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Löckener I, Behrmann LV, Reuter J, Schiefer A, Klöckner A, Krannich S, Otten C, Mölleken K, Ichikawa S, Hoerauf A, Schneider T, Pfarr KM, Henrichfreise B. The MraY Inhibitor Muraymycin D2 and Its Derivatives Induce Enlarged Cells in Obligate Intracellular Chlamydia and Wolbachia and Break the Persistence Phenotype in Chlamydia. Antibiotics (Basel) 2024; 13:421. [PMID: 38786149 PMCID: PMC11117252 DOI: 10.3390/antibiotics13050421] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2024] [Revised: 04/26/2024] [Accepted: 04/28/2024] [Indexed: 05/25/2024] Open
Abstract
Chlamydial infections and diseases caused by filarial nematodes are global health concerns. However, treatment presents challenges due to treatment failures potentially caused by persisting Chlamydia and long regimens against filarial infections accompanied by low compliance. A new treatment strategy could be the targeting of the reduced peptidoglycan structures involved in cell division in the obligate intracellular bacteria Chlamydia and Wolbachia, the latter being obligate endosymbionts supporting filarial development, growth, and survival. Here, cell culture experiments with C. trachomatis and Wolbachia showed that the nucleoside antibiotics muraymycin and carbacaprazamycin interfere with bacterial cell division and induce enlarged, aberrant cells resembling the penicillin-induced persistence phenotype in Chlamydia. Enzymatic inhibition experiments with purified C. pneumoniae MraY revealed that muraymycin derivatives abolish the synthesis of the peptidoglycan precursor lipid I. Comparative in silico analyses of chlamydial and wolbachial MraY with the corresponding well-characterized enzyme in Aquifex aeolicus revealed a high degree of conservation, providing evidence for a similar mode of inhibition. Muraymycin D2 treatment eradicated persisting non-dividing C. trachomatis cells from an established penicillin-induced persistent infection. This finding indicates that nucleoside antibiotics may have additional properties that can break bacterial persistence.
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Affiliation(s)
- Iris Löckener
- Institute for Pharmaceutical Microbiology (IPM), University of Bonn, University Hospital Bonn, Meckenheimer Allee 168, 53115 Bonn, Germany (C.O.); (B.H.)
| | - Lara Vanessa Behrmann
- Institute for Medical Microbiology, Immunology and Parasitology (IMMIP), University Hospital Bonn, Venusberg-Campus 1, 53127 Bonn, Germany; (L.V.B.)
| | - Jula Reuter
- Institute for Pharmaceutical Microbiology (IPM), University of Bonn, University Hospital Bonn, Meckenheimer Allee 168, 53115 Bonn, Germany (C.O.); (B.H.)
| | - Andrea Schiefer
- Institute for Medical Microbiology, Immunology and Parasitology (IMMIP), University Hospital Bonn, Venusberg-Campus 1, 53127 Bonn, Germany; (L.V.B.)
| | - Anna Klöckner
- Institute for Pharmaceutical Microbiology (IPM), University of Bonn, University Hospital Bonn, Meckenheimer Allee 168, 53115 Bonn, Germany (C.O.); (B.H.)
| | - Sebastian Krannich
- Institute for Pharmaceutical Microbiology (IPM), University of Bonn, University Hospital Bonn, Meckenheimer Allee 168, 53115 Bonn, Germany (C.O.); (B.H.)
| | - Christian Otten
- Institute for Pharmaceutical Microbiology (IPM), University of Bonn, University Hospital Bonn, Meckenheimer Allee 168, 53115 Bonn, Germany (C.O.); (B.H.)
| | - Katja Mölleken
- Institute for Functional Microbial Genomics, Heinrich Heine University Düsseldorf, Universitätsstraße 1, 40225 Düsseldorf, Germany;
| | - Satoshi Ichikawa
- Faculty of Pharmaceutical Sciences, Hokkaido University, Kita-12, Nishi-6, Kita-ku, Sapporo 060-0812, Japan
| | - Achim Hoerauf
- Institute for Medical Microbiology, Immunology and Parasitology (IMMIP), University Hospital Bonn, Venusberg-Campus 1, 53127 Bonn, Germany; (L.V.B.)
- German Center for Infection Research (DZIF), Partner Site Bonn-Cologne, 53127 Bonn, Germany
| | - Tanja Schneider
- Institute for Pharmaceutical Microbiology (IPM), University of Bonn, University Hospital Bonn, Meckenheimer Allee 168, 53115 Bonn, Germany (C.O.); (B.H.)
- German Center for Infection Research (DZIF), Partner Site Bonn-Cologne, 53127 Bonn, Germany
| | - Kenneth M. Pfarr
- Institute for Medical Microbiology, Immunology and Parasitology (IMMIP), University Hospital Bonn, Venusberg-Campus 1, 53127 Bonn, Germany; (L.V.B.)
- German Center for Infection Research (DZIF), Partner Site Bonn-Cologne, 53127 Bonn, Germany
| | - Beate Henrichfreise
- Institute for Pharmaceutical Microbiology (IPM), University of Bonn, University Hospital Bonn, Meckenheimer Allee 168, 53115 Bonn, Germany (C.O.); (B.H.)
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Hatch ND, Ouellette SP. Identification of the alternative sigma factor regulons of Chlamydia trachomatis using multiplexed CRISPR interference. mSphere 2023; 8:e0039123. [PMID: 37747235 PMCID: PMC10597470 DOI: 10.1128/msphere.00391-23] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2023] [Accepted: 08/07/2023] [Indexed: 09/26/2023] Open
Abstract
Chlamydia trachomatis is a developmentally regulated, obligate intracellular bacterium that encodes three sigma factors: σ66, σ54, and σ28. σ66 is the major sigma factor controlling most transcription initiation during early- and mid-cycle development as the infectious elementary body (EB) transitions to the non-infectious reticulate body (RB) that replicates within an inclusion inside the cell. The roles of the minor sigma factors, σ54 and σ28, have not been well characterized to date; however, there are data to suggest each functions in late-stage development and secondary differentiation as RBs transition to EBs. As the process of secondary differentiation itself is poorly characterized, clarifying the function of these alternative sigma factors by identifying the genes regulated by them will further our understanding of chlamydial differentiation. We hypothesize that σ54 and σ28 have non-redundant and essential functions for initiating late gene transcription thus mediating secondary differentiation in Chlamydia. Here, we demonstrate the necessity of each minor sigma factor in successfully completing the developmental cycle. We have implemented and validated multiplexed Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) interference techniques, novel to the chlamydial field to examine the effects of knocking down each alternative sigma factor individually and simultaneously. In parallel, we also overexpressed each sigma factor. Altering transcript levels for either or both alternative sigma factors resulted in a severe defect in EB production as compared to controls. Furthermore, RNA sequencing identified differentially expressed genes during alternative sigma factor dysregulation, indicating the putative regulons of each. These data demonstrate that the levels of alternative sigma factors must be carefully regulated to facilitate chlamydial growth and differentiation. IMPORTANCE Chlamydia trachomatis is a significant human pathogen in both developed and developing nations. Due to the organism's unique developmental cycle and intracellular niche, basic research has been slow and arduous. However, recent advances in chlamydial genetics have allowed the field to make significant progress in experimentally interrogating the basic physiology of Chlamydia. Broadly speaking, the driving factors of chlamydial development are poorly understood, particularly regarding how the later stages of development are regulated. Here, we employ a novel genetic tool for use in Chlamydia while investigating the effects of dysregulating the two alternative sigma factors in the organism that help control transcription initiation. We provide further evidence for both sigma factors' essential roles in late-stage development and their potential regulons, laying the foundation for deeper experimentation to uncover the molecular pathways involved in chlamydial differentiation.
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Affiliation(s)
- Nathan D. Hatch
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, Nebraska, USA
| | - Scot P. Ouellette
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, Nebraska, USA
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Lee J, Cox JV, Ouellette SP. The Unique N-Terminal Domain of Chlamydial Bactofilin Mediates Its Membrane Localization and Ring-Forming Properties. J Bacteriol 2023; 205:e0009223. [PMID: 37191556 PMCID: PMC10294636 DOI: 10.1128/jb.00092-23] [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: 03/10/2023] [Accepted: 05/01/2023] [Indexed: 05/17/2023] Open
Abstract
Chlamydia trachomatis is an obligate intracellular bacterial pathogen. In evolving to the intracellular niche, Chlamydia has reduced its genome size compared to other bacteria and, as a consequence, has a number of unique features. For example, Chlamydia engages the actin-like protein MreB, rather than the tubulin-like protein FtsZ, to direct peptidoglycan (PG) synthesis exclusively at the septum of cells undergoing polarized cell division. Interestingly, Chlamydia possesses another cytoskeletal element-a bactofilin ortholog, BacA. Recently, we reported BacA is a cell size-determining protein that forms dynamic membrane-associated ring structures in Chlamydia that have not been observed in other bacteria with bactofilins. Chlamydial BacA possesses a unique N-terminal domain, and we hypothesized this domain imparts the membrane-binding and ring-forming properties of BacA. We show that different truncations of the N terminus result in distinct phenotypes: removal of the first 50 amino acids (ΔN50) results in large ring structures at the membrane whereas removal of the first 81 amino acids (ΔN81) results in an inability to form filaments and rings and a loss of membrane association. Overexpression of the ΔN50 isoform altered cell size, similar to loss of BacA, suggesting that the dynamic properties of BacA are essential for the regulation of cell size. We further show that the region from amino acid 51 to 81 imparts membrane association as appending it to green fluorescent protein (GFP) resulted in the relocalization of GFP from the cytosol to the membrane. Overall, our findings suggest two important functions for the unique N-terminal domain of BacA and help explain its role as a cell size determinant. IMPORTANCE Bacteria use a variety of filament-forming cytoskeletal proteins to regulate and control various aspects of their physiology. For example, the tubulin-like FtsZ recruits division proteins to the septum whereas the actin-like MreB recruits peptidoglycan (PG) synthases to generate the cell wall in rod-shaped bacteria. Recently, a third class of cytoskeletal protein has been identified in bacteria-bactofilins. These proteins have been primarily linked to spatially localized PG synthesis. Interestingly, Chlamydia, an obligate intracellular bacterium, does not have PG in its cell wall and yet possesses a bactofilin ortholog. In this study, we characterize a unique N-terminal domain of chlamydial bactofilin and show that this domain controls two important functions that affect cell size: its ring-forming and membrane-associating properties.
