bruno M Saraiva
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade NOVA de Lisboa, Oeiras, Portugal
- Instituto Gulbenkian de Ciência, Oeiras, Portugal
| | - Georgia R Squyres
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA, USA
| | - Matthew J Holmes
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA, USA
| | - Ethan C Garner
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA, USA
| | - Zach Hensel
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade NOVA de Lisboa, Oeiras, Portugal
| | - Ricardo Henriques
- Instituto Gulbenkian de Ciência, Oeiras, Portugal
- MRC-Laboratory for Molecular Cell Biology, University College London, London, UK
| | - Mariana G Pinho
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade NOVA de Lisboa, Oeiras, Portugal.
| |
Collapse
|
2
|
Costa SF, Saraiva BM, Veiga H, Marques LB, Schäper S, Sporniak M, Vega DE, Jorge AM, Duarte AM, Brito AD, Tavares AC, Reed P, Pinho MG. The role of GpsB in Staphylococcus aureus cell morphogenesis. mBio 2024; 15:e0323523. [PMID: 38319093 PMCID: PMC10936418 DOI: 10.1128/mbio.03235-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2023] [Accepted: 12/20/2023] [Indexed: 02/07/2024] Open
Abstract
For decades, cells of the Gram-positive bacterial pathogen Staphylococcus aureus were thought to lack a dedicated elongation machinery. However, S. aureus cells were recently shown to elongate before division, in a process that requires a shape elongation division and sporulation (SEDS)/penicillin-binding protein (PBP) pair for peptidoglycan synthesis, consisting of the glycosyltransferase RodA and the transpeptidase PBP3. In ovococci and rod-shaped bacteria, the elongation machinery, or elongasome, is composed of various proteins besides a dedicated SEDS/PBP pair. To identify proteins required for S. aureus elongation, we screened the Nebraska Transposon Mutant Library, which contains transposon mutants in virtually all non-essential staphylococcal genes, for mutants with modified cell shape. We confirmed the roles of RodA/PBP3 in S. aureus elongation and identified GpsB, SsaA, and RodZ as additional proteins involved in this process. The gpsB mutant showed the strongest phenotype, mediated by the partial delocalization from the division septum of PBP2 and PBP4, two penicillin-binding proteins that synthesize and cross-link peptidoglycan. Increased levels of these PBPs at the cell periphery versus the septum result in higher levels of peptidoglycan insertion/crosslinking throughout the entire cell, possibly overriding the RodA/PBP3-mediated peptidoglycan synthesis at the outer edge of the septum and/or increasing stiffness of the peripheral wall, impairing elongation. Consequently, in the absence of GpsB, S. aureus cells become more spherical. We propose that GpsB has a role in the spatio-temporal regulation of PBP2 and PBP4 at the septum versus cell periphery, contributing to the maintenance of the correct cell morphology in S. aureus. IMPORTANCE Staphylococcus aureus is a Gram-positive clinical pathogen, which is currently the second cause of death by antibiotic-resistant infections worldwide. For decades, S. aureus cells were thought to be spherical and lack the ability to undergo elongation. However, super-resolution microscopy techniques allowed us to observe the minor morphological changes that occur during the cell cycle of this pathogen, including cell elongation. S. aureus elongation is not required for normal growth in laboratory conditions. However, it seems to be essential in the context of some infections, such as osteomyelitis, during which S. aureus cells apparently elongate to invade small channels in the bones. In this work, we uncovered new determinants required for S. aureus cell elongation. In particular, we show that GpsB has an important role in the spatio-temporal regulation of PBP2 and PBP4, two proteins involved in peptidoglycan synthesis, contributing to the maintenance of the correct cell morphology in S. aureus.
