1
|
Khadka S, Kinney EL, Ryan BE, Mike LA. Mechanisms governing bacterial capsular polysaccharide attachment and chain length. Ann N Y Acad Sci 2025. [PMID: 40369709 DOI: 10.1111/nyas.15364] [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] [Indexed: 05/16/2025]
Abstract
Capsular polysaccharides (CPSs) are high-molecular weight glycopolymers that form a capsule layer on the surface of many bacterial species. This layer serves as a crucial barrier between bacteria and their environment, protecting them from host immune responses and environmental stressors while facilitating adaptation to host niches. The capsule also affects other critical virulence factors of plant and human pathogens such as biofilm production and exchange of antimicrobial-resistance genes. Bacterial pathogens modulate several CPS properties including abundance, chain length, and cell surface retainment to optimize niche-specific fitness. CPS composition varies greatly among bacterial species due to differences in sugar units comprising the polymer. Despite the diversity in composition, three conserved CPS biosynthetic systems are common across bacterial species. Although less explored than CPS polymerization and export, the processes of chain length control and attachment are also broadly conserved among bacterial species. Here, we discuss the common strategies that bacteria use to retain CPS to their cell surface and the mechanisms by which bacteria define and control CPS chain length. Additionally, we highlight the outstanding questions related to these processes, identifying areas where future research is needed to gain better insights into these crucial CPS systems.
Collapse
Affiliation(s)
- Saroj Khadka
- Department of Medicine/Division of Infectious Diseases, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Emily L Kinney
- Department of Medicine/Division of Infectious Diseases, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Brooke E Ryan
- Department of Medical Microbiology and Immunology, University of Toledo College of Medicine and Life Sciences, Toledo, Ohio, USA
| | - Laura A Mike
- Department of Medicine/Division of Infectious Diseases, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| |
Collapse
|
2
|
Kanojiya P, Haldar T, Saroj SD. Environmental desiccation stress induces viable but non culturable state in Neisseria meningitidis. Arch Microbiol 2025; 207:46. [PMID: 39878836 DOI: 10.1007/s00203-025-04249-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2024] [Accepted: 01/16/2025] [Indexed: 01/31/2025]
Abstract
Environmental factors play a crucial role in bacterial virulence. During transmission, in a non-host environment bacteria are exposed to various environmental stress which could alter bacterial physiology and virulence. N. meningitidis is transmitted from person to person through direct contact. However, the role of environmental desiccation in the virulence of bacterial pathogens is not clearly understood. Therefore, the effect of environmental desiccation on survival, transmission, and virulence needs further investigation. We demonstrate that N. meningitidis was sensitive to desiccation stress. The viable counts reduced significantly (p < 0.05) after desiccation. It was found that desiccation induces a viable but non-culturable state (VBNC) in N. meningitidis. We considered cells to be in VBNC when no viable counts were obtained on growth media and live cells were detected after live-dead staining. After resuscitation, N. meningitidis retained virulence characteristics which indicate that it can transit between the host in VBNC state. Furthermore, the relative expression of capsule increased significantly after 12 and 24 h of desiccation. The observations indicate that the environmental desiccation might induce capsule biosynthesis in N. meningitidis, leading to enhanced virulence and survival in macrophages.
Collapse
Affiliation(s)
- Poonam Kanojiya
- Symbiosis School of Biological Sciences, Symbiosis International (Deemed University)Lavale, Pune, Maharashtra, 412115, India
| | - Tiyasa Haldar
- Symbiosis School of Biological Sciences, Symbiosis International (Deemed University)Lavale, Pune, Maharashtra, 412115, India
| | - Sunil D Saroj
- Symbiosis School of Biological Sciences, Symbiosis International (Deemed University)Lavale, Pune, Maharashtra, 412115, India.
| |
Collapse
|
3
|
Dewar AE, Belcher LJ, West SA. A phylogenetic approach to comparative genomics. Nat Rev Genet 2025:10.1038/s41576-024-00803-0. [PMID: 39779997 PMCID: PMC7617348 DOI: 10.1038/s41576-024-00803-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/05/2024] [Indexed: 01/11/2025]
Abstract
Comparative genomics, whereby the genomes of different species are compared, has the potential to address broad and fundamental questions at the intersection of genetics and evolution. However, species, genomes and genes cannot be considered as independent data points within statistical tests. Closely related species tend to be similar because they share genes by common descent, which must be accounted for in analyses. This problem of non-independence may be exacerbated when examining genomes or genes but can be addressed by applying phylogeny-based methods to comparative genomic analyses. Here, we review how controlling for phylogeny can change the conclusions of comparative genomics studies. We address common questions on how to apply these methods and illustrate how they can be used to test causal hypotheses. The combination of rapidly expanding genomic datasets and phylogenetic comparative methods is set to revolutionize the biological insights possible from comparative genomic studies.
Collapse
Affiliation(s)
- Anna E Dewar
- Department of Biology, University of Oxford, Oxford, UK.
- St John's College, Oxford, UK.
| | | | - Stuart A West
- Department of Biology, University of Oxford, Oxford, UK
| |
Collapse
|
4
|
Xu L, Li J, Wu W, Wu X, Ren J. Klebsiella pneumoniae capsular polysaccharide: Mechanism in regulation of synthesis, virulence, and pathogenicity. Virulence 2024; 15:2439509. [PMID: 39668724 PMCID: PMC11649230 DOI: 10.1080/21505594.2024.2439509] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2024] [Revised: 09/04/2024] [Accepted: 12/03/2024] [Indexed: 12/14/2024] Open
Abstract
Hypervirulent Klebsiella pneumoniae exhibits strong pathogenicity and can cause severe invasive infections but is historically recognized as antibiotic-susceptible. In recent years, the escalating global prevalence of antibiotic-resistant hypervirulent K. pneumoniae has raised substantial concerns and created an urgent demand for effective treatment options. Capsular polysaccharide (CPS) is one of the main virulence determinants contributing to the hypervirulent phenotype. The structure of CPS varies widely among strains, and both the structure and composition of CPS can influence the virulence of K. pneumoniae. CPS possesses various immune evasion mechanisms that promote the survival of K. pneumoniae, as well as its colonization and dissemination. Given the proven viability of therapies that target the capsule, improving our understanding of the CPS structure is critical to effectively directing treatment strategies. In this review, the structure and typing of CPS are addressed as well as genes related to synthesis and regulation, relationships with virulence, and pathogenic mechanisms. We aim to provide a reference for research on the pathogenesis of K. pneumoniae.
Collapse
Affiliation(s)
- Li Xu
- Research Institute of General Surgery, Jinling Hospital, the Affiliated Hospital of Medical School, Nanjing Medical University, Nanjing, China
| | - Jiayang Li
- Research Institute of General Surgery, Jinling Hospital, the Affiliated Hospital of Medical School, Nanjing University, Nanjing, China
| | - Wenqi Wu
- Research Institute of General Surgery, Jinling Hospital, the Affiliated Hospital of Medical School, Nanjing University, Nanjing, China
| | - Xiuwen Wu
- Research Institute of General Surgery, Jinling Hospital, the Affiliated Hospital of Medical School, Nanjing Medical University, Nanjing, China
- Research Institute of General Surgery, Jinling Hospital, the Affiliated Hospital of Medical School, Nanjing University, Nanjing, China
| | - Jianan Ren
- Research Institute of General Surgery, Jinling Hospital, the Affiliated Hospital of Medical School, Nanjing Medical University, Nanjing, China
- Research Institute of General Surgery, Jinling Hospital, the Affiliated Hospital of Medical School, Nanjing University, Nanjing, China
| |
Collapse
|
5
|
Gaborieau B, Vaysset H, Tesson F, Charachon I, Dib N, Bernier J, Dequidt T, Georjon H, Clermont O, Hersen P, Debarbieux L, Ricard JD, Denamur E, Bernheim A. Prediction of strain level phage-host interactions across the Escherichia genus using only genomic information. Nat Microbiol 2024; 9:2847-2861. [PMID: 39482383 DOI: 10.1038/s41564-024-01832-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2023] [Accepted: 09/13/2024] [Indexed: 11/03/2024]
Abstract
Predicting bacteriophage infection of specific bacterial strains promises advancements in phage therapy and microbial ecology. Whether the dynamics of well-established phage-host model systems generalize to the wide diversity of microbes is currently unknown. Here we show that we could accurately predict the outcomes of phage-bacteria interactions at the strain level in natural isolates from the genus Escherichia using only genomic data (area under the receiver operating characteristic curve (AUROC) of 86%). We experimentally established a dataset of interactions between 403 diverse Escherichia strains and 96 phages. Most interactions are explained by adsorption factors as opposed to antiphage systems which play a marginal role. We trained predictive algorithms and pinpoint poorly predicted interactions to direct future research efforts. Finally, we established a pipeline to recommend tailored phage cocktails, demonstrating efficiency on 100 pathogenic E. coli isolates. This work provides quantitative insights into phage-host specificity and supports the use of predictive algorithms in phage therapy.
Collapse
Affiliation(s)
- Baptiste Gaborieau
- Université Paris Cité, INSERM, UMR1137, IAME, Paris, France.
- AP-HP, Hôpital Louis Mourier, DMU ESPRIT, Service de Médecine Intensive Réanimation, Colombes, France.
- Institut Pasteur, Université Paris Cité, CNRS UMR6047, Microbiologie Intégrative et Moléculaire, Bacteriophage Bacterium Host, Paris, France.
| | - Hugo Vaysset
- AgroParisTech, Université Paris-Saclay, Paris, France
- Institut Pasteur, Université Paris Cité, INSERM U1284, SEED, Molecular Diversity of Microbes lab, Paris, France
- Institut Curie, Université PSL, Sorbonne Université, CNRS UMR168, Laboratoire Physico Chimie Curie, Paris, France
| | - Florian Tesson
- Université Paris Cité, INSERM, UMR1137, IAME, Paris, France
- Institut Pasteur, Université Paris Cité, INSERM U1284, SEED, Molecular Diversity of Microbes lab, Paris, France
| | - Inès Charachon
- Université Paris Cité, INSERM, UMR1137, IAME, Paris, France
| | - Nicolas Dib
- Université Paris Cité, INSERM, UMR1137, IAME, Paris, France
| | | | - Tanguy Dequidt
- Institut Pasteur, Université Paris Cité, CNRS UMR6047, Microbiologie Intégrative et Moléculaire, Bacteriophage Bacterium Host, Paris, France
| | - Héloïse Georjon
- Institut Pasteur, Université Paris Cité, INSERM U1284, SEED, Molecular Diversity of Microbes lab, Paris, France
| | | | - Pascal Hersen
- Institut Curie, Université PSL, Sorbonne Université, CNRS UMR168, Laboratoire Physico Chimie Curie, Paris, France
| | - Laurent Debarbieux
- Institut Pasteur, Université Paris Cité, CNRS UMR6047, Microbiologie Intégrative et Moléculaire, Bacteriophage Bacterium Host, Paris, France
| | - Jean-Damien Ricard
- Université Paris Cité, INSERM, UMR1137, IAME, Paris, France
- AP-HP, Hôpital Louis Mourier, DMU ESPRIT, Service de Médecine Intensive Réanimation, Colombes, France
| | - Erick Denamur
- Université Paris Cité, INSERM, UMR1137, IAME, Paris, France
- AP-HP, Hôpital Bichat, Laboratoire de Génétique Moléculaire, Paris, France
| | - Aude Bernheim
- Institut Pasteur, Université Paris Cité, INSERM U1284, SEED, Molecular Diversity of Microbes lab, Paris, France.
| |
Collapse
|
6
|
Gaborieau B, Delattre R, Adiba S, Clermont O, Denamur E, Ricard JD, Debarbieux L. Variable fitness effects of bacteriophage resistance mutations in Escherichia coli: implications for phage therapy. J Virol 2024; 98:e0111324. [PMID: 39213164 PMCID: PMC11495123 DOI: 10.1128/jvi.01113-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2024] [Accepted: 07/10/2024] [Indexed: 09/04/2024] Open
Abstract
Bacteria exposed to bactericidal treatment, such as antibiotics or bacteriophages (phages), often develop resistance. While phage therapy is proposed as a solution to the antibiotic resistance crisis, the bacterial resistance emerging during phage therapy remains poorly characterized. In this study, we examined a large population of phage-resistant extra-intestinal pathogenic Escherichia coli 536 clones that emerged from both in vitro (non-limited liquid medium) and in vivo (murine pneumonia) conditions. Genome sequencing uncovered a convergent mutational pattern in phage resistance mechanisms under both conditions, particularly targeting two cell-wall components, the K15 capsule and the lipopolysaccharide (LPS). This suggests that their identification in vivo could be predicted from in vitro assays. Phage-resistant clones exhibited a wide range of fitness according to in vitro tests, growth rate, and resistance to amoeba grazing, which could not distinguish between the K15 capsule and LPS mutants. In contrast, K15 capsule mutants retained virulence comparable to the wild-type strain, whereas LPS mutants showed significant attenuation in the murine pneumonia model. Additionally, we observed that resistance to the therapeutic phage through a nonspecific mechanism, such as capsule overproduction, did not systematically lead to co-resistance to other phages that were initially capable or incapable of infecting the wild-type strain. Our findings highlight the importance of incorporating a diverse range of phages in the design of therapeutic cocktails to target potential future phage-resistant clones effectively. IMPORTANCE This study isolated more than 50 phage-resistant mutants from both in vitro and in vivo conditions, exposing an extra-intestinal pathogenic Escherichia coli strain to a single virulent phage. The characterization of these clones revealed several key findings: (1) mutations occurring during phage treatment affect the same pathways as those identified in vitro; (2) the resistance mechanisms are associated with the modification of two cell-wall components, with one involving receptor deletion (phage-specific mechanism) and the other, less frequent, involving receptor masking (phage-nonspecific mechanism); (3) an in vivo virulence assay demonstrated that the absence of the receptor abolishes virulence while masking the receptor preserves it; and (4) clones with a resistance mechanism nonspecific to a particular phage can remain susceptible to other phages. This supports the idea of incorporating diverse phages into therapeutic cocktails designed to collectively target both wild-type and phage-resistant strains, including those with resistance mechanisms nonspecific to a phage.
Collapse
Affiliation(s)
- Baptiste Gaborieau
- Université Paris Cité, INSERM UMR1137, IAME, Paris, France
- Institut Pasteur, Université Paris Cité, CNRS UMR6047, Bacteriophage Bacterium Host, Paris, France
- APHP, Hôpital Louis Mourier, DMU ESPRIT, Service de Médecine Intensive Réanimation, Colombes, France
| | - Raphaëlle Delattre
- Université Paris Cité, INSERM UMR1137, IAME, Paris, France
- Institut Pasteur, Université Paris Cité, CNRS UMR6047, Bacteriophage Bacterium Host, Paris, France
| | - Sandrine Adiba
- Institut de Biologie de l'ENS (IBENS), École Normale Supérieure CNRS UMR8197, Paris, France
| | | | - Erick Denamur
- Université Paris Cité, INSERM UMR1137, IAME, Paris, France
- APHP, Hôpital Bichat, Service de Génétique Moléculaire, Paris, France
| | - Jean-Damien Ricard
- Université Paris Cité, INSERM UMR1137, IAME, Paris, France
- APHP, Hôpital Louis Mourier, DMU ESPRIT, Service de Médecine Intensive Réanimation, Colombes, France
| | - Laurent Debarbieux
- Institut Pasteur, Université Paris Cité, CNRS UMR6047, Bacteriophage Bacterium Host, Paris, France
| |
Collapse
|
7
|
Fruet C, Martinez-Goikoetxea M, Merino F, Lupas AN. A computational model for lipid-anchored polysaccharide export by the outer membrane protein GfcD. Biophys J 2024; 123:3491-3499. [PMID: 39164969 PMCID: PMC11494523 DOI: 10.1016/j.bpj.2024.08.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2023] [Revised: 07/01/2024] [Accepted: 08/15/2024] [Indexed: 08/22/2024] Open
Abstract
Many bacteria are protected by different types of polysaccharide capsules, structures formed of long repetitive glycan chains that are sometimes free and sometimes anchored to the outer membrane via lipid tails. One type, called group 4 capsule, results from the expression of the gfcABCDE-etp-etk operon in Escherichia coli. Of the proteins encoded in this operon, GfcE is thought to provide the export pore for free polysaccharide chains, but none of the proteins has been implicated in the export of chains carrying a lipid anchor. For this function, GfcD has been a focus of attention as the only outer membrane β-barrel encoded in the operon. AlphaFold predicts two β-barrel domains in GfcD, a canonical N-terminal one of 12 strands and an unusual C-terminal one of 13 strands, which features a large lateral aperture between strands β1 and β13. This immediately suggests a lateral exit gate for hydrophobic molecules into the membrane, analogous to the one proposed for the lipopolysaccharide export pore LptD. Here, we report an unsteered molecular dynamics study of GfcD embedded in the bacterial outer membrane, with the common polysaccharide anchor, lipid A, inserted in the pore of the C-terminal barrel. Our results show that the lateral aperture does not collapse during simulations and membrane lipids nevertheless do not penetrate the barrel but the lipid chains of the lipid A molecule readily exit into the membrane.