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Affiliation(s)
- Junghoon Lee
- Department of Pathology and Microbiology, College of Medicine, University of Nebraska Medical Center, Omaha, Nebraska, USA
| | - John V. Cox
- Department of Microbiology, Immunology, and Biochemistry, University of Tennessee Health Science Center, Memphis, Tennessee, USA
| | - Scot P. Ouellette
- Department of Pathology and Microbiology, College of Medicine, University of Nebraska Medical Center, Omaha, Nebraska, USA
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You C, Liao M, Wang M, Zhao L, Li L, Ye X, Yang T. The Effect of Amoxicillin Pre-Exposure on Treatment Outcomes and Antimicrobial Susceptibility in Patients with Urogenital Chlamydia trachomatis Infection. Infect Drug Resist 2023; 16:3575-3587. [PMID: 37305735 PMCID: PMC10257477 DOI: 10.2147/idr.s410410] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Accepted: 05/25/2023] [Indexed: 06/13/2023] Open
Abstract
Purpose We investigated the influence of amoxicillin pre-exposure on treatment outcomes, Chlamydia trachomatis (CT) culture, the presence of drug-resistant genes, minimum inhibitory concentrations (MICs), and fractional inhibitory concentrations (FICs) in CT clinical strains. Additionally, we explored the effect of different antimicrobial combinations on CT. Patients and Methods Clinical data of 62 patients with CT infection were recorded. Of these, 33 had pre-exposure to amoxicillin and 29 did not. Among patients with pre-exposure, 17 received azithromycin and 16 received minocycline. Among the patients without pre-exposure, 15 received azithromycin and 14 received minocycline. All patients underwent microbiological cure follow-ups one month after completing the treatment. 23S rRNA gene mutations, acquisition of tet(M) and tet(C) were detected using reverse transcription PCR (RT-PCR) and PCR, respectively. The MICs and FICs of azithromycin, minocycline, and moxifloxacin, alone or in combination, were determined using the microdilution and checkerboard methods, respectively. Results More cases of treatment failure occurred in pre-exposed patients, in both treatment groups (P <0.05). No 23S rRNA gene mutations or tet(M) and tet(C) acquisitions were found. More inclusion bodies were cultured from patients without amoxicillin pre-exposure than from those with pre-exposure (P <0.0001). The MICs of all antibiotics were higher in pre-exposed patients than in those without pre-exposure (P <0.01). The FICs of azithromycin plus moxifloxacin were lower than those of the other antibiotic combinations (P <0.0001). The synergy rate of azithromycin plus moxifloxacin was significantly higher than those of azithromycin plus minocycline and minocycline plus moxifloxacin (P <0.001). The FICs of all antibiotic combinations were comparable between isolates from the two patient groups (all P >0.05). Conclusion Pre-exposure to amoxicillin in CT patients may inhibit CT growth and decrease sensitivity of CT strains to antibiotics. Azithromycin plus moxifloxacin may be a promising treatment regimen for genital CT infections with treatment failure.
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Affiliation(s)
- Cong You
- Department of Dermatology and Venereology; Candidate Branch of National Clinical Research Centre for Skin and Immune Diseases, the First Affiliated Hospital of Gannan Medical University, Ganzhou, People’s Republic of China
| | - Mingyi Liao
- Department of Dermatology and Venereology; Candidate Branch of National Clinical Research Centre for Skin and Immune Diseases, the First Affiliated Hospital of Gannan Medical University, Ganzhou, People’s Republic of China
| | - Mei Wang
- Department of Dermatology, Tianjin First Central Hospital, School of Medicine, Nankai University, Tianjin, People’s Republic of China
| | - Leran Zhao
- Department of Dermatology and Venereology, the General Hospital of Tianjin Medical University, Tianjin, People’s Republic of China
| | - Longnian Li
- Department of Dermatology and Venereology; Candidate Branch of National Clinical Research Centre for Skin and Immune Diseases, the First Affiliated Hospital of Gannan Medical University, Ganzhou, People’s Republic of China
| | - Xiaoying Ye
- Department of Dermatology and Venereology; Candidate Branch of National Clinical Research Centre for Skin and Immune Diseases, the First Affiliated Hospital of Gannan Medical University, Ganzhou, People’s Republic of China
| | - Tao Yang
- Department of Dermatology and Venereology; Candidate Branch of National Clinical Research Centre for Skin and Immune Diseases, the First Affiliated Hospital of Gannan Medical University, Ganzhou, People’s Republic of China
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5
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Hatch ND, Ouellette SP. Identification of the alternative sigma factor regulons of Chlamydia trachomatis using multiplexed CRISPR interference. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.04.27.538638. [PMID: 37162869 PMCID: PMC10168357 DOI: 10.1101/2023.04.27.538638] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
C. trachomatis is a developmentally regulated, obligate intracellular bacterium that encodes three sigma factors: σ66, σ54, and σ28. σ66 is the major sigma factor controlling most transcription initiation during early and mid-cycle development as the infectious EB transitions to the non-infectious RB that replicates within an inclusion inside the cell. The roles of the minor sigma factors, σ54 and σ28, have not been well characterized to date - however, there are data to suggest each functions in late-stage development and secondary differentiation as RBs transition to EBs. As the process of secondary differentiation itself is poorly characterized, clarifying the function of these alternative sigma factors by identifying the genes regulated by them will further our understanding of chlamydial differentiation. We hypothesize that σ54 and σ28 have non-redundant and essential functions for initiating late gene transcription thus mediating secondary differentiation in Chlamydia . Here, we demonstrate the necessity of each minor sigma factor in successfully completing the developmental cycle. We have implemented and validated multiplexed CRISPRi techniques novel to the chlamydial field to examine effects of knocking down each alternative sigma factor individually and simultaneously. In parallel, we also overexpressed each sigma factor. Altering transcript levels for either or both alternative sigma factors resulted in a severe defect in EB production as compared to controls. Furthermore, RNA sequencing identified differentially expressed genes during alternative sigma factor dysregulation, indicating the putative regulons of each. These data demonstrate the levels of alternative sigma factors must be carefully regulated to facilitate chlamydial growth and differentiation. Importance Chlamydia trachomatis is a significant human pathogen in both developed and developing nations. Due to the organism's unique developmental cycle and intracellular niche, basic research has been slow and arduous. However, recent advances in chlamydial genetics have allowed the field to make significant progress in experimentally interrogating the basic physiology of Chlamydia . Broadly speaking, the driving factors of chlamydial development are poorly understood, particularly regarding how the later stages of development are regulated. Here, we employ a novel genetic tool for use in Chlamydia while investigating the effects of dysregulating the two alternative sigma factors in the organism that help control transcription initiation. We provide further evidence for both sigma factors' essential roles in late-stage development and their potential regulons, laying the foundation for deeper experimentation to uncover the molecular pathways involved in chlamydial differentiation.
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6
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Onorini D, Schoborg R, Borel N, Leonard C. Beta lactamase-producing Neisseria gonorrhoeae alleviates Amoxicillin-induced chlamydial persistence in a novel in vitro co-infection model. CURRENT RESEARCH IN MICROBIAL SCIENCES 2023; 4:100188. [PMID: 37025122 PMCID: PMC10070076 DOI: 10.1016/j.crmicr.2023.100188] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/03/2023] Open
Abstract
Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (NG) cause most bacterial sexually transmitted infections (STIs) worldwide. Epidemiological studies have shown high percentages of co-infections with CT/NG and indicate that NG co-infection can reactivate CT shedding during persistent chlamydial infection. These data also suggest that biological interaction between the two bacteria may increase susceptibility or transmissibility. CT is an obligate intracellular bacterium with a developmental cycle that alternates between two forms: infectious elementary bodies (EBs) which invade the epithelium and non-infectious reticulate bodies (RBs) which divide and replicate inside the inclusion. Adverse environmental conditions can interrupt chlamydial development, with a consequent temporary halt in RB division, reduction in infectious EB production and formation of enlarged chlamydiae (aberrant bodies, ABs) - characterizing chlamydial persistence. When the stressor is removed, the chlamydial developmental cycle is restored, together with production of infectious EBs. The beta-lactam amoxicillin (AMX) induces chlamydial persistence, both in vitro and in mice. We investigated the impact of penicillinase-producing NG strain (PPNG) on AMX-persistent chlamydial infection utilizing our recently developed, contact-independent in vitro model of co-infection. We hypothesized that co-infection with PPNG could prevent and/or reverse AMX-induced chlamydial persistence. Our results showed that PPNG can ameliorate AMX-persistence in two chlamydial species, CT and C. muridarum (CM), providing novel evidence for a range of Chlamydia/NG interactions.