Collapse
Affiliation(s)
- Sara F. Costa
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade NOVA de Lisboa, Oeiras, Portugal
| | - Bruno M. Saraiva
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade NOVA de Lisboa, Oeiras, Portugal
| | - Helena Veiga
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade NOVA de Lisboa, Oeiras, Portugal
| | - Leonor B. Marques
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade NOVA de Lisboa, Oeiras, Portugal
| | - Simon Schäper
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade NOVA de Lisboa, Oeiras, Portugal
| | - Marta Sporniak
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade NOVA de Lisboa, Oeiras, Portugal
| | - Daniel E. Vega
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade NOVA de Lisboa, Oeiras, Portugal
| | - Ana M. Jorge
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade NOVA de Lisboa, Oeiras, Portugal
| | - Andreia M. Duarte
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade NOVA de Lisboa, Oeiras, Portugal
| | - António D. Brito
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade NOVA de Lisboa, Oeiras, Portugal
| | - Andreia C. Tavares
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade NOVA de Lisboa, Oeiras, Portugal
| | - Patricia Reed
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade NOVA de Lisboa, Oeiras, Portugal
| | - Mariana G. Pinho
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade NOVA de Lisboa, Oeiras, Portugal
| |
Collapse
|
3
|
Mandal S, Tannert A, Löffler B, Neugebauer U, Silva LB. Findaureus: An open-source application for locating Staphylococcus aureus in fluorescence-labelled infected bone tissue slices. PLoS One 2024; 19:e0296854. [PMID: 38295056 PMCID: PMC10830009 DOI: 10.1371/journal.pone.0296854] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2023] [Accepted: 12/20/2023] [Indexed: 02/02/2024] Open
Abstract
Staphylococcus aureus (S. aureus) is a facultative pathogenic bacterium that can cause infections in various tissue types in humans. Fluorescence imaging techniques have been employed to visualize the bacteria in ex-vivo samples mostly in research, aiding in the understanding of the etiology of the pathogen. However, the multispectral images generated from fluorescence microscopes are complex, making it difficult to locate bacteria across image files, especially in consecutive planes with different imaging depths. To address this issue, we present Findaureus, an open-source application specifically designed to locate and extract critical information about bacteria, especially S. aureus. Due to the limited availability of datasets, we tested the application on a dataset comprising fluorescence-labelled infected mouse bone tissue images, achieving an accuracy of 95%. We compared Findaureus with other state-of-the-art image analysis tools and found that it performed better, given its specificity toward bacteria localization. The proposed approach has the potential to aid in medical research of bone infections and can be extended to other tissue and bacteria types in the future.
Collapse
Affiliation(s)
- Shibarjun Mandal
- Leibniz-Institute of Photonic Technology (Member of Leibniz Health Technologies, Member of the Leibniz Centre for Photonics in Infection Research, LPI), Jena, Germany
| | - Astrid Tannert
- Leibniz-Institute of Photonic Technology (Member of Leibniz Health Technologies, Member of the Leibniz Centre for Photonics in Infection Research, LPI), Jena, Germany
- Center for Sepsis Control and Care, Jena University Hospital, Jena, Germany
| | - Bettina Löffler
- Center for Sepsis Control and Care, Jena University Hospital, Jena, Germany
- Institute of Medical Microbiology, Jena University Hospital, Jena, Germany
| | - Ute Neugebauer
- Leibniz-Institute of Photonic Technology (Member of Leibniz Health Technologies, Member of the Leibniz Centre for Photonics in Infection Research, LPI), Jena, Germany
- Center for Sepsis Control and Care, Jena University Hospital, Jena, Germany
| | | |
Collapse
|
4
|
Reed P, Sorg M, Alwardt D, Serra L, Veiga H, Schäper S, Pinho MG. A CRISPRi-based genetic resource to study essential Staphylococcus aureus genes. mBio 2024; 15:e0277323. [PMID: 38054745 PMCID: PMC10870820 DOI: 10.1128/mbio.02773-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2023] [Accepted: 10/19/2023] [Indexed: 12/07/2023] Open
Abstract
IMPORTANCE Staphylococcus aureus is an important clinical pathogen that causes a high number of antibiotic-resistant infections. The study of S. aureus biology, and particularly of the function of essential proteins, is of particular importance to develop new approaches to combat this pathogen. We have optimized a clustered regularly interspaced short palindromic repeat interference (CRISPRi) system that allows efficient targeting of essential S. aureus genes. Furthermore, we have used that system to construct a library comprising 261 strains, which allows the depletion of essential proteins encoded by 200 genes/operons. This library, which we have named Lisbon CRISPRi Mutant Library, should facilitate the study of S. aureus pathogenesis and biology.
Collapse
Affiliation(s)
- Patricia Reed
- Bacterial Cell Biology, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Moritz Sorg
- Bacterial Cell Biology, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Dominik Alwardt
- Bacterial Cell Biology, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Lúcia Serra
- Bacterial Cell Biology, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Helena Veiga
- Bacterial Cell Biology, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Simon Schäper
- Bacterial Cell Biology, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Mariana G. Pinho
- Bacterial Cell Biology, Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| |
Collapse
|
5
|
Guignet M, Schmuck M, Harvey DJ, Nguyen D, Bruun D, Echeverri A, Gurkoff G, Lein PJ. Novel image analysis tool for rapid screening of cell morphology in preclinical animal models of disease. Heliyon 2023; 9:e13449. [PMID: 36873154 PMCID: PMC9975095 DOI: 10.1016/j.heliyon.2023.e13449] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2022] [Revised: 12/18/2022] [Accepted: 01/30/2023] [Indexed: 02/10/2023] Open
Abstract
The field of cell biology has seen major advances in both cellular imaging modalities and the development of automated image analysis platforms that increase rigor, reproducibility, and throughput for large imaging data sets. However, there remains a need for tools that provide accurate morphometric analysis of single cells with complex, dynamic cytoarchitecture in a high-throughput and unbiased manner. We developed a fully automated image-analysis algorithm to rapidly detect and quantify changes in cellular morphology using microglia cells, an innate immune cell within the central nervous system, as representative of cells that exhibit dynamic and complex cytoarchitectural changes. We used two preclinical animal models that exhibit robust changes in microglia morphology: (1) a rat model of acute organophosphate intoxication, which was used to generate fluorescently labeled images for algorithm development; and (2) a rat model of traumatic brain injury, which was used to validate the algorithm using cells labeled using chromogenic detection methods. All ex vivo brain sections were immunolabeled for IBA-1 using fluorescence or diaminobenzidine (DAB) labeling, images were acquired using a high content imaging system and analyzed using a custom-built algorithm. The exploratory data set revealed eight statistically significant and quantitative morphometric parameters that distinguished between phenotypically distinct groups of microglia. Manual validation of single-cell morphology was strongly correlated with the automated analysis and was further supported by a comparison with traditional stereology methods. Existing image analysis pipelines rely on high-resolution images of individual cells, which limits sample size and is subject to selection bias. However, our fully automated method integrates quantification of morphology and fluorescent/chromogenic signals in images from multiple brain regions acquired using high-content imaging. In summary, our free, customizable image analysis tool provides a high-throughput, unbiased method for accurately detecting and quantifying morphological changes in cells with complex morphologies.
Collapse
Affiliation(s)
- Michelle Guignet
- Department of Molecular Biosciences, School of Veterinary Medicine, University of California-Davis, 1089 Veterinary Medicine Drive, Davis, CA, 95616, USA
| | - Martin Schmuck
- Department of Molecular Biosciences, School of Veterinary Medicine, University of California-Davis, 1089 Veterinary Medicine Drive, Davis, CA, 95616, USA
| | - Danielle J. Harvey
- Department of Public Health Sciences, University of California-Davis, One Shields Avenue, Davis, CA, 95616, USA
| | - Danh Nguyen
- Division of General Internal Medicine, Department of Medicine, School of Medicine, University of California-Irvine, 100 Theory, Suite 120, Irvine, CA, 92617, USA
| | - Donald Bruun
- Department of Molecular Biosciences, School of Veterinary Medicine, University of California-Davis, 1089 Veterinary Medicine Drive, Davis, CA, 95616, USA
| | - Angela Echeverri
- Department of Neurological Surgery, School of Medicine, University of California-Davis, 4800 Y Street, Sacramento, CA, 95817, USA
| | - Gene Gurkoff
- Department of Neurological Surgery, School of Medicine, University of California-Davis, 4800 Y Street, Sacramento, CA, 95817, USA
- Center for Neuroscience, University of California-Davis, 1544 Newton Court, Davis, CA, 95618, USA
| | - Pamela J. Lein
- Department of Molecular Biosciences, School of Veterinary Medicine, University of California-Davis, 1089 Veterinary Medicine Drive, Davis, CA, 95616, USA
- MIND Institute, School of Medicine, University of California-Davis, 2825 50th Street, Sacramento, CA, 95817, USA
| |
Collapse
|
6
|
Spahn C, Gómez-de-Mariscal E, Laine RF, Pereira PM, von Chamier L, Conduit M, Pinho MG, Jacquemet G, Holden S, Heilemann M, Henriques R. DeepBacs for multi-task bacterial image analysis using open-source deep learning approaches. Commun Biol 2022; 5:688. [PMID: 35810255 PMCID: PMC9271087 DOI: 10.1038/s42003-022-03634-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Accepted: 06/23/2022] [Indexed: 11/09/2022] Open
Abstract
This work demonstrates and guides how to use a range of state-of-the-art artificial neural-networks to analyse bacterial microscopy images using the recently developed ZeroCostDL4Mic platform. We generated a database of image datasets used to train networks for various image analysis tasks and present strategies for data acquisition and curation, as well as model training. We showcase different deep learning (DL) approaches for segmenting bright field and fluorescence images of different bacterial species, use object detection to classify different growth stages in time-lapse imaging data, and carry out DL-assisted phenotypic profiling of antibiotic-treated cells. To also demonstrate the ability of DL to enhance low-phototoxicity live-cell microscopy, we showcase how image denoising can allow researchers to attain high-fidelity data in faster and longer imaging. Finally, artificial labelling of cell membranes and predictions of super-resolution images allow for accurate mapping of cell shape and intracellular targets. Our purposefully-built database of training and testing data aids in novice users' training, enabling them to quickly explore how to analyse their data through DL. We hope this lays a fertile ground for the efficient application of DL in microbiology and fosters the creation of tools for bacterial cell biology and antibiotic research.
Collapse
Affiliation(s)
- Christoph Spahn
- Department of Natural Products in Organismic Interaction, Max Planck Institute for Terrestrial Microbiology, Marburg, Germany.
- Institute of Physical and Theoretical Chemistry, Goethe-University Frankfurt, Frankfurt, Germany.
| | | | - Romain F Laine
- MRC-Laboratory for Molecular Cell Biology, University College London, London, UK
- The Francis Crick Institute, London, UK
- Micrographia Bio, Translation and Innovation hub 84 Wood lane, W120BZ, London, UK
| | - Pedro M Pereira
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Lucas von Chamier
- MRC-Laboratory for Molecular Cell Biology, University College London, London, UK
| | - Mia Conduit
- Centre for Bacterial Cell Biology, Newcastle University Biosciences Institute, Faculty of Medical Sciences, Newcastle upon Tyne, NE24AX, United Kingdom
| | - Mariana G Pinho
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Guillaume Jacquemet
- Turku Bioscience Centre, University of Turku and Åbo Akademi University, Turku, Finland
- Faculty of Science and Engineering, Cell Biology, Åbo Akademi University, Turku, Finland
- Turku Bioimaging, University of Turku and Åbo Akademi University, Turku, Finland
| | - Séamus Holden
- Centre for Bacterial Cell Biology, Newcastle University Biosciences Institute, Faculty of Medical Sciences, Newcastle upon Tyne, NE24AX, United Kingdom
| | - Mike Heilemann
- Institute of Physical and Theoretical Chemistry, Goethe-University Frankfurt, Frankfurt, Germany.
| | - Ricardo Henriques
- Instituto Gulbenkian de Ciência, 2780-156, Oeiras, Portugal.
- MRC-Laboratory for Molecular Cell Biology, University College London, London, UK.
- The Francis Crick Institute, London, UK.
| |
Collapse
|
7
|
Gouveia A, Pinto D, Veiga H, Antunes W, Pinho MG, São-José C. Synthetic antimicrobial peptides as enhancers of the bacteriolytic action of staphylococcal phage endolysins. Sci Rep 2022; 12:1245. [PMID: 35075218 PMCID: PMC8786859 DOI: 10.1038/s41598-022-05361-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2021] [Accepted: 01/10/2022] [Indexed: 01/09/2023] Open
Abstract
Bacteriophage endolysins degrade the bacterial cell wall and are therefore considered promising antimicrobial alternatives to fight pathogens resistant to conventional antibiotics. Gram-positive bacteria are usually considered easy targets to exogenously added endolysins, since their cell walls are not shielded by an outer membrane. However, in nutrient rich environments these bacteria can also tolerate endolysin attack if they keep an energized cytoplasmic membrane. Hence, we have hypothesized that the membrane depolarizing action of antimicrobial peptides (AMPs), another attractive class of alternative antibacterials, could be explored to overcome bacterial tolerance to endolysins and consequently improve their antibacterial potential. Accordingly, we show that under conditions supporting bacterial growth, Staphylococcus aureus becomes much more susceptible to the bacteriolytic action of endolysins if an AMP is also present. The bactericidal gain resulting from the AMP/endolysin combined action ranged from 1 to 3 logs for different S. aureus strains, which included drug-resistant clinical isolates. In presence of an AMP, as with a reduced content of cell wall teichoic acids, higher endolysin binding to cells is observed. However, our results indicate that this higher endolysin binding alone does not fully explain the higher susceptibility of S. aureus to lysis in these conditions. Other factors possibly contributing to the increased endolysin susceptibility in presence of an AMP are discussed.
Collapse
Affiliation(s)
- Ana Gouveia
- Research Institute for Medicines (iMed.ULisboa), Faculdade de Farmácia da Universidade de Lisboa, Av. Prof. Gama Pinto, 1649-003, Lisbon, Portugal
| | - Daniela Pinto
- Research Institute for Medicines (iMed.ULisboa), Faculdade de Farmácia da Universidade de Lisboa, Av. Prof. Gama Pinto, 1649-003, Lisbon, Portugal
| | - Helena Veiga
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Av. da Républica, 2780-157, Oeiras, Portugal
| | - Wilson Antunes
- Unidade Militar Laboratorial de Defesa Biológica e Química (UMLDBQ), Instituto Universitário Militar, Centro de Investigação da Academia Militar (CINAMIL), Av. Dr. Alfredo Bensaúde, 1849-012, Lisbon, Portugal
| | - Mariana G Pinho
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Av. da Républica, 2780-157, Oeiras, Portugal
| | - Carlos São-José
- Research Institute for Medicines (iMed.ULisboa), Faculdade de Farmácia da Universidade de Lisboa, Av. Prof. Gama Pinto, 1649-003, Lisbon, Portugal.
| |
Collapse
|