1
|
Muñoz-Cazalla A, de Quinto I, Álvaro-Llorente L, Rodríguez-Beltrán J, Herencias C. The role of bacterial metabolism in human gut colonization. Int Microbiol 2024:10.1007/s10123-024-00550-6. [PMID: 38937311 DOI: 10.1007/s10123-024-00550-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2024] [Revised: 06/12/2024] [Accepted: 06/14/2024] [Indexed: 06/29/2024]
Abstract
Can we anticipate the emergence of the next pandemic antibiotic-resistant bacterial clone? Addressing such an ambitious question relies on our ability to comprehensively understand the ecological and epidemiological factors fostering the evolution of high-risk clones. Among these factors, the ability to persistently colonize and thrive in the human gut is crucial for most high-risk clones. Nonetheless, the causes and mechanisms facilitating successful gut colonization remain obscure. Here, we review recent evidence that suggests that bacterial metabolism plays a pivotal role in determining the ability of high-risk clones to colonize the human gut. Subsequently, we outline novel approaches that enable the exploration of microbial metabolism at an unprecedented scale and level of detail. A thorough understanding of the constraints and opportunities of bacterial metabolism in gut colonization will foster our ability to predict the emergence of high-risk clones and take appropriate containment strategies.
Collapse
Affiliation(s)
- Ada Muñoz-Cazalla
- Servicio de Microbiología, Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), Hospital Universitario Ramón y Cajal, Madrid, Spain
| | - Ignacio de Quinto
- Servicio de Microbiología, Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), Hospital Universitario Ramón y Cajal, Madrid, Spain
| | - Laura Álvaro-Llorente
- Servicio de Microbiología, Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), Hospital Universitario Ramón y Cajal, Madrid, Spain
| | - Jerónimo Rodríguez-Beltrán
- Servicio de Microbiología, Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), Hospital Universitario Ramón y Cajal, Madrid, Spain.
- Centro de Investigación Biomédica en Red de Enfermedades Infecciosas-CIBERINFEC, Instituto de Salud Carlos III, Madrid, Spain.
| | - Cristina Herencias
- Servicio de Microbiología, Instituto Ramón y Cajal de Investigación Sanitaria (IRYCIS), Hospital Universitario Ramón y Cajal, Madrid, Spain.
- Centro de Investigación Biomédica en Red de Enfermedades Infecciosas-CIBERINFEC, Instituto de Salud Carlos III, Madrid, Spain.
| |
Collapse
|
2
|
Yared MJ, Marcelot A, Barraud P. Beyond the Anticodon: tRNA Core Modifications and Their Impact on Structure, Translation and Stress Adaptation. Genes (Basel) 2024; 15:374. [PMID: 38540433 PMCID: PMC10969862 DOI: 10.3390/genes15030374] [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: 02/21/2024] [Revised: 03/15/2024] [Accepted: 03/18/2024] [Indexed: 06/14/2024] Open
Abstract
Transfer RNAs (tRNAs) are heavily decorated with post-transcriptional chemical modifications. Approximately 100 different modifications have been identified in tRNAs, and each tRNA typically contains 5-15 modifications that are incorporated at specific sites along the tRNA sequence. These modifications may be classified into two groups according to their position in the three-dimensional tRNA structure, i.e., modifications in the tRNA core and modifications in the anticodon-loop (ACL) region. Since many modified nucleotides in the tRNA core are involved in the formation of tertiary interactions implicated in tRNA folding, these modifications are key to tRNA stability and resistance to RNA decay pathways. In comparison to the extensively studied ACL modifications, tRNA core modifications have generally received less attention, although they have been shown to play important roles beyond tRNA stability. Here, we review and place in perspective selected data on tRNA core modifications. We present their impact on tRNA structure and stability and report how these changes manifest themselves at the functional level in translation, fitness and stress adaptation.
Collapse
Affiliation(s)
| | | | - Pierre Barraud
- Expression Génétique Microbienne, Université Paris Cité, CNRS, Institut de Biologie Physico-Chimique, F-75005 Paris, France; (M.-J.Y.); (A.M.)
| |
Collapse
|
3
|
Calero P, Gurdo N, Nikel PI. Role of the CrcB transporter of Pseudomonas putida in the multi-level stress response elicited by mineral fluoride. Environ Microbiol 2022; 24:5082-5104. [PMID: 35726888 PMCID: PMC9796867 DOI: 10.1111/1462-2920.16110] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2022] [Revised: 06/16/2022] [Accepted: 06/19/2022] [Indexed: 01/07/2023]
Abstract
The presence of mineral fluoride (F- ) in the environment has both a geogenic and anthropogenic origin, and the halide has been described to be toxic in virtually all living organisms. While the evidence gathered in different microbial species supports this notion, a systematic exploration of the effects of F- salts on the metabolism and physiology of environmental bacteria remained underexplored thus far. In this work, we studied and characterized tolerance mechanisms deployed by the model soil bacterium Pseudomonas putida KT2440 against NaF. By adopting systems-level omic approaches, including functional genomics and metabolomics, we gauged the impact of this anion at different regulatory levels under conditions that impair bacterial growth. Several genes involved in halide tolerance were isolated in a genome-wide Tn-Seq screening-among which crcB, encoding an F- -specific exporter, was shown to play the predominant role in detoxification. High-resolution metabolomics, combined with the assessment of intracellular and extracellular pH values and quantitative physiology experiments, underscored the key nodes in central carbon metabolism affected by the presence of F- . Taken together, our results indicate that P. putida undergoes a general, multi-level stress response when challenged with NaF that significantly differs from that caused by other saline stressors. While microbial stress responses to saline and oxidative challenges have been extensively studied and described in the literature, very little is known about the impact of fluoride (F- ) on bacterial physiology and metabolism. This state of affairs contrasts with the fact that F- is more abundant than other halides in the Earth crust (e.g. in some soils, the F- concentration can reach up to 1 mg gsoil -1 ). Understanding the global effects of NaF treatment on bacterial physiology is not only relevant to unveil distinct mechanisms of detoxification but it could also guide microbial engineering approaches for the target incorporation of fluorine into value-added organofluorine molecules. In this regard, the soil bacterium P. putida constitutes an ideal model to explore such scenarios, since this species is particularly known for its high level of stress resistance against a variety of physicochemical perturbations.
Collapse
Affiliation(s)
- Patricia Calero
- The Novo Nordisk Foundation Center for BiosustainabilityTechnical University of DenmarkKongens LyngbyDenmark
| | - Nicolás Gurdo
- The Novo Nordisk Foundation Center for BiosustainabilityTechnical University of DenmarkKongens LyngbyDenmark
| | - Pablo I. Nikel
- The Novo Nordisk Foundation Center for BiosustainabilityTechnical University of DenmarkKongens LyngbyDenmark
| |
Collapse
|
4
|
López-López N, Gil-Campillo C, Díez-Martínez R, Garmendia J. Learning from -omics strategies applied to uncover Haemophilus influenzae host-pathogen interactions: Current status and perspectives. Comput Struct Biotechnol J 2021; 19:3042-3050. [PMID: 34136102 PMCID: PMC8178019 DOI: 10.1016/j.csbj.2021.05.026] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Revised: 05/11/2021] [Accepted: 05/11/2021] [Indexed: 11/15/2022] Open
Abstract
Haemophilus influenzae has contributed to key bacterial genome sequencing hallmarks, as being not only the first bacterium to be genome-sequenced, but also starring the first genome-wide analysis of chromosomes directly transformed with DNA from a divergent genotype, and pioneering Tn-seq methodologies. Over the years, the phenomenal and constantly evolving development of -omic technologies applied to a whole range of biological questions of clinical relevance in the H. influenzae-host interplay, has greatly moved forward our understanding of this human-adapted pathogen, responsible for multiple acute and chronic infections of the respiratory tract. In this way, essential genes, virulence factors, pathoadaptive traits, and multi-layer gene expression regulatory networks with both genomic and epigenomic complexity levels are being elucidated. Likewise, the unstoppable increasing whole genome sequencing information underpinning H. influenzae great genomic plasticity, mainly when referring to non-capsulated strains, poses major challenges to understand the genomic basis of clinically relevant phenotypes and even more, to clearly highlight potential targets of clinical interest for diagnostic, therapeutic or vaccine development. We review here how genomic, transcriptomic, proteomic and metabolomic-based approaches are great contributors to our current understanding of the interactions between H. influenzae and the human airways, and point possible strategies to maximize their usefulness in the context of biomedical research and clinical needs on this human-adapted bacterial pathogen.
Collapse
Affiliation(s)
- Nahikari López-López
- Instituto de Agrobiotecnología, Consejo Superior de Investigaciones Científicas (IdAB-CSIC)-Gobierno de Navarra, Mutilva, Spain
| | - Celia Gil-Campillo
- Instituto de Agrobiotecnología, Consejo Superior de Investigaciones Científicas (IdAB-CSIC)-Gobierno de Navarra, Mutilva, Spain
| | | | - Junkal Garmendia
- Instituto de Agrobiotecnología, Consejo Superior de Investigaciones Científicas (IdAB-CSIC)-Gobierno de Navarra, Mutilva, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Respiratorias (CIBERES), Madrid, Spain
| |
Collapse
|
5
|
Kim H, Wu K, Lee C. Stress-Responsive Periplasmic Chaperones in Bacteria. Front Mol Biosci 2021; 8:678697. [PMID: 34046432 PMCID: PMC8144458 DOI: 10.3389/fmolb.2021.678697] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Accepted: 04/19/2021] [Indexed: 01/14/2023] Open
Abstract
Periplasmic proteins are involved in a wide range of bacterial functions, including motility, biofilm formation, sensing environmental cues, and small-molecule transport. In addition, a wide range of outer membrane proteins and proteins that are secreted into the media must travel through the periplasm to reach their final destinations. Since the porous outer membrane allows for the free diffusion of small molecules, periplasmic proteins and those that travel through this compartment are more vulnerable to external environmental changes, including those that result in protein unfolding, than cytoplasmic proteins are. To enable bacterial survival under various stress conditions, a robust protein quality control system is required in the periplasm. In this review, we focus on several periplasmic chaperones that are stress responsive, including Spy, which responds to envelope-stress, DegP, which responds to temperature to modulate chaperone/protease activity, HdeA and HdeB, which respond to acid stress, and UgpB, which functions as a bile-responsive chaperone.
Collapse
Affiliation(s)
- Hyunhee Kim
- Department of Biological Sciences, Ajou University, Suwon, South Korea
- Molecular, Cellular, and Developmental Biology, Howard Hughes Medical Institute, University of Michigan, Ann Arbor, MI, United States
| | - Kevin Wu
- Molecular, Cellular, and Developmental Biology, Howard Hughes Medical Institute, University of Michigan, Ann Arbor, MI, United States
- Department of Biophysics, University of Michigan, Ann Arbor, MI, United States
| | - Changhan Lee
- Department of Biological Sciences, Ajou University, Suwon, South Korea
| |
Collapse
|
6
|
Kobras CM, Fenton AK, Sheppard SK. Next-generation microbiology: from comparative genomics to gene function. Genome Biol 2021; 22:123. [PMID: 33926534 PMCID: PMC8082670 DOI: 10.1186/s13059-021-02344-9] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Accepted: 04/08/2021] [Indexed: 11/12/2022] Open
Abstract
Microbiology is at a turning point in its 120-year history. Widespread next-generation sequencing has revealed genetic complexity among bacteria that could hardly have been imagined by pioneers such as Pasteur, Escherich and Koch. This data cascade brings enormous potential to improve our understanding of individual bacterial cells and the genetic basis of phenotype variation. However, this revolution in data science cannot replace established microbiology practices, presenting the challenge of how to integrate these new techniques. Contrasting comparative and functional genomic approaches, we evoke molecular microbiology theory and established practice to present a conceptual framework and practical roadmap for next-generation microbiology.
Collapse
Affiliation(s)
- Carolin M Kobras
- Department of Molecular Biology & Biotechnology, University of Sheffield, The Florey Institute for Host-Pathogen Interactions, Sheffield, UK
| | - Andrew K Fenton
- Department of Molecular Biology & Biotechnology, University of Sheffield, The Florey Institute for Host-Pathogen Interactions, Sheffield, UK.
| | - Samuel K Sheppard
- Department of Biology & Biochemistry, University of Bath, Milner Centre for Evolution, Bath, UK.
| |
Collapse
|
7
|
Le Breton Y, Belew AT, McIver KS. Protocols for Tn-seq Analyses in the Group A Streptococcus. Methods Mol Biol 2021; 2136:33-57. [PMID: 32430812 DOI: 10.1007/978-1-0716-0467-0_4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Transposon-sequencing (Tn-seq) has revolutionized forward-genetic analyses to study genotype-phenotype associations and interrogate bacterial cell physiology. The Tn-seq approach allows the en masse monitoring of highly complex mutant libraries, leveraging massive parallel DNA sequencing as a means to characterize the composition of these mutant pools on a genome-scale with unprecedented nucleotide-level high resolution. In this chapter, we present step-by-step protocols for Tn-seq analyses in the human pathogen Streptococcus pyogenes (Group A Streptococcus or GAS) using the mariner-based Krmit transposon. We detail how to generate highly complex Krmit mutant libraries in GAS and the en masse production of Krmit insertion tags for Illumina sequencing of the transposon-genome junctions for Tn-seq analyses. Most of the protocols presented here were developed and implemented using the S. pyogenes M1T1 serotype clinical isolate 5448, but they have been successfully applied to multiple GAS serotypes as well as other pathogenic Streptococci.
Collapse
Affiliation(s)
- Yoann Le Breton
- Wound Infections Department, Bacterial Diseases Branch, Walter Reed Army Institute for Research, Silver Spring, MD, USA.
| | - Ashton T Belew
- Department of Cell Biology and Molecular Genetics and Maryland Pathogen Research Institute, University of Maryland, College Park, College Park, MD, USA.,Center for Bioinformatics and Computational Biology, University of Maryland, College Park, College Park, MD, USA
| | - Kevin S McIver
- Department of Cell Biology and Molecular Genetics and Maryland Pathogen Research Institute, University of Maryland, College Park, College Park, MD, USA
| |
Collapse
|
8
|
Miller DP, Scott DA. Inherently and Conditionally Essential Protein Catabolism Genes of Porphyromonas gingivalis. Trends Microbiol 2020; 29:54-64. [PMID: 33071035 DOI: 10.1016/j.tim.2020.09.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Revised: 07/01/2020] [Accepted: 09/02/2020] [Indexed: 02/06/2023]
Abstract
Proteases are critical virulence determinants of Porphyromonas gingivalis, an emerging Alzheimer's disease, cancer, and arthritis pathogen and established agent of periodontitis. Transposon sequencing has been employed to define the core essential genome of this bacterium and genes conditionally essential in multiple environments - abscess formation; epithelial colonization; and cigarette smoke toxin exposure; as well as to elucidate genes required for iron acquisition and a functional type 9 secretion system. Validated and predicted protein catabolism genes identified include a combination of established virulence factors and a larger set of seemingly more mundane proteolytic genes. The functions and relevance of genes that share essentiality in multiple disease-relevant conditions are examined. These common stress-related genes may represent particularly attractive therapeutic targets for the control of P. gingivalis infections.
Collapse
Affiliation(s)
- Daniel P Miller
- Department of Microbiology and Immunology, Virginia Commonwealth University, Richmond, VA, USA
| | - David A Scott
- Department of Oral Immunology and Infectious Diseases, University of Louisville, Louisville, KY, USA.
| |
Collapse
|
9
|
Lee C, Betschinger P, Wu K, Żyła DS, Glockshuber R, Bardwell JC. A metabolite binding protein moonlights as a bile-responsive chaperone. EMBO J 2020; 39:e104231. [PMID: 32882062 DOI: 10.15252/embj.2019104231] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Revised: 07/12/2020] [Accepted: 07/17/2020] [Indexed: 12/27/2022] Open
Abstract
Bile salts are secreted into the gastrointestinal tract to aid in the absorption of lipids. In addition, bile salts show potent antimicrobial activity in part by mediating bacterial protein unfolding and aggregation. Here, using a protein folding sensor, we made the surprising discovery that the Escherichia coli periplasmic glycerol-3-phosphate (G3P)-binding protein UgpB can serve, in the absence of its substrate, as a potent molecular chaperone that exhibits anti-aggregation activity against bile salt-induced protein aggregation. The substrate G3P, which is known to accumulate in the later compartments of the digestive system, triggers a functional switch between UgpB's activity as a molecular chaperone and its activity as a G3P transporter. A UgpB mutant unable to bind G3P is constitutively active as a chaperone, and its crystal structure shows that it contains a deep surface groove absent in the G3P-bound wild-type UgpB. Our work illustrates how evolution may be able to convert threats into signals that first activate and then inactivate a chaperone at the protein level in a manner that bypasses the need for ATP.
Collapse
Affiliation(s)
- Changhan Lee
- Department of Molecular, Cellular, and Developmental Biology, Howard Hughes Medical Institute, University of Michigan, Ann Arbor, MI, USA
| | - Patrick Betschinger
- Department of Molecular, Cellular, and Developmental Biology, Howard Hughes Medical Institute, University of Michigan, Ann Arbor, MI, USA
| | - Kevin Wu
- Department of Molecular, Cellular, and Developmental Biology, Howard Hughes Medical Institute, University of Michigan, Ann Arbor, MI, USA.,Department of Biophysics, University of Michigan, Ann Arbor, MI, USA
| | - Dawid S Żyła
- Institute of Molecular Biology and Biophysics, Department of Biology, ETH Zurich, Zurich, Switzerland
| | - Rudi Glockshuber
- Institute of Molecular Biology and Biophysics, Department of Biology, ETH Zurich, Zurich, Switzerland
| | - James Ca Bardwell
- Department of Molecular, Cellular, and Developmental Biology, Howard Hughes Medical Institute, University of Michigan, Ann Arbor, MI, USA
| |
Collapse
|
10
|
Røder HL, Olsen NMC, Whiteley M, Burmølle M. Unravelling interspecies interactions across heterogeneities in complex biofilm communities. Environ Microbiol 2019; 22:5-16. [DOI: 10.1111/1462-2920.14834] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2019] [Revised: 10/15/2019] [Accepted: 10/17/2019] [Indexed: 01/29/2023]
Affiliation(s)
- Henriette L. Røder
- Section of Microbiology, Department of BiologyUniversity of Copenhagen Copenhagen Denmark
| | - Nanna M. C. Olsen
- Section of Microbiology, Department of BiologyUniversity of Copenhagen Copenhagen Denmark
| | - Marvin Whiteley
- School of Biological SciencesGeorgia Institute of Technology, Atlanta Georgia USA
- Emory‐Children's Cystic Fibrosis Center, Atlanta Georgia USA
- Center for Microbial Dynamics and InfectionGeorgia Institute of Technology, Atlanta Georgia USA
| | - Mette Burmølle
- Section of Microbiology, Department of BiologyUniversity of Copenhagen Copenhagen Denmark
| |
Collapse
|
11
|
Abstract
Transposon insertion sequencing (Tn-seq) is a powerful method for identifying genes required for virtually any growth or survival trait in bacteria. The technology employs next-generation DNA sequencing to identify and quantify the relative abundances of individual transposon mutants within complex pools of such mutants. When applied to pools of thousands to millions of random transposon mutants grown under selective pressure, the technique can rapidly identify, at genome scale, the mutants and corresponding genes negatively or positively selected. This chapter presents core protocols for Tn-seq analysis of Acinetobacter baumannii: generation of a high-saturation random transposon mutant pool, and isolation and sequencing of transposon-genome junctions from such a pool for identifying and quantifying the individual mutants. With these tools, the researcher can address diverse biological questions by carrying out selective growth of a mutant pool followed by Tn-seq analysis to identify genotype-phenotype associations.
Collapse
|
12
|
Cieplik F, Jakubovics NS, Buchalla W, Maisch T, Hellwig E, Al-Ahmad A. Resistance Toward Chlorhexidine in Oral Bacteria - Is There Cause for Concern? Front Microbiol 2019; 10:587. [PMID: 30967854 PMCID: PMC6439480 DOI: 10.3389/fmicb.2019.00587] [Citation(s) in RCA: 203] [Impact Index Per Article: 40.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2018] [Accepted: 03/07/2019] [Indexed: 12/20/2022] Open
Abstract
The threat of antibiotic resistance has attracted strong interest during the last two decades, thus stimulating stewardship programs and research on alternative antimicrobial therapies. Conversely, much less attention has been given to the directly related problem of resistance toward antiseptics and biocides. While bacterial resistances toward triclosan or quaternary ammonium compounds have been considered in this context, the bis-biguanide chlorhexidine (CHX) has been put into focus only very recently when its use was associated with emergence of stable resistance to the last-resort antibiotic colistin. The antimicrobial effect of CHX is based on damaging the bacterial cytoplasmic membrane and subsequent leakage of cytoplasmic material. Consequently, mechanisms conferring resistance toward CHX include multidrug efflux pumps and cell membrane changes. For instance, in staphylococci it has been shown that plasmid-borne qac ("quaternary ammonium compound") genes encode Qac efflux proteins that recognize cationic antiseptics as substrates. In Pseudomonas stutzeri, changes in the outer membrane protein and lipopolysaccharide profiles have been implicated in CHX resistance. However, little is known about the risk of resistance toward CHX in oral bacteria and potential mechanisms conferring this resistance or even cross-resistances toward antibiotics. Interestingly, there is also little awareness about the risk of CHX resistance in the dental community even though CHX has been widely used in dental practice as the gold-standard antiseptic for more than 40 years and is also included in a wide range of oral care consumer products. This review provides an overview of general resistance mechanisms toward CHX and the evidence for CHX resistance in oral bacteria. Furthermore, this work aims to raise awareness among the dental community about the risk of resistance toward CHX and accompanying cross-resistance to antibiotics. We propose new research directions related to the effects of CHX on bacteria in oral biofilms.
Collapse
Affiliation(s)
- Fabian Cieplik
- Department of Conservative Dentistry and Periodontology, University Medical Center Regensburg, Regensburg, Germany
| | - Nicholas S Jakubovics
- Centre for Oral Health Research, School of Dental Sciences, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Wolfgang Buchalla
- Department of Conservative Dentistry and Periodontology, University Medical Center Regensburg, Regensburg, Germany
| | - Tim Maisch
- Department of Dermatology, University Medical Center Regensburg, Regensburg, Germany
| | - Elmar Hellwig
- Department of Operative Dentistry and Periodontology, Center for Dental Medicine, Faculty of Medicine, University of Freiburg, Freiburg im Breisgau, Germany
| | - Ali Al-Ahmad
- Department of Operative Dentistry and Periodontology, Center for Dental Medicine, Faculty of Medicine, University of Freiburg, Freiburg im Breisgau, Germany
| |
Collapse
|
13
|
Shields RC, Jensen PA. The bare necessities: Uncovering essential and condition-critical genes with transposon sequencing. Mol Oral Microbiol 2019; 34:39-50. [PMID: 30739386 DOI: 10.1111/omi.12256] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2018] [Revised: 01/18/2019] [Accepted: 02/06/2019] [Indexed: 12/11/2022]
Abstract
Querying gene function in bacteria has been greatly accelerated by the advent of transposon sequencing (Tn-seq) technologies (related Tn-seq strategies are known as TraDIS, INSeq, RB-TnSeq, and HITS). Pooled populations of transposon mutants are cultured in an environment and next-generation sequencing tools are used to determine areas of the genome that are important for bacterial fitness. In this review we provide an overview of Tn-seq methodologies and discuss how Tn-seq has been applied, or could be applied, to the study of oral microbiology. These applications include studying the essential genome as a means to rationally design therapeutic agents. Tn-seq has also contributed to our understanding of well-studied biological processes in oral bacteria. Other important applications include in vivo pathogenesis studies and use of Tn-seq to probe the molecular basis of microbial interactions. We also highlight recent advancements in techniques that act in synergy with Tn-seq such as clustered regularly interspaced short palindromic repeats (CRISPR) interference and microfluidic chip platforms.
Collapse
Affiliation(s)
- Robert C Shields
- Department of Oral Biology, College of Dentistry, University of Florida, Gainesville, Florida
| | - Paul A Jensen
- Department of Bioengineering and Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois
| |
Collapse
|
14
|
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
|
15
|
Le Breton Y, Belew AT, Freiberg JA, Sundar GS, Islam E, Lieberman J, Shirtliff ME, Tettelin H, El-Sayed NM, McIver KS. Genome-wide discovery of novel M1T1 group A streptococcal determinants important for fitness and virulence during soft-tissue infection. PLoS Pathog 2017; 13:e1006584. [PMID: 28832676 PMCID: PMC5584981 DOI: 10.1371/journal.ppat.1006584] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2017] [Revised: 09/05/2017] [Accepted: 08/15/2017] [Indexed: 01/08/2023] Open
Abstract
The Group A Streptococcus remains a significant human pathogen causing a wide array of disease ranging from self-limiting to life-threatening invasive infections. Epithelium (skin or throat) colonization with progression to the subepithelial tissues is the common step in all GAS infections. Here, we used transposon-sequencing (Tn-seq) to define the GAS 5448 genetic requirements for in vivo fitness in subepithelial tissue. A near-saturation transposon library of the M1T1 GAS 5448 strain was injected subcutaneously into mice, producing suppurative inflammation at 24 h that progressed to prominent abscesses with tissue necrosis at 48 h. The library composition was monitored en masse by Tn-seq and ratios of mutant abundance comparing the output (12, 24 and 48 h) versus input (T0) mutant pools were calculated for each gene. We identified a total of 273 subcutaneous fitness (scf) genes with 147 genes (55 of unknown function) critical for the M1T1 GAS 5448 fitness in vivo; and 126 genes (53 of unknown function) potentially linked to in vivo fitness advantage. Selected scf genes were validated in competitive subcutaneous infection with parental 5448. Two uncharacterized genes, scfA and scfB, encoding putative membrane-associated proteins and conserved among Gram-positive pathogens, were further characterized. Defined scfAB mutants in GAS were outcompeted by wild type 5448 in vivo, attenuated for lesion formation in the soft tissue infection model and dissemination to the bloodstream. We hypothesize that scfAB play an integral role in enhancing adaptation and fitness of GAS during localized skin infection, and potentially in propagation to other deeper host environments. The WHO ranks the Group A Streptococcus (GAS) in the top 10 leading causes of morbidity and mortality from infectious diseases worldwide. GAS is a strict human pathogen causing both benign superficial infections as well as life-threatening invasive diseases. All GAS infections begin by colonization of an epithelium (throat or skin) followed by propagation into subepithelial tissues. The genetic requirements for M1T1 GAS 5448 within this niche were interrogated by in vivo transposon sequencing (Tn-seq), identifying 273 subcutaneous fitness (scf) genes with 108 of those previously of “unknown function”. Two yet uncharacterized genes, scfA and scfB, were shown to be critical during GAS 5448 soft tissue infection and dissemination into the bloodstream. Thus, this study improves the functional annotation of the GAS genome, providing new insights into GAS pathophysiology and enhancing the development of novel GAS therapeutics.
Collapse
Affiliation(s)
- Yoann Le Breton
- Department of Cell Biology & Molecular Genetics and Maryland Pathogen Research Institute, University of Maryland, College Park, Maryland, United States of America
- * E-mail: (YLB); (KSM)
| | - Ashton T. Belew
- Department of Cell Biology & Molecular Genetics and Maryland Pathogen Research Institute, University of Maryland, College Park, Maryland, United States of America
- Center for Bioinformatics and Computational Biology, University of Maryland, College Park, Maryland, United States of America
| | - Jeffrey A. Freiberg
- Graduate Program in Life Sciences, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - Ganesh S. Sundar
- Department of Cell Biology & Molecular Genetics and Maryland Pathogen Research Institute, University of Maryland, College Park, Maryland, United States of America
| | - Emrul Islam
- Department of Cell Biology & Molecular Genetics and Maryland Pathogen Research Institute, University of Maryland, College Park, Maryland, United States of America
| | - Joshua Lieberman
- Division of Infectious Diseases, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - Mark E. Shirtliff
- Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
- Department of Microbial Pathogenesis, Dental School, University of Maryland, Baltimore, Maryland, United States of America
| | - Hervé Tettelin
- Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
- Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
| | - Najib M. El-Sayed
- Department of Cell Biology & Molecular Genetics and Maryland Pathogen Research Institute, University of Maryland, College Park, Maryland, United States of America
- Center for Bioinformatics and Computational Biology, University of Maryland, College Park, Maryland, United States of America
| | - Kevin S. McIver
- Department of Cell Biology & Molecular Genetics and Maryland Pathogen Research Institute, University of Maryland, College Park, Maryland, United States of America
- * E-mail: (YLB); (KSM)
| |
Collapse
|