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Affiliation(s)
- Delia Onorini
- Institute of Veterinary Pathology, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland
| | - Robert Schoborg
- Department of Medical Education, Center for Infectious Disease, Inflammation and Immunity, Quillen College of Medicine, East Tennessee State University, Johnson City, TN, United States
| | - Nicole Borel
- Institute of Veterinary Pathology, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland
| | - Cory Leonard
- Institute of Veterinary Pathology, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland
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Reuter J, Otten C, Jacquier N, Lee J, Mengin-Lecreulx D, Löckener I, Kluj R, Mayer C, Corona F, Dannenberg J, Aeby S, Bühl H, Greub G, Vollmer W, Ouellette SP, Schneider T, Henrichfreise B. An NlpC/P60 protein catalyzes a key step in peptidoglycan recycling at the intersection of energy recovery, cell division and immune evasion in the intracellular pathogen Chlamydia trachomatis. PLoS Pathog 2023; 19:e1011047. [PMID: 36730465 PMCID: PMC9928106 DOI: 10.1371/journal.ppat.1011047] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Revised: 02/14/2023] [Accepted: 12/06/2022] [Indexed: 02/04/2023] Open
Abstract
The obligate intracellular Chlamydiaceae do not need to resist osmotic challenges and thus lost their cell wall in the course of evolution. Nevertheless, these pathogens maintain a rudimentary peptidoglycan machinery for cell division. They build a transient peptidoglycan ring, which is remodeled during the process of cell division and degraded afterwards. Uncontrolled degradation of peptidoglycan poses risks to the chlamydial cell, as essential building blocks might get lost or trigger host immune response upon release into the host cell. Here, we provide evidence that a primordial enzyme class prevents energy intensive de novo synthesis and uncontrolled release of immunogenic peptidoglycan subunits in Chlamydia trachomatis. Our data indicate that the homolog of a Bacillus NlpC/P60 protein is widely conserved among Chlamydiales. We show that the enzyme is tailored to hydrolyze peptidoglycan-derived peptides, does not interfere with peptidoglycan precursor biosynthesis, and is targeted by cysteine protease inhibitors in vitro and in cell culture. The peptidase plays a key role in the underexplored process of chlamydial peptidoglycan recycling. Our study suggests that chlamydiae orchestrate a closed-loop system of peptidoglycan ring biosynthesis, remodeling, and recycling to support cell division and maintain long-term residence inside the host. Operating at the intersection of energy recovery, cell division and immune evasion, the peptidoglycan recycling NlpC/P60 peptidase could be a promising target for the development of drugs that combine features of classical antibiotics and anti-virulence drugs.
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Affiliation(s)
- Jula Reuter
- Institute for Pharmaceutical Microbiology, University Hospital Bonn, University of Bonn, Bonn, Germany
| | - Christian Otten
- Institute for Pharmaceutical Microbiology, University Hospital Bonn, University of Bonn, Bonn, Germany
| | - Nicolas Jacquier
- Institute of Microbiology, University Hospital Center and University of Lausanne, Lausanne, Switzerland
| | - Junghoon Lee
- Department of Pathology and Microbiology, College of Medicine, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
| | - Dominique Mengin-Lecreulx
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), Gif-sur-Yvette, France
| | - Iris Löckener
- Institute for Pharmaceutical Microbiology, University Hospital Bonn, University of Bonn, Bonn, Germany
| | - Robert Kluj
- Interfaculty Institute of Microbiology and Infection Medicine, Organismic Interactions/Glycobiology, Eberhard Karls Universität Tübingen, Tübingen, Germany
| | - Christoph Mayer
- Interfaculty Institute of Microbiology and Infection Medicine, Organismic Interactions/Glycobiology, Eberhard Karls Universität Tübingen, Tübingen, Germany
| | - Federico Corona
- Centre for Bacterial Cell Biology, Biosciences Institute, Newcastle University, Newcastle Upon Tyne, United Kingdom
| | - Julia Dannenberg
- Institute for Pharmaceutical Microbiology, University Hospital Bonn, University of Bonn, Bonn, Germany
| | - Sébastien Aeby
- Institute of Microbiology, University Hospital Center and University of Lausanne, Lausanne, Switzerland
| | - Henrike Bühl
- Institute for Pharmaceutical Microbiology, University Hospital Bonn, University of Bonn, Bonn, Germany
| | - Gilbert Greub
- Institute of Microbiology, University Hospital Center and University of Lausanne, Lausanne, Switzerland
| | - Waldemar Vollmer
- Centre for Bacterial Cell Biology, Biosciences Institute, Newcastle University, Newcastle Upon Tyne, United Kingdom
| | - Scot P. Ouellette
- Department of Pathology and Microbiology, College of Medicine, University of Nebraska Medical Center, Omaha, Nebraska, United States of America
| | - Tanja Schneider
- Institute for Pharmaceutical Microbiology, University Hospital Bonn, University of Bonn, Bonn, Germany
| | - Beate Henrichfreise
- Institute for Pharmaceutical Microbiology, University Hospital Bonn, University of Bonn, Bonn, Germany
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Host Cell Amplification of Nutritional Stress Contributes To Persistence in Chlamydia trachomatis. mBio 2022; 13:e0271922. [PMID: 36377897 PMCID: PMC9765610 DOI: 10.1128/mbio.02719-22] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Persistence, a viable but non-replicating growth state, has been implicated in diseases caused by Chlamydia trachomatis. Starvation of distinct nutrients produces a superficially similar persistent state, implying convergence on a common intracellular environment. We employed host-pathogen dual RNA-sequencing under both iron- and tryptophan-starved conditions to systematically characterize the persistent chlamydial transcriptome and to define common contributions of the host cell transcriptional stress response in shaping the intracellular environment. The transcriptome of the infected host cells was highly specific to each nutritional stress, despite comparable effects on chlamydial growth and development in each condition. In contrast, the chlamydial transcriptomes between nutritional conditions were highly similar, suggesting some overlap in host cell responses to iron limitation and tryptophan starvation that contribute to a common persistent phenotype. We demonstrate that a commonality in the host cell responses is the suppression of GTP biosynthesis, a nucleotide for which Chlamydia are auxotrophic. Pharmacological inhibition of host IMP dehydrogenase (IMPDH1), which catalyzes the rate-limiting step in de novo guanine nucleotide synthesis, resulted in comparable GTP depletion to both iron and tryptophan starvation and induced chlamydial persistence. Moreover, IMPDH1 inhibition and iron starvation acted synergistically to control chlamydial growth. Thus, host cell reduction in GTP levels amplifies the nutritional stress to intracellular chlamydiae in infection-relevant models of persistence, illustrating the determinative role the infected host cell plays in bacterial stress responses. IMPORTANCE Bacteria respond to nutritional stress through universal and unique mechanisms. Genome reduction in the Chlamydiaceae, a consequence of coevolution with their obligate eukaryotic hosts, has reduced their repertoire of stress response mechanisms. Here, we demonstrate that the infected host cell may provide the context within which universal stress responses emerge for Chlamydia trachomatis. We report that during starvation of the essential nutrients iron or tryptophan, a common response of the infected epithelial cell is the suppression of GTP biosynthesis, which induces a persistent developmental state in the pathogen. Thus, chlamydial persistence results from the combined effects of primary stresses on the pathogen and the host, with the latter eliciting a secondary host cell response that intensifies the inhospitable intracellular environment.
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Huang X, Liufu Q, Xu R, Chen X, Liu M, Han J, Guan H, Ma C. Integrating lncRNAs and mRNAs Expression Profiles in Penicillin-Induced Persistent Chlamydial Infection in HeLa Cells. Front Mol Biosci 2022; 9:744901. [PMID: 35252346 PMCID: PMC8890745 DOI: 10.3389/fmolb.2022.744901] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Accepted: 01/31/2022] [Indexed: 11/13/2022] Open
Abstract
Chlamydia trachomatis (C. trachomatis) is a major etiological agent of sexually transmitted infection. Some stressing conditions can result in persistent chlamydial infection, which is thought to be associated with severe complications including ectopic pregnancy and tubal factor infertility. Long noncoding RNAs (lncRNAs) have been identified as key modulators in many biological processes. Nevertheless, the role of lncRNAs in persistent chlamydial infection is still unclear. In this study, we used lncRNA and mRNA microarray to identify the global lncRNAs and mRNAs expression in penicillin-induced persistent chlamydial infection in HeLa cells as well as the control group (HeLa cells without C. trachomatis infection). Among 1005 differentially expressed lncRNAs, 585 lncRNAs were upregulated and 420 downregulated in persistent chlamydial infection, while 410 mRNAs were identified to express differentially, of which 113 mRNAs were upregulated and 297 downregulated. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis with differentially expressed genes were performed. We then constructed the lncRNA-miRNA-mRNA competing endogenous RNAs (ceRNAs) network. Four mRNAs were validated to be changed by quantitative real-time PCR which were correlated with the microarray result. Integration of protein-protein interaction network was constructed and hub genes were identified. These findings provide a new perspective on the molecular mechanisms of penicillin-induced persistent chlamydial infection.
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Affiliation(s)
- Xiaobao Huang
- Department of Dermatology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Qian Liufu
- Department of Dermatology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Rui Xu
- Department of Dermatology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Xiaohong Chen
- Department of Dermatology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Mingna Liu
- Department of Dermatology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Jiande Han
- Department of Dermatology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Hongyu Guan
- Department of Endocrinology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
- *Correspondence: Chunguang Ma, ; Hongyu Guan,
| | - Chunguang Ma
- Department of Dermatology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
- *Correspondence: Chunguang Ma, ; Hongyu Guan,
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10
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Sixt BS. Host cell death during infection with Chlamydia: a double-edged sword. FEMS Microbiol Rev 2021; 45:5902849. [PMID: 32897321 PMCID: PMC7794043 DOI: 10.1093/femsre/fuaa043] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Accepted: 09/02/2020] [Indexed: 12/12/2022] Open
Abstract
The phylum Chlamydiae constitutes a group of obligate intracellular bacteria that infect a remarkably diverse range of host species. Some representatives are significant pathogens of clinical or veterinary importance. For instance, Chlamydia trachomatis is the leading infectious cause of blindness and the most common bacterial agent of sexually transmitted diseases. Chlamydiae are exceptionally dependent on their eukaryotic host cells as a consequence of their developmental biology. At the same time, host cell death is an integral part of the chlamydial infection cycle. It is therefore not surprising that the bacteria have evolved exquisite and versatile strategies to modulate host cell survival and death programs to their advantage. The recent introduction of tools for genetic modification of Chlamydia spp., in combination with our increasing awareness of the complexity of regulated cell death in eukaryotic cells, and in particular of its connections to cell-intrinsic immunity, has revived the interest in this virulence trait. However, recent advances also challenged long-standing assumptions and highlighted major knowledge gaps. This review summarizes current knowledge in the field and discusses possible directions for future research, which could lead us to a deeper understanding of Chlamydia's virulence strategies and may even inspire novel therapeutic approaches.
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Affiliation(s)
- Barbara S Sixt
- The Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå Centre for Microbial Research (UCMR), Department of Molecular Biology, Umeå University, SE-901 87 Umeå, Sweden
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11
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Grieshaber NA, Runac J, Turner S, Dean M, Appa C, Omsland A, Grieshaber SS. The sRNA Regulated Protein DdbA Is Involved in Development and Maintenance of the Chlamydia trachomatis EB Cell Form. Front Cell Infect Microbiol 2021; 11:692224. [PMID: 34368013 PMCID: PMC8343073 DOI: 10.3389/fcimb.2021.692224] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Accepted: 06/23/2021] [Indexed: 11/18/2022] Open
Abstract
The chlamydial small non coding RNA, IhtA, regulates the expression of both HctA and DdbA, the uncharacterized product of the C. trachomatis L2 CTL0322 gene. HctA is a small, highly basic, DNA binding protein that is expressed late in development and mediates the condensation of the genome during RB to EB differentiation. DdbA is conserved throughout the chlamydial lineage, and is predicted to express a small, basic, cytoplasmic protein. As it is common for sRNAs to regulate multiple mRNAs within the same physiological pathway, we hypothesize that DdbA, like HctA, is involved in RB to EB differentiation. Here, we show that DdbA is a DNA binding protein, however unlike HctA, DdbA does not contribute to genome condensation but instead likely has nuclease activity. Using a DdbA temperature sensitive mutant, we show that DdbAts creates inclusions indistinguishable from WT L2 in size and that early RB replication is likewise similar at the nonpermissive temperature. However, the number of DdbAts infectious progeny is dramatically lower than WT L2 overall, although production of EBs is initiated at a similar time. The expression of a late gene reporter construct followed live at 40°C indicates that late gene expression is severely compromised in the DdbAts strain. Viability assays, both in host cells and in axenic media indicate that the DdbAts strain is defective in the maintenance of EB infectivity. Additionally, using Whole Genome Sequencing we demonstrate that chromosome condensation is temporally separated from DNA replication during the RB to EB transition. Although DdbA does not appear to be directly involved in this process, our data suggest it is a DNA binding protein that is important in the production and maintenance of infectivity of the EB, perhaps by contributing to the remodeling of the EB chromosome.
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Affiliation(s)
- Nicole A. Grieshaber
- Department of Biological Sciences, University of Idaho, Moscow, ID, United States
| | - Justin Runac
- College of Dentistry, University of Florida, Gainesville, FL, United States
| | - Sierra Turner
- Department of Biological Sciences, University of Idaho, Moscow, ID, United States
| | - Marissa Dean
- Department of Biological Sciences, University of Idaho, Moscow, ID, United States
| | - Cody Appa
- Department of Biological Sciences, University of Idaho, Moscow, ID, United States
| | - Anders Omsland
- Paul G. Allen School for Global Animal Health, College of Veterinary Medicine, Washington State University, Pullman, WA, United States
| | - Scott S. Grieshaber
- Department of Biological Sciences, University of Idaho, Moscow, ID, United States
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12
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Huang X, Tan J, Chen X, Liu M, Zhu H, Li W, He Z, Han J, Ma C. Akt Phosphorylation Influences Persistent Chlamydial Infection and Chlamydia-Induced Golgi Fragmentation Without Involving Rab14. Front Cell Infect Microbiol 2021; 11:675890. [PMID: 34169005 PMCID: PMC8218875 DOI: 10.3389/fcimb.2021.675890] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Accepted: 04/29/2021] [Indexed: 11/30/2022] Open
Abstract
Chlamydia trachomatis is an obligate intracellular bacterium that causes multiple diseases involving the eyes, gastrointestinal tract, and genitourinary system. Previous studies have identified that in acute chlamydial infection, C. trachomatis requires Akt pathway phosphorylation and Rab14-positive vesicles to transmit essential lipids from the Golgi apparatus in survival and replication. However, the roles that Akt phosphorylation and Rab14 play in persistent chlamydial infection remain unclear. Here, we discovered that the level of Akt phosphorylation was lower in persistent chlamydial infection, and positively correlated with the effect of activating the development of Chlamydia but did not change the infectivity and 16s rRNA gene expression. Rab14 was found to exert a limited effect on persistent infection. Akt phosphorylation might regulate Chlamydia development and Chlamydia-induced Golgi fragmentation in persistent infection without involving Rab14. Our results provide a new insight regarding the potential of synergistic repressive effects of an Akt inhibitor with antibiotics in the treatment of persistent chlamydial infection induced by penicillin.
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Affiliation(s)
- Xiaobao Huang
- Department of Dermatology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Jinfeng Tan
- Department of Gynecology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Xiaohong Chen
- Department of Dermatology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Mingna Liu
- Department of Dermatology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Huiling Zhu
- Department of Dermatology, The First Affiliated Hospital of Guangzhou Medical College, Guangzhou, China
| | - Wenjing Li
- Department of Dermatology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Zhenjian He
- School of Public Health, Sun Yat-sen University, Guangzhou, China
| | - Jiande Han
- Department of Dermatology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Chunguang Ma
- Department of Dermatology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
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13
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Filardo S, Di Pietro M, Pasqualetti P, Manera M, Diaco F, Sessa R. In-cell western assay as a high-throughput approach for Chlamydia trachomatis quantification and susceptibility testing to antimicrobials. PLoS One 2021; 16:e0251075. [PMID: 33974662 PMCID: PMC8112659 DOI: 10.1371/journal.pone.0251075] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Accepted: 04/19/2021] [Indexed: 11/24/2022] Open
Abstract
Chlamydia trachomatis, the leading cause of bacterial sexually transmitted diseases in developed countries, with around 127 million new cases per year, is mainly responsible for urethritis and cervicitis in women, and urethritis and epididymitis in men. Most C. trachomatis infections remain asymptomatic (>50%) and, hence, untreated, leading to severe reproductive complications in both women and men, like infertility. Therefore, the detection of C. trachomatis as well as the antimicrobial susceptibility testing becomes a priority, and, along the years, several methods have been recommended, like cell culture and direct immunofluorescence (DFA) on cell cultures. Herein, we described the application of In-Cell Western assay (ICW) via Odyssey CLx as a fast, more accessible, and high-throughput platform for the quantification of C. trachomatis and the screening of anti-chlamydial drugs. As a first step, we set up a standard curve by infecting cell monolayers with 2-fold serial dilutions of C. trachomatis Elementary Body (EB) suspension. Then, different unknown C. trachomatis EB suspensions were quantified and the chlamydial susceptibility testing to erythromycin was performed, using the DFA as comparison. Our results showed a very high concordance between these two assays, as evidenced by the enumeration of chlamydial IFUs as well as the determination of erythromycin Minimum Inhibitory Concentration (MIC). In conclusion, the ICW assay may be a promising candidate as an accurate and accessible methodology for C. trachomatis antimicrobial susceptibility testing.
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Affiliation(s)
- Simone Filardo
- Department of Public Health and Infectious Diseases, Section of Microbiology, University of Rome “Sapienza”, Rome, Italy
- * E-mail:
| | - Marisa Di Pietro
- Department of Public Health and Infectious Diseases, Section of Microbiology, University of Rome “Sapienza”, Rome, Italy
| | - Patrizio Pasqualetti
- Department of Public Health and Infectious Diseases, Section of Health Statistics and Biometry, University of Rome “Sapienza”, Rome, Italy
| | - Martina Manera
- Department of Public Health and Infectious Diseases, Section of Microbiology, University of Rome “Sapienza”, Rome, Italy
| | - Fabiana Diaco
- Department of Public Health and Infectious Diseases, Section of Microbiology, University of Rome “Sapienza”, Rome, Italy
| | - Rosa Sessa
- Department of Public Health and Infectious Diseases, Section of Microbiology, University of Rome “Sapienza”, Rome, Italy
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14
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Shima K, Kaufhold I, Eder T, Käding N, Schmidt N, Ogunsulire IM, Deenen R, Köhrer K, Friedrich D, Isay SE, Grebien F, Klinger M, Richer BC, Günther UL, Deepe GS, Rattei T, Rupp J. Regulation of the Mitochondrion-Fatty Acid Axis for the Metabolic Reprogramming of Chlamydia trachomatis during Treatment with β-Lactam Antimicrobials. mBio 2021; 12:e00023-21. [PMID: 33785629 PMCID: PMC8092193 DOI: 10.1128/mbio.00023-21] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2021] [Accepted: 02/23/2021] [Indexed: 12/18/2022] Open
Abstract
Infection with the obligate intracellular bacterium Chlamydia trachomatis is the most common bacterial sexually transmitted disease worldwide. Since no vaccine is available to date, antimicrobial therapy is the only alternative in C. trachomatis infection. However, changes in chlamydial replicative activity and the occurrence of chlamydial persistence caused by diverse stimuli have been proven to impair treatment effectiveness. Here, we report the mechanism for C. trachomatis regulating host signaling processes and mitochondrial function, which can be used for chlamydial metabolic reprogramming during treatment with β-lactam antimicrobials. Activation of signal transducer and activator of transcription 3 (STAT3) is a well-known host response in various bacterial and viral infections. In C. trachomatis infection, inactivation of STAT3 by host protein tyrosine phosphatases increased mitochondrial respiration in both the absence and presence of β-lactam antimicrobials. However, during treatment with β-lactam antimicrobials, C. trachomatis increased the production of citrate as well as the activity of host ATP-citrate lyase involved in fatty acid synthesis. Concomitantly, chlamydial metabolism switched from the tricarboxylic acid cycle to fatty acid synthesis. This metabolic switch was a unique response in treatment with β-lactam antimicrobials and was not observed in gamma interferon (IFN-γ)-induced persistent infection. Inhibition of fatty acid synthesis was able to attenuate β-lactam-induced chlamydial persistence. Our findings highlight the importance of the mitochondrion-fatty acid interplay for the metabolic reprogramming of C. trachomatis during treatment with β-lactam antimicrobials.IMPORTANCE The mitochondrion generates most of the ATP in eukaryotic cells, and its activity is used for controlling the intracellular growth of Chlamydia trachomatis Furthermore, mitochondrial activity is tightly connected to host fatty acid synthesis that is indispensable for chlamydial membrane biogenesis. Phospholipids, which are composed of fatty acids, are the central components of the bacterial membrane and play a crucial role in the protection against antimicrobials. Chlamydial persistence that is induced by various stimuli is clinically relevant. While one of the well-recognized inducers, β-lactam antimicrobials, has been used to characterize chlamydial persistence, little is known about the role of mitochondria in persistent infection. Here, we demonstrate how C. trachomatis undergoes metabolic reprogramming to switch from the tricarboxylic acid cycle to fatty acid synthesis with promoted host mitochondrial activity in response to treatment with β-lactam antimicrobials.
