1
|
Lê-Bury P, Echenique-Rivera H, Pizarro-Cerdá J, Dussurget O. Determinants of bacterial survival and proliferation in blood. FEMS Microbiol Rev 2024; 48:fuae013. [PMID: 38734892 PMCID: PMC11163986 DOI: 10.1093/femsre/fuae013] [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: 11/06/2023] [Revised: 04/29/2024] [Accepted: 05/10/2024] [Indexed: 05/13/2024] Open
Abstract
Bloodstream infection is a major public health concern associated with high mortality and high healthcare costs worldwide. Bacteremia can trigger fatal sepsis whose prevention, diagnosis, and management have been recognized as a global health priority by the World Health Organization. Additionally, infection control is increasingly threatened by antimicrobial resistance, which is the focus of global action plans in the framework of a One Health response. In-depth knowledge of the infection process is needed to develop efficient preventive and therapeutic measures. The pathogenesis of bloodstream infection is a dynamic process resulting from the invasion of the vascular system by bacteria, which finely regulate their metabolic pathways and virulence factors to overcome the blood immune defenses and proliferate. In this review, we highlight our current understanding of determinants of bacterial survival and proliferation in the bloodstream and discuss their interactions with the molecular and cellular components of blood.
Collapse
Affiliation(s)
- Pierre Lê-Bury
- Institut Pasteur, Université Paris Cité, CNRS UMR6047, Yersinia Research Unit, 28 rue du Dr Roux, 75015 Paris, France
- Université Paris-Saclay, Inserm, CEA, Center for Immunology of Viral, Autoimmune, Hematological and Bacterial Diseases (IMVA-HB/IDMIT), 18 route du Panorama, 92260 Fontenay-aux-Roses, France
| | - Hebert Echenique-Rivera
- Institut Pasteur, Université Paris Cité, CNRS UMR6047, Yersinia Research Unit, 28 rue du Dr Roux, 75015 Paris, France
| | - Javier Pizarro-Cerdá
- Institut Pasteur, Université Paris Cité, CNRS UMR6047, Yersinia Research Unit, 28 rue du Dr Roux, 75015 Paris, France
- Institut Pasteur, Université Paris Cité, Yersinia National Reference Laboratory, WHO Collaborating Research & Reference Centre for Plague FRA-146, 28 rue du Dr Roux, 75015 Paris, France
| | - Olivier Dussurget
- Institut Pasteur, Université Paris Cité, CNRS UMR6047, Yersinia Research Unit, 28 rue du Dr Roux, 75015 Paris, France
| |
Collapse
|
2
|
Paskey AC, Schully KL, Voegtly LJ, Arnold CE, Cer RZ, Frey KG, Blair PW, Clark DV, Ge H, Richards AL, Farris CM, Bishop-Lilly KA. A proof of concept for a targeted enrichment approach to the simultaneous detection and characterization of rickettsial pathogens from clinical specimens. Front Microbiol 2024; 15:1387208. [PMID: 38659991 PMCID: PMC11039911 DOI: 10.3389/fmicb.2024.1387208] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2024] [Accepted: 03/26/2024] [Indexed: 04/26/2024] Open
Abstract
Infection with either Rickettsia prowazekii or Orientia tsutsugamushi is common, yet diagnostic capabilities are limited due to the short window for positive identification. Until now, although targeted enrichment had been applied to increase sensitivity of sequencing-based detection for various microorganisms, it had not been applied to sequencing of R. prowazekii in clinical samples. Additionally, hybridization-based targeted enrichment strategies had only scarcely been applied to qPCR of any pathogens in clinical samples. Therefore, we tested a targeted enrichment technique as a proof of concept and found that it dramatically reduced the limits of detection of these organisms by both qPCR and high throughput sequencing. The enrichment methodology was first tested in contrived clinical samples with known spiked-in concentrations of R. prowazekii and O. tsutsugamushi DNA. This method was also evaluated using clinical samples, resulting in the simultaneous identification and characterization of O. tsutsugamushi directly from clinical specimens taken from sepsis patients. We demonstrated that the targeted enrichment technique is helpful by lowering the limit of detection, not only when applied to sequencing, but also when applied to qPCR, suggesting the technique could be applied more broadly to include other assays and/or microbes for which there are limited diagnostic or detection modalities.
Collapse
Affiliation(s)
- Adrian C. Paskey
- Genomics and Bioinformatics Department, Biological Defense Research Directorate, Naval Medical Research Command, Frederick, MD, United States
- Leidos, Reston, VA, United States
| | - Kevin L. Schully
- Austere Environments Consortium for Enhanced Sepsis Outcomes (ACESO), Biological Defense Research Directorate, Naval Medical Research Command, Frederick, MD, United States
| | - Logan J. Voegtly
- Genomics and Bioinformatics Department, Biological Defense Research Directorate, Naval Medical Research Command, Frederick, MD, United States
- Leidos, Reston, VA, United States
| | - Catherine E. Arnold
- Genomics and Bioinformatics Department, Biological Defense Research Directorate, Naval Medical Research Command, Frederick, MD, United States
- Defense Threat Reduction Agency, Fort Belvoir, VA, United States
| | - Regina Z. Cer
- Genomics and Bioinformatics Department, Biological Defense Research Directorate, Naval Medical Research Command, Frederick, MD, United States
| | - Kenneth G. Frey
- Genomics and Bioinformatics Department, Biological Defense Research Directorate, Naval Medical Research Command, Frederick, MD, United States
| | - Paul W. Blair
- Austere Environments Consortium for Enhanced Sepsis Outcomes (ACESO), Biological Defense Research Directorate, Naval Medical Research Command, Frederick, MD, United States
- The Henry M. Jackson Foundation for the Advancement of Military Medicine, Bethesda, MD, United States
| | - Danielle V. Clark
- Austere Environments Consortium for Enhanced Sepsis Outcomes (ACESO), Biological Defense Research Directorate, Naval Medical Research Command, Frederick, MD, United States
- The Henry M. Jackson Foundation for the Advancement of Military Medicine, Bethesda, MD, United States
| | - Hong Ge
- Viral and Rickettsial Diseases Department, Infectious Diseases Directorate, Naval Medical Research Command, Silver Spring, MD, United States
| | - Allen L. Richards
- Viral and Rickettsial Diseases Department, Infectious Diseases Directorate, Naval Medical Research Command, Silver Spring, MD, United States
| | - Christina M. Farris
- Viral and Rickettsial Diseases Department, Infectious Diseases Directorate, Naval Medical Research Command, Silver Spring, MD, United States
| | - Kimberly A. Bishop-Lilly
- Genomics and Bioinformatics Department, Biological Defense Research Directorate, Naval Medical Research Command, Frederick, MD, United States
| |
Collapse
|
3
|
Jiang JH, Cameron DR, Nethercott C, Aires-de-Sousa M, Peleg AY. Virulence attributes of successful methicillin-resistant Staphylococcus aureus lineages. Clin Microbiol Rev 2023; 36:e0014822. [PMID: 37982596 PMCID: PMC10732075 DOI: 10.1128/cmr.00148-22] [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: 11/21/2023] Open
Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) is a leading cause of severe and often fatal infections. MRSA epidemics have occurred in waves, whereby a previously successful lineage has been replaced by a more fit and better adapted lineage. Selection pressures in both hospital and community settings are not uniform across the globe, which has resulted in geographically distinct epidemiology. This review focuses on the mechanisms that trigger the establishment and maintenance of current, dominant MRSA lineages across the globe. While the important role of antibiotic resistance will be mentioned throughout, factors which influence the capacity of S. aureus to colonize and cause disease within a host will be the primary focus of this review. We show that while MRSA possesses a diverse arsenal of toxins including alpha-toxin, the success of a lineage involves more than just producing toxins that damage the host. Success is often attributed to the acquisition or loss of genetic elements involved in colonization and niche adaptation such as the arginine catabolic mobile element, as well as the activity of regulatory systems, and shift metabolism accordingly (e.g., the accessory genome regulator, agr). Understanding exactly how specific MRSA clones cause prolonged epidemics may reveal targets for therapies, whereby both core (e.g., the alpha toxin) and acquired virulence factors (e.g., the Panton-Valentine leukocidin) may be nullified using anti-virulence strategies.
Collapse
Affiliation(s)
- Jhih-Hang Jiang
- Department of Microbiology, Infection Program, Monash Biomedicine Discovery Institute, Monash University, Clayton, Victoria, Australia
- Department of Infectious Diseases, The Alfred Hospital and Central Clinical School, Monash University, Melbourne, Victoria, Australia
| | - David R. Cameron
- Department of Biomedical Research, University of Bern, Bern, Switzerland
| | - Cara Nethercott
- Department of Microbiology, Infection Program, Monash Biomedicine Discovery Institute, Monash University, Clayton, Victoria, Australia
| | - Marta Aires-de-Sousa
- Laboratory of Molecular Genetics, Institutode Tecnologia Químicae Biológica António Xavier (ITQB-NOVA), Universidade Nova de Lisboa, Oeiras, Portugal
- Escola Superior de Saúde da Cruz Vermelha Portuguesa-Lisboa (ESSCVP-Lisboa), Lisbon, Portugal
| | - Anton Y. Peleg
- Department of Microbiology, Infection Program, Monash Biomedicine Discovery Institute, Monash University, Clayton, Victoria, Australia
- Department of Infectious Diseases, The Alfred Hospital and Central Clinical School, Monash University, Melbourne, Victoria, Australia
- Centre to Impact Antimicrobial Resistance, Monash University, Clayton, Melbourne, Victoria, Australia
| |
Collapse
|
4
|
Ba X, Matuszewska M, Kalmar L, Fan J, Zou G, Corander D, Raisen CL, Li S, Li L, Weinert LA, Tucker AW, Grant AJ, Zhou R, Holmes MA. High-Throughput Mutagenesis Reveals a Role for Antimicrobial Resistance- and Virulence-Associated Mobile Genetic Elements in Staphylococcus aureus Host Adaptation. Microbiol Spectr 2023; 11:e0421322. [PMID: 36815781 PMCID: PMC10101091 DOI: 10.1128/spectrum.04213-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2022] [Accepted: 02/01/2023] [Indexed: 02/24/2023] Open
Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) clonal-complex 398 (CC398) is the dominant livestock-associated (LA) MRSA lineage in European livestock and an increasing cause of difficult-to-treat human disease. LA-CC398 MRSA evolved from a diverse human-associated methicillin-sensitive population, and this transition from humans to livestock was associated with three mobile genetic elements (MGEs). In this study, we apply transposon-directed insertion site sequencing (TraDIS), a high-throughput transposon mutagenesis approach, to investigate genetic signatures that contribute to LA-CC398 causing disease in humans. We identified 26 genes associated with LA-CC398 survival in human blood and 47 genes in porcine blood. We carried out phylogenetic reconstruction on 1,180 CC398 isolates to investigate the genetic context of all identified genes. We found that all genes associated with survival in human blood were part of the CC398 core genome, while 2/47 genes essential for survival in porcine blood were located on MGEs. Gene SAPIG0966 was located on the previously identified Tn916 transposon carrying a tetracycline resistance gene, which has been shown to be stably inherited within LA-CC398. Gene SAPIG1525 was carried on a phage element, which in part, matched phiSa2wa_st1, a previously identified bacteriophage carrying the Panton-Valentine leucocidin (PVL) virulence factor. Gene deletion mutants constructed in two LA-CC398 strains confirmed that the SAPIG0966 carrying Tn916 and SAPIG1525 were important for CC398 survival in porcine blood. Our study shows that MGEs that carry antimicrobial resistance and virulence genes could have a secondary function in bacterial survival in blood and may be important for host adaptation. IMPORTANCE CC398 is the dominant type of methicillin-resistant Staphylococcus aureus (MRSA) in European livestock and a growing cause of human infections. Previous studies have suggested MRSA CC398 evolved from human-associated methicillin-sensitive Staphylococcus aureus and is capable of rapidly readapting to human hosts while maintaining antibiotic resistance. Using high-throughput transposon mutagenesis, our study identified 26 and 47 genes important for MRSA CC398 survival in human and porcine blood, respectively. Two of the genes important for MRSA CC398 survival in porcine blood were located on mobile genetic elements (MGEs) carrying resistance or virulence genes. Our study shows that these MGEs carrying antimicrobial resistance and virulence genes could have a secondary function in bacterial survival in blood and may be important for blood infection and host adaptation.
Collapse
Affiliation(s)
- Xiaoliang Ba
- Department of Veterinary Medicine, University of Cambridge, Cambridge, United Kingdom
| | - Marta Matuszewska
- Department of Veterinary Medicine, University of Cambridge, Cambridge, United Kingdom
- Department of Medicine, University of Cambridge, Cambridge, United Kingdom
| | - Lajos Kalmar
- Department of Veterinary Medicine, University of Cambridge, Cambridge, United Kingdom
| | - Jingyan Fan
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University College of Veterinary Medicine, Wuhan, China
| | - Geng Zou
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University College of Veterinary Medicine, Wuhan, China
| | - Desirée Corander
- Department of Biochemistry, Faculty of Science and Engineering, Åbo Akademi University, Turku, Finland
| | - Claire L. Raisen
- Department of Veterinary Medicine, University of Cambridge, Cambridge, United Kingdom
| | - Shaowen Li
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University College of Veterinary Medicine, Wuhan, China
| | - Lu Li
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University College of Veterinary Medicine, Wuhan, China
- Cooperative Innovation Centre of Sustainable Pig Production, Wuhan, China
- International Research Centre for Animal Diseases (MOST), Wuhan, China
| | - Lucy A. Weinert
- Department of Veterinary Medicine, University of Cambridge, Cambridge, United Kingdom
| | - Alexander W. Tucker
- Department of Veterinary Medicine, University of Cambridge, Cambridge, United Kingdom
| | - Andrew J. Grant
- Department of Veterinary Medicine, University of Cambridge, Cambridge, United Kingdom
| | - Rui Zhou
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University College of Veterinary Medicine, Wuhan, China
- Cooperative Innovation Centre of Sustainable Pig Production, Wuhan, China
- International Research Centre for Animal Diseases (MOST), Wuhan, China
| | - Mark A. Holmes
- Department of Veterinary Medicine, University of Cambridge, Cambridge, United Kingdom
| |
Collapse
|
5
|
Spoto M, Riera Puma JP, Fleming E, Guan C, Ondouah Nzutchi Y, Kim D, Oh J. Large-Scale CRISPRi and Transcriptomics of Staphylococcus epidermidis Identify Genetic Factors Implicated in Lifestyle Versatility. mBio 2022; 13:e0263222. [PMID: 36409086 PMCID: PMC9765180 DOI: 10.1128/mbio.02632-22] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2022] [Accepted: 10/27/2022] [Indexed: 11/23/2022] Open
Abstract
Staphylococcus epidermidis is a ubiquitous human commensal skin bacterium that is also one of the most prevalent nosocomial pathogens. The genetic factors underlying this remarkable lifestyle plasticity are incompletely understood, mainly due to the difficulties of genetic manipulation, precluding high-throughput functional profiling of this species. To probe the versatility of S. epidermidis to survive across a diversity of environmental conditions, we developed a large-scale CRISPR interference (CRISPRi) screen complemented by transcriptional profiling (RNA sequencing) across 24 diverse conditions and piloted a droplet-based CRISPRi approach to enhance throughput and sensitivity. We identified putative essential genes, importantly revealing amino acid metabolism as crucial to survival across diverse environments, and demonstrated the importance of trace metal uptake for survival under multiple stress conditions. We identified pathways significantly enriched and repressed across our range of stress and nutrient-limited conditions, demonstrating the considerable plasticity of S. epidermidis in responding to environmental stressors. Additionally, we postulate a mechanism by which nitrogen metabolism is linked to lifestyle versatility in response to hyperosmotic challenges, such as those encountered on human skin. Finally, we examined the survival of S. epidermidis under acid stress and hypothesize a role for cell wall modification as a vital component of the survival response under acidic conditions. Taken together, this study integrates large-scale CRISPRi and transcriptomics data across multiple environments to provide insights into a keystone member of the human skin microbiome. Our results additionally provide a valuable benchmarking analysis for CRISPRi screens and are a rich resource for other staphylococcal researchers. IMPORTANCE Staphylococcus epidermidis is a bacteria that broadly inhabits healthy human skin, yet it is also a common cause of skin infections and bloodstream infections associated with implanted medical devices. Because human skin has many different types of S. epidermidis, each containing different genes, our goal is to determine how these different genes allow S. epidermidis to switch from healthy growth in the skin to being an infectious pathogen. Understanding this switch is critical to developing new strategies to prevent and treat S. epidermidis infections.
Collapse
Affiliation(s)
- Michelle Spoto
- The Jackson Laboratory for Genomic Medicine, Farmington, Connecticut, USA
- The University of Connecticut Health Center, Farmington, Connecticut, USA
| | | | - Elizabeth Fleming
- The Jackson Laboratory for Genomic Medicine, Farmington, Connecticut, USA
| | - Changhui Guan
- The Jackson Laboratory for Genomic Medicine, Farmington, Connecticut, USA
| | | | - Dean Kim
- The Jackson Laboratory for Genomic Medicine, Farmington, Connecticut, USA
| | - Julia Oh
- The Jackson Laboratory for Genomic Medicine, Farmington, Connecticut, USA
| |
Collapse
|
6
|
Hogan AM, Cardona ST. Gradients in gene essentiality reshape antibacterial research. FEMS Microbiol Rev 2022; 46:fuac005. [PMID: 35104846 PMCID: PMC9075587 DOI: 10.1093/femsre/fuac005] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Revised: 01/14/2022] [Accepted: 01/24/2022] [Indexed: 02/03/2023] Open
Abstract
Essential genes encode the processes that are necessary for life. Until recently, commonly applied binary classifications left no space between essential and non-essential genes. In this review, we frame bacterial gene essentiality in the context of genetic networks. We explore how the quantitative properties of gene essentiality are influenced by the nature of the encoded process, environmental conditions and genetic background, including a strain's distinct evolutionary history. The covered topics have important consequences for antibacterials, which inhibit essential processes. We argue that the quantitative properties of essentiality can thus be used to prioritize antibacterial cellular targets and desired spectrum of activity in specific infection settings. We summarize our points with a case study on the core essential genome of the cystic fibrosis pathobiome and highlight avenues for targeted antibacterial development.
Collapse
Affiliation(s)
- Andrew M Hogan
- Department of Microbiology, University of Manitoba, 45 Chancellor's Circle, Winnipeg, Manitoba R3T 2N2, Canada
| | - Silvia T Cardona
- Department of Microbiology, University of Manitoba, 45 Chancellor's Circle, Winnipeg, Manitoba R3T 2N2, Canada
- Department of Medical Microbiology and Infectious Diseases, Max Rady College of Medicine, University of Manitoba, Room 543 - 745 Bannatyne Avenue, Winnipeg, Manitoba, R3E 0J9, Canada
| |
Collapse
|
7
|
Ong ZX, Kannan B, Becker DL. Exploiting transposons in the study of Staphylococcus aureus pathogenesis and virulence. Crit Rev Microbiol 2022; 49:297-317. [PMID: 35438613 DOI: 10.1080/1040841x.2022.2052794] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
The opportunistic pathogen Staphylococcus aureus has an extremely complex relationship with humans. While the bacteria can exist as a commensal in many, it can cause a wide range of diseases and infections when turned pathogenic. Its presence is a determinant of chronicity and poor prognosis in numerous diseases, and its genomic plasticity causes S. aureus antimicrobial resistance to be one of the most dire contemporary medical problems to solve. Genetic manipulation of S. aureus has led to numerous findings that are vital in the fight against its pathogenesis. The utilisation of transposon mutant libraries for the systematic inspection of the S. aureus genome led to many landmark discoveries pertaining to the bacteria's pathogenicity, antimicrobial resistance acquisition, and virulence regulation. In this review, we describe mutant libraries, and their significant contributions, from various S. aureus strains created with commonly used transposons. The general workflow for the construction of libraries will be presented, along with a discussion of the challenges of undertaking the task of large-scale library construction. As the accessibility of transposon mutant library construction, screening, and analysis increases, this genetic tool could be further exploited in the study of the S. aureus genome.
Collapse
Affiliation(s)
- Zi Xin Ong
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore.,Skin Research Institute, Singapore.,Nanyang Institute of Technology in Health and Medicine, Interdisciplinary Graduate Programme, Nanyang Technological University, Singapore
| | - Bavani Kannan
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore.,Skin Research Institute, Singapore
| | - David L Becker
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore.,Skin Research Institute, Singapore
| |
Collapse
|
8
|
Antimicrobial Peptides from Plants: A cDNA-Library Based Isolation, Purification, Characterization Approach and Elucidating Their Modes of Action. Int J Mol Sci 2021; 22:ijms22168712. [PMID: 34445412 PMCID: PMC8395713 DOI: 10.3390/ijms22168712] [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: 06/15/2021] [Revised: 08/05/2021] [Accepted: 08/10/2021] [Indexed: 12/19/2022] Open
Abstract
Even in a natural ecosystem, plants are continuously threatened by various microbial diseases. To save themselves from these diverse infections, plants build a robust, multilayered immune system through their natural chemical compounds. Among the several crucial bioactive compounds possessed by plants’ immune systems, antimicrobial peptides (AMPs) rank in the first tier. These AMPs are environmentally friendly, anti-pathogenic, and do not bring harm to humans. Antimicrobial peptides can be isolated in several ways, but recombinant protein production has become increasingly popular in recent years, with the Escherichia coli expression system being the most widely used. However, the efficacy of this expression system is compromised due to the difficulty of removing endotoxin from its system. Therefore, this review suggests a high-throughput cDNA library-based plant-derived AMP isolation technique using the Bacillus subtilis expression system. This method can be performed for large-scale screening of plant sources to classify unique or homologous AMPs for the agronomic and applied field of plant studies. Furthermore, this review also focuses on the efficacy of plant AMPs, which are dependent on their numerous modes of action and exceptional structural stability to function against a wide range of invaders. To conclude, the findings from this study will be useful in investigating how novel AMPs are distributed among plants and provide detailed guidelines for an effective screening strategy of AMPs.
Collapse
|
9
|
Nlebedim VU, Chaudhuri RR, Walters K. Probabilistic Identification of Bacterial Essential Genes via insertion density using TraDIS Data with Tn5 libraries. Bioinformatics 2021; 37:4343-4349. [PMID: 34255819 PMCID: PMC8652038 DOI: 10.1093/bioinformatics/btab508] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2021] [Revised: 06/24/2021] [Accepted: 07/23/2021] [Indexed: 11/29/2022] Open
Abstract
Motivation Probabilistic Identification of bacterial essential genes using transposon-directed insertion-site sequencing (TraDIS) data based on Tn5 libraries has received relatively little attention in the literature; most methods are designed for mariner transposon insertions. Analysis of Tn5 transposon-based genomic data is challenging due to the high insertion density and genomic resolution. We present a novel probabilistic Bayesian approach for classifying bacterial essential genes using transposon insertion density derived from transposon insertion sequencing data. We implement a Markov chain Monte Carlo sampling procedure to estimate the posterior probability that any given gene is essential. We implement a Bayesian decision theory approach to selecting essential genes. We assess the effectiveness of our approach via analysis of both simulated data and three previously published Escherichia coli, Salmonella Typhimurium and Staphylococcus aureus datasets. These three bacteria have relatively well characterized essential genes which allows us to test our classification procedure using receiver operating characteristic curves and area under the curves. We compare the classification performance with that of Bio-Tradis, a standard tool for bacterial gene classification. Results Our method is able to classify genes in the three datasets with areas under the curves between 0.967 and 0.983. Our simulated synthetic datasets show that both the number of insertions and the extent to which insertions are tolerated in the distal regions of essential genes are both important in determining classification accuracy. Importantly our method gives the user the option of classifying essential genes based on the user-supplied costs of false discovery and false non-discovery. Availability and implementation An R package that implements the method presented in this paper is available for download from https://github.com/Kevin-walters/insdens. Supplementary information Supplementary data are available at Bioinformatics online.
Collapse
Affiliation(s)
- Valentine U Nlebedim
- School of Mathematics and Statistics, University of Sheffield, Sheffield, S10 2TN, United Kingdom
| | - Roy R Chaudhuri
- Department of Molecular Biology and Biotechnology, University of Sheffield, Sheffield, S10 2TN, United Kingdom
| | - Kevin Walters
- School of Mathematics and Statistics, University of Sheffield, Sheffield, S10 2TN, United Kingdom
| |
Collapse
|
10
|
Sargison FA, Fitzgerald JR. Advances in Transposon Mutagenesis of Staphylococcus aureus: Insights into Pathogenesis and Antimicrobial Resistance. Trends Microbiol 2021; 29:282-285. [PMID: 33279382 DOI: 10.1016/j.tim.2020.11.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Revised: 11/03/2020] [Accepted: 11/05/2020] [Indexed: 10/22/2022]
Abstract
Our capacity to investigate the biology of the major human and animal pathogen Staphylococcus aureus has been greatly enhanced by technological advances in transposon (Tn) mutagenesis. Here we provide a perspective on how these advances can further our understanding of pathogenesis and antibiotic resistance.
Collapse
Affiliation(s)
- Fiona A Sargison
- Roslin Institute, University of Edinburgh, Easter Bush Campus, Edinburgh EH25 9RG, UK
| | - J Ross Fitzgerald
- Roslin Institute, University of Edinburgh, Easter Bush Campus, Edinburgh EH25 9RG, UK.
| |
Collapse
|
11
|
Zondervan NA, Martins Dos Santos VAP, Suarez-Diez M, Saccenti E. Phenotype and multi-omics comparison of Staphylococcus and Streptococcus uncovers pathogenic traits and predicts zoonotic potential. BMC Genomics 2021; 22:102. [PMID: 33541265 PMCID: PMC7860044 DOI: 10.1186/s12864-021-07388-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Accepted: 01/13/2021] [Indexed: 01/19/2023] Open
Abstract
BACKGROUND Staphylococcus and Streptococcus species can cause many different diseases, ranging from mild skin infections to life-threatening necrotizing fasciitis. Both genera consist of commensal species that colonize the skin and nose of humans and animals, and of which some can display a pathogenic phenotype. RESULTS We compared 235 Staphylococcus and 315 Streptococcus genomes based on their protein domain content. We show the relationships between protein persistence and essentiality by integrating essentiality predictions from two metabolic models and essentiality measurements from six large-scale transposon mutagenesis experiments. We identified clusters of strains within species based on proteins associated to similar biological processes. We built Random Forest classifiers that predicted the zoonotic potential. Furthermore, we identified shared attributes between of Staphylococcus aureus and Streptococcus pyogenes that allow them to cause necrotizing fasciitis. CONCLUSIONS Differences observed in clustering of strains based on functional groups of proteins correlate with phenotypes such as host tropism, capability to infect multiple hosts and drug resistance. Our method provides a solid basis towards large-scale prediction of phenotypes based on genomic information.
Collapse
Affiliation(s)
- Niels A Zondervan
- Laboratory of Systems and Synthetic Biology, Wageningen University & Research, Stippeneng 4, 6708WE, Wageningen, Netherlands
| | - Vitor A P Martins Dos Santos
- Laboratory of Systems and Synthetic Biology, Wageningen University & Research, Stippeneng 4, 6708WE, Wageningen, Netherlands
- LifeGlimmer GmBH, Markelstraße 38, 12163, Berlin, Germany
| | - Maria Suarez-Diez
- Laboratory of Systems and Synthetic Biology, Wageningen University & Research, Stippeneng 4, 6708WE, Wageningen, Netherlands
| | - Edoardo Saccenti
- Laboratory of Systems and Synthetic Biology, Wageningen University & Research, Stippeneng 4, 6708WE, Wageningen, Netherlands.
| |
Collapse
|
12
|
Abstract
The division and cell wall (dcw) cluster is a highly conserved region of the bacterial genome consisting of genes that encode several cell division and cell wall synthesis factors, including the central division protein FtsZ. The region immediately downstream of ftsZ encodes the ylm genes and is conserved across diverse lineages of Gram-positive bacteria and Cyanobacteria In some organisms, this region remains part of the dcw cluster, but in others, it appears as an independent operon. A well-studied protein coded from this region is the positive FtsZ regulator SepF (YlmF), which anchors FtsZ to the membrane. Recent developments have shed light on the importance of SepF in a range of species. Additionally, new studies are highlighting the importance of the other conserved genes in this neighborhood. In this minireview, we aim to bring together the current research linking the ylm region to cell division and highlight further questions surrounding these conserved genes.
Collapse
|
13
|
Fu T, Islam MS, Ali M, Wu J, Dong W. Two antimicrobial genes from Aegilops tauschii Cosson identified by the Bacillus subtilis expression system. Sci Rep 2020; 10:13346. [PMID: 32770019 PMCID: PMC7414872 DOI: 10.1038/s41598-020-70314-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Accepted: 07/21/2020] [Indexed: 01/08/2023] Open
Abstract
Antimicrobial genes play an important role as a primary defense mechanism in all multicellular organisms. We chose Bacillus subtilis as a target pathogen indicator and transferred the Aegilops tauschii Cosson cDNA library into B. subtilis cells. Expression of the candidate antimicrobial gene can inhibit B. subtilis cell growth. Using this strategy, we screened six genes that have an internal effect on the indicator bacteria. Then, the secreted proteins were extracted and tested; two genes, AtR100 and AtR472, were found to have strong external antimicrobial activities with broad-spectrum resistance against Xanthomonas oryzae pv. oryzicola, Clavibacter fangii, and Botrytis cinerea. Additionally, thermal stability tests indicated that the antimicrobial activities of both proteins were thermostable. Furthermore, these two proteins exhibited no significant hemolytic activities. To test the feasibility of application at the industrial level, liquid fermentation and spray drying of these two proteins were conducted. Powder dilutions were shown to have significant inhibitory effects on B. cinerea. Fluorescence microscopy and flow cytometry results showed that the purified protein impaired and targeted the cell membranes. This study revealed that these two antimicrobial peptides could potentially be used for replacing antibiotics, which would provide the chance to reduce the emergence of drug resistance.
Collapse
Affiliation(s)
- Tingting Fu
- Department of Plant Pathology, College of Plant Science and Technology and the Key Lab of Crop Disease Monitoring and Safety Control in Hubei Province, Huazhong Agricultural University, Wuhan, 430070, Hubei Province, China
| | - Md Samiul Islam
- Department of Plant Pathology, College of Plant Science and Technology and the Key Lab of Crop Disease Monitoring and Safety Control in Hubei Province, Huazhong Agricultural University, Wuhan, 430070, Hubei Province, China
| | - Mohsin Ali
- Department of Plant Pathology, College of Plant Science and Technology and the Key Lab of Crop Disease Monitoring and Safety Control in Hubei Province, Huazhong Agricultural University, Wuhan, 430070, Hubei Province, China
| | - Jia Wu
- Department of Plant Pathology, College of Plant Science and Technology and the Key Lab of Crop Disease Monitoring and Safety Control in Hubei Province, Huazhong Agricultural University, Wuhan, 430070, Hubei Province, China
| | - Wubei Dong
- Department of Plant Pathology, College of Plant Science and Technology and the Key Lab of Crop Disease Monitoring and Safety Control in Hubei Province, Huazhong Agricultural University, Wuhan, 430070, Hubei Province, China.
| |
Collapse
|
14
|
Coe KA, Lee W, Stone MC, Komazin-Meredith G, Meredith TC, Grad YH, Walker S. Multi-strain Tn-Seq reveals common daptomycin resistance determinants in Staphylococcus aureus. PLoS Pathog 2019; 15:e1007862. [PMID: 31738809 PMCID: PMC6934316 DOI: 10.1371/journal.ppat.1007862] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2019] [Revised: 12/27/2019] [Accepted: 09/24/2019] [Indexed: 01/30/2023] Open
Abstract
Antibiotic-resistant Staphylococcus aureus remains a leading cause of antibiotic resistance-associated mortality in the United States. Given the reality of multi-drug resistant infections, it is imperative that we establish and maintain a pipeline of new compounds to replace or supplement our current antibiotics. A first step towards this goal is to prioritize targets by identifying the genes most consistently required for survival across the S. aureus phylogeny. Here we report the first direct comparison of multiple strains of S. aureus via transposon sequencing. We show that mutant fitness varies by strain in key pathways, underscoring the importance of using more than one strain to differentiate between core and strain-dependent essential genes. We treated the libraries with daptomycin to assess whether the strain-dependent differences impact pathways important for survival. Despite baseline differences in gene importance, several pathways, including the lipoteichoic acid pathway, consistently promote survival under daptomycin exposure, suggesting core vulnerabilities that can be exploited to resensitize daptomycin-nonsusceptible isolates. We also demonstrate the merit of using transposons with outward-facing promoters capable of overexpressing nearby genes for identifying clinically-relevant gain-of-function resistance mechanisms. Together, the daptomycin vulnerabilities and resistance mechanisms support a mode of action with wide-ranging effects on the cell envelope and cell division. This work adds to a growing body of literature demonstrating the nuanced insights gained by comparing Tn-Seq results across multiple bacterial strains. Antibiotic-resistant Staphylococcus aureus kills thousands of people every year in the United States alone. To stay ahead of the looming threat of multidrug-resistant infections, we must continue to develop new antibiotics and find ways to make our current repertoire of antibiotics more effective, including by finding pairs of compounds that perform best when administered together. In the age of next-generation sequencing, we can now use transposon sequencing to find potential targets for new antibiotics on a genome-wide scale, identified as either essential genes or genes that positively influence survival in the presence of an antibiotic. In this work, we created a compendium of genes that are essential across a range of S. aureus strains, as well as those that are important for growth in the presence of the antibiotic daptomycin. The results will be a resource for researchers working to develop the next generation of antibiotic therapies.
Collapse
Affiliation(s)
- Kathryn A. Coe
- Department of Microbiology, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Wonsik Lee
- Department of Microbiology, Harvard Medical School, Boston, Massachusetts, United States of America
- School of Pharmacy, Sungkyunkwan University, Suwon, Republic of Korea
| | - Madeleine C. Stone
- Department of Microbiology, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Gloria Komazin-Meredith
- Department of Biochemistry and Molecular Biology, Pennsylvania State University, Pennsylvania, United States of America
| | - Timothy C. Meredith
- Department of Microbiology, Harvard Medical School, Boston, Massachusetts, United States of America
- Department of Biochemistry and Molecular Biology, Pennsylvania State University, Pennsylvania, United States of America
- * E-mail: (TCM); (YHG); (SW)
| | - Yonatan H. Grad
- Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, United States of America
- Division of Infectious Diseases, Brigham and Women’s Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
- * E-mail: (TCM); (YHG); (SW)
| | - Suzanne Walker
- Department of Microbiology, Harvard Medical School, Boston, Massachusetts, United States of America
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts, United States of America
- * E-mail: (TCM); (YHG); (SW)
| |
Collapse
|
15
|
Anjum MF, Marco-Jimenez F, Duncan D, Marín C, Smith RP, Evans SJ. Livestock-Associated Methicillin-Resistant Staphylococcus aureus From Animals and Animal Products in the UK. Front Microbiol 2019; 10:2136. [PMID: 31572341 PMCID: PMC6751287 DOI: 10.3389/fmicb.2019.02136] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2018] [Accepted: 08/30/2019] [Indexed: 01/08/2023] Open
Abstract
Livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA) is an emerging problem in many parts of the world. Although animal-adapted LA-MRSA has been known for many years, recent reports suggest a possible increasing trend in the zoonotic transmission of LA-MRSA in Europe. Since its emergence in the early 2000's, several investigations have indicated that persons in prolonged, repeated contact with affected livestock are at a higher risk of becoming colonized with LA-MRSA. LA-MRSA monitoring in livestock is voluntary under current EU legislation, and not all member states, including the UK, participate. UK LA-MRSA isolates have been detected through scanning surveillance, where samples are submitted from clinically diseased livestock for diagnostic investigation, and research studies. Surveys conducted on retail beef, pig and poultry meat on sale in the UK have also detected LA-MRSA. Taken together these results suggest that LA-MRSA is present in the UK, possibly at low prevalence level, as suggested by available evidence. In this review, we examine the data available from UK livestock and animal products, and make recommendations for future. We also review the findings from whole genome sequencing (WGS) of the possible lineage of some UK livestock isolates.
Collapse
Affiliation(s)
- Muna F. Anjum
- Department of Bacteriology, Animal and Plant Health Agency, Weybridge, United Kingdom
| | - Francisco Marco-Jimenez
- Instituto de Ciencia y Tecnología Animal, Universitat Politècnica de València, Valencia, Spain
- Department of Epidemiological Sciences, Animal and Plant Health Agency, Weybridge, United Kingdom
| | - Daisy Duncan
- Department of Epidemiological Sciences, Animal and Plant Health Agency, Weybridge, United Kingdom
| | - Clara Marín
- Department of Bacteriology, Animal and Plant Health Agency, Weybridge, United Kingdom
- Departamento de Producción Animal, Sanidad Animal, Salud Pública Veterinaria y Ciencia y Tecnología de los Alimentos, Facultad de Veterinaria, Instituto de Ciencias Biomédicas, Universidad CEU Cardenal Herrera, CEU Universities, Valencia, Spain
| | - Richard P. Smith
- Department of Epidemiological Sciences, Animal and Plant Health Agency, Weybridge, United Kingdom
| | - Sarah J. Evans
- Department of Bacteriology, Animal and Plant Health Agency, Weybridge, United Kingdom
| |
Collapse
|
16
|
Roles of Staphylococcus aureus Mnh1 and Mnh2 Antiporters in Salt Tolerance, Alkali Tolerance, and Pathogenesis. J Bacteriol 2018; 200:JB.00611-17. [PMID: 29263099 PMCID: PMC5809693 DOI: 10.1128/jb.00611-17] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2017] [Accepted: 12/08/2017] [Indexed: 01/19/2023] Open
Abstract
Staphylococcus aureus has three types of cation/proton antiporters. The type 3 family includes two multisubunit Na+/H+ (Mnh) antiporters, Mnh1 and Mnh2. These antiporters are clusters of seven hydrophobic membrane-bound protein subunits. Mnh antiporters play important roles in maintaining cytoplasmic pH in prokaryotes, enabling their survival under extreme environmental stress. In this study, we investigated the physiological roles and catalytic properties of Mnh1 and Mnh2 in S. aureus. Both Mnh1 and Mnh2 were cloned separately into a pGEM3Z+ vector in the antiporter-deficient KNabc Escherichia coli strain. The catalytic properties of the antiporters were measured in everted (inside out) vesicles. The Mnh1 antiporter exhibited a significant exchange of Na+/H+ cations at pH 7.5. Mnh2 showed a significant exchange of both Na+/H+ and K+/H+ cations, especially at pH 8.5. Under elevated salt conditions, deletion of the mnhA1 gene resulted in a significant reduction in the growth rate of S. aureus in the range of pH 7.5 to 9. Deletion of mnhA2 had similar effects but mainly in the range of pH 8.5 to 9.5. Double deletion of mnhA1 and mnhA2 led to a severe reduction in the S. aureus growth rate mainly at pH values above 8.5. The effects of functional losses of both antiporters in S. aureus were also assessed via their support of virulence in a mouse in vivo infection model. Deletion of the mnhA1 gene led to a major loss of S. aureus virulence in mice, while deletion of mnh2 led to no change in virulence. IMPORTANCE This study focuses on the catalytic properties and physiological roles of Mnh1 and Mnh2 cation/proton antiporters in S. aureus and their contributions under different stress conditions. The Mnh1 antiporter was found to have catalytic activity for Na+/H+ antiport, and it plays a significant role in maintaining halotolerance at pH 7.5 while the Mnh2 antiporter has catalytic antiporter activities for Na+/H+ and K+/H+ that have roles in both osmotolerance and halotolerance in S. aureus. Study of S. aureus with a single deletion of either mnhA1 or mnhA2 was assessed in an infection model of mice. The result shows that mnhA1, but not mnhA2, plays a major role in S. aureus virulence.
Collapse
|
17
|
Identification of Fitness Determinants during Energy-Limited Growth Arrest in Pseudomonas aeruginosa. mBio 2017; 8:mBio.01170-17. [PMID: 29184024 PMCID: PMC5705914 DOI: 10.1128/mbio.01170-17] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Microbial growth arrest can be triggered by diverse factors, one of which is energy limitation due to scarcity of electron donors or acceptors. Genes that govern fitness during energy-limited growth arrest and the extent to which they overlap between different types of energy limitation are poorly defined. In this study, we exploited the fact that Pseudomonas aeruginosa can remain viable over several weeks when limited for organic carbon (pyruvate) as an electron donor or oxygen as an electron acceptor. ATP values were reduced under both types of limitation, yet more severely in the absence of oxygen. Using transposon-insertion sequencing (Tn-seq), we identified fitness determinants in these two energy-limited states. Multiple genes encoding general functions like transcriptional regulation and energy generation were required for fitness during carbon or oxygen limitation, yet many specific genes, and thus specific activities, differed in their relevance between these states. For instance, the global regulator RpoS was required during both types of energy limitation, while other global regulators such as DksA and LasR were required only during carbon or oxygen limitation, respectively. Similarly, certain ribosomal and tRNA modifications were specifically required during oxygen limitation. We validated fitness defects during energy limitation using independently generated mutants of genes detected in our screen. Mutants in distinct functional categories exhibited different fitness dynamics: regulatory genes generally manifested a phenotype early, whereas genes involved in cell wall metabolism were required later. Together, these results provide a new window into how P. aeruginosa survives growth arrest. Growth-arrested bacteria are ubiquitous in nature and disease yet understudied at the molecular level. For example, growth-arrested cells constitute a major subpopulation of mature biofilms, serving as an antibiotic-tolerant reservoir in chronic infections. Identification of the genes required for survival of growth arrest (encompassing entry, maintenance, and exit) is an important first step toward understanding the physiology of bacteria in this state. Using Tn-seq, we identified and validated genes required for fitness of Pseudomonas aeruginosa when energy limited for organic carbon or oxygen, which represent two common causes of growth arrest for P. aeruginosa in diverse habitats. This unbiased, genome-wide survey is the first to reveal essential activities for a pathogen experiencing different types of energy limitation, finding both shared and divergent activities that are relevant at different survival stages. Future efforts can now be directed toward understanding how the biomolecules responsible for these activities contribute to fitness under these conditions.
Collapse
|
18
|
Cardona ST, Choy M, Hogan AM. Essential Two-Component Systems Regulating Cell Envelope Functions: Opportunities for Novel Antibiotic Therapies. J Membr Biol 2017; 251:75-89. [DOI: 10.1007/s00232-017-9995-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2017] [Accepted: 10/20/2017] [Indexed: 01/22/2023]
|
19
|
Kwon YM, Ricke SC, Mandal RK. Transposon sequencing: methods and expanding applications. Appl Microbiol Biotechnol 2015; 100:31-43. [DOI: 10.1007/s00253-015-7037-8] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2015] [Revised: 09/15/2015] [Accepted: 09/20/2015] [Indexed: 12/26/2022]
|
20
|
Coady A, Xu M, Phung Q, Cheung TK, Bakalarski C, Alexander MK, Lehar SM, Kim J, Park S, Tan MW, Nishiyama M. The Staphylococcus aureus ABC-Type Manganese Transporter MntABC Is Critical for Reinitiation of Bacterial Replication Following Exposure to Phagocytic Oxidative Burst. PLoS One 2015; 10:e0138350. [PMID: 26379037 PMCID: PMC4574778 DOI: 10.1371/journal.pone.0138350] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2015] [Accepted: 07/31/2015] [Indexed: 01/04/2023] Open
Abstract
Manganese plays a central role in cellular detoxification of reactive oxygen species (ROS). Therefore, manganese acquisition is considered to be important for bacterial pathogenesis by counteracting the oxidative burst of phagocytic cells during host infection. However, detailed analysis of the interplay between bacterial manganese acquisition and phagocytic cells and its impact on bacterial pathogenesis has remained elusive for Staphylococcus aureus, a major human pathogen. Here, we show that a mntC mutant, which lacks the functional manganese transporter MntABC, was more sensitive to killing by human neutrophils but not murine macrophages, unless the mntC mutant was pre-exposed to oxidative stress. Notably, the mntC mutant formed strikingly small colonies when recovered from both type of phagocytic cells. We show that this phenotype is a direct consequence of the inability of the mntC mutant to reinitiate growth after exposure to phagocytic oxidative burst. Transcript and quantitative proteomics analyses revealed that the manganese-dependent ribonucleotide reductase complex NrdEF, which is essential for DNA synthesis and repair, was highly induced in the mntC mutant under oxidative stress conditions including after phagocytosis. Since NrdEF proteins are essential for S. aureus viability we hypothesize that cells lacking MntABC might attempt to compensate for the impaired function of NrdEF by increasing their expression. Our data suggest that besides ROS detoxification, functional manganese acquisition is likely crucial for S. aureus pathogenesis by repairing oxidative damages, thereby ensuring efficient bacterial growth after phagocytic oxidative burst, which is an attribute critical for disseminating and establishing infection in the host.
Collapse
Affiliation(s)
- Alison Coady
- Department of Infectious Diseases, Genentech Inc., South San Francisco, California, United States of America
| | - Min Xu
- Department of Translational Immunology, Genentech Inc., South San Francisco, California, United States of America
| | - Qui Phung
- Department of Protein Chemistry, Genentech Inc., South San Francisco, California, United States of America
| | - Tommy K. Cheung
- Department of Protein Chemistry, Genentech Inc., South San Francisco, California, United States of America
| | - Corey Bakalarski
- Department of Protein Chemistry, Genentech Inc., South San Francisco, California, United States of America
- Department of Bioinformatics, Genentech Inc., South San Francisco, California, United States of America
| | - Mary Kate Alexander
- Department of Infectious Diseases, Genentech Inc., South San Francisco, California, United States of America
| | - Sophie M. Lehar
- Department of Infectious Diseases, Genentech Inc., South San Francisco, California, United States of America
| | - Janice Kim
- Department of Translational Immunology, Genentech Inc., South San Francisco, California, United States of America
| | - Summer Park
- Department of Translational Immunology, Genentech Inc., South San Francisco, California, United States of America
| | - Man-Wah Tan
- Department of Infectious Diseases, Genentech Inc., South San Francisco, California, United States of America
| | - Mireille Nishiyama
- Department of Infectious Diseases, Genentech Inc., South San Francisco, California, United States of America
- * E-mail:
| |
Collapse
|
21
|
Santiago M, Matano LM, Moussa SH, Gilmore MS, Walker S, Meredith TC. A new platform for ultra-high density Staphylococcus aureus transposon libraries. BMC Genomics 2015; 16:252. [PMID: 25888466 PMCID: PMC4389836 DOI: 10.1186/s12864-015-1361-3] [Citation(s) in RCA: 66] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2014] [Accepted: 02/19/2015] [Indexed: 01/17/2023] Open
Abstract
BACKGROUND Staphylococcus aureus readily develops resistance to antibiotics and achieving effective therapies to overcome resistance requires in-depth understanding of S. aureus biology. High throughput, parallel-sequencing methods for analyzing transposon mutant libraries have the potential to revolutionize studies of S. aureus, but the genetic tools to take advantage of the power of next generation sequencing have not been fully developed. RESULTS Here we report a phage-based transposition system to make ultra-high density transposon libraries for genome-wide analysis of mutant fitness in any Φ11-transducible S. aureus strain. The high efficiency of the delivery system has made it possible to multiplex transposon cassettes containing different regulatory elements in order to make libraries in which genes are over- or under-expressed as well as deleted. By incorporating transposon-specific barcodes into the cassettes, we can evaluate how null mutations and changes in gene expression levels affect fitness in a single sequencing data set. Demonstrating the power of the system, we have prepared a library containing more than 690,000 unique insertions. Because one unique feature of the phage-based approach is that temperature-sensitive mutants are retained, we have carried out a genome-wide study of S. aureus genes involved in withstanding temperature stress. We find that many genes previously identified as essential are temperature sensitive and also identify a number of genes that, when disrupted, confer a growth advantage at elevated temperatures. CONCLUSIONS The platform described here reliably provides mutant collections of unparalleled genotypic diversity and will enable a wide range of functional genomic studies in S. aureus.
Collapse
Affiliation(s)
- Marina Santiago
- Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA, 02115, USA.
| | - Leigh M Matano
- Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA, 02115, USA.
| | - Samir H Moussa
- Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA, 02115, USA.
| | - Michael S Gilmore
- Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA, 02115, USA.
- Department of Ophthalmology, Harvard Medical School, Massachusetts Eye and Ear Infirmary, Boston, MA, 02114, USA.
| | - Suzanne Walker
- Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA, 02115, USA.
| | - Timothy C Meredith
- Department of Microbiology and Immunobiology, Harvard Medical School, Boston, MA, 02115, USA.
- Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, PA, 16802, USA.
| |
Collapse
|