Collapse
Affiliation(s)
- Cecilia Fruet
- Department of Protein Evolution, Max Planck Institute for Biology Tübingen, Tübingen, Germany
| | | | - Felipe Merino
- Department of Protein Evolution, Max Planck Institute for Biology Tübingen, Tübingen, Germany
| | - Andrei N Lupas
- Department of Protein Evolution, Max Planck Institute for Biology Tübingen, Tübingen, Germany.
| |
Collapse
|
8
|
Ferriol-González C, Concha-Eloko R, Bernabéu-Gimeno M, Fernández-Cuenca F, Cañada-García JE, García-Cobos S, Sanjuán R, Domingo-Calap P. Targeted phage hunting to specific Klebsiella pneumoniae clinical isolates is an efficient antibiotic resistance and infection control strategy. Microbiol Spectr 2024; 12:e0025424. [PMID: 39194291 PMCID: PMC11448410 DOI: 10.1128/spectrum.00254-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2024] [Accepted: 08/06/2024] [Indexed: 08/29/2024] Open
Abstract
Klebsiella pneumoniae is one of the most threatening multi-drug-resistant pathogens today, with phage therapy being a promising alternative for personalized treatments. However, the intrinsic capsule diversity in Klebsiella spp. poses a substantial barrier to the phage host range, complicating the development of broad-spectrum phage-based treatments. Here, we have isolated and genomically characterized phages capable of infecting each of the acquired 77 reference serotypes of Klebsiella spp., including capsular types widespread among high-risk K. pneumoniae clones causing nosocomial infections. We demonstrated the possibility of isolating phages for all capsular types in the collection, revealing high capsular specificity among taxonomically related phages, in contrast to a few phages that exhibited broad-spectrum infection capabilities. To decipher the determinants of the specificity of these phages, we focused on their receptor-binding proteins, with particular attention to depolymerases. We also explored the possibility of designing a broad-spectrum phage cocktail based on phages isolated in reference capsular-type strains and determining the ability to lyse relevant clinical isolates. A combination of 12 phages capable of infecting 55% of the reference Klebsiella spp. serotypes was tested on a panel of carbapenem-resistant K. pneumoniae clinical isolates. Thirty-one percent of isolates were susceptible to the phage cocktail. However, our results suggest that in a highly variable encapsulated bacterial host, phage hunting must be directed to the specific Klebsiella isolates. This work is a step forward in the understanding of the complexity of phage-host interactions and highlights the importance of implementing precise and phage-specific strategies to treat K. pneumoniae infections worldwide.IMPORTANCEThe emergence of resistant bacteria is a serious global health problem. In the absence of effective treatments, phages are a personalized and effective therapeutic alternative. However, little is still known about phage-host interactions, which are key to implementing effective strategies. Here, we focus on the study of Klebsiella pneumoniae, a highly pathogenic encapsulated bacterium. The complexity and variability of the capsule, where in most cases phage receptors are found, make it difficult for phage-based treatments. Here, we isolated a large collection of Klebsiella phages against all the reference strains and in a cohort of clinical isolates. Our results suggest that clinical isolates represent a challenge, especially high-risk clones. Thus, we propose targeted phage hunting as an effective strategy to implement phage-derived therapies. Our results are a step forward for new phage-based strategies to control K. pneumoniae infections, highlighting the importance of understanding phage-host interactions to design personalized treatments against Klebsiella spp.
Collapse
Affiliation(s)
- Celia Ferriol-González
- Instituto de Biología Integrativa de Sistemas, Universitat de València-CSIC, Paterna, Spain
| | - Robby Concha-Eloko
- Instituto de Biología Integrativa de Sistemas, Universitat de València-CSIC, Paterna, Spain
| | - Mireia Bernabéu-Gimeno
- Instituto de Biología Integrativa de Sistemas, Universitat de València-CSIC, Paterna, Spain
| | - Felipe Fernández-Cuenca
- Unidad Clínica de Enfermedades Infecciosas y Microbiología, Hospital Universitario Virgen Macarena, Sevilla, Spain
- Instituto de Biomedicina de Sevilla, Hospital Universitario Virgen Macarena-CSIC-Universidad de Sevilla, Sevilla, Spain
- CIBER de Enfermedades Infecciosas (CIBERINFEC), Instituto de Salud Carlos III, Madrid, Spain
| | - Javier E Cañada-García
- CIBER de Enfermedades Infecciosas (CIBERINFEC), Instituto de Salud Carlos III, Madrid, Spain
- Laboratorio de Referencia e Investigación en Resistencia a Antibióticos e Infecciones Relacionadas con la Asistencia Sanitaria, Centro Nacional de Microbiología, Instituto de Salud Carlos III, Madrid, Spain
| | - Silvia García-Cobos
- CIBER de Enfermedades Infecciosas (CIBERINFEC), Instituto de Salud Carlos III, Madrid, Spain
- Laboratorio de Referencia e Investigación en Resistencia a Antibióticos e Infecciones Relacionadas con la Asistencia Sanitaria, Centro Nacional de Microbiología, Instituto de Salud Carlos III, Madrid, Spain
| | - Rafael Sanjuán
- Instituto de Biología Integrativa de Sistemas, Universitat de València-CSIC, Paterna, Spain
| | - Pilar Domingo-Calap
- Instituto de Biología Integrativa de Sistemas, Universitat de València-CSIC, Paterna, Spain
| |
Collapse
|
9
|
Goh KJ, Altuvia Y, Argaman L, Raz Y, Bar A, Lithgow T, Margalit H, Gan YH. RIL-seq reveals extensive involvement of small RNAs in virulence and capsule regulation in hypervirulent Klebsiella pneumoniae. Nucleic Acids Res 2024; 52:9119-9138. [PMID: 38804271 PMCID: PMC11347178 DOI: 10.1093/nar/gkae440] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2023] [Revised: 04/29/2024] [Accepted: 05/09/2024] [Indexed: 05/29/2024] Open
Abstract
Hypervirulent Klebsiella pneumoniae (hvKp) can infect healthy individuals, in contrast to classical strains that commonly cause nosocomial infections. The recent convergence of hypervirulence with carbapenem-resistance in K. pneumoniae can potentially create 'superbugs' that are challenging to treat. Understanding virulence regulation of hvKp is thus critical. Accumulating evidence suggest that posttranscriptional regulation by small RNAs (sRNAs) plays a role in bacterial virulence, but it has hardly been studied in K. pneumoniae. We applied RIL-seq to a prototypical clinical isolate of hvKp to unravel the Hfq-dependent RNA-RNA interaction (RRI) network. The RRI network is dominated by sRNAs, including predicted novel sRNAs, three of which we validated experimentally. We constructed a stringent subnetwork composed of RRIs that involve at least one hvKp virulence-associated gene and identified the capsule gene loci as a hub target where multiple sRNAs interact. We found that the sRNA OmrB suppressed both capsule production and hypermucoviscosity when overexpressed. Furthermore, OmrB base-pairs within kvrA coding region and partially suppresses translation of the capsule regulator KvrA. This agrees with current understanding of capsule as a major virulence and fitness factor. It emphasizes the intricate regulatory control of bacterial phenotypes by sRNAs, particularly of genes critical to bacterial physiology and virulence.
Collapse
Affiliation(s)
- Kwok Jian Goh
- Infectious Diseases Translational Research Programme, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117545, Singapore
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117596, Singapore
- Infection and Immunity Program, Biomedicine Discovery Institute and Department of Microbiology, Monash University, Clayton, Victoria, Australia
| | - Yael Altuvia
- Department of Microbiology and Molecular Genetics, Institute for Medical Research Israel-Canada, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 9112102, Israel
| | - Liron Argaman
- Department of Microbiology and Molecular Genetics, Institute for Medical Research Israel-Canada, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 9112102, Israel
| | - Yair Raz
- Department of Microbiology and Molecular Genetics, Institute for Medical Research Israel-Canada, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 9112102, Israel
| | - Amir Bar
- Department of Microbiology and Molecular Genetics, Institute for Medical Research Israel-Canada, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 9112102, Israel
| | - Trevor Lithgow
- Infection and Immunity Program, Biomedicine Discovery Institute and Department of Microbiology, Monash University, Clayton, Victoria, Australia
| | - Hanah Margalit
- Department of Microbiology and Molecular Genetics, Institute for Medical Research Israel-Canada, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 9112102, Israel
| | - Yunn-Hwen Gan
- Infectious Diseases Translational Research Programme, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117545, Singapore
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117596, Singapore
| |
Collapse
|
10
|
Lau M, Monis PT, King BJ. The efficacy of current treatment processes to remove, inactivate, or reduce environmental bloom-forming Escherichia coli. Microbiol Spectr 2024; 12:e0085624. [PMID: 38980016 PMCID: PMC11302305 DOI: 10.1128/spectrum.00856-24] [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: 04/03/2024] [Accepted: 06/06/2024] [Indexed: 07/10/2024] Open
Abstract
Escherichia coli is excreted in high numbers from the intestinal tract of humans, other mammals, and birds. Traditionally, it had been thought that E. coli could grow only within human or animal hosts and would perish in the environment. Therefore, the presence of E. coli in water has become universally accepted as a key water quality indicator of fecal pollution. However, recent research challenges the assumption that the presence of E. coli in water is always an indicator of fecal contamination, with some types of E. coli having evolved to survive and grow in aquatic environments. These strains can form blooms in water storages, resulting in high E. coli counts even without fecal contamination. Although these bloom-forming strains lack virulence genes and pose little threat to public health, their presence in treated water triggers the same response as fecal-derived E. coli. Yet, little is known about the effectiveness of treatment processes in removing or inactivating them. This study evaluated the effectiveness of current treatment processes to remove bloom-forming strains, in comparison to fecal-derived strains, with conventional coagulation-flocculation-sedimentation and filtration investigated. Second, the effectiveness of current disinfection processes-chlorination, chloramination, and ultraviolet (UV) light to disinfect bloom-forming strains in comparison to fecal-derived strains-was assessed. These experiments showed that the responses of bloom isolates were not significantly different from those of fecal E. coli strains. Therefore, commonly used water treatment and disinfection processes are effective to remove bloom-forming E. coli strains from water.IMPORTANCEThe presence of Escherichia coli in water has long been used globally as a key indicator of fecal pollution and for quantifying water safety. Traditionally, it was believed that E. coli could only thrive within hosts and would perish outside, making its presence in water indicative of fecal contamination. However, recent research has unveiled strains of E. coli capable of surviving and proliferating in aquatic environments, forming blooms even in the absence of fecal contamination. While these bloom-forming strains lack the genes to be pathogenic, their detection in source or drinking water triggers the same response as fecal-derived E. coli. Yet, little is known about the efficacy of treatment processes in removing them. This study evaluated the effectiveness of conventional treatment and disinfection processes in removing bloom-forming strains compared to fecal-derived strains. Results indicate that these commonly used processes are equally effective against both types of E. coli, reassuring that bloom-forming E. coli strains can be eliminated from water.
Collapse
Affiliation(s)
- Melody Lau
- South Australian Water Corporation, Adelaide, South Australia, Australia
| | - Paul T. Monis
- South Australian Water Corporation, Adelaide, South Australia, Australia
| | - Brendon J. King
- South Australian Water Corporation, Adelaide, South Australia, Australia
| |
Collapse
|
11
|
Qiu X, Ye K, Ma Y, Zhao Q, Wang L, Yang J. Genome sequence-based species classification of Enterobacter cloacae complex: a study among clinical isolates. Microbiol Spectr 2024; 12:e0431223. [PMID: 38687068 PMCID: PMC11237491 DOI: 10.1128/spectrum.04312-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2023] [Accepted: 04/13/2024] [Indexed: 05/02/2024] Open
Abstract
Accurate species-level identification of Enterobacter cloacae complex (ECC) is crucial for related research. The classification of ECC is based on strain-to-strain phylogenetic congruence, as well as genomic features including average nucleotide identity (ANI) and digitalized DNA-DNA hybridization (dDDH). ANI and dDDH derived from whole-genome sequencing have emerged as a reliable metric for assessing genetic relatedness between genomes and are increasingly recognized as a standard for species delimitation. Up to now, there are two different classification methods for ECC. The first one categorizes E. hormaechei, a species within ECC, into five subspecies (E. hormaechei subsp. steigerwaltii, subsp. oharae, subsp. xiangfangensis, subsp. hoffmannii, and subsp. hormaechei). The second classifies E. hormaechei as three species: E. hormaechei, "E. xiangfangensis," "E. hoffmanii." While the former is well-accepted in the academic area, the latter may have a greater ability to distinguish different species of ECC. To assess the suitability of these identification criteria for clinical ECC isolates, we conducted a comprehensive analysis involving phylogenetic analysis, ANI and dDDH value alignment, virulence gene identification, and capsule typing on 256 clinical ECC strains isolated from the bloodstream. Our findings indicated that the method of categorizing E. hormaechei into five subspecies has better correlation and consistency with the molecular characteristics of clinical ECC isolates, as evidenced by phylogenetic analysis, virulence genes, and capsule typing. Therefore, the subspecies-based classification method appears more suitable for taxonomic assignments of clinical ECC isolates. IMPORTANCE Standardizing taxonomy of the Enterobacter cloacae complex (ECC) is necessary for data integration across diverse studies. The study utilized whole-genome data to accurately identify 256 clinical ECC isolated from bloodstream infections using average nucleotide identity (ANI), digitalized DNA-DNA hybridization (dDDH), and phylogenetic analysis. Through comprehensive assessments including phylogenetic analysis, ANI and dDDH comparisons, virulence gene, and capsule typing of the 256 clinical isolates, it was concluded that the classification method based on subspecies exhibited better correlation and consistency with the molecular characteristics of clinical ECC isolates. In summary, this research contributes to the precise identification of clinical ECC at the species level and expands our understanding of ECC.
Collapse
Affiliation(s)
- Xuemei Qiu
- Laboratory Medicine Department, First Medical Center of Chinese PLA General Hospital, Beijing, China
- Medical school of Chinese PLA, Beijing, China
| | - Kun Ye
- Laboratory Medicine Department, First Medical Center of Chinese PLA General Hospital, Beijing, China
| | - Yanning Ma
- Laboratory Medicine Department, First Medical Center of Chinese PLA General Hospital, Beijing, China
| | - Qiang Zhao
- Laboratory Medicine Department, First Medical Center of Chinese PLA General Hospital, Beijing, China
| | - Lifeng Wang
- Laboratory Medicine Department, First Medical Center of Chinese PLA General Hospital, Beijing, China
| | - Jiyong Yang
- Laboratory Medicine Department, First Medical Center of Chinese PLA General Hospital, Beijing, China
| |
Collapse
|
12
|
Castro J, Oliveira R, Fernandes L, Carvalho I, Oliveira H, Brinks E, Cho GS, Franz C, Almeida C, Silva S, Araújo D. Molecular characterization and virulence profile of Klebsiella pneumoniae and Klebsiella oxytoca isolated from ill cats and dogs in Portugal. Vet Microbiol 2024; 292:110056. [PMID: 38537400 DOI: 10.1016/j.vetmic.2024.110056] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2024] [Revised: 03/11/2024] [Accepted: 03/15/2024] [Indexed: 04/10/2024]
Abstract
Klebsiella spp. are important pathogens of humans and companion animals such as cats and dogs, capable of causing severe life-threatening diseases. The aim of this study was to characterize the molecular and phenotypic properties of Klebsiella pneumoniae and Klebsiella oxytoca isolated from ill companion animals by whole genome sequencing, followed by in vitro assessment of biofilm formation and in vivo pathogenicity using the Galleria mellonella model. Two LPS O-types were identified for all the K. pneumoniae isolates tested (O3B and O1/O2v2) and only one for K. oxytoca isolates (OL104), and the most common STs found were ST11 and ST266. Furthermore, a high diversity of K-locus types was found for K. pneumoniae (KL102; KL105; KL31, and KL13). Within K. pneumoniae, one specific O/K/ST-types combination (i.e., KL105-ST11-O1/O2v2) showed results that were of concern, as it exhibited a high inflammatory response at 12 h post-infection in G. mellonella with 80% of the larvae dead at 72 h post-infection. This virulence potential, on the other hand, did not appear to be directly related to the biofilm-forming capacity. Also, virulence and resistance scores obtained for this set of strains did surpass score 1. The present study demonstrated that Klebsiella spp. isolated from companion animals belonging to STs that can cause human infections and present virulence on an invertebrate model. Thus, this study underscores the role of dogs and cats as reservoirs of resistant Klebsiella spp. that could potentially be transmitted to humans.
Collapse
Affiliation(s)
- Joana Castro
- INIAV, IP - National Institute for Agrarian and Veterinary Research, Rua dos Lagidos, Lugar da Madalena, Vairão 4485-655, Portugal; Centre of Biological Engineering, University of Minho, 4710-057, Braga, Portugal
| | - Ricardo Oliveira
- INIAV, IP - National Institute for Agrarian and Veterinary Research, Rua dos Lagidos, Lugar da Madalena, Vairão 4485-655, Portugal; LEPABE - Laboratory for Process Engineering, Environment, Biotechnology and Energy, Faculty of Engineering, University of Porto, 4200-465 Porto, Portugal; ALiCE - Associate Laboratory in Chemical Engineering, Faculty of Engineering, University of Porto, 4200-465 Porto, Portugal
| | - Liliana Fernandes
- Centre of Biological Engineering, University of Minho, 4710-057, Braga, Portugal; LABBELS - Associate Laboratory, Braga/Guimarães, Portugal
| | - Isabel Carvalho
- Centre of Biological Engineering, University of Minho, 4710-057, Braga, Portugal; LABBELS - Associate Laboratory, Braga/Guimarães, Portugal
| | - Hugo Oliveira
- Centre of Biological Engineering, University of Minho, 4710-057, Braga, Portugal; LABBELS - Associate Laboratory, Braga/Guimarães, Portugal
| | - Erik Brinks
- Department of Microbiology and Biotechnology, Max Rubner-Institut, Federal Research Institute of Nutrition and Food, Kiel, Germany
| | - Gyu-Sung Cho
- Department of Microbiology and Biotechnology, Max Rubner-Institut, Federal Research Institute of Nutrition and Food, Kiel, Germany
| | - Charles Franz
- Department of Microbiology and Biotechnology, Max Rubner-Institut, Federal Research Institute of Nutrition and Food, Kiel, Germany
| | - Carina Almeida
- INIAV, IP - National Institute for Agrarian and Veterinary Research, Rua dos Lagidos, Lugar da Madalena, Vairão 4485-655, Portugal; Centre of Biological Engineering, University of Minho, 4710-057, Braga, Portugal; LEPABE - Laboratory for Process Engineering, Environment, Biotechnology and Energy, Faculty of Engineering, University of Porto, 4200-465 Porto, Portugal; ALiCE - Associate Laboratory in Chemical Engineering, Faculty of Engineering, University of Porto, 4200-465 Porto, Portugal
| | - Sónia Silva
- INIAV, IP - National Institute for Agrarian and Veterinary Research, Rua dos Lagidos, Lugar da Madalena, Vairão 4485-655, Portugal; Centre of Biological Engineering, University of Minho, 4710-057, Braga, Portugal; LABBELS - Associate Laboratory, Braga/Guimarães, Portugal
| | - Daniela Araújo
- INIAV, IP - National Institute for Agrarian and Veterinary Research, Rua dos Lagidos, Lugar da Madalena, Vairão 4485-655, Portugal; Centre of Biological Engineering, University of Minho, 4710-057, Braga, Portugal; LABBELS - Associate Laboratory, Braga/Guimarães, Portugal.
| |
Collapse
|
13
|
Huang T, Zhang Z, Tao X, Shi X, Lin P, Liao D, Ma C, Cai X, Lin W, Jiang X, Luo P, Wu S, Xie Y. Structural and functional basis of bacteriophage K64-ORF41 depolymerase for capsular polysaccharide degradation of Klebsiella pneumoniae K64. Int J Biol Macromol 2024; 265:130917. [PMID: 38513899 DOI: 10.1016/j.ijbiomac.2024.130917] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2024] [Revised: 03/04/2024] [Accepted: 03/14/2024] [Indexed: 03/23/2024]
Abstract
Capsule polysaccharide is an important virulence factor of Klebsiella pneumoniae (K. pneumoniae), which protects bacteria against the host immune response. A promising therapeutic approach is using phage-derived depolymerases to degrade the capsular polysaccharide and expose and sensitize the bacteria to the host immune system. Here we determined the cryo-electron microscopy (cryo-EM) structures of a bacteriophage tail-spike protein against K. pneumoniae K64, ORF41 (K64-ORF41) and ORF41 in EDTA condition (K64-ORF41EDTA), at 2.37 Å and 2.50 Å resolution, respectively, for the first time. K64-ORF41 exists as a trimer and each protomer contains a β-helix domain including a right-handed parallel β-sheet helix fold capped at both ends, an insertion domain, and one β-sheet jellyroll domain. Moreover, our structural comparison with other depolymerases of K. pneumoniae suggests that the catalytic residues (Tyr528, His574 and Arg628) are highly conserved although the substrate of capsule polysaccharide is variable. Besides that, we figured out the important residues involved in the substrate binding pocket including Arg405, Tyr526, Trp550 and Phe669. This study establishes the structural and functional basis for the promising phage-derived broad-spectrum activity depolymerase therapeutics and effective CPS-degrading agents for the treatment of carbapenem-resistant K. pneumoniae K64 infections.
Collapse
Affiliation(s)
- Tianyun Huang
- Department of Neurosurgery, Xijing Hospital, Fourth Military Medical University, Xi'an, Shaanxi 710032, China; Department of Pharmacy, Xi'an No.3 Hospital, the Affiliated Hospital of Northwest University, Xi'an, Shaanxi 710021, China; School of Pharmacy, Health Science Center, Xi'an Jiaotong University, Xi'an, Shaanxi 710061, China
| | - Zhuoyuan Zhang
- Department of Neurosurgery, Xijing Hospital, Fourth Military Medical University, Xi'an, Shaanxi 710032, China; College of Life Sciences, Northwest University, Xi'an 710069, China
| | - Xin Tao
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Hubei Collaborative Innovation Center for Green Transformation of Bio-Resources, Hubei Key Laboratory of Industrial Biotechnology, School of Life Sciences, Hubei University, Wuhan, Hubei 430062, China
| | - Xinyu Shi
- Department of Neurosurgery, Xijing Hospital, Fourth Military Medical University, Xi'an, Shaanxi 710032, China
| | - Peng Lin
- National Translational Science Center for Molecular Medicine & Department of Cell Biology, Fourth Military Medical University, Xi'an, Shaanxi 710032, China
| | - Dan Liao
- Department of Neurosurgery, Xijing Hospital, Fourth Military Medical University, Xi'an, Shaanxi 710032, China
| | - Chenyu Ma
- Department of Neurosurgery, Xijing Hospital, Fourth Military Medical University, Xi'an, Shaanxi 710032, China
| | - Xinle Cai
- Department of Neurosurgery, Xijing Hospital, Fourth Military Medical University, Xi'an, Shaanxi 710032, China
| | - Wei Lin
- Department of Neurosurgery, Xijing Hospital, Fourth Military Medical University, Xi'an, Shaanxi 710032, China
| | - Xiaofan Jiang
- Department of Neurosurgery, Xijing Hospital, Fourth Military Medical University, Xi'an, Shaanxi 710032, China.
| | - Peng Luo
- Department of Neurosurgery, Xijing Hospital, Fourth Military Medical University, Xi'an, Shaanxi 710032, China.
| | - Shan Wu
- State Key Laboratory of Biocatalysis and Enzyme Engineering, Hubei Collaborative Innovation Center for Green Transformation of Bio-Resources, Hubei Key Laboratory of Industrial Biotechnology, School of Life Sciences, Hubei University, Wuhan, Hubei 430062, China.
| | - Yuan Xie
- Department of Neurosurgery, Xijing Hospital, Fourth Military Medical University, Xi'an, Shaanxi 710032, China.
| |
Collapse
|
14
|
Gao S, Jin W, Quan Y, Li Y, Shen Y, Yuan S, Yi L, Wang Y, Wang Y. Bacterial capsules: Occurrence, mechanism, and function. NPJ Biofilms Microbiomes 2024; 10:21. [PMID: 38480745 PMCID: PMC10937973 DOI: 10.1038/s41522-024-00497-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2023] [Accepted: 03/05/2024] [Indexed: 03/17/2024] Open
Abstract
In environments characterized by extended multi-stress conditions, pathogens develop a variety of immune escape mechanisms to enhance their ability to infect the host. The capsules, polymers that bacteria secrete near their cell wall, participates in numerous bacterial life processes and plays a crucial role in resisting host immune attacks and adapting to their niche. Here, we discuss the relationship between capsules and bacterial virulence, summarizing the molecular mechanisms of capsular regulation and pathogenesis to provide new insights into the research on the pathogenesis of pathogenic bacteria.
Collapse
Affiliation(s)
- Shuji Gao
- College of Animal Science and Technology, Henan University of Science and Technology, Luoyang, 471000, China
- Henan Provincial Engineering Research Center for Detection and Prevention and Control of Emerging Infectious Diseases in Livestock and Poultry, Luoyang, 471003, China
| | - Wenjie Jin
- College of Animal Science and Technology, Henan University of Science and Technology, Luoyang, 471000, China
- Henan Provincial Engineering Research Center for Detection and Prevention and Control of Emerging Infectious Diseases in Livestock and Poultry, Luoyang, 471003, China
| | - Yingying Quan
- College of Animal Science and Technology, Henan University of Science and Technology, Luoyang, 471000, China
- Henan Provincial Engineering Research Center for Detection and Prevention and Control of Emerging Infectious Diseases in Livestock and Poultry, Luoyang, 471003, China
| | - Yue Li
- College of Animal Science and Technology, Henan University of Science and Technology, Luoyang, 471000, China
- Henan Provincial Engineering Research Center for Detection and Prevention and Control of Emerging Infectious Diseases in Livestock and Poultry, Luoyang, 471003, China
| | - Yamin Shen
- College of Animal Science and Technology, Henan University of Science and Technology, Luoyang, 471000, China
- Henan Provincial Engineering Research Center for Detection and Prevention and Control of Emerging Infectious Diseases in Livestock and Poultry, Luoyang, 471003, China
| | - Shuo Yuan
- College of Animal Science and Technology, Henan University of Science and Technology, Luoyang, 471000, China
- Henan Provincial Engineering Research Center for Detection and Prevention and Control of Emerging Infectious Diseases in Livestock and Poultry, Luoyang, 471003, China
| | - Li Yi
- Henan Provincial Engineering Research Center for Detection and Prevention and Control of Emerging Infectious Diseases in Livestock and Poultry, Luoyang, 471003, China
- College of Life Science, Luoyang Normal University, Luoyang, 471934, China
| | - Yuxin Wang
- College of Animal Science and Technology, Henan University of Science and Technology, Luoyang, 471000, China.
- Henan Provincial Engineering Research Center for Detection and Prevention and Control of Emerging Infectious Diseases in Livestock and Poultry, Luoyang, 471003, China.
| | - Yang Wang
- College of Animal Science and Technology, Henan University of Science and Technology, Luoyang, 471000, China.
- Henan Provincial Engineering Research Center for Detection and Prevention and Control of Emerging Infectious Diseases in Livestock and Poultry, Luoyang, 471003, China.
| |
Collapse
|
15
|
Haudiquet M, Le Bris J, Nucci A, Bonnin RA, Domingo-Calap P, Rocha EPC, Rendueles O. Capsules and their traits shape phage susceptibility and plasmid conjugation efficiency. Nat Commun 2024; 15:2032. [PMID: 38448399 PMCID: PMC10918111 DOI: 10.1038/s41467-024-46147-5] [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: 05/31/2023] [Accepted: 02/14/2024] [Indexed: 03/08/2024] Open
Abstract
Bacterial evolution is affected by mobile genetic elements like phages and conjugative plasmids, offering new adaptive traits while incurring fitness costs. Their infection is affected by the bacterial capsule. Yet, its importance has been difficult to quantify because of the high diversity of confounding mechanisms in bacterial genomes such as anti-viral systems and surface receptor modifications. Swapping capsule loci between Klebsiella pneumoniae strains allowed us to quantify their impact on plasmid and phage infection independently of genetic background. Capsule swaps systematically invert phage susceptibility, revealing serotypes as key determinants of phage infection. Capsule types also influence conjugation efficiency in both donor and recipient cells, a mechanism shaped by capsule volume and conjugative pilus structure. Comparative genomics confirmed that more permissive serotypes in the lab correspond to the strains acquiring more conjugative plasmids in nature. The least capsule-sensitive pili (F-like) are the most frequent in the species' plasmids, and are the only ones associated with both antibiotic resistance and virulence factors, driving the convergence between virulence and antibiotics resistance in the population. These results show how traits of cellular envelopes define slow and fast lanes of infection by mobile genetic elements, with implications for population dynamics and horizontal gene transfer.
Collapse
Affiliation(s)
- Matthieu Haudiquet
- Institut Pasteur, Université Paris Cité, CNRS UMR3525, Microbial Evolutionary Genomics, Paris, 75015, France.
- Ecole Doctoral FIRE-Programme Bettencourt, CRI, Paris, France.
| | - Julie Le Bris
- Institut Pasteur, Université Paris Cité, CNRS UMR3525, Microbial Evolutionary Genomics, Paris, 75015, France
- Sorbonne Université, Collège Doctoral, Ecole Doctorale Complexité du Vivant, 75005, Paris, France
| | - Amandine Nucci
- Institut Pasteur, Université Paris Cité, CNRS UMR3525, Microbial Evolutionary Genomics, Paris, 75015, France
| | - Rémy A Bonnin
- Team Resist UMR1184 Université Paris Saclay, CEA, Inserm, Le Kremlin-Bicêtre, Paris, France
- Service de bactériologie, Hôpital Bicêtre, Université Paris Saclay, AP-HP, Le Kremlin-Bicêtre, Paris, France
- Centre National de Référence Associé de la Résistance aux Antibiotiques, Le Kremlin-Bicêtre, Paris, France
| | - Pilar Domingo-Calap
- Instituto de Biología Integrativa de Sistemas, Universitat de València-CSIC, 46980, Paterna, Spain
| | - Eduardo P C Rocha
- Institut Pasteur, Université Paris Cité, CNRS UMR3525, Microbial Evolutionary Genomics, Paris, 75015, France.
| | - Olaya Rendueles
- Institut Pasteur, Université Paris Cité, CNRS UMR3525, Microbial Evolutionary Genomics, Paris, 75015, France.
| |
Collapse
|
16
|
Alonso-del Valle A, Toribio-Celestino L, Quirant A, Pi CT, DelaFuente J, Canton R, Rocha EPC, Ubeda C, Peña-Miller R, San Millan A. Antimicrobial resistance level and conjugation permissiveness shape plasmid distribution in clinical enterobacteria. Proc Natl Acad Sci U S A 2023; 120:e2314135120. [PMID: 38096417 PMCID: PMC10741383 DOI: 10.1073/pnas.2314135120] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2023] [Accepted: 10/26/2023] [Indexed: 12/18/2023] Open
Abstract
Conjugative plasmids play a key role in the dissemination of antimicrobial resistance (AMR) genes across bacterial pathogens. AMR plasmids are widespread in clinical settings, but their distribution is not random, and certain associations between plasmids and bacterial clones are particularly successful. For example, the globally spread carbapenem resistance plasmid pOXA-48 can use a wide range of enterobacterial species as hosts, but it is usually associated with a small number of specific Klebsiella pneumoniae clones. These successful associations represent an important threat for hospitalized patients. However, knowledge remains limited about the factors determining AMR plasmid distribution in clinically relevant bacteria. Here, we combined in vitro and in vivo experimental approaches to analyze pOXA-48-associated AMR levels and conjugation dynamics in a collection of wild-type enterobacterial strains isolated from hospitalized patients. Our results revealed significant variability in these traits across different bacterial hosts, with Klebsiella spp. strains showing higher pOXA-48-mediated AMR and conjugation frequencies than Escherichia coli strains. Using experimentally determined parameters, we developed a simple mathematical model to interrogate the contribution of AMR levels and conjugation permissiveness to plasmid distribution in bacterial communities. The simulations revealed that a small subset of clones, combining high AMR levels and conjugation permissiveness, play a critical role in stabilizing the plasmid in different polyclonal microbial communities. These results help to explain the preferential association of plasmid pOXA-48 with K. pneumoniae clones in clinical settings. More generally, our study reveals that species- and strain-specific variability in plasmid-associated phenotypes shape AMR evolution in clinically relevant bacterial communities.
Collapse
Affiliation(s)
- Aida Alonso-del Valle
- Centro Nacional de Biotecnología, Consejo Superior de Investigaciones Cientificas, Madrid28049, Spain
| | - Laura Toribio-Celestino
- Centro Nacional de Biotecnología, Consejo Superior de Investigaciones Cientificas, Madrid28049, Spain
| | - Anna Quirant
- Fundación para el Fomento de la Investigación Sanitaria y Biomédica de la Comunitat Valenciana, Valencia46020, Spain
| | - Carles Tardio Pi
- Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Cuernavaca62209, México
- Instituto de Investigaciones en Matemáticas Aplicadas y en Sistemas, Unidad Académica Yucatán, Universidad Nacional Autónoma de México, Yucatán04510, México
| | - Javier DelaFuente
- Centro Nacional de Biotecnología, Consejo Superior de Investigaciones Cientificas, Madrid28049, Spain
| | - Rafael Canton
- Servicio de Microbiología, Hospital Universitario Ramón y Cajal-Instituto Ramon y Cajal de Investigacion Sanitaria, Madrid28034, Spain
- Centro de Investigación Biológica en Red de Enfermedades Infecciosas, Instituto de Salud Carlos III, Madrid28029, Spain
| | - Eduardo P. C. Rocha
- Institut Pasteur, Université de Paris Cité, CNRS UMR3525, Microbial Evolutionary Genomics, Paris75015, France
| | - Carles Ubeda
- Fundación para el Fomento de la Investigación Sanitaria y Biomédica de la Comunitat Valenciana, Valencia46020, Spain
- Centro de Investigación Biológica en Red de Epidemiología y Salud Pública, Instituto de Salud Carlos III, Madrid28029, Spain
| | - Rafael Peña-Miller
- Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Cuernavaca62209, México
| | - Alvaro San Millan
- Centro Nacional de Biotecnología, Consejo Superior de Investigaciones Cientificas, Madrid28049, Spain
- Centro de Investigación Biológica en Red de Epidemiología y Salud Pública, Instituto de Salud Carlos III, Madrid28029, Spain
| |
Collapse
|
17
|
Arredondo-Alonso S, Blundell-Hunter G, Fu Z, Gladstone RA, Fillol-Salom A, Loraine J, Cloutman-Green E, Johnsen PJ, Samuelsen Ø, Pöntinen AK, Cléon F, Chavez-Bueno S, De la Cruz MA, Ares MA, Vongsouvath M, Chmielarczyk A, Horner C, Klein N, McNally A, Reis JN, Penadés JR, Thomson NR, Corander J, Taylor PW, McCarthy AJ. Evolutionary and functional history of the Escherichia coli K1 capsule. Nat Commun 2023; 14:3294. [PMID: 37322051 PMCID: PMC10272209 DOI: 10.1038/s41467-023-39052-w] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2023] [Accepted: 05/26/2023] [Indexed: 06/17/2023] Open
Abstract
Escherichia coli is a leading cause of invasive bacterial infections in humans. Capsule polysaccharide has an important role in bacterial pathogenesis, and the K1 capsule has been firmly established as one of the most potent capsule types in E. coli through its association with severe infections. However, little is known about its distribution, evolution and functions across the E. coli phylogeny, which is fundamental to elucidating its role in the expansion of successful lineages. Using systematic surveys of invasive E. coli isolates, we show that the K1-cps locus is present in a quarter of bloodstream infection isolates and has emerged in at least four different extraintestinal pathogenic E. coli (ExPEC) phylogroups independently in the last 500 years. Phenotypic assessment demonstrates that K1 capsule synthesis enhances E. coli survival in human serum independent of genetic background, and that therapeutic targeting of the K1 capsule re-sensitizes E. coli from distinct genetic backgrounds to human serum. Our study highlights that assessing the evolutionary and functional properties of bacterial virulence factors at population levels is important to better monitor and predict the emergence of virulent clones, and to also inform therapies and preventive medicine to effectively control bacterial infections whilst significantly lowering antibiotic usage.
Collapse
Affiliation(s)
- Sergio Arredondo-Alonso
- Department of Biostatistics, University of Oslo, 0317, Oslo, Norway
- Parasites and Microbes, Wellcome Sanger Institute, Cambridge, UK
| | | | - Zuyi Fu
- Department of Infectious Disease, Centre for Bacterial Resistance Biology, Imperial College London, London, UK
| | - Rebecca A Gladstone
- Department of Biostatistics, University of Oslo, 0317, Oslo, Norway
- Parasites and Microbes, Wellcome Sanger Institute, Cambridge, UK
| | - Alfred Fillol-Salom
- Department of Infectious Disease, Centre for Bacterial Resistance Biology, Imperial College London, London, UK
| | | | - Elaine Cloutman-Green
- Great Ormond Street Institute of Child Health, University College London, London, UK
| | - Pål J Johnsen
- Department of Pharmacy, Faculty of Health Sciences, UiT The Arctic University of Norway, Tromsø, Norway
| | - Ørjan Samuelsen
- Department of Pharmacy, Faculty of Health Sciences, UiT The Arctic University of Norway, Tromsø, Norway
- Norwegian National Advisory Unit on Detection of Antimicrobial Resistance, Department of Microbiology and Infection Control, University Hospital of North Norway, Tromsø, Norway
| | - Anna K Pöntinen
- Department of Biostatistics, University of Oslo, 0317, Oslo, Norway
- Norwegian National Advisory Unit on Detection of Antimicrobial Resistance, Department of Microbiology and Infection Control, University Hospital of North Norway, Tromsø, Norway
| | - François Cléon
- Department of Pharmacy, Faculty of Health Sciences, UiT The Arctic University of Norway, Tromsø, Norway
| | - Susana Chavez-Bueno
- University of Missouri Kansas City, Kansas City, USA
- Division of Infectious Diseases, Children's Mercy Hospital Kansas City, UMKC School of Medicine, Kansas City, USA
| | - Miguel A De la Cruz
- Unidad de Investigación Médica en Enfermedades Infecciosas y Parasitarias, Hospital de Pediatría, Centro Médico Nacional Siglo XXI Instituto Mexicano del Seguro Social, Mexico City, Mexico
- Facultad de Medicina, Benemérita Universidad Autónoma de Puebla, Puebla, Mexico
| | - Miguel A Ares
- Unidad de Investigación Médica en Enfermedades Infecciosas y Parasitarias, Hospital de Pediatría, Centro Médico Nacional Siglo XXI Instituto Mexicano del Seguro Social, Mexico City, Mexico
| | - Manivanh Vongsouvath
- Lao-Oxford-Mahosot Hospital-Wellcome Trust Research Unit (LOMWRU), Microbiology Laboratory, Mahosot Hospital, Vientiane, Lao PDR
| | - Agnieszka Chmielarczyk
- Faculty of Medicine, Chair of Microbiology, Jagiellonian University Medical College, Czysta str. 18, 31-121, Kraków, Poland
| | - Carolyne Horner
- British Society for Antimicrobial Chemotherapy, Birmingham, UK
| | - Nigel Klein
- Great Ormond Street Institute of Child Health, University College London, London, UK
| | - Alan McNally
- Institute of Microbiology and Infection, College of Medical and Dental Sciences, University of Birmingham, Birmingham, UK
| | - Joice N Reis
- Laboratory of Pathology and Molecular Biology (LPBM), Gonçalo Moniz Research Institute, Oswaldo Cruz Foundation, Salvador, Brazil
- Faculdade de Farmácia, Universidade Federal da Bahia, Salvador, Brazil
| | - José R Penadés
- Department of Infectious Disease, Centre for Bacterial Resistance Biology, Imperial College London, London, UK
| | - Nicholas R Thomson
- Parasites and Microbes, Wellcome Sanger Institute, Cambridge, UK
- London School of Hygiene and Tropical Medicine, London, UK
| | - Jukka Corander
- Department of Biostatistics, University of Oslo, 0317, Oslo, Norway.
- Parasites and Microbes, Wellcome Sanger Institute, Cambridge, UK.
- Helsinki Institute of Information Technology, Department of Mathematics and Statistics, University of Helsinki, Helsinki, Finland.
| | - Peter W Taylor
- School of Pharmacy, University College London, London, UK.
| | - Alex J McCarthy
- Department of Infectious Disease, Centre for Bacterial Resistance Biology, Imperial College London, London, UK.
| |
Collapse
|
18
|
Beamud B, García-González N, Gómez-Ortega M, González-Candelas F, Domingo-Calap P, Sanjuan R. Genetic determinants of host tropism in Klebsiella phages. Cell Rep 2023; 42:112048. [PMID: 36753420 PMCID: PMC9989827 DOI: 10.1016/j.celrep.2023.112048] [Citation(s) in RCA: 38] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2022] [Revised: 11/25/2022] [Accepted: 01/13/2023] [Indexed: 02/08/2023] Open
Abstract
Bacteriophages play key roles in bacterial ecology and evolution and are potential antimicrobials. However, the determinants of phage-host specificity remain elusive. Here, we isolate 46 phages to challenge 138 representative clinical isolates of Klebsiella pneumoniae, a widespread opportunistic pathogen. Spot tests show a narrow host range for most phages, with <2% of 6,319 phage-host combinations tested yielding detectable interactions. Bacterial capsule diversity is the main factor restricting phage host range. Consequently, phage-encoded depolymerases are key determinants of host tropism, and depolymerase sequence types are associated with the ability to infect specific capsular types across phage families. However, all phages with a broader host range found do not encode canonical depolymerases, suggesting alternative modes of entry. These findings expand our knowledge of the complex interactions between bacteria and their viruses and point out the feasibility of predicting the first steps of phage infection using bacterial and phage genome sequences.
Collapse
Affiliation(s)
- Beatriz Beamud
- Joint Research Unit Infection and Public Health, FISABIO-Universitat de València, 46020 València, Spain; Institute for Integrative Systems Biology (I(2)SysBio), Universitat de València-CSIC, 46980 Paterna, Spain
| | - Neris García-González
- Joint Research Unit Infection and Public Health, FISABIO-Universitat de València, 46020 València, Spain; Institute for Integrative Systems Biology (I(2)SysBio), Universitat de València-CSIC, 46980 Paterna, Spain
| | - Mar Gómez-Ortega
- Joint Research Unit Infection and Public Health, FISABIO-Universitat de València, 46020 València, Spain
| | - Fernando González-Candelas
- Joint Research Unit Infection and Public Health, FISABIO-Universitat de València, 46020 València, Spain; Institute for Integrative Systems Biology (I(2)SysBio), Universitat de València-CSIC, 46980 Paterna, Spain.
| | - Pilar Domingo-Calap
- Institute for Integrative Systems Biology (I(2)SysBio), Universitat de València-CSIC, 46980 Paterna, Spain.
| | - Rafael Sanjuan
- Institute for Integrative Systems Biology (I(2)SysBio), Universitat de València-CSIC, 46980 Paterna, Spain.
| |
Collapse
|
19
|
Cruz-López F, Martínez-Meléndez A, Garza-González E. How Does Hospital Microbiota Contribute to Healthcare-Associated Infections? Microorganisms 2023; 11:microorganisms11010192. [PMID: 36677484 PMCID: PMC9867428 DOI: 10.3390/microorganisms11010192] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Revised: 01/09/2023] [Accepted: 01/10/2023] [Indexed: 01/13/2023] Open
Abstract
Healthcare-associated infections (HAIs) are still a global public health concern, associated with high mortality and increased by the phenomenon of antimicrobial resistance. Causative agents of HAIs are commonly found in the hospital environment and are monitored in epidemiological surveillance programs; however, the hospital environment is a potential reservoir for pathogenic microbial strains where microorganisms may persist on medical equipment surfaces, on the environment surrounding patients, and on corporal surfaces of patients and healthcare workers (HCWs). The characterization of hospital microbiota may provide knowledge regarding the relatedness between commensal and pathogenic microorganisms, their role in HAIs development, and the environmental conditions that favor its proliferation. This information may contribute to the effective control of the dissemination of pathogens and to improve infection control programs. In this review, we describe evidence of the contribution of hospital microbiota to HAI development and the role of environmental factors, antimicrobial resistance, and virulence factors of the microbial community in persistence on hospital surfaces.
Collapse
Affiliation(s)
- Flora Cruz-López
- Subdirección Académica de Químico Farmacéutico Biólogo, Facultad de Ciencias Químicas, Universidad Autónoma de Nuevo León, Pedro de Alba S/N, Ciudad Universitaria, San Nicolás de los Garza 66450, Nuevo León, Mexico
| | - Adrián Martínez-Meléndez
- Subdirección Académica de Químico Farmacéutico Biólogo, Facultad de Ciencias Químicas, Universidad Autónoma de Nuevo León, Pedro de Alba S/N, Ciudad Universitaria, San Nicolás de los Garza 66450, Nuevo León, Mexico
| | - Elvira Garza-González
- Laboratorio de Microbiología Molecular, Departamento de Bioquímica y Medicina Molecular, Facultad de Medicina/Hospital Universitario “Dr. José Eleuterio González”, Universidad Autónoma de Nuevo León, Avenida Gonzalitos y Madero s/n, Colonia Mitras Centro, Monterrey 64460, Nuevo León, Mexico
- Correspondence:
| |
Collapse
|
20
|
Nucci A, Rocha EPC, Rendueles O. Adaptation to novel spatially-structured environments is driven by the capsule and alters virulence-associated traits. Nat Commun 2022; 13:4751. [PMID: 35963864 PMCID: PMC9376106 DOI: 10.1038/s41467-022-32504-9] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Accepted: 08/02/2022] [Indexed: 12/14/2022] Open
Abstract
The extracellular capsule is a major virulence factor, but its ubiquity in free-living bacteria with large environmental breadths suggests that it shapes adaptation to novel niches. Yet, how it does so, remains unexplored. Here, we evolve three Klebsiella strains and their capsule mutants in parallel. Their comparison reveals different phenotypic and genotypic evolutionary changes that alter virulence-associated traits. Non-capsulated populations accumulate mutations that reduce exopolysaccharide production and increase biofilm formation and yield, whereas most capsulated populations become hypermucoviscous, a signature of hypervirulence. Hence, adaptation to novel environments primarily occurs by fine-tuning expression of the capsular locus. The same evolutionary conditions selecting for mutations in the capsular gene wzc leading to hypermucoviscosity also result in increased susceptibility to antibiotics by mutations in the ramA regulon. This implies that general adaptive processes outside the host can affect capsule evolution and its role in virulence and infection outcomes may be a by-product of such adaptation. Phenotypic and genotypic evolution in worrisome Klebsiella spp. is influenced by the capsule. Here the authors show that adaptation outside the host can impact virulence-associated traits, including de novo emergence of hypermucoviscosity.
Collapse
Affiliation(s)
- Amandine Nucci
- Institut Pasteur, Université de Paris, CNRS, UMR3525, Microbial Evolutionary Genomics, F-75015, Paris, France
| | - Eduardo P C Rocha
- Institut Pasteur, Université de Paris, CNRS, UMR3525, Microbial Evolutionary Genomics, F-75015, Paris, France
| | - Olaya Rendueles
- Institut Pasteur, Université de Paris, CNRS, UMR3525, Microbial Evolutionary Genomics, F-75015, Paris, France.
| |
Collapse
|
21
|
Huang X, Li X, An H, Wang J, Ding M, Wang L, Li L, Ji Q, Qu F, Wang H, Xu Y, Lu X, He Y, Zhang JR. Capsule type defines the capability of Klebsiella pneumoniae in evading Kupffer cell capture in the liver. PLoS Pathog 2022; 18:e1010693. [PMID: 35914009 PMCID: PMC9342791 DOI: 10.1371/journal.ppat.1010693] [Citation(s) in RCA: 41] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Accepted: 06/22/2022] [Indexed: 11/21/2022] Open
Abstract
Polysaccharide capsule is the main virulence factor of K. pneumoniae, a major pathogen of bloodstream infections in humans. While more than 80 capsular serotypes have been identified in K. pneumoniae, only several serotypes are frequently identified in invasive infections. It is documented that the capsule enhances bacterial resistance to phagocytosis, antimicrobial peptides and complement deposition under in vitro conditions. However, the precise role of the capsule in the process of K. pneumoniae bloodstream infections remains to be elucidated. Here we show that the capsule promotes K. pneumoniae survival in the bloodstream by protecting bacteria from being captured by liver resident macrophage Kupffer cells (KCs). Our real-time in vivo imaging revealed that blood-borne acapsular K. pneumoniae mutant is rapidly captured and killed by KCs in the liver sinusoids of mice, whereas, to various extents, encapsulated strains bypass the anti-bacterial machinery in a serotype-dependent manner. Using capsule switched strains, we show that certain high-virulence (HV) capsular serotypes completely block KC’s capture, whereas the low-virulence (LV) counterparts confer partial protection against KC’s capture. Moreover, KC’s capture of the LV K. pneumoniae could be in vivo neutralized by free capsular polysaccharides of homologous but not heterologous serotypes, indicating that KCs specifically recognize the LV capsules. Finally, immunization with inactivated K. pneumoniae enables KCs to capture the HV K. pneumoniae. Together, our findings have uncovered that KCs are the major target cells of K. pneumoniae capsule to promote bacterial survival and virulence, which can be reversed by vaccination. Klebsiella pneumoniae is a major human pathogen. While capsule is the main virulence factor of the pathogen, only several of more than 80 capsule serotypes are frequently identified in invasive infections. However, it remains unclear how capsule contributes to K. pneumoniae virulence. Here we show that capsule type defines K. pneumoniae virulence by differential escape of immune surveillance in the liver. While low-virulence (LV) types are captured by Kupffer cells (KCs), high-virulence (HV) types circumvent the anti-bacterial machinery. Further, inactivated K. pneumoniae vaccine enables KCs to capture the HV K. pneumoniae and protects mice from lethal infection. Our findings explain the clinical prevalence of HV capsule types, and provide promising insights for future vaccine development.
Collapse
Affiliation(s)
- Xueting Huang
- Center for Infectious Disease Research, Department of Basic Medical Science, School of Medicine, Tsinghua University, Beijing, China
- Tsinghua-Peking Center for Life Sciences, Tsinghua University, Beijing, China
| | - Xiuyuan Li
- Center for Infectious Disease Research, Department of Basic Medical Science, School of Medicine, Tsinghua University, Beijing, China
| | - Haoran An
- Center for Infectious Disease Research, Department of Basic Medical Science, School of Medicine, Tsinghua University, Beijing, China
- Tsinghua-Peking Center for Life Sciences, Tsinghua University, Beijing, China
| | - Juanjuan Wang
- Center for Infectious Disease Research, Department of Basic Medical Science, School of Medicine, Tsinghua University, Beijing, China
- Tsinghua-Peking Center for Life Sciences, Tsinghua University, Beijing, China
| | - Ming Ding
- Center for Infectious Disease Research, Department of Basic Medical Science, School of Medicine, Tsinghua University, Beijing, China
| | - Lijun Wang
- Center for Infectious Disease Research, Department of Basic Medical Science, School of Medicine, Tsinghua University, Beijing, China
- Beijing Tsinghua Changgung Hospital, Tsinghua University, Beijing, China
| | - Lulu Li
- Center for Infectious Disease Research, Department of Basic Medical Science, School of Medicine, Tsinghua University, Beijing, China
| | - Quanjiang Ji
- School of Physical Science and Technology, Shanghai Tech University, Shanghai, China
| | - Fen Qu
- The Center of Clinical Diagnosis Laboratory, 302 Hospital of PLA, Beijing, China
- China Aviation General Hospital of China Medical University, Beijing, China
| | - Hui Wang
- Department of Clinical Laboratory, Peking University People’s Hospital, Beijing, China
| | - Yingchun Xu
- Department of Clinical Laboratory, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences, Beijing, China
| | - Xinxin Lu
- Department of Clinical Laboratory, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Yuan He
- Research Beyond Borders, Boehringer Ingelheim (China), Shanghai, China
| | - Jing-Ren Zhang
- Center for Infectious Disease Research, Department of Basic Medical Science, School of Medicine, Tsinghua University, Beijing, China
- Tsinghua-Peking Center for Life Sciences, Tsinghua University, Beijing, China
- * E-mail:
| |
Collapse
|
22
|
Sheppard SK. Strain wars and the evolution of opportunistic pathogens. Curr Opin Microbiol 2022; 67:102138. [DOI: 10.1016/j.mib.2022.01.009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Revised: 01/13/2022] [Accepted: 01/20/2022] [Indexed: 01/28/2023]
|
23
|
Rhodes KA, Ma MC, Rendón MA, So M. Neisseria genes required for persistence identified via in vivo screening of a transposon mutant library. PLoS Pathog 2022; 18:e1010497. [PMID: 35580146 PMCID: PMC9140248 DOI: 10.1371/journal.ppat.1010497] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Revised: 05/27/2022] [Accepted: 04/04/2022] [Indexed: 11/30/2022] Open
Abstract
The mechanisms used by human adapted commensal Neisseria to shape and maintain a niche in their host are poorly defined. These organisms are common members of the mucosal microbiota and share many putative host interaction factors with Neisseria meningitidis and Neisseria gonorrhoeae. Evaluating the role of these shared factors during host carriage may provide insight into bacterial mechanisms driving both commensalism and asymptomatic infection across the genus. We identified host interaction factors required for niche development and maintenance through in vivo screening of a transposon mutant library of Neisseria musculi, a commensal of wild-caught mice which persistently and asymptomatically colonizes the oral cavity and gut of CAST/EiJ and A/J mice. Approximately 500 candidate genes involved in long-term host interaction were identified. These included homologs of putative N. meningitidis and N. gonorrhoeae virulence factors which have been shown to modulate host interactions in vitro. Importantly, many candidate genes have no assigned function, illustrating how much remains to be learned about Neisseria persistence. Many genes of unknown function are conserved in human adapted Neisseria species; they are likely to provide a gateway for understanding the mechanisms allowing pathogenic and commensal Neisseria to establish and maintain a niche in their natural hosts. Validation of a subset of candidate genes confirmed a role for a polysaccharide capsule in N. musculi persistence but not colonization. Our findings highlight the potential utility of the Neisseria musculi-mouse model as a tool for studying the pathogenic Neisseria; our work represents a first step towards the identification of novel host interaction factors conserved across the genus. The Neisseria genus contains many genetically related commensals of animals and humans, and two human pathogens, Neisseria gonorrhoeae and Neisseria meningitidis. The mechanisms allowing commensal Neisseria to maintain a niche in their host is little understood. To identify genes required for persistence, we screened a library of transposon mutants of Neisseria musculi, a commensal of wild-caught mice, in CAST/EiJ mice, which persistently and asymptomatically colonizes. Approximately 500 candidate host interaction genes were identified. A subset of these are homologs of N. meningitidis and N. gonorrhoeae genes known to modulate pathogen-host interactions in vitro. Many candidate genes have no known function, demonstrating how much remains to be learned about N. musculi niche maintenance. As many genes of unknown function are conserved in human adapted Neisseria, they provide a gateway for understanding Neisseria persistence mechanisms in general.
Collapse
Affiliation(s)
- Katherine A. Rhodes
- Immunobiology Department, University of Arizona, Tucson, Arizona, United States of America
- BIO5 Institute, University of Arizona, Tucson, Arizona, United States of America
- * E-mail:
| | - Man Cheong Ma
- Immunobiology Department, University of Arizona, Tucson, Arizona, United States of America
- BIO5 Institute, University of Arizona, Tucson, Arizona, United States of America
| | - María A. Rendón
- Immunobiology Department, University of Arizona, Tucson, Arizona, United States of America
- BIO5 Institute, University of Arizona, Tucson, Arizona, United States of America
| | - Magdalene So
- Immunobiology Department, University of Arizona, Tucson, Arizona, United States of America
- BIO5 Institute, University of Arizona, Tucson, Arizona, United States of America
| |
Collapse
|
24
|
Gazioglu O, Kareem BO, Afzal M, Shafeeq S, Kuipers OP, Ulijasz AT, Andrew PW, Yesilkaya H. Glutamate Dehydrogenase (GdhA) of Streptococcus pneumoniae Is Required for High Temperature Adaptation. Infect Immun 2021; 89:e0040021. [PMID: 34491792 PMCID: PMC8594611 DOI: 10.1128/iai.00400-21] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Accepted: 08/25/2021] [Indexed: 11/20/2022] Open
Abstract
During its progression from the nasopharynx to other sterile and nonsterile niches of its human host, Streptococcus pneumoniae must cope with changes in temperature. We hypothesized that the temperature adaptation is an important facet of pneumococcal survival in the host. Here, we evaluated the effect of temperature on pneumococcus and studied the role of glutamate dehydrogenase (GdhA) in thermal adaptation associated with virulence and survival. Microarray analysis revealed a significant transcriptional response to changes in temperature, affecting the expression of 252 genes in total at 34°C and 40°C relative to at 37°C. One of the differentially regulated genes was gdhA, which is upregulated at 40°C and downregulated at 34°C relative to 37°C. Deletion of gdhA attenuated the growth, cell size, biofilm formation, pH survival, and biosynthesis of proteins associated with virulence in a temperature-dependent manner. Moreover, deletion of gdhA stimulated formate production irrespective of temperature fluctuation. Finally, ΔgdhA grown at 40°C was less virulent than other temperatures or the wild type at the same temperature in a Galleria mellonella infection model, suggesting that GdhA is required for pneumococcal virulence at elevated temperature.
Collapse
Affiliation(s)
- Ozcan Gazioglu
- Department of Respiratory Sciences, University of Leicester, Leicester, United Kingdom
| | - Banaz O. Kareem
- Department of Respiratory Sciences, University of Leicester, Leicester, United Kingdom
- Department of Medical Laboratory Science, College of Medicals and Applied Sciences, University of Charmo, Chamchamal, Iraq
| | - Muhammad Afzal
- Molecular Genetics, University of Groningen, Groningen, The Netherlands
| | - Sulman Shafeeq
- Molecular Genetics, University of Groningen, Groningen, The Netherlands
| | - Oscar P. Kuipers
- Molecular Genetics, University of Groningen, Groningen, The Netherlands
| | - Andrew T. Ulijasz
- Department of Microbiology and Immunology, Loyola University Chicago, Maywood, Illinois, USA
| | - Peter W. Andrew
- Department of Respiratory Sciences, University of Leicester, Leicester, United Kingdom
| | - Hasan Yesilkaya
- Department of Respiratory Sciences, University of Leicester, Leicester, United Kingdom
| |
Collapse
|
25
|
High-Throughput Mutagenesis and Cross-Complementation Experiments Reveal Substrate Preference and Critical Residues of the Capsule Transporters in Streptococcus pneumoniae. mBio 2021; 12:e0261521. [PMID: 34724815 PMCID: PMC8561386 DOI: 10.1128/mbio.02615-21] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
MOP (Multidrug/Oligosaccharidyl-lipid/Polysaccharide) family transporters are found in almost all life forms. They are responsible for transporting lipid-linked precursors across the cell membrane to support the synthesis of various glycoconjugates. While significant progress has been made in elucidating their transport mechanism, how these transporters select their substrates remains unclear. Here, we systematically tested the MOP transporters in the Streptococcus pneumoniae capsule pathway for their ability to translocate noncognate capsule precursors. Sequence similarity cannot predict whether these transporters are interchangeable. We showed that subtle changes in the central aqueous cavity of the transporter are sufficient to accommodate a different cargo. These changes can occur naturally, suggesting a potential mechanism of expanding substrate selectivity. A directed evolution experiment was performed to identify gain-of-function variants that translocate a noncognate cargo. Coupled with a high-throughput mutagenesis and sequencing (Mut-seq) experiment, residues that are functionally important for the capsule transporter were revealed. Lastly, we showed that the expression of a flippase that can transport unfinished precursors resulted in an increased susceptibility to bacitracin and mild cell shape defects, which may be a driving force to maintain transporter specificity. IMPORTANCE All licensed pneumococcal vaccines target the capsular polysaccharide (CPS). This layer is highly variable and is important for virulence in many bacterial pathogens. Most of the CPSs are produced by the Wzx/Wzy mechanism. In this pathway, CPS repeating units are synthesized in the cytoplasm, which must be flipped across the cytoplasmic membrane before polymerization. This step is mediated by the widely conserved MOP (Multidrug/Oligosaccharidyl-lipid/Polysaccharide) family transporters. Here, we systematically evaluated the interchangeability of these transporters and identified the residues important for substrate specificity and function. Understanding how CPS is synthesized will inform glycoengineering, vaccine development, and antimicrobial discovery.
Collapse
|
26
|
Human commensal gut Proteobacteria withstand type VI secretion attacks through immunity protein-independent mechanisms. Nat Commun 2021; 12:5751. [PMID: 34599171 PMCID: PMC8486750 DOI: 10.1038/s41467-021-26041-0] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Accepted: 09/13/2021] [Indexed: 12/26/2022] Open
Abstract
While the major virulence factors for Vibrio cholerae, the cause of the devastating diarrheal disease cholera, have been extensively studied, the initial intestinal colonization of the bacterium is not well understood because non-human adult animals are refractory to its colonization. Recent studies suggest the involvement of an interbacterial killing device known as the type VI secretion system (T6SS). Here, we tested the T6SS-dependent interaction of V. cholerae with a selection of human gut commensal isolates. We show that the pathogen efficiently depleted representative genera of the Proteobacteria in vitro, while members of the Enterobacter cloacae complex and several Klebsiella species remained unaffected. We demonstrate that this resistance against T6SS assaults was mediated by the production of superior T6SS machinery or a barrier exerted by group I capsules. Collectively, our data provide new insights into immunity protein-independent T6SS resistance employed by the human microbiota and colonization resistance in general.
Collapse
|
27
|
Haudiquet M, Buffet A, Rendueles O, Rocha EPC. Interplay between the cell envelope and mobile genetic elements shapes gene flow in populations of the nosocomial pathogen Klebsiella pneumoniae. PLoS Biol 2021; 19:e3001276. [PMID: 34228700 PMCID: PMC8259999 DOI: 10.1371/journal.pbio.3001276] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Accepted: 05/07/2021] [Indexed: 01/01/2023] Open
Abstract
Mobile genetic elements (MGEs) drive genetic transfers between bacteria using mechanisms that require a physical interaction with the cellular envelope. In the high-priority multidrug-resistant nosocomial pathogens (ESKAPE), the first point of contact between the cell and virions or conjugative pili is the capsule. While the capsule can be a barrier to MGEs, it also evolves rapidly by horizontal gene transfer (HGT). Here, we aim at understanding this apparent contradiction by studying the covariation between the repertoire of capsule genes and MGEs in approximately 4,000 genomes of Klebsiella pneumoniae (Kpn). We show that capsules drive phage-mediated gene flow between closely related serotypes. Such serotype-specific phage predation also explains the frequent inactivation of capsule genes, observed in more than 3% of the genomes. Inactivation is strongly epistatic, recapitulating the capsule biosynthetic pathway. We show that conjugative plasmids are acquired at higher rates in natural isolates lacking a functional capsular locus and confirmed experimentally this result in capsule mutants. This suggests that capsule inactivation by phage pressure facilitates its subsequent reacquisition by conjugation. Accordingly, capsule reacquisition leaves long recombination tracts around the capsular locus. The loss and regain process rewires gene flow toward other lineages whenever it leads to serotype swaps. Such changes happen preferentially between chemically related serotypes, hinting that the fitness of serotype-swapped strains depends on the host genetic background. These results enlighten the bases of trade-offs between the evolution of virulence and multidrug resistance and caution that some alternatives to antibiotics by selecting for capsule inactivation may facilitate the acquisition of antibiotic resistance genes (ARGs). A study of how the complex interaction between capsules and mobile genetic elements shapes gene flow in populations of Klebsiella pneumoniae reveals that capsule inactivation by phage pressure facilitates its subsequent re-acquisition by conjugation, and this loss and re-gain process influences the gene flow towards other lineages whenever it leads to serotype changes.
Collapse
Affiliation(s)
- Matthieu Haudiquet
- Microbial Evolutionary Genomics, Institut Pasteur, CNRS, UMR3525, Paris, France
- Ecole Doctoral FIRE–Programme Bettencourt, CRI, Paris, France
- * E-mail:
| | - Amandine Buffet
- Microbial Evolutionary Genomics, Institut Pasteur, CNRS, UMR3525, Paris, France
| | - Olaya Rendueles
- Microbial Evolutionary Genomics, Institut Pasteur, CNRS, UMR3525, Paris, France
| | - Eduardo P. C. Rocha
- Microbial Evolutionary Genomics, Institut Pasteur, CNRS, UMR3525, Paris, France
| |
Collapse
|
28
|
Marian M, Fujikawa T, Shimizu M. Genome analysis provides insights into the biocontrol ability of Mitsuaria sp. strain TWR114. Arch Microbiol 2021; 203:3373-3388. [PMID: 33880605 DOI: 10.1007/s00203-021-02327-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Revised: 04/07/2021] [Accepted: 04/09/2021] [Indexed: 12/31/2022]
Abstract
Mitsuaria sp. TWR114 is a biocontrol agent against tomato bacterial wilt (TBW). We aimed to gain genomic insights relevant to the biocontrol mechanisms and colonization ability of this strain. The draft genome size was found to be 5,632,523 bp, with a GC content of 69.5%, assembled into 1144 scaffolds. Genome annotation predicted a total of 4675 protein coding sequences (CDSs), 914 pseudogenes, 49 transfer RNAs, 3 noncoding RNAs, and 2 ribosomal RNAs. Genome analysis identified multiple CDSs associated with various pathways for the metabolism and transport of amino acids and carbohydrates, motility and chemotactic capacities, protection against stresses (oxidative, antibiotic, and phage), production of secondary metabolites, peptidases, quorum-quenching enzymes, and indole-3-acetic acid, as well as protein secretion systems and their related appendages. The genome resource will extend our understanding of the genomic features related to TWR114's biocontrol and colonization abilities and facilitate its development as a new biopesticide against TBW.
Collapse
Affiliation(s)
- Malek Marian
- Faculty of Applied Biological Sciences, Gifu University, Gifu, 501-1193, Japan.,College of Agriculture, Ibaraki University, Ami, Inashiki, Ibaraki, 300-0393, Japan
| | - Takashi Fujikawa
- Institute of Fruit Tree and Tea Science, National Agriculture and Food Research Organization (NARO), Tsukuba, Ibaraki, 305-8605, Japan
| | - Masafumi Shimizu
- Faculty of Applied Biological Sciences, Gifu University, Gifu, 501-1193, Japan.
| |
Collapse
|
29
|
Buffet A, Rocha EPC, Rendueles O. Nutrient conditions are primary drivers of bacterial capsule maintenance in Klebsiella. Proc Biol Sci 2021; 288:20202876. [PMID: 33653142 PMCID: PMC7935059 DOI: 10.1098/rspb.2020.2876] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2020] [Accepted: 02/05/2021] [Indexed: 02/06/2023] Open
Abstract
The fitness cost associated with the production of bacterial capsules is considered to be offset by the protection provided by these extracellular structures against biotic aggressions or abiotic stress. However, it is unknown if the capsule contributes to fitness in the absence of these. Here, we explored conditions favouring the maintenance of the capsule in Klebsiella pneumoniae, where the capsule is known to be a major virulence factor. Using short-term experimental evolution on different Klebsiella strains, we showed that small environmental variations have a strong impact on the maintenance of the capsule. Capsule inactivation is frequent in nutrient-rich, but scarce in nutrient-poor media. Competitions between wild-type and capsule mutants in nine different strains confirmed that the capsule is costly in nutrient-rich media. Surprisingly, these results also showed that the presence of a capsule provides a clear fitness advantage in nutrient-poor conditions by increasing both growth rates and population yields. The comparative analyses of the wild-type and capsule mutants reveal complex interactions between the environment, genetic background and serotype even in relation to traits known to be relevant during pathogenesis. In conclusion, our data suggest there are novel roles for bacterial capsules yet to be discovered and further supports the notion that the capsule's role in virulence may be a by-product of its contribution to bacterial adaptation outside the host.
Collapse
Affiliation(s)
- Amandine Buffet
- Microbial Evolutionary Genomics, Institut Pasteur, CNRS, UMR3525, Paris 75015, France
| | - Eduardo P. C. Rocha
- Microbial Evolutionary Genomics, Institut Pasteur, CNRS, UMR3525, Paris 75015, France
| | - Olaya Rendueles
- Microbial Evolutionary Genomics, Institut Pasteur, CNRS, UMR3525, Paris 75015, France
| |
Collapse
|
30
|
Ranjan M, Khokhani D, Nayaka S, Srivastava S, Keyser ZP, Ranjan A. Genomic diversity and organization of complex polysaccharide biosynthesis clusters in the genus Dickeya. PLoS One 2021; 16:e0245727. [PMID: 33571209 PMCID: PMC7877592 DOI: 10.1371/journal.pone.0245727] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2020] [Accepted: 01/07/2021] [Indexed: 11/18/2022] Open
Abstract
The pectinolytic genus Dickeya (formerly Erwinia chrysanthemi) comprises numerous pathogenic species which cause diseases in various crops and ornamental plants across the globe. Their pathogenicity is governed by complex multi-factorial processes of adaptive virulence gene regulation. Extracellular polysaccharides and lipopolysaccharides present on bacterial envelope surface play a significant role in the virulence of phytopathogenic bacteria. However, very little is known about the genomic location, diversity, and organization of the polysaccharide and lipopolysaccharide biosynthetic gene clusters in Dickeya. In the present study, we report the diversity and structural organization of the group 4 capsule (G4C)/O-antigen capsule, putative O-antigen lipopolysaccharide, enterobacterial common antigen, and core lipopolysaccharide biosynthesis clusters from 54 Dickeya strains. The presence of these clusters suggests that Dickeya has both capsule and lipopolysaccharide carrying O-antigen to their external surface. These gene clusters are key regulatory components in the composition and structure of the outer surface of Dickeya. The O-antigen capsule/group 4 capsule (G4C) coding region shows a variation in gene content and organization. Based on nucleotide sequence homology in these Dickeya strains, two distinct groups, G4C group I and G4C group II, exist. However, comparatively less variation is observed in the putative O-antigen lipopolysaccharide cluster in Dickeya spp. except for in Dickeya zeae. Also, enterobacterial common antigen and core lipopolysaccharide biosynthesis clusters are present mostly as conserved genomic regions. The variation in the O-antigen capsule and putative O-antigen lipopolysaccharide coding region in relation to their phylogeny suggests a role of multiple horizontal gene transfer (HGT) events. These multiple HGT processes might have been manifested into the current heterogeneity of O-antigen capsules and O-antigen lipopolysaccharides in Dickeya strains during its evolution.
Collapse
Affiliation(s)
- Manish Ranjan
- CSIR-National Botanical Research Institute (CSIR-NBRI), Lucknow, Uttar Pradesh, India
| | - Devanshi Khokhani
- Department of Bacteriology, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
- Department of Plant Pathology, University of Minnesota—Twin Cities, St. Paul, Minnesota, United States of America
| | - Sanjeeva Nayaka
- CSIR-National Botanical Research Institute (CSIR-NBRI), Lucknow, Uttar Pradesh, India
| | - Suchi Srivastava
- CSIR-National Botanical Research Institute (CSIR-NBRI), Lucknow, Uttar Pradesh, India
| | - Zachary P. Keyser
- Department of Agronomy, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Ashish Ranjan
- Department of Plant Pathology, University of Minnesota—Twin Cities, St. Paul, Minnesota, United States of America
- Department of Plant Sciences (SLS), University of Hyderabad, Hyderabad, India
| |
Collapse
|
31
|
Bian S, Zeng W, Li Q, Li Y, Wong NK, Jiang M, Zuo L, Hu Q, Li L. Genetic Structure, Function, and Evolution of Capsule Biosynthesis Loci in Vibrio parahaemolyticus. Front Microbiol 2021; 11:546150. [PMID: 33505361 PMCID: PMC7829505 DOI: 10.3389/fmicb.2020.546150] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Accepted: 11/24/2020] [Indexed: 01/29/2023] Open
Abstract
Capsule-forming extracellular polysaccharides are crucial for bacterial host colonization, invasion, immune evasion, and ultimately pathogenicity. Due to warming ocean waters and human encroachment of coastal ecosystems, Vibrio parahaemolyticus has emerged as a globally important foodborne enteropathogen implicated in acute gastroenteritis, wound infections, and septic shock. Conventionally, the antigenic properties of lipopolysaccharide (LPS, O antigen) and capsular polysaccharide (CPS, K antigen) have provided a basis for serotyping V. parahaemolyticus, whereas disclosure of genetic elements encoding 13 O-serogroups have allowed molecular serotyping methods to be developed. However, the genetic structure of CPS loci for 71 K-serogroups has remained unidentified, limiting progress in understanding its roles in V. parahaemolyticus pathophysiology. In this study, we identified and characterized the genetic structure and their evolutionary relationship of CPS loci of 40 K-serogroups through whole genome sequencing of 443 V. parahaemolyticus strains. We found a distinct pattern of CPS gene cluster across different K-serogroups and expanded its new 3'-border by identifying glpX as a key gene conserved across all K-serogroups. A total of 217 genes involved in CPS biosynthesis were annotated. Functional contents and genetic structure of the 40 K-serogroups were analyzed. Based on inferences from species trees and gene trees, we proposed an evolution model of the CPS gene clusters of 40 K-serogroups. Horizontal gene transfer by recombination from other Vibrio species, gene duplication is likely to play instrumental roles in the evolution of CPS in V. parahaemolyticus. This is the first time, to the best of our knowledge, that a large scale of CPS gene clusters of different K-serogroups in V. parahaemolyticus have been identified and characterized in evolutionary contexts. This work should help advance understanding on the variation of CPS in V. parahaemolyticus and provide a framework for developing diagnostically relevant serotyping methods.
Collapse
Affiliation(s)
- Shengzhe Bian
- BGI Education Center, University of Chinese Academy of Sciences, Shenzhen, China
- BGI-Shenzhen, Shenzhen, China
- Shenzhen Key Laboratory of Unknown Pathogen Identification, Shenzhen, China
- School of Public Health (Shenzhen), Sun Yat-sen University, Guangzhou, China
| | - Wenhong Zeng
- Jiangxi University of Traditional Chinese Medicine, Nanchang, China
| | - Qiwen Li
- BGI-Shenzhen, Shenzhen, China
- Shenzhen Key Laboratory of Unknown Pathogen Identification, Shenzhen, China
| | - Yinghui Li
- Shenzhen Center for Disease Control and Prevention, Shenzhen, China
| | - Nai-Kei Wong
- National Clinical Research Center for Infectious Diseases, Shenzhen Third People’s Hospital, The Second Hospital Affiliated to Southern University of Science and Technology, Shenzhen, China
| | - Min Jiang
- Shenzhen Center for Disease Control and Prevention, Shenzhen, China
| | - Le Zuo
- Shenzhen Center for Disease Control and Prevention, Shenzhen, China
| | - Qinghua Hu
- Shenzhen Center for Disease Control and Prevention, Shenzhen, China
| | - Liqiang Li
- BGI-Shenzhen, Shenzhen, China
- Shenzhen Key Laboratory of Unknown Pathogen Identification, Shenzhen, China
| |
Collapse
|
32
|
Smith LM, Jackson SA, Malone LM, Ussher JE, Gardner PP, Fineran PC. The Rcs stress response inversely controls surface and CRISPR-Cas adaptive immunity to discriminate plasmids and phages. Nat Microbiol 2021; 6:162-172. [PMID: 33398095 DOI: 10.1038/s41564-020-00822-7] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2020] [Accepted: 10/23/2020] [Indexed: 12/16/2022]
Abstract
Bacteria harbour multiple innate defences and adaptive CRISPR-Cas systems that provide immunity against bacteriophages and mobile genetic elements. Although some bacteria modulate defences in response to population density, stress and metabolic state, a lack of high-throughput methods to systematically reveal regulators has hampered efforts to understand when and how immune strategies are deployed. We developed a robust approach called SorTn-seq, which combines saturation transposon mutagenesis, fluorescence-activated cell sorting and deep sequencing to characterize regulatory networks controlling CRISPR-Cas immunity in Serratia sp. ATCC 39006. We applied our technology to assess csm gene expression for ~300,000 mutants and uncovered multiple pathways regulating type III-A CRISPR-Cas expression. Mutation of igaA or mdoG activated the Rcs outer-membrane stress response, eliciting cell-surface-based innate immunity against diverse phages via the transcriptional regulators RcsB and RcsA. Activation of this Rcs phosphorelay concomitantly attenuated adaptive immunity by three distinct type I and III CRISPR-Cas systems. Rcs-mediated repression of CRISPR-Cas defence enabled increased acquisition and retention of plasmids. Dual downregulation of cell-surface receptors and adaptive immunity in response to stress by the Rcs pathway enables protection from phage infection without preventing the uptake of plasmids that may harbour beneficial traits.
Collapse
Affiliation(s)
- Leah M Smith
- Department of Microbiology and Immunology, University of Otago, Dunedin, New Zealand
| | - Simon A Jackson
- Department of Microbiology and Immunology, University of Otago, Dunedin, New Zealand.,Genetics Otago, University of Otago, Dunedin, New Zealand
| | - Lucia M Malone
- Department of Microbiology and Immunology, University of Otago, Dunedin, New Zealand
| | - James E Ussher
- Department of Microbiology and Immunology, University of Otago, Dunedin, New Zealand
| | - Paul P Gardner
- Genetics Otago, University of Otago, Dunedin, New Zealand.,Department of Biochemistry, University of Otago, Dunedin, New Zealand.,Bio-Protection Research Centre, University of Otago, Dunedin, New Zealand
| | - Peter C Fineran
- Department of Microbiology and Immunology, University of Otago, Dunedin, New Zealand. .,Genetics Otago, University of Otago, Dunedin, New Zealand. .,Bio-Protection Research Centre, University of Otago, Dunedin, New Zealand.
| |
Collapse
|
33
|
Su T, Nakamoto R, Chun YY, Chua WZ, Chen JH, Zik JJ, Sham LT. Decoding capsule synthesis in Streptococcus pneumoniae. FEMS Microbiol Rev 2020; 45:6041728. [PMID: 33338218 DOI: 10.1093/femsre/fuaa067] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Accepted: 12/07/2020] [Indexed: 12/20/2022] Open
Abstract
Streptococcus pneumoniae synthesizes more than one hundred types of capsular polysaccharides (CPS). While the diversity of the enzymes and transporters involved is enormous, it is not limitless. In this review, we summarized the recent progress on elucidating the structure-function relationships of CPS, the mechanisms by which they are synthesized, how their synthesis is regulated, the host immune response against them, and the development of novel pneumococcal vaccines. Based on the genetic and structural information available, we generated provisional models of the CPS repeating units that remain unsolved. In addition, to facilitate cross-species comparisons and assignment of glycosyltransferases, we illustrated the biosynthetic pathways of the known CPS in a standardized format. Studying the intricate steps of pneumococcal CPS assembly promises to provide novel insights for drug and vaccine development as well as improve our understanding of related pathways in other species.
Collapse
Affiliation(s)
- Tong Su
- Infectious Diseases Translational Research Programme, Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, 117545, Singapore
| | - Rei Nakamoto
- Infectious Diseases Translational Research Programme, Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, 117545, Singapore
| | - Ye Yu Chun
- Infectious Diseases Translational Research Programme, Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, 117545, Singapore
| | - Wan Zhen Chua
- Infectious Diseases Translational Research Programme, Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, 117545, Singapore
| | - Jia Hui Chen
- Infectious Diseases Translational Research Programme, Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, 117545, Singapore
| | - Justin J Zik
- Infectious Diseases Translational Research Programme, Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, 117545, Singapore
| | - Lok-To Sham
- Infectious Diseases Translational Research Programme, Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, 117545, Singapore
| |
Collapse
|
34
|
Abstract
Species belonging to the family Lactobacillaceae are found in highly diverse environments and play an important role in fermented foods and probiotic products. Many of these species have been individually reported to harbour plasmids that encode important genes. In this study, we performed comparative genomic analysis of publicly available data for 512 plasmids from 282 strains represented by 51 species of this family and correlated the genomic features of plasmids with the ecological niches in which these species are found. Two-thirds of the species had at least one plasmid-harbouring strain. Plasmid abundance and GC content were significantly lower in vertebrate-adapted species as compared to nomadic and free-living species. Hierarchical clustering highlighted the distinct nature of plasmids from the nomadic and free-living species than those from the vertebrate-adapted species. EggNOG-assisted functional annotation revealed that genes associated with transposition, conjugation, DNA repair and recombination, exopolysaccharide production, metal ion transport, toxin–antitoxin system, and stress tolerance were significantly enriched on the plasmids of the nomadic and in some cases nomadic and free-living species. On the other hand, genes related to anaerobic metabolism, ABC transporters and the major facilitator superfamily were overrepresented on the plasmids of the vertebrate-adapted species. These genomic signatures correlate with the comparatively nutrient-depleted, stressful and dynamic environments of nomadic and free-living species and nutrient-rich and anaerobic environments of vertebrate-adapted species. Thus, these results indicate the contribution of the plasmids in the adaptation of lactobacilli to their respective habitats. This study also underlines the potential application of these plasmids in improving the technological and probiotic properties of lactic acid bacteria.
Collapse
Affiliation(s)
- Dimple Davray
- Symbiosis School of Biological Sciences, Symbiosis International (Deemed University), Lavale, Pune 412115, India
| | - Dipti Deo
- Symbiosis School of Biological Sciences, Symbiosis International (Deemed University), Lavale, Pune 412115, India
| | - Ram Kulkarni
- Symbiosis School of Biological Sciences, Symbiosis International (Deemed University), Lavale, Pune 412115, India
| |
Collapse
|
35
|
Modular prophage interactions driven by capsule serotype select for capsule loss under phage predation. ISME JOURNAL 2020; 14:2980-2996. [PMID: 32732904 PMCID: PMC7784688 DOI: 10.1038/s41396-020-0726-z] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/07/2020] [Revised: 07/15/2020] [Accepted: 07/20/2020] [Indexed: 01/21/2023]
Abstract
Klebsiella species are able to colonize a wide range of environments and include worrisome nosocomial pathogens. Here, we sought to determine the abundance and infectivity of prophages of Klebsiella to understand how the interactions between induced prophages and bacteria affect population dynamics and evolution. We identified many prophages in the species, placing these taxa among the top 5% of the most polylysogenic bacteria. We selected 35 representative strains of the Klebsiella pneumoniae species complex to establish a network of induced phage-bacteria interactions. This revealed that many prophages are able to enter the lytic cycle, and subsequently kill or lysogenize closely related Klebsiella strains. Although 60% of the tested strains could produce phages that infect at least one other strain, the interaction network of all pairwise cross-infections is very sparse and mostly organized in modules corresponding to the strains' capsule serotypes. Accordingly, capsule mutants remain uninfected showing that the capsule is a key factor for successful infections. Surprisingly, experiments in which bacteria are predated by their own prophages result in accelerated loss of the capsule. Our results show that phage infectiousness defines interaction modules between small subsets of phages and bacteria in function of capsule serotype. This limits the role of prophages as competitive weapons because they can infect very few strains of the species complex. This should also restrict phage-driven gene flow across the species. Finally, the accelerated loss of the capsule in bacteria being predated by their own phages, suggests that phages drive serotype switch in nature.
Collapse
|
36
|
Holt KE, Lassalle F, Wyres KL, Wick R, Mostowy RJ. Diversity and evolution of surface polysaccharide synthesis loci in Enterobacteriales. THE ISME JOURNAL 2020; 14:1713-1730. [PMID: 32249276 PMCID: PMC7305143 DOI: 10.1038/s41396-020-0628-0] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Revised: 02/11/2020] [Accepted: 02/28/2020] [Indexed: 12/26/2022]
Abstract
Bacterial capsules and lipopolysaccharides are diverse surface polysaccharides (SPs) that serve as the frontline for interactions with the outside world. While SPs can evolve rapidly, their diversity and evolutionary dynamics across different taxonomic scales has not been investigated in detail. Here, we focused on the bacterial order Enterobacteriales (including the medically relevant Enterobacteriaceae), to carry out comparative genomics of two SP locus synthesis regions, cps and kps, using 27,334 genomes from 45 genera. We identified high-quality cps loci in 22 genera and kps in 11 genera, around 4% of which were detected in multiple species. We found SP loci to be highly dynamic genetic entities: their evolution was driven by high rates of horizontal gene transfer (HGT), both of whole loci and component genes, and relaxed purifying selection, yielding large repertoires of SP diversity. In spite of that, we found the presence of (near-)identical locus structures in distant taxonomic backgrounds that could not be explained by recent exchange, pointing to long-term selective preservation of locus structures in some populations. Our results reveal differences in evolutionary dynamics driving SP diversity within different bacterial species, with lineages of Escherichia coli, Enterobacter hormaechei and Klebsiella aerogenes most likely to share SP loci via recent exchange; and lineages of Salmonella enterica, Citrobacter sakazakii and Serratia marcescens most likely to share SP loci via other mechanisms such as long-term preservation. Overall, the evolution of SP loci in Enterobacteriales is driven by a range of evolutionary forces and their dynamics and relative importance varies between different species.
Collapse
Affiliation(s)
- Kathryn E Holt
- Department of Infectious Diseases, Central Clinical School, Monash University, Melbourne, Victoria, Australia
- London School of Hygiene and Tropical Medicine, London, UK
| | - Florent Lassalle
- Department of Infectious Disease Epidemiology, School of Public Health, Imperial College London, London, UK
| | - Kelly L Wyres
- Department of Infectious Diseases, Central Clinical School, Monash University, Melbourne, Victoria, Australia
| | - Ryan Wick
- Department of Infectious Diseases, Central Clinical School, Monash University, Melbourne, Victoria, Australia
| | - Rafał J Mostowy
- Department of Infectious Disease Epidemiology, School of Public Health, Imperial College London, London, UK.
- Malopolska Centre of Biotechnology, Jagiellonian University, Krakow, Poland.
| |
Collapse
|
37
|
Touchon M, Perrin A, de Sousa JAM, Vangchhia B, Burn S, O’Brien CL, Denamur E, Gordon D, Rocha EPC. Phylogenetic background and habitat drive the genetic diversification of Escherichia coli. PLoS Genet 2020; 16:e1008866. [PMID: 32530914 PMCID: PMC7314097 DOI: 10.1371/journal.pgen.1008866] [Citation(s) in RCA: 110] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Revised: 06/24/2020] [Accepted: 05/18/2020] [Indexed: 12/15/2022] Open
Abstract
Escherichia coli is mostly a commensal of birds and mammals, including humans, where it can act as an opportunistic pathogen. It is also found in water and sediments. We investigated the phylogeny, genetic diversification, and habitat-association of 1,294 isolates representative of the phylogenetic diversity of more than 5,000 isolates from the Australian continent. Since many previous studies focused on clinical isolates, we investigated mostly other isolates originating from humans, poultry, wild animals and water. These strains represent the species genetic diversity and reveal widespread associations between phylogroups and isolation sources. The analysis of strains from the same sequence types revealed very rapid change of gene repertoires in the very early stages of divergence, driven by the acquisition of many different types of mobile genetic elements. These elements also lead to rapid variations in genome size, even if few of their genes rise to high frequency in the species. Variations in genome size are associated with phylogroup and isolation sources, but the latter determine the number of MGEs, a marker of recent transfer, suggesting that gene flow reinforces the association of certain genetic backgrounds with specific habitats. After a while, the divergence of gene repertoires becomes linear with phylogenetic distance, presumably reflecting the continuous turnover of mobile element and the occasional acquisition of adaptive genes. Surprisingly, the phylogroups with smallest genomes have the highest rates of gene repertoire diversification and fewer but more diverse mobile genetic elements. This suggests that smaller genomes are associated with higher, not lower, turnover of genetic information. Many of these genomes are from freshwater isolates and have peculiar traits, including a specific capsule, suggesting adaptation to this environment. Altogether, these data contribute to explain why epidemiological clones tend to emerge from specific phylogenetic groups in the presence of pervasive horizontal gene transfer across the species. Previous large scale studies on the evolution of E. coli focused on clinical isolates emphasizing virulence and antibiotic resistance in medically important lineages. Yet, most E. coli strains are either human commensals or not associated with humans at all. Here, we analyzed a large collection of non-clinical isolates of the species to assess the mechanisms of gene repertoire diversification in the light of isolation sources and phylogeny. We show that gene repertoires evolve so rapidly by the high turnover of mobile genetic elements that epidemiologically indistinguishable strains can be phenotypically extremely heterogeneous, illustrating the velocity of bacterial adaptation and the importance of accounting for the information on the whole genome at the epidemiological scale. Phylogeny and habitat shape the genetic diversification of E. coli to similar extents. Surprisingly, freshwater strains seem specifically adapted to this environment, breaking the paradigm that E. coli environmental isolates are systematically fecal contaminations. As a consequence, the evolution of this species is also shaped by environmental habitats, and it may diversify by acquiring genes and mobile elements from environmental bacteria (and not just from gut bacteria). This may facilitate the acquisition of virulence factors and antibiotic resistance in the strains that become pathogenic.
Collapse
Affiliation(s)
- Marie Touchon
- Microbial Evolutionary Genomics, Institut Pasteur, CNRS, UMR3525, 25-28 rue Dr Roux, Paris, 75015, France
- * E-mail:
| | - Amandine Perrin
- Microbial Evolutionary Genomics, Institut Pasteur, CNRS, UMR3525, 25-28 rue Dr Roux, Paris, 75015, France
- Sorbonne Université, Collège doctoral, F-75005 Paris, France
| | - Jorge André Moura de Sousa
- Microbial Evolutionary Genomics, Institut Pasteur, CNRS, UMR3525, 25-28 rue Dr Roux, Paris, 75015, France
| | - Belinda Vangchhia
- Ecology and Evolution, Research School of Biology, The Australian National University, Acton, ACT, Australia
- Department of Veterinary Microbiology, College of Veterinary Sciences & Animal Husbandry, Central Agricultural University, Selesih, Aizawl, Mizoram, India
| | - Samantha Burn
- Ecology and Evolution, Research School of Biology, The Australian National University, Acton, ACT, Australia
| | - Claire L. O’Brien
- School of Medicine, University of Wollongong, Northfields Ave Wollongong, Australia
| | - Erick Denamur
- Université de Paris, IAME, UMR 1137, INSERM, Paris, 75018, France
- AP-HP, Laboratoire de Génétique Moléculaire, Hôpital Bichat, 75018, Paris, France
| | - David Gordon
- Ecology and Evolution, Research School of Biology, The Australian National University, Acton, ACT, Australia
| | - Eduardo PC Rocha
- Microbial Evolutionary Genomics, Institut Pasteur, CNRS, UMR3525, 25-28 rue Dr Roux, Paris, 75015, France
| |
Collapse
|
38
|
Islam ST, Vergara Alvarez I, Saïdi F, Guiseppi A, Vinogradov E, Sharma G, Espinosa L, Morrone C, Brasseur G, Guillemot JF, Benarouche A, Bridot JL, Ravicoularamin G, Cagna A, Gauthier C, Singer M, Fierobe HP, Mignot T, Mauriello EMF. Modulation of bacterial multicellularity via spatio-specific polysaccharide secretion. PLoS Biol 2020; 18:e3000728. [PMID: 32516311 PMCID: PMC7310880 DOI: 10.1371/journal.pbio.3000728] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Revised: 06/23/2020] [Accepted: 05/21/2020] [Indexed: 11/21/2022] Open
Abstract
The development of multicellularity is a key evolutionary transition allowing for differentiation of physiological functions across a cell population that confers survival benefits; among unicellular bacteria, this can lead to complex developmental behaviors and the formation of higher-order community structures. Herein, we demonstrate that in the social δ-proteobacterium Myxococcus xanthus, the secretion of a novel biosurfactant polysaccharide (BPS) is spatially modulated within communities, mediating swarm migration as well as the formation of multicellular swarm biofilms and fruiting bodies. BPS is a type IV pilus (T4P)-inhibited acidic polymer built of randomly acetylated β-linked tetrasaccharide repeats. Both BPS and exopolysaccharide (EPS) are produced by dedicated Wzx/Wzy-dependent polysaccharide-assembly pathways distinct from that responsible for spore-coat assembly. While EPS is preferentially produced at the lower-density swarm periphery, BPS production is favored in the higher-density swarm interior; this is consistent with the former being known to stimulate T4P retraction needed for community expansion and a function for the latter in promoting initial cell dispersal. Together, these data reveal the central role of secreted polysaccharides in the intricate behaviors coordinating bacterial multicellularity. A study of the social bacterium Myxococcus xanthus reveals that the bacteria preferentially secrete specific polysaccharides within distinct zones of a swarm to facilitate spreading across a surface.
Collapse
Affiliation(s)
- Salim T. Islam
- Armand Frappier Health & Biotechnology Research Centre, Institut National de la Recherche Scientifique, Université du Québec, Institut Pasteur International Network, Laval, Québec, Canada
- PROTEO, the Quebec Network for Research on Protein Function, Engineering, and Applications, Université Laval, Québec, Québec, Canada
- Laboratoire de Chimie Bactérienne, CNRS–Université Aix-Marseille UMR, Institut de Microbiologie de la Méditerranée, Marseille, France
- * E-mail: (STI); (EMFM)
| | - Israel Vergara Alvarez
- Laboratoire de Chimie Bactérienne, CNRS–Université Aix-Marseille UMR, Institut de Microbiologie de la Méditerranée, Marseille, France
| | - Fares Saïdi
- Armand Frappier Health & Biotechnology Research Centre, Institut National de la Recherche Scientifique, Université du Québec, Institut Pasteur International Network, Laval, Québec, Canada
- PROTEO, the Quebec Network for Research on Protein Function, Engineering, and Applications, Université Laval, Québec, Québec, Canada
- Laboratoire de Chimie Bactérienne, CNRS–Université Aix-Marseille UMR, Institut de Microbiologie de la Méditerranée, Marseille, France
| | - Annick Guiseppi
- Laboratoire de Chimie Bactérienne, CNRS–Université Aix-Marseille UMR, Institut de Microbiologie de la Méditerranée, Marseille, France
| | - Evgeny Vinogradov
- Human Health Therapeutics Portfolio, National Research Council of Canada, Ottawa, Ontario, Canada
| | - Gaurav Sharma
- Department of Microbiology and Molecular Genetics, University of California–Davis, Davis, California, United States of America
- Institute of Bioinformatics and Applied Biotechnology, Electronic City, Bengaluru, Karnataka, India
| | - Leon Espinosa
- Laboratoire de Chimie Bactérienne, CNRS–Université Aix-Marseille UMR, Institut de Microbiologie de la Méditerranée, Marseille, France
| | - Castrese Morrone
- Laboratoire de Chimie Bactérienne, CNRS–Université Aix-Marseille UMR, Institut de Microbiologie de la Méditerranée, Marseille, France
| | - Gael Brasseur
- Laboratoire de Chimie Bactérienne, CNRS–Université Aix-Marseille UMR, Institut de Microbiologie de la Méditerranée, Marseille, France
| | | | | | | | - Gokulakrishnan Ravicoularamin
- Armand Frappier Health & Biotechnology Research Centre, Institut National de la Recherche Scientifique, Université du Québec, Institut Pasteur International Network, Laval, Québec, Canada
| | - Alain Cagna
- Teclis Scientific, Civrieux d’Azergue, France
| | - Charles Gauthier
- Armand Frappier Health & Biotechnology Research Centre, Institut National de la Recherche Scientifique, Université du Québec, Institut Pasteur International Network, Laval, Québec, Canada
| | - Mitchell Singer
- Department of Microbiology and Molecular Genetics, University of California–Davis, Davis, California, United States of America
| | - Henri-Pierre Fierobe
- Laboratoire de Chimie Bactérienne, CNRS–Université Aix-Marseille UMR, Institut de Microbiologie de la Méditerranée, Marseille, France
| | - Tâm Mignot
- Laboratoire de Chimie Bactérienne, CNRS–Université Aix-Marseille UMR, Institut de Microbiologie de la Méditerranée, Marseille, France
| | - Emilia M. F. Mauriello
- Laboratoire de Chimie Bactérienne, CNRS–Université Aix-Marseille UMR, Institut de Microbiologie de la Méditerranée, Marseille, France
- * E-mail: (STI); (EMFM)
| |
Collapse
|
39
|
Surveillance of Enterococcus spp. reveals distinct species and antimicrobial resistance diversity across a One-Health continuum. Sci Rep 2020; 10:3937. [PMID: 32127598 PMCID: PMC7054549 DOI: 10.1038/s41598-020-61002-5] [Citation(s) in RCA: 128] [Impact Index Per Article: 25.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2019] [Accepted: 02/13/2020] [Indexed: 11/24/2022] Open
Abstract
For a One-Health investigation of antimicrobial resistance (AMR) in Enterococcus spp., isolates from humans and beef cattle along with abattoirs, manured fields, natural streams, and wastewater from both urban and cattle feedlot sources were collected over two years. Species identification of Enterococcus revealed distinct associations across the continuum. Of the 8430 isolates collected, Enterococcus faecium and Enterococcus faecalis were the main species in urban wastewater (90%) and clinical human isolates (99%); Enterococcus hirae predominated in cattle (92%) and feedlot catch-basins (60%), whereas natural streams harbored environmental Enterococcus spp. Whole-genome sequencing of E. faecalis (n = 366 isolates) and E. faecium (n = 342 isolates), revealed source clustering of isolates, indicative of distinct adaptation to their respective environments. Phenotypic resistance to tetracyclines and macrolides encoded by tet(M) and erm(B) respectively, was prevalent among Enterococcus spp. regardless of source. For E. faecium from cattle, resistance to β-lactams and quinolones was observed among 3% and 8% of isolates respectively, compared to 76% and 70% of human clinical isolates. Clinical vancomycin-resistant E. faecium exhibited high rates of multi-drug resistance, with resistance to all β-lactam, macrolides, and quinolones tested. Differences in the AMR profiles among isolates reflected antimicrobial use practices in each sector of the One-Health continuum.
Collapse
|
40
|
Rendueles O. Deciphering the role of the capsule of Klebsiella pneumoniae during pathogenesis: A cautionary tale. Mol Microbiol 2020; 113:883-888. [PMID: 31997409 PMCID: PMC7317218 DOI: 10.1111/mmi.14474] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2020] [Revised: 01/20/2020] [Accepted: 01/20/2020] [Indexed: 01/31/2023]
Abstract
Extracellular capsule polysaccharides increase the cellular fitness under abiotic stresses and during competition with other bacteria. They are best-known for their role in virulence, particularly in human hosts. Specifically, capsules facilitate tissue invasion by enhancing bacterial evasion from phagocytosis and protect cells from biocidal molecules. Klebsiella pneumoniae is a worrisome nosocomial pathogen with few known virulence factors, but the most important one is its capsule. In this issue, Tan et al. assess the fitness advantage of the capsule by competing a wild-type strain against four different mutants where capsule production is interrupted at different stages of the biosynthetic pathway. Strikingly, not all mutants provide a fitness advantage. They suggest that some mutants have secondary defects altering virulence-associated phenotypes and blurring the role of the capsule in pathogenesis. This study indicates that the K1 capsule in K. pneumoniae is not required for gut colonization but that it is critical for bloodstream dissemination to other organs. These results contribute to clarify the contradictory literature on the role of the Klebsiella capsule during infection. Finally, the varying fitness effects of different capsule mutations observed for K. pneumoniae K1 might apply also to other capsulated diderm bacteria that are facultative or emerging pathogens.
Collapse
Affiliation(s)
- Olaya Rendueles
- Microbial Evolutionary Genomics, Institut Pasteur, CNRS, UMR3525, Paris, France
| |
Collapse
|
41
|
Cania B, Vestergaard G, Kublik S, Köhne JM, Fischer T, Albert A, Winkler B, Schloter M, Schulz S. Biological Soil Crusts from Different Soil Substrates Harbor Distinct Bacterial Groups with the Potential to Produce Exopolysaccharides and Lipopolysaccharides. MICROBIAL ECOLOGY 2020; 79:326-341. [PMID: 31372685 DOI: 10.1007/s00248-019-01415-6] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2019] [Accepted: 07/16/2019] [Indexed: 06/10/2023]
Abstract
Biological soil crusts (biocrusts) play an important role in improving soil stability and resistance to erosion by promoting aggregation of soil particles. During initial development, biocrusts are dominated by bacteria. Some bacterial members of the biocrusts can contribute to the formation of soil aggregates by producing exopolysaccharides and lipopolysaccharides that act as "glue" for soil particles. However, little is known about the dynamics of "soil glue" producers during the initial development of biocrusts. We hypothesized that different types of initial biocrusts harbor distinct producers of adhesive polysaccharides. To investigate this, we performed a microcosm experiment, cultivating biocrusts on two soil substrates. High-throughput shotgun sequencing was used to obtain metagenomic information on microbiomes of bulk soils from the beginning of the experiment, and biocrusts sampled after 4 and 10 months of incubation. We discovered that the relative abundance of genes involved in the biosynthesis of exopolysaccharides and lipopolysaccharides increased in biocrusts compared with bulk soils. At the same time, communities of potential "soil glue" producers that were highly similar in bulk soils underwent differentiation once biocrusts started to develop. In the bulk soils, the investigated genes were harbored mainly by Betaproteobacteria, whereas in the biocrusts, the major potential producers of adhesive polysaccharides were, aside from Alphaproteobacteria, either Cyanobacteria or Chloroflexi and Acidobacteria. Overall, our results indicate that the potential to form exopolysaccharides and lipopolysaccharides is an important bacterial trait for initial biocrusts and is maintained despite the shifts in bacterial community composition during biocrust development.
Collapse
Affiliation(s)
- Barbara Cania
- Research Unit Comparative Microbiome Analysis, Helmholtz Zentrum München Research Center for Environmental Health (GmbH), Ingolstädter Landstraße 1, 85764, Neuherberg, Germany
| | - Gisle Vestergaard
- Research Unit Comparative Microbiome Analysis, Helmholtz Zentrum München Research Center for Environmental Health (GmbH), Ingolstädter Landstraße 1, 85764, Neuherberg, Germany
- Section for Bioinformatics, Department of Health Technology, Technical University of Denmark, 2800, Lyngby, Denmark
| | - Susanne Kublik
- Research Unit Comparative Microbiome Analysis, Helmholtz Zentrum München Research Center for Environmental Health (GmbH), Ingolstädter Landstraße 1, 85764, Neuherberg, Germany
| | - John Maximilian Köhne
- Department of Soil System Science, Helmholtz Centre for Environmental Research (UFZ), Theodor-Lieser-Straße 4, 06120, Halle, Germany
| | - Thomas Fischer
- Central Analytical Laboratory, Brandenburg Technical University, Konrad-Wachsmann-Allee 6, 03046, Cottbus, Germany
| | - Andreas Albert
- Research Unit Environmental Simulation, Helmholtz Zentrum München Research Center for Environmental Health (GmbH), Ingolstädter Landstraße 1, 85764, Neuherberg, Germany
| | - Barbro Winkler
- Research Unit Environmental Simulation, Helmholtz Zentrum München Research Center for Environmental Health (GmbH), Ingolstädter Landstraße 1, 85764, Neuherberg, Germany
| | - Michael Schloter
- Research Unit Comparative Microbiome Analysis, Helmholtz Zentrum München Research Center for Environmental Health (GmbH), Ingolstädter Landstraße 1, 85764, Neuherberg, Germany
- Chair for Soil Science, Technical University of Munich, Emil-Ramann-Straße 2, 85354, Freising, Germany
| | - Stefanie Schulz
- Research Unit Comparative Microbiome Analysis, Helmholtz Zentrum München Research Center for Environmental Health (GmbH), Ingolstädter Landstraße 1, 85764, Neuherberg, Germany.
| |
Collapse
|
42
|
Sanderson H, Ortega-Polo R, Zaheer R, Goji N, Amoako KK, Brown RS, Majury A, Liss SN, McAllister TA. Comparative genomics of multidrug-resistant Enterococcus spp. isolated from wastewater treatment plants. BMC Microbiol 2020; 20:20. [PMID: 31980014 PMCID: PMC6982392 DOI: 10.1186/s12866-019-1683-4] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2019] [Accepted: 12/12/2019] [Indexed: 01/23/2023] Open
Abstract
BACKGROUND Wastewater treatment plants (WWTPs) are considered hotspots for the environmental dissemination of antimicrobial resistance (AMR) determinants. Vancomycin-Resistant Enterococcus (VRE) are candidates for gauging the degree of AMR bacteria in wastewater. Enterococcus faecalis and Enterococcus faecium are recognized indicators of fecal contamination in water. Comparative genomics of enterococci isolated from conventional activated sludge (CAS) and biological aerated filter (BAF) WWTPs was conducted. RESULTS VRE isolates, including E. faecalis (n = 24), E. faecium (n = 11), E. casseliflavus (n = 2) and E. gallinarum (n = 2) were selected for sequencing based on WWTP source, species and AMR phenotype. The pangenomes of E. faecium and E. faecalis were both open. The genomic fraction related to the mobilome was positively correlated with genome size in E. faecium (p < 0.001) and E. faecalis (p < 0.001) and with the number of AMR genes in E. faecium (p = 0.005). Genes conferring vancomycin resistance, including vanA and vanM (E. faecium), vanG (E. faecalis), and vanC (E. casseliflavus/E. gallinarum), were detected in 20 genomes. The most prominent functional AMR genes were efflux pumps and transporters. A minimum of 16, 6, 5 and 3 virulence genes were detected in E. faecium, E. faecalis, E. casseliflavus and E. gallinarum, respectively. Virulence genes were more common in E. faecalis and E. faecium, than E. casseliflavus and E. gallinarum. A number of mobile genetic elements were shared among species. Functional CRISPR/Cas arrays were detected in 13 E. faecalis genomes, with all but one also containing a prophage. The lack of a functional CRISPR/Cas arrays was associated with multi-drug resistance in E. faecium. Phylogenetic analysis demonstrated differential clustering of isolates based on original source but not WWTP. Genes related to phage and CRISPR/Cas arrays could potentially serve as environmental biomarkers. CONCLUSIONS There was no discernible difference between enterococcal genomes from the CAS and BAF WWTPs. E. faecalis and E. faecium have smaller genomes and harbor more virulence, AMR, and mobile genetic elements than other Enterococcus spp.
Collapse
Affiliation(s)
- Haley Sanderson
- Agriculture and AgriFood Canada, Lethbridge Research and Development Center, 5403 1 Avenue South, PO Box 3000, Lethbridge, T1J 4B1 Canada
- School of Environmental Studies, Queen’s University, Kingston, K7L 3N6 Canada
| | - Rodrigo Ortega-Polo
- Agriculture and AgriFood Canada, Lethbridge Research and Development Center, 5403 1 Avenue South, PO Box 3000, Lethbridge, T1J 4B1 Canada
| | - Rahat Zaheer
- Agriculture and AgriFood Canada, Lethbridge Research and Development Center, 5403 1 Avenue South, PO Box 3000, Lethbridge, T1J 4B1 Canada
| | - Noriko Goji
- Canadian Food Inspection Agency, National Centre for Animal Disease, Lethbridge Laboratory, Lethbridge, T1J 3Z4 Canada
| | - Kingsley K. Amoako
- Canadian Food Inspection Agency, National Centre for Animal Disease, Lethbridge Laboratory, Lethbridge, T1J 3Z4 Canada
| | - R. Stephen Brown
- School of Environmental Studies, Queen’s University, Kingston, K7L 3N6 Canada
- Department of Chemistry, Queen’s University, Kingston, K7L 3N6 Canada
| | - Anna Majury
- School of Environmental Studies, Queen’s University, Kingston, K7L 3N6 Canada
- Public Health Ontario, Kingston, K7L 3K3 Canada
| | - Steven N. Liss
- School of Environmental Studies, Queen’s University, Kingston, K7L 3N6 Canada
- Department of Biology, Ryerson University, Toronto, M5B 2K3 Canada
| | - Tim A. McAllister
- Agriculture and AgriFood Canada, Lethbridge Research and Development Center, 5403 1 Avenue South, PO Box 3000, Lethbridge, T1J 4B1 Canada
| |
Collapse
|
43
|
Sequeira RP, McDonald JAK, Marchesi JR, Clarke TB. Commensal Bacteroidetes protect against Klebsiella pneumoniae colonization and transmission through IL-36 signalling. Nat Microbiol 2020; 5:304-313. [PMID: 31907407 PMCID: PMC7610889 DOI: 10.1038/s41564-019-0640-1] [Citation(s) in RCA: 88] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Accepted: 11/07/2019] [Indexed: 01/18/2023]
Abstract
The microbiota primes immune defences but the identity of specific commensal microorganisms that protect against infection is unclear. Conversely, how pathogens compete with the microbiota to establish their host niche is also poorly understood. In the present study, we investigate the antagonism between the microbiota and Klebsiella pneumoniae during colonization and transmission. We discover that maturation of the microbiota drives the development of distinct immune defence programmes in the upper airways and intestine to limit K. pneumoniae colonization within these niches. Immune protection in the intestine depends on the development of Bacteroidetes, interleukin (IL)-36 signalling and macrophages. This effect of Bacteroidetes requires the polysaccharide utilization locus of their conserved commensal colonization factor. Conversely, in the upper airways, Proteobacteria prime immunity through IL-17A, but K. pneumoniae overcomes these defences through encapsulation to effectively colonize this site. Ultimately, we find that host-to-host spread of K. pneumoniae occurs principally from its intestinal reservoir, and that commensal-colonization-factor-producing Bacteroidetes are sufficient to prevent transmission between hosts through IL-36. Thus, our study provides mechanistic insight into when, where and how commensal Bacteroidetes protect against K. pneumoniae colonization and contagion, providing insight into how these protective microorganisms could be harnessed to confer population-level protection against K. pneumoniae infection.
Collapse
Affiliation(s)
- Richard P Sequeira
- MRC Centre for Molecular Bacteriology and Infection, Department of Infectious Diseases, Imperial College London, London, UK
| | - Julie A K McDonald
- Division of Integrative Systems Medicine and Digestive Disease, Department of Surgery and Cancer, Imperial College London, London, UK
| | - Julian R Marchesi
- Division of Integrative Systems Medicine and Digestive Disease, Department of Surgery and Cancer, Imperial College London, London, UK.,School of Biosciences, Cardiff University, Cardiff, UK
| | - Thomas B Clarke
- MRC Centre for Molecular Bacteriology and Infection, Department of Infectious Diseases, Imperial College London, London, UK.
| |
Collapse
|
44
|
Nanayakkara BS, O'Brien CL, Gordon DM. Phenotypic characteristics contributing to the enhanced growth of Escherichia coli bloom strains. ENVIRONMENTAL MICROBIOLOGY REPORTS 2019; 11:817-824. [PMID: 31642169 DOI: 10.1111/1758-2229.12801] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2019] [Accepted: 10/18/2019] [Indexed: 06/10/2023]
Abstract
During bloom events, Escherichia coli cell counts increase to between 10,000 and 100,000 cfu/100 ml of water. The strains responsible for bloom events belong to E. coli phylogenetic groups A and B1, and all have acquired a capsule from Klebsiella. A pan-genome comparison of phylogroup A E. coli revealed that the ferric citrate uptake system (fecIRABCDE) was overrepresented in phylogroup A bloom strains compared with non-bloom E. coli. A series of experiments were carried out to investigate if the capsule together with ferric citrate uptake system could confer a growth rate advantage on E. coli. Capsulated strains had a growth rate advantage regardless of the media composition and the presence/absence of the fec operon, and they had a shorter lag phase compared with capsule-negative strains. The results suggest that the Klebsiella capsule may facilitate nutrient uptake or utilization by a strain. This, together with the protective roles played by the capsule and the shorter lag phase of capsule-positive strains, may explain why it is only capsule-positive strains that produce elevated counts in response to nutrient influx.
Collapse
Affiliation(s)
- Buddhie S Nanayakkara
- Division of Ecology and Evolution, Research School of Biology, The Australian National University, RN Robertson Building, 46 Sullivans Creek Road, Canberra, ACT, 2601, Australia
- Department of Botany, Faculty of Science, University of Peradeniya, Peradeniya, 20400, Sri Lanka
| | - Claire L O'Brien
- Medical School, The Australian National University, Canberra, ACT, 2601, Australia
- Gastroenterology and Hepatology Unit, Canberra Hospital, Canberra, ACT, Australia
| | - David M Gordon
- Division of Ecology and Evolution, Research School of Biology, The Australian National University, RN Robertson Building, 46 Sullivans Creek Road, Canberra, ACT, 2601, Australia
| |
Collapse
|
45
|
The Mycobacterium tuberculosis capsule: a cell structure with key implications in pathogenesis. Biochem J 2019; 476:1995-2016. [PMID: 31320388 PMCID: PMC6698057 DOI: 10.1042/bcj20190324] [Citation(s) in RCA: 75] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2019] [Revised: 06/19/2019] [Accepted: 06/20/2019] [Indexed: 01/17/2023]
Abstract
Bacterial capsules have evolved to be at the forefront of the cell envelope, making them an essential element of bacterial biology. Efforts to understand the Mycobacterium tuberculosis (Mtb) capsule began more than 60 years ago, but the relatively recent development of mycobacterial genetics combined with improved chemical and immunological tools have revealed a more refined view of capsule molecular composition. A glycogen-like α-glucan is the major constituent of the capsule, with lower amounts of arabinomannan and mannan, proteins and lipids. The major Mtb capsular components mediate interactions with phagocytes that favor bacterial survival. Vaccination approaches targeting the mycobacterial capsule have proven successful in controlling bacterial replication. Although the Mtb capsule is composed of polysaccharides of relatively low complexity, the concept of antigenic variability associated with this structure has been suggested by some studies. Understanding how Mtb shapes its envelope during its life cycle is key to developing anti-infective strategies targeting this structure at the host-pathogen interface.
Collapse
|
46
|
Remigi P, Ferguson GC, McConnell E, De Monte S, Rogers DW, Rainey PB. Ribosome Provisioning Activates a Bistable Switch Coupled to Fast Exit from Stationary Phase. Mol Biol Evol 2019; 36:1056-1070. [PMID: 30835283 PMCID: PMC6501884 DOI: 10.1093/molbev/msz041] [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] [Indexed: 12/18/2022] Open
Abstract
Observations of bacteria at the single-cell level have revealed many instances of phenotypic heterogeneity within otherwise clonal populations, but the selective causes, molecular bases, and broader ecological relevance remain poorly understood. In an earlier experiment in which the bacterium Pseudomonas fluorescens SBW25 was propagated under a selective regime that mimicked the host immune response, a genotype evolved that stochastically switched between capsulation states. The genetic cause was a mutation in carB that decreased the pyrimidine pool (and growth rate), lowering the activation threshold of a preexisting but hitherto unrecognized phenotypic switch. Genetic components surrounding bifurcation of UTP flux toward DNA/RNA or UDP-glucose (a precursor of colanic acid forming the capsules) were implicated as key components. Extending these molecular analyses-and based on a combination of genetics, transcriptomics, biochemistry, and mathematical modeling-we show that pyrimidine limitation triggers an increase in ribosome biosynthesis and that switching is caused by competition between ribosomes and CsrA/RsmA proteins for the mRNA transcript of a positively autoregulated activator of colanic acid biosynthesis. We additionally show that in the ancestral bacterium the switch is part of a program that determines stochastic entry into a semiquiescent capsulated state, ensures that such cells are provisioned with excess ribosomes, and enables provisioned cells to exit rapidly from stationary phase under permissive conditions.
Collapse
Affiliation(s)
- Philippe Remigi
- New Zealand Institute for Advanced Study, Massey University, Auckland, New Zealand.,Laboratoire des Interactions Plantes-Microorganismes (LIPM), Université de Toulouse, INRA, CNRS, Castanet-Tolosan, France
| | - Gayle C Ferguson
- School of Natural and Computational Sciences, Massey University, Auckland, New Zealand
| | - Ellen McConnell
- Department of Microbial Population Biology, Max Planck Institute for Evolutionary Biology, Plön, Germany
| | - Silvia De Monte
- Institut de Biologie de l'Ecole Normale Supérieure (IBENS), Ecole Normale Supérieure, CNRS, INSERM, PSL Research University, Paris, France.,Department of Evolutionary Theory, Max Planck Institute for Evolutionary Biology, Plön, Germany
| | - David W Rogers
- Department of Microbial Population Biology, Max Planck Institute for Evolutionary Biology, Plön, Germany
| | - Paul B Rainey
- New Zealand Institute for Advanced Study, Massey University, Auckland, New Zealand.,Department of Microbial Population Biology, Max Planck Institute for Evolutionary Biology, Plön, Germany.,Ecole Supérieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris Tech), CNRS UMR 8231, PSL Research University, Paris, France
| |
Collapse
|
47
|
Nanayakkara BS, O'Brien CL, Gordon DM. Diversity and distribution of Klebsiella capsules in Escherichia coli. ENVIRONMENTAL MICROBIOLOGY REPORTS 2019; 11:107-117. [PMID: 30411512 DOI: 10.1111/1758-2229.12710] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2018] [Revised: 10/31/2018] [Accepted: 11/03/2018] [Indexed: 06/08/2023]
Abstract
E. coli strains responsible for elevated counts (blooms) in freshwater reservoirs in Australia carry a capsule originating from Klebsiella. The occurrence of Klebsiella capsules in E. coli was about 7% overall and 23 different capsule types were detected. Capsules were observed in strains from phylogroups A, B1 and C, but were absent from phylogroup B2, D, E and F strains. In general, few A, B1 or C lineages were capsule-positive, but when a lineage was encapsulated multiple different capsule types were present. All Klebsiella capsule-positive strains were of serogroups O8, O9 and O89. Regardless of the phylogroup, O9 strains were more likely to be capsule-positive than O8 strains. Given the sequence similarity, it appears that both the capsule region and the O-antigen gene region are transferred to E. coli from Klebsiella as a single block via horizontal gene transfer events. Pan genome analysis indicated that there were only modest differences between encapsulated and non-encapsulated strains belonging to phylogroup A. The possession of a Klebsiella capsule, but not the type of capsule, is likely a key determinant of the bloom status of a strain.
Collapse
Affiliation(s)
- Buddhie S Nanayakkara
- Division of Ecology and Evolution, Research School of Biology, The Australian National University, Canberra, ACT 2601, Australia
- Department of Botany, Faculty of Science, University of Peradeniya, Peradeniya, 20400, Sri Lanka
| | - Claire L O'Brien
- Medical School, The Australian National University, Canberra, ACT 2601, Australia
- Gastroenterology and Hepatology Unit, Canberra Hospital, Canberra, ACT, Australia
| | - David M Gordon
- Division of Ecology and Evolution, Research School of Biology, The Australian National University, Canberra, ACT 2601, Australia
| |
Collapse
|
48
|
Transcriptome and Comparative Genomics Analyses Reveal New Functional Insights on Key Determinants of Pathogenesis and Interbacterial Competition in Pectobacterium and Dickeya spp. Appl Environ Microbiol 2019; 85:AEM.02050-18. [PMID: 30413477 DOI: 10.1128/aem.02050-18] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2018] [Accepted: 10/29/2018] [Indexed: 02/07/2023] Open
Abstract
Soft-rot Enterobacteriaceae (SRE), typified by Pectobacterium and Dickeya genera, are phytopathogenic bacteria inflicting soft-rot disease in crops worldwide. By combining genomic information from 100 SRE with whole-transcriptome data sets, we identified novel genomic and transcriptional associations among key pathogenicity themes in this group. Comparative genomics revealed solid linkage between the type I secretion system (T1SS) and the carotovoricin bacteriophage (Ctv) conserved in 96.7% of Pectobacterium genomes. Moreover, their coactivation during infection indicates a novel functional association involving T1SS and Ctv. Another bacteriophage-borne genomic region, mostly confined to less than 10% of Pectobacterium strains, was found, presumably comprising a novel lineage-specific prophage in the genus. We also detected the transcriptional coregulation of a previously predicted toxin/immunity pair (WHH and SMI1_KNR4 families), along with the type VI secretion system (T6SS), which includes hcp and/or vgrG genes, suggesting a role in disease development as T6SS-dependent effectors. Further, we showed that another predicted T6SS-dependent endonuclease (AHH family) exhibited toxicity in ectopic expression assays, indicating antibacterial activity. Additionally, we report the striking conservation of the group 4 capsule (GFC) cluster in 100 SRE strains which consistently features adjacently conserved serotype-specific gene arrays comprising a previously unknown organization in GFC clusters. Also, extensive sequence variations found in gfcA orthologs suggest a serotype-specific role in the GfcABCD machinery.IMPORTANCE Despite the considerable loss inflicted on important crops yearly by Pectobacterium and Dickeya diseases, investigations on key virulence and interbacterial competition assets relying on extensive comparative genomics are still surprisingly lacking for these genera. Such approaches become more powerful over time, underpinned by the growing amount of genomic information in public databases. In particular, our findings point to new functional associations among well-known genomic themes enabling alternative means of neutralizing SRE diseases through disruption of pivotal virulence programs. By elucidating novel transcriptional and genomic associations, this study adds valuable information on virulence candidates that could be decisive in molecular applications in the near future. The utilization of 100 genomes of Pectobacterium and Dickeya strains in this study is unprecedented for comparative analyses in these taxa, and it provides novel insights on the biology of economically important plant pathogens.
Collapse
|
49
|
Rendueles O, de Sousa JAM, Bernheim A, Touchon M, Rocha EPC. Genetic exchanges are more frequent in bacteria encoding capsules. PLoS Genet 2018; 14:e1007862. [PMID: 30576310 PMCID: PMC6322790 DOI: 10.1371/journal.pgen.1007862] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2018] [Revised: 01/07/2019] [Accepted: 11/29/2018] [Indexed: 12/12/2022] Open
Abstract
Capsules allow bacteria to colonize novel environments, to withstand numerous stresses, and to resist antibiotics. Yet, even though genetic exchanges with other cells should be adaptive under such circumstances, it has been suggested that capsules lower the rates of homologous recombination and horizontal gene transfer. We analysed over one hundred pan-genomes and thousands of bacterial genomes for the evidence of an association between genetic exchanges (or lack thereof) and the presence of a capsule system. We found that bacteria encoding capsules have larger pan-genomes, higher rates of horizontal gene transfer, and higher rates of homologous recombination in their core genomes. Accordingly, genomes encoding capsules have more plasmids, conjugative elements, transposases, prophages, and integrons. Furthermore, capsular loci are frequent in plasmids, and can be found in prophages. These results are valid for Bacteria, independently of their ability to be naturally transformable. Since we have shown previously that capsules are commonly present in nosocomial pathogens, we analysed their co-occurrence with antibiotic resistance genes. Genomes encoding capsules have more antibiotic resistance genes, especially those encoding efflux pumps, and they constitute the majority of the most worrisome nosocomial bacteria. We conclude that bacteria with capsule systems are more genetically diverse and have fast-evolving gene repertoires, which may further contribute to their success in colonizing novel niches such as humans under antibiotic therapy. Previous works showed that bacteria encoding capsules are better colonizers and are dominant in most environments suggesting a positive role for capsules in the genetic diversification of bacteria. Yet, it has been repeatedly suggested, based almost exclusively studies in few model species, that such bacteria are less diverse and engage in fewer genetic exchanges. Here, we reverse the current paradigm and show that bacteria encoding capsules have larger and more diverse gene repertoires, which change faster by horizontal gene transfer and recombination. Our study alters the traditional view of the capsule as a barrier to gene flow and raises novel questions about the role of capsules in bacterial adaptation.
Collapse
Affiliation(s)
- Olaya Rendueles
- Microbial Evolutionary Genomics, Institut Pasteur, Paris, France
- UMR 3525, CNRS, Paris, France
- * E-mail:
| | - Jorge A. Moura de Sousa
- Microbial Evolutionary Genomics, Institut Pasteur, Paris, France
- UMR 3525, CNRS, Paris, France
| | - Aude Bernheim
- Microbial Evolutionary Genomics, Institut Pasteur, Paris, France
- UMR 3525, CNRS, Paris, France
| | - Marie Touchon
- Microbial Evolutionary Genomics, Institut Pasteur, Paris, France
- UMR 3525, CNRS, Paris, France
| | - Eduardo P. C. Rocha
- Microbial Evolutionary Genomics, Institut Pasteur, Paris, France
- UMR 3525, CNRS, Paris, France
| |
Collapse
|
50
|
Mostowy RJ, Holt KE. Diversity-Generating Machines: Genetics of Bacterial Sugar-Coating. Trends Microbiol 2018; 26:1008-1021. [PMID: 30037568 PMCID: PMC6249986 DOI: 10.1016/j.tim.2018.06.006] [Citation(s) in RCA: 73] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2018] [Revised: 06/08/2018] [Accepted: 06/22/2018] [Indexed: 12/11/2022]
Abstract
Bacterial pathogens and commensals are surrounded by diverse surface polysaccharides which include capsules and lipopolysaccharides. These carbohydrates play a vital role in bacterial ecology and interactions with the environment. Here, we review recent rapid advancements in this field, which have improved our understanding of the roles, structures, and genetics of bacterial polysaccharide antigens. Genetic loci encoding the biosynthesis of these antigens may have evolved as bacterial diversity-generating machines, driven by selection from a variety of forces, including host immunity, bacteriophages, and cell-cell interactions. We argue that the high adaptive potential of polysaccharide antigens should be taken into account in the design of polysaccharide-targeting medical interventions like conjugate vaccines and phage-based therapies.
Collapse
Affiliation(s)
- Rafał J Mostowy
- Department of Infectious Disease Epidemiology, School of Public Health, Imperial College London, London, UK.
| | - Kathryn E Holt
- Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Victoria, Australia; The London School of Hygiene and Tropical Medicine, London, United Kingdom
| |
Collapse
|