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Affiliation(s)
- Kensuke Shima
- Department of Infectious Diseases and Microbiology, University of Lübeck, Lübeck, Germany
| | - Inga Kaufhold
- Department of Infectious Diseases and Microbiology, University of Lübeck, Lübeck, Germany
| | - Thomas Eder
- Division of Computational Systems Biology, University Vienna, Vienna, Austria
- Institute for Medical Biochemistry, University of Veterinary Medicine Vienna, Vienna, Austria
| | - Nadja Käding
- Department of Infectious Diseases and Microbiology, University of Lübeck, Lübeck, Germany
| | - Nis Schmidt
- Department of Infectious Diseases and Microbiology, University of Lübeck, Lübeck, Germany
| | - Iretiolu M Ogunsulire
- Department of Infectious Diseases and Microbiology, University of Lübeck, Lübeck, Germany
| | - René Deenen
- Biological and Medical Research Center (BMFZ), Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Karl Köhrer
- Biological and Medical Research Center (BMFZ), Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Dirk Friedrich
- Department of Infectious Diseases and Microbiology, University of Lübeck, Lübeck, Germany
| | - Sophie E Isay
- Department of Infectious Diseases and Microbiology, University of Lübeck, Lübeck, Germany
| | - Florian Grebien
- Institute for Medical Biochemistry, University of Veterinary Medicine Vienna, Vienna, Austria
| | | | - Barbara C Richer
- Institute of Chemistry and Metabolomics, University of Lübeck, Lübeck, Germany
| | - Ulrich L Günther
- Institute of Chemistry and Metabolomics, University of Lübeck, Lübeck, Germany
| | - George S Deepe
- Division of Infectious Diseases, College of Medicine, University of Cincinnati, Cincinnati, Ohio, USA
| | - Thomas Rattei
- Division of Computational Systems Biology, University Vienna, Vienna, Austria
| | - Jan Rupp
- Department of Infectious Diseases and Microbiology, University of Lübeck, Lübeck, Germany
- German Center for Infection Research (DZIF), Partner Site Hamburg-Lübeck-Borstel-Riems, Lübeck, Germany
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15
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Eisenreich W, Rudel T, Heesemann J, Goebel W. Persistence of Intracellular Bacterial Pathogens-With a Focus on the Metabolic Perspective. Front Cell Infect Microbiol 2021; 10:615450. [PMID: 33520740 PMCID: PMC7841308 DOI: 10.3389/fcimb.2020.615450] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Accepted: 11/30/2020] [Indexed: 12/19/2022] Open
Abstract
Persistence has evolved as a potent survival strategy to overcome adverse environmental conditions. This capability is common to almost all bacteria, including all human bacterial pathogens and likely connected to chronic infections caused by some of these pathogens. Although the majority of a bacterial cell population will be killed by the particular stressors, like antibiotics, oxygen and nitrogen radicals, nutrient starvation and others, a varying subpopulation (termed persisters) will withstand the stress situation and will be able to revive once the stress is removed. Several factors and pathways have been identified in the past that apparently favor the formation of persistence, such as various toxin/antitoxin modules or stringent response together with the alarmone (p)ppGpp. However, persistence can occur stochastically in few cells even of stress-free bacterial populations. Growth of these cells could then be induced by the stress conditions. In this review, we focus on the persister formation of human intracellular bacterial pathogens, some of which belong to the most successful persister producers but lack some or even all of the assumed persistence-triggering factors and pathways. We propose a mechanism for the persister formation of these bacterial pathogens which is based on their specific intracellular bipartite metabolism. We postulate that this mode of metabolism ultimately leads, under certain starvation conditions, to the stalling of DNA replication initiation which may be causative for the persister state.
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Affiliation(s)
- Wolfgang Eisenreich
- Department of Chemistry, Chair of Biochemistry, Technische Universität München, Garching, Germany
| | - Thomas Rudel
- Chair of Microbiology, Biocenter, University of Würzburg, Würzburg, Germany
| | - Jürgen Heesemann
- Max von Pettenkofer-Institute, Ludwig Maximilian University of Munich, München, Germany
| | - Werner Goebel
- Max von Pettenkofer-Institute, Ludwig Maximilian University of Munich, München, Germany
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16
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The ClpX and ClpP2 Orthologs of Chlamydia trachomatis Perform Discrete and Essential Functions in Organism Growth and Development. mBio 2020; 11:mBio.02016-20. [PMID: 32873765 PMCID: PMC7468207 DOI: 10.1128/mbio.02016-20] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Chlamydia trachomatis is the leading cause of infectious blindness globally and the most reported bacterial sexually transmitted infection both domestically and internationally. Given the economic burden, the lack of an approved vaccine, and the use of broad-spectrum antibiotics for treatment of infections, an understanding of chlamydial growth and development is critical for the advancement of novel targeted antibiotics. The Clp proteins comprise an important and conserved protease system in bacteria. Our work highlights the importance of the chlamydial Clp proteins to this clinically important bacterium. Additionally, our study implicates the Clp system playing an integral role in chlamydial developmental cycle progression, which may help establish models of how Chlamydia spp. and other bacteria progress through their respective developmental cycles. Our work also contributes to a growing body of Clp-specific research that underscores the importance and versatility of this system throughout bacterial evolution and further validates Clp proteins as drug targets. Chlamydia trachomatis is an obligate intracellular bacterium that undergoes a complex developmental cycle in which the bacterium differentiates between two functionally and morphologically distinct forms, the elementary body (EB) and reticulate body (RB), each of which expresses its own specialized repertoire of proteins. Both primary (EB to RB) and secondary (RB to EB) differentiations require protein turnover, and we hypothesize that proteases are critical for mediating differentiation. The Clp protease system is well conserved in bacteria and important for protein turnover. Minimally, the system relies on a serine protease subunit, ClpP, and an AAA+ ATPase, such as ClpX, that recognizes and unfolds substrates for ClpP degradation. In Chlamydia, ClpX is encoded within an operon 3′ to clpP2. We present evidence that the chlamydial ClpX and ClpP2 orthologs are essential to organism viability and development. We demonstrate here that chlamydial ClpX is a functional ATPase and forms the expected homohexamer in vitro. Overexpression of a ClpX mutant lacking ATPase activity had a limited impact on DNA replication or secondary differentiation but, nonetheless, reduced EB viability with observable defects in EB morphology noted. Conversely, overexpression of a catalytically inactive ClpP2 mutant significantly impacted developmental cycle progression by reducing the overall number of organisms. Blocking clpP2X transcription using CRISPR interference led to a decrease in bacterial growth, and this effect was complemented in trans by a plasmid copy of clpP2. Taken together, our data indicate that ClpX and the associated ClpP2 serve distinct functions in chlamydial developmental cycle progression and differentiation.
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17
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Abstract
Chlamydia is an obligate intracellular bacterial pathogen that has significantly reduced its genome size in adapting to its intracellular niche. Among the genes that Chlamydia has eliminated is ftsZ, encoding the central organizer of cell division that directs cell wall synthesis in the division septum. These Gram-negative pathogens have cell envelopes that lack peptidoglycan (PG), yet they use PG for cell division purposes. Recent research into chlamydial PG synthesis, components of the chlamydial divisome, and the mechanism of chlamydial division have significantly advanced our understanding of these processes in a unique and important pathogen. For example, it has been definitively confirmed that chlamydiae synthesize a canonical PG structure during cell division. Various studies have suggested and provided evidence that Chlamydia uses MreB to substitute for FtsZ in organizing and coordinating the divisome during division, components of which have been identified and characterized. Finally, as opposed to using an FtsZ-dependent binary fission process, Chlamydia employs an MreB-dependent polarized budding process to divide. A brief historical context for these key advances is presented along with a discussion of the current state of knowledge of chlamydial cell division.
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18
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Penicillin-binding proteins regulate multiple steps in the polarized cell division process of Chlamydia. Sci Rep 2020; 10:12588. [PMID: 32724139 PMCID: PMC7387471 DOI: 10.1038/s41598-020-69397-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2020] [Accepted: 07/08/2020] [Indexed: 12/26/2022] Open
Abstract
Chlamydia trachomatis serovar L2 and Chlamydia muridarum, which do not express FtsZ, undergo polarized cell division. During division, peptidoglycan assembles at the pole of dividing Chlamydia trachomatis cells where daughter cell formation occurs, and peptidoglycan regulates at least two distinct steps in the polarized division of Chlamydia trachomatis and Chlamydia muridarum. Cells treated with inhibitors that prevent peptidoglycan synthesis or peptidoglycan crosslinking by penicillin-binding protein 2 (PBP2) are unable to initiate polarized division, while cells treated with inhibitors that prevent peptidoglycan crosslinking by penicillin-binding protein 3 (PBP3/FtsI) initiate polarized division, but the process arrests at an early stage of daughter cell growth. Consistent with their distinct roles in polarized division, peptidoglycan organization is different in cells treated with PBP2 and PBP3-specific inhibitors. Our analyses indicate that the sequential action of PBP2 and PBP3 drives changes in peptidoglycan organization that are essential for the polarized division of these obligate intracellular bacteria. Furthermore, the roles we have characterized for PBP2 and PBP3 in regulating specific steps in chlamydial cell division have not been described in other bacteria.
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Shao L, You C, Cao J, Jiang Y, Liu Y, Liu Q. High treatment failure rate is better explained by resistance gene detection than by minimum inhibitory concentration in patients with urogenital Chlamydia trachomatis infection. Int J Infect Dis 2020; 96:121-127. [PMID: 32173573 DOI: 10.1016/j.ijid.2020.03.015] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2020] [Revised: 03/01/2020] [Accepted: 03/06/2020] [Indexed: 01/30/2023] Open
Abstract
OBJECTIVE The aim of this study was to investigate the relationships between treatment outcomes of patients with urogenital Chlamydia trachomatis infections and minimum inhibitory concentrations (MICs) and drug resistance genes. METHODS The clinical data of 92 patients diagnosed with Chlamydia trachomatis (C. trachomatis) infections were collected. Of these patients, 28 received regular treatment with azithromycin and 64 received minocycline. All patients underwent three monthly follow-ups after the completion of treatment. The microdilution method was used for the in vitro susceptibility tests. The acquisition of 23S rRNA mutations and presence of the tet(M) gene were detected by gene amplification and sequencing. RESULTS The MICs of azithromycin, clarithromycin, erythromycin, tetracycline, doxycycline, and minocycline were comparable for isolates from the treatment failure and treatment success groups. Higher detection rates of 23S rRNA gene mutations and tet(M) were found in the treatment failure group (57.14% and 71.43%, respectively) than in the treatment success group (14.29% and 30.23%, respectively) (p < 0.05). The A2057G, C2452A, and T2611C gene mutations of 23S rRNA were detected in eight clinical isolates from the azithromycin treatment failure group, while the T2611C gene mutation was detected in one clinical strain from the treatment success group. CONCLUSIONS The detection of resistance genes could better explain the high treatment failure rate than the MIC results in patients with urogenital C. trachomatis infections, highlighting the need for genetic antimicrobial resistance testing in infected patients.
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Affiliation(s)
- Lili Shao
- Department of Dermatology and Venereology, The General Hospital of Tianjin Medical University, No. 154 Anshan Road, Heping District, Tianjin 300052, China.
| | - Cong You
- Department of Dermatology and Venereology, The General Hospital of Tianjin Medical University, No. 154 Anshan Road, Heping District, Tianjin 300052, China.
| | - Junya Cao
- Department of Dermatology and Venereology, The General Hospital of Tianjin Medical University, No. 154 Anshan Road, Heping District, Tianjin 300052, China.
| | - Yong Jiang
- Department of Dermatology and Venereology, The Secondary Hospital of Tianjin Medical University, No. 23 Pingjiang Road, Hexi District, Tianjin 300211, China.
| | - Yuanjun Liu
- Department of Dermatology and Venereology, The General Hospital of Tianjin Medical University, No. 154 Anshan Road, Heping District, Tianjin 300052, China.
| | - Quanzhong Liu
- Department of Dermatology and Venereology, The General Hospital of Tianjin Medical University, No. 154 Anshan Road, Heping District, Tianjin 300052, China.
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20
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Foschi C, Bortolotti M, Polito L, Marangoni A, Zalambani C, Liparulo I, Fato R, Bolognesi A. Insights into penicillin-induced Chlamydia trachomatis persistence. Microb Pathog 2020; 142:104035. [PMID: 32017957 DOI: 10.1016/j.micpath.2020.104035] [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: 11/22/2019] [Revised: 01/15/2020] [Accepted: 01/31/2020] [Indexed: 12/23/2022]
Abstract
Chlamydia persistence is a viable, but non-cultivable, growth stage, resulting in a long-term relationship with the infected host cell. In vitro, this condition can be induced by different stressor agents, including beta-lactam antibiotics, as penicillin. The aim of this study was to get new insights into the interactions between Chlamydia trachomatis (serovars D and L2) and the epithelial host cells (HeLa) during persistence condition. In particular, we evaluated the following aspects, by comparing the normal chlamydial development cycle with penicillin-induced persistence: (i) cell survival/death, (ii) externalization of phosphatidylserine, (iii) caspase 1 and caspase 3/7 activation, and (iv) reactive oxygen species (ROS) production by the infected cells. At 72 h post-infection, the cytotoxic effect displayed by CT was completely abolished for both serovars and for all levels of multiplicity of infection only in the cells with aberrant CT inclusions. At the same time, CT was able to switch off the exposure of the lipid phosphatidylserine on the surface of epithelial cells and to strongly inhibit the activation of caspase 1 and caspase 3/7 only in penicillin-treated cells. Forty-eight hours post-infection, CT elicited a significant ROS expression both in case of a normal cycle and in case of persistence. However, serovar L and penicillin-free infection activated a higher ROS production compared to serovar D and to penicillin-induced persistence, respectively. In conclusion, we added knowledge to the cellular dynamics taking place during chlamydial persistence, demonstrating that CT creates a suitable niche to survive, switching off signals able to activate phagocytes/leukocytes recruitment. Nevertheless, persistent CT elicits ROS production by the infected cells, potentially contributing to the onset of chronic inflammation and tissue damages.
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Affiliation(s)
- Claudio Foschi
- University of Bologna, Department of Experimental, Diagnostic and Specialty Medicine-DIMES, Microbiology Unit, Via Massarenti 9, Bologna, Italy
| | - Massimo Bortolotti
- University of Bologna, Department of Experimental, Diagnostic and Specialty Medicine-DIMES, General Pathology Unit, Via S. Giacomo 14, Bologna, Italy
| | - Letizia Polito
- University of Bologna, Department of Experimental, Diagnostic and Specialty Medicine-DIMES, General Pathology Unit, Via S. Giacomo 14, Bologna, Italy
| | - Antonella Marangoni
- University of Bologna, Department of Experimental, Diagnostic and Specialty Medicine-DIMES, Microbiology Unit, Via Massarenti 9, Bologna, Italy.
| | - Chiara Zalambani
- University of Bologna, Department of Experimental, Diagnostic and Specialty Medicine-DIMES, Microbiology Unit, Via Massarenti 9, Bologna, Italy
| | - Irene Liparulo
- University of Bologna, FaBiT Department, Via Irnerio 48, Bologna, Italy
| | - Romana Fato
- University of Bologna, FaBiT Department, Via Irnerio 48, Bologna, Italy
| | - Andrea Bolognesi
- University of Bologna, Department of Experimental, Diagnostic and Specialty Medicine-DIMES, General Pathology Unit, Via S. Giacomo 14, Bologna, Italy
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21
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Abstract
The evolutionary separated Gram-negative Chlamydiales show a biphasic life cycle and replicate exclusively within eukaryotic host cells. Members of the genus Chlamydia are responsible for many acute and chronic diseases in humans, and Chlamydia-related bacteria are emerging pathogens. We revisit past efforts to detect cell wall material in Chlamydia and Chlamydia-related bacteria in the context of recent breakthroughs in elucidating the underlying cellular and molecular mechanisms of the chlamydial cell wall biosynthesis. In this review, we also discuss the role of cell wall biosynthesis in chlamydial FtsZ-independent cell division and immune modulation. In the past, penicillin susceptibility of an invisible wall was referred to as the "chlamydial anomaly." In light of new mechanistic insights, chlamydiae may now emerge as model systems to understand how a minimal and modified cell wall biosynthetic machine supports bacterial cell division and how cell wall-targeting beta-lactam antibiotics can also act bacteriostatically rather than bactericidal. On the heels of these discussions, we also delve into the effects of other cell wall antibiotics in individual chlamydial lineages.
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22
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Rother M, Teixeira da Costa AR, Zietlow R, Meyer TF, Rudel T. Modulation of Host Cell Metabolism by Chlamydia trachomatis. Microbiol Spectr 2019; 7:10.1128/microbiolspec.bai-0012-2019. [PMID: 31111817 PMCID: PMC11026074 DOI: 10.1128/microbiolspec.bai-0012-2019] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2018] [Indexed: 11/20/2022] Open
Abstract
Propagation of the intracellular bacterial pathogen Chlamydia trachomatis is strictly bound to its host cells. The bacterium has evolved by minimizing its genome size at the cost of being completely dependent on its host. Many of the vital nutrients are synthesized only by the host, and this has complex implications. Recent advances in loss-of-function analyses and the metabolomics of human infected versus noninfected cells have provided comprehensive insight into the molecular changes that host cells undergo during the stage of infection. Strikingly, infected cells acquire a stage of high metabolic activity, featuring distinct aspects of the Warburg effect, a condition originally assigned to cancer cells. This condition is characterized by aerobic glycolysis and an accumulation of certain metabolites, altogether promoting the synthesis of crucial cellular building blocks, such as nucleotides required for DNA and RNA synthesis. The altered metabolic program enables tumor cells to rapidly proliferate as well as C. trachomatis-infected cells to feed their occupants and still survive. This program is largely orchestrated by a central control board, the tumor suppressor protein p53. Its downregulation in C. trachomatis-infected cells or mutation in cancer cells not only alters the metabolic state of cells but also conveys the prevention of programmed cell death involving mitochondrial pathways. While this points toward common features in the metabolic reprogramming of infected and rapidly proliferating cells, it also forwards novel treatment options against chronic intracellular infections involving well-characterized host cell targets and established drugs.
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Affiliation(s)
- Marion Rother
- Steinbeis Innovation Center for Systems Biomedicine, 14612 Berlin-Falkensee, Germany
- Institute of Experimental Internal Medicine, Otto von Guericke University Magdeburg, 39120 Magdeburg, Germany
- Max Planck Institute for Infection Biology, Department of Molecular Biology, 10117 Berlin, Germany
| | | | - Rike Zietlow
- Max Planck Institute for Infection Biology, Department of Molecular Biology, 10117 Berlin, Germany
| | - Thomas F Meyer
- Max Planck Institute for Infection Biology, Department of Molecular Biology, 10117 Berlin, Germany
| | - Thomas Rudel
- Department of Microbiology, Biocenter, University of Wuerzburg, 97074 Wuerzburg, Germany
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23
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Panzetta ME, Luján AL, Bastidas RJ, Damiani MT, Valdivia RH, Saka HA. Ptr/CTL0175 Is Required for the Efficient Recovery of Chlamydia trachomatis From Stress Induced by Gamma-Interferon. Front Microbiol 2019; 10:756. [PMID: 31024512 PMCID: PMC6467971 DOI: 10.3389/fmicb.2019.00756] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2018] [Accepted: 03/26/2019] [Indexed: 12/26/2022] Open
Abstract
Chlamydia trachomatis is the most common sexually transmitted bacterial pathogen in humans and a frequent cause of asymptomatic, persistent infections leading to serious complications, particularly in young women. Chlamydia displays a unique obligate intracellular lifestyle involving the infectious elementary body and the replicative reticulate body. In the presence of stressors such as gamma-interferon (IFNγ) or beta-lactam antibiotics, C. trachomatis undergoes an interruption in its replication cycle and enters a viable but non-cultivable state. Upon removal of the stressors, surviving C. trachomatis resume cell division and developmental transitions. In this report, we describe a genetic screen to identify C. trachomatis mutants with defects in recovery from IFNγ- and/or penicillin-induced stress and characterized a chemically derived C. trachomatis mutant strain that exhibited a significant decrease in recovery from IFNγ- but not penicillin-induced stress. Through lateral gene transfer and targeted insertional gene inactivation we identified ptr, encoding a predicted protease, as a gene required for recovery from IFNγ-induced stress. A C. trachomatis LGV-L2 ptr-null strain displayed reduced generation of infectious progeny and impaired genome replication upon removal of IFNγ. This defect was restored by introducing a wild type copy of ptr on a plasmid, indicating that Ptr is required for a rapid growth upon removal of IFNγ. Ptr was expressed throughout the developmental cycle and localized to the inclusion lumen. Overall, our findings indicate that the putative secreted protease Ptr is required for C. trachomatis to specifically recover from IFNγ- but not penicillin-induced stress.
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Affiliation(s)
- María E Panzetta
- Centro de Investigaciones en Bioquímica Clínica e Inmunología, CONICET, Córdoba, Argentina.,Departamento de Bioquímica Clínica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba, Argentina
| | - Agustín L Luján
- Instituto de Medicina y Biología Experimental de Cuyo, CONICET, Mendoza, Argentina.,Área de Química Biológica, Facultad de Ciencias Médicas, Universidad Nacional de Cuyo, Mendoza, Argentina
| | - Robert J Bastidas
- Center for Host-Microbe Interactions, Department of Molecular Genetics and Microbiology, Duke University, Durham, NC, United States
| | - María T Damiani
- Instituto de Medicina y Biología Experimental de Cuyo, CONICET, Mendoza, Argentina.,Área de Química Biológica, Facultad de Ciencias Médicas, Universidad Nacional de Cuyo, Mendoza, Argentina
| | - Raphael H Valdivia
- Center for Host-Microbe Interactions, Department of Molecular Genetics and Microbiology, Duke University, Durham, NC, United States
| | - Héctor A Saka
- Centro de Investigaciones en Bioquímica Clínica e Inmunología, CONICET, Córdoba, Argentina.,Departamento de Bioquímica Clínica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba, Argentina
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24
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Panzetta ME, Valdivia RH, Saka HA. Chlamydia Persistence: A Survival Strategy to Evade Antimicrobial Effects in-vitro and in-vivo. Front Microbiol 2018; 9:3101. [PMID: 30619180 PMCID: PMC6299033 DOI: 10.3389/fmicb.2018.03101] [Citation(s) in RCA: 65] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2018] [Accepted: 11/30/2018] [Indexed: 11/13/2022] Open
Abstract
The Chlamydiaceae comprise a group of highly adapted bacterial pathogens sharing a unique intracellular lifestyle. Three Chlamydia species are pathogenic to humans: Chlamydia trachomatis, Chlamydia pneumoniae, and Chlamydia psittaci. C. trachomatis is the leading bacterial cause of sexually-transmitted infections and infectious blindness worldwide. Chlamydia pneumoniae is a major cause of community-acquired atypical pneumonia. C. psittaci primarily affects psittacine birds and can be transmitted to humans causing psittacosis, a potentially fatal form of pneumonia. As opposed to other bacterial pathogens, the spread of clinically relevant antimicrobial resistance genes does not seem to be a major problem for the treatment of Chlamydia infections. However, when exposed to stressing conditions, like those arising from exposure to antimicrobial stimuli, these bacteria undergo a temporary interruption in their replication cycle and enter a viable but non-cultivable state known as persistence. When the stressing conditions are removed, Chlamydia resumes replication and generation of infectious particles. This review gives an overview of the different survival strategies used by Chlamydia to evade the deleterious effects of penicillin and IFNγ, with a focus on the different models used to study Chlamydia persistence, their contribution to elucidating the molecular basis of this complex phenomenon and their potential implications for studies in animal models of infection.
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Affiliation(s)
- Maria Emilia Panzetta
- CIBICI-CONICET, Departamento de Bioquímica Clínica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba, Argentina
| | - Raphael H. Valdivia
- Department of Molecular Genetics and Microbiology, Duke University School of Medicine, Durham, NC, United States
| | - Hector Alex Saka
- CIBICI-CONICET, Departamento de Bioquímica Clínica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba, Argentina
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25
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Impact of Active Metabolism on Chlamydia trachomatis Elementary Body Transcript Profile and Infectivity. J Bacteriol 2018; 200:JB.00065-18. [PMID: 29735758 DOI: 10.1128/jb.00065-18] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2018] [Accepted: 05/01/2018] [Indexed: 11/20/2022] Open
Abstract
Bacteria of the genus Chlamydia include the significant human pathogens Chlamydia trachomatis and C. pneumoniae All chlamydiae are obligate intracellular parasites that depend on infection of a host cell and transition through a biphasic developmental cycle. Following host cell invasion by the infectious elementary body (EB), the pathogen transitions to the replicative but noninfectious reticulate body (RB). Differentiation of the RB back to the EB is essential to generate infectious progeny. While the EB form has historically been regarded as metabolically inert, maintenance of infectivity during incubation with specific nutrients has revealed active maintenance of the infectious phenotype. Using transcriptome sequencing, we show that the transcriptome of extracellular EBs incubated under metabolically stimulating conditions does not cluster with germinating EBs but rather with the transcriptome of EBs isolated directly from infected cells. In addition, the transcriptional profile of the extracellular metabolizing EBs more closely resembled that of EB production than germination. Maintenance of infectivity of extracellular EBs was achieved by metabolizing chemically diverse compounds, including glucose 6-phosphate, ATP, and amino acids, all of which can be found in extracellular environments, including mucosal secretions. We further show that the EB cell type actively maintains infectivity in the inclusion after terminal differentiation. Overall, these findings contribute to the emerging understanding that the EB cell form is actively maintained through metabolic processes after terminal differentiation to facilitate prolonged infectivity within the inclusion and under host cell free conditions, for example, following deposition at mucosal surfaces.IMPORTANCE Chlamydiae are obligate intracellular Gram-negative bacteria that are responsible for a wide range of diseases in both animal and human hosts. According to the Centers for Disease Control and Prevention, C. trachomatis is the most frequently reported sexually transmitted infection in the United States, costing the American health care system nearly $2.4 billion annually. Every year, there are over 4 million new cases of Chlamydia infections in the United States and an estimated 100 million cases worldwide. To cause disease, Chlamydia must successfully complete its complex biphasic developmental cycle, alternating between an infectious cell form (EB) specialized for initiating entry into target cells and a replicative form (RB) specialized for creating and maintaining the intracellular replication niche. The EB cell form has historically been considered metabolically quiescent, a passive entity simply waiting for contact with a host cell to initiate the next round of infection. Recent studies and data presented here demonstrate that the EB maintains its infectious phenotype by actively metabolizing a variety of nutrients. Therefore, the EB appears to have an active role in chlamydial biology, possibly within multiple environments, such as mucosal surfaces, fomites, and inside the host cell after formation.
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26
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Otten C, Brilli M, Vollmer W, Viollier PH, Salje J. Peptidoglycan in obligate intracellular bacteria. Mol Microbiol 2018; 107:142-163. [PMID: 29178391 PMCID: PMC5814848 DOI: 10.1111/mmi.13880] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/11/2017] [Indexed: 01/08/2023]
Abstract
Peptidoglycan is the predominant stress-bearing structure in the cell envelope of most bacteria, and also a potent stimulator of the eukaryotic immune system. Obligate intracellular bacteria replicate exclusively within the interior of living cells, an osmotically protected niche. Under these conditions peptidoglycan is not necessarily needed to maintain the integrity of the bacterial cell. Moreover, the presence of peptidoglycan puts bacteria at risk of detection and destruction by host peptidoglycan recognition factors and downstream effectors. This has resulted in a selective pressure and opportunity to reduce the levels of peptidoglycan. In this review we have analysed the occurrence of genes involved in peptidoglycan metabolism across the major obligate intracellular bacterial species. From this comparative analysis, we have identified a group of predicted 'peptidoglycan-intermediate' organisms that includes the Chlamydiae, Orientia tsutsugamushi, Wolbachia and Anaplasma marginale. This grouping is likely to reflect biological differences in their infection cycle compared with peptidoglycan-negative obligate intracellular bacteria such as Ehrlichia and Anaplasma phagocytophilum, as well as obligate intracellular bacteria with classical peptidoglycan such as Coxiella, Buchnera and members of the Rickettsia genus. The signature gene set of the peptidoglycan-intermediate group reveals insights into minimal enzymatic requirements for building a peptidoglycan-like sacculus and/or division septum.
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Affiliation(s)
- Christian Otten
- The Centre for Bacterial Cell BiologyInstitute for Cell and Molecular Biosciences, Newcastle UniversityNewcastle upon TyneNE2 4AXUK
| | - Matteo Brilli
- Department of Agronomy, Food, Natural Resources, Animals and Environment (DAFNAE)University of Padova. Agripolis ‐ V.le dell'Università, 16 | 35020 Legnaro PadovaItaly
- Present address:
Department of BiosciencesUniversity of Milan, via Celoria 26(MI)Italy
| | - Waldemar Vollmer
- The Centre for Bacterial Cell BiologyInstitute for Cell and Molecular Biosciences, Newcastle UniversityNewcastle upon TyneNE2 4AXUK
| | - Patrick H. Viollier
- Department of Microbiology and Molecular MedicineInstitute of Genetics & Genomics in Geneva (iGE3), University of GenevaGenevaSwitzerland
| | - Jeanne Salje
- Nuffield Department of Medicine, Centre for Tropical Medicine and Global HealthUniversity of OxfordOxfordUK
- Mahidol‐Oxford Tropical Medicine Research UnitMahidol UniversityBangkokThailand
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27
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Qi ML, Guo YL, Wang QQ, Chen XS, Han JD, Su XH, Lun WH, Cheng H, Xu JH, Tian HQ, Chen L, Yao ZY, Feng WL, Jiang J, Zhou PY, Zou XB, Xu HH, Shi WM, Liu J, Zhu L, Liu QZ. Consensus by Chinese Expert Panel on Chlamydia trachomatis-Resistant and Chlamydia trachomatis-Persistent Infection. Chin Med J (Engl) 2017; 130:2852-2856. [PMID: 29176144 PMCID: PMC5717865 DOI: 10.4103/0366-6999.219159] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2017] [Indexed: 11/09/2022] Open
Affiliation(s)
- Man-Li Qi
- Department of Dermatovenerology, Tianjin Medical University General Hospital, Tianjin Neurological Institute, Ministry of Education and Tianjin City Key Laboratory of Post-neuroinjury Neuro-repair and Regeneration in Central Nervous System, Tianjin 300052, China
| | - Yuan-Li Guo
- Department of Dermatovenerology, Tianjin Union Medical Center, Tianjin 300121, China
| | - Qian-Qiu Wang
- Department of Clinical Management, National Center of STD Control, Institute of Dermatology, Chinese Academy of Medical Sciences, China CDC, Nanjing, Jiangsu 210042, China
| | - Xiang-Sheng Chen
- Department of Clinical Management, National Center of STD Control, Institute of Dermatology, Chinese Academy of Medical Sciences, China CDC, Nanjing, Jiangsu 210042, China
| | - Jian-De Han
- Department of Dermatovenerology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong 510080, China
| | - Xiao-Hong Su
- Institute of Dermatology, Chinese Academy of Medical Sciences and Peking Union Medical College, Nanjing, Jiangsu 210042, China
| | - Wen-Hui Lun
- Department of Dermatovenerology, Beijing Ditan Hospital Capital Medical University, Beijing 100015, China
| | - Hao Cheng
- Department of Dermatology, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang 310020, China
| | - Jin-Hua Xu
- Department of Dermatology, Huashan Hospital, Fudan University, Shanghai 200040, China
| | - Hong-Qing Tian
- Shandong Provincial Institute of Dermatology and Venereology, Provincial Academy of Medical Science, Jinan, Shandong 250022, China
| | - Li Chen
- Department of Dermatovenerology, The First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi 330006, China
| | - Zhi-Yuan Yao
- Department of Infection Management and Disease Prevention, China-Japan Friendship Hospital, Beijing 100029, China
| | - Wen-Li Feng
- Department of Dermatovenerology, The Second Hospital of Shanxi Medical University, Taiyuan, Shanxi 030001, China
| | - Juan Jiang
- Institute of Dermatology, Chinese Academy of Medical Sciences and Peking Union Medical College, Nanjing, Jiangsu 210042, China
| | - Ping-Yu Zhou
- STD Institute, Shanghai Skin Disease Hospital, Shanghai 200050, China
| | - Xian-Biao Zou
- Department of Dermatology, The First Affiliated Hospital of PLA General Hospital, Beijing 100048, China
| | - Hong-Hui Xu
- Department of Dermatology, The First Hospital of China Medical University, Shenyang, Liaoning 110001, China
| | - Wei-Min Shi
- Department of Dermatovenerology, Shanghai General Hospital, Shanghai 200080, China
| | - Jun Liu
- Department of Dermatovenerology, The 4 People's Hospital of Qinghai Province, Xining, Qinghai 810014, China
| | - Lin Zhu
- Department of Dermatovenerology, Shenzhen Hospital Southern Medical University, Shenzhen, Guangdong 518000, China
| | - Quan-Zhong Liu
- Department of Dermatovenerology, Tianjin Medical University General Hospital, Tianjin Neurological Institute, Ministry of Education and Tianjin City Key Laboratory of Post-neuroinjury Neuro-repair and Regeneration in Central Nervous System, Tianjin 300052, China
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28
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Scherler A, Jacquier N, Greub G. Chlamydiales, Anaplasma and Bartonella: persistence and immune escape of intracellular bacteria. Microbes Infect 2017; 20:416-423. [PMID: 29162422 DOI: 10.1016/j.micinf.2017.11.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2017] [Revised: 11/06/2017] [Accepted: 11/07/2017] [Indexed: 12/25/2022]
Abstract
Intracellular bacteria, such as Chlamydiales, Anaplasma or Bartonella, need to persist inside their host in order to complete their developmental cycle and to infect new hosts. In order to escape from the host immune system, intracellular bacteria have developed diverse mechanisms of persistence, which can directly impact the health of their host.
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Affiliation(s)
- Aurélie Scherler
- Centre for Research on Intracellular Bacteria, Institute of Microbiology, University Hospital Centre and University of Lausanne, Lausanne, Switzerland
| | - Nicolas Jacquier
- Centre for Research on Intracellular Bacteria, Institute of Microbiology, University Hospital Centre and University of Lausanne, Lausanne, Switzerland
| | - Gilbert Greub
- Centre for Research on Intracellular Bacteria, Institute of Microbiology, University Hospital Centre and University of Lausanne, Lausanne, Switzerland.
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29
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Zigangirova NA, Kost EA, Didenko LV, Kapotina LN, Zayakin ES, Luyksaar SI, Morgunova EY, Fedina ED, Artyukhova OA, Samorodov AV, Kobets NV. A small-molecule compound belonging to a class of 2,4-disubstituted 1,3,4-thiadiazine-5-ones inhibits intracellular growth and persistence of Chlamydia trachomatis. J Med Microbiol 2016; 65:91-98. [PMID: 26489840 DOI: 10.1099/jmm.0.000189] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Chlamydia trachomatis is one of the most common sexually transmitted pathogens in the world and often causes chronic inflammatory diseases that are insensitive to antibiotics. The type 3 secretion system (T3SS) of pathogenic bacteria is a promising target for therapeutic intervention aimed at bacterial virulence and can be an attractive alternative for the treatment of chronic infections. Recently, we have shown that a small-molecule compound belonging to a class of 2,4-disubstituted 1,3,4-thiadiazine-5-ones produced through the chemical modification of the thiohydrazides of oxamic acids, designated CL-55, inhibited the intracellular growth of C. trachomatis in a T3SS-dependent manner. To assess the feasibility of CL-55 as a therapeutic agent, our aim was to determine which point(s) in the developmental cycle CL-55 affects. We found that CL-55 had no effect on the adhesion of elementary bodies (EBs) to host cells but significantly suppressed EB internalization. We further found that CL-55 inhibited the intracellular division of reticulate bodies (RBs). An ultrastructural analysis revealed loss of contact between the RBs and the inclusion membrane in the presence of CL-55. Finally, we found that our T3SS inhibitor prevented the persistence of Chlamydia in cell culture and its reversion to the infectious state. Our findings indicate that our T3SS inhibitor may be effective in the treatment of both productive and persistent infections.
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Affiliation(s)
- Naylia A Zigangirova
- Gamaleya Center of Epidemiology and Microbiology, Ministry of Health Russian Federation, 123098, Gamaleya Str. 18, Moscow, Russian Federation
| | - Elena A Kost
- Gamaleya Center of Epidemiology and Microbiology, Ministry of Health Russian Federation, 123098, Gamaleya Str. 18, Moscow, Russian Federation
| | - Lubov V Didenko
- Gamaleya Center of Epidemiology and Microbiology, Ministry of Health Russian Federation, 123098, Gamaleya Str. 18, Moscow, Russian Federation
| | - Lydia N Kapotina
- Gamaleya Center of Epidemiology and Microbiology, Ministry of Health Russian Federation, 123098, Gamaleya Str. 18, Moscow, Russian Federation
| | - Egor S Zayakin
- Gamaleya Center of Epidemiology and Microbiology, Ministry of Health Russian Federation, 123098, Gamaleya Str. 18, Moscow, Russian Federation
| | - Sergei I Luyksaar
- Gamaleya Center of Epidemiology and Microbiology, Ministry of Health Russian Federation, 123098, Gamaleya Str. 18, Moscow, Russian Federation
| | - Elena Y Morgunova
- Gamaleya Center of Epidemiology and Microbiology, Ministry of Health Russian Federation, 123098, Gamaleya Str. 18, Moscow, Russian Federation
| | - Elena D Fedina
- Gamaleya Center of Epidemiology and Microbiology, Ministry of Health Russian Federation, 123098, Gamaleya Str. 18, Moscow, Russian Federation
| | - Olga A Artyukhova
- Bauman Moscow State Technical University, 105005, 2nd Baumanskaya Str. 5, Moscow, Russian Federation
| | - Andrey V Samorodov
- Bauman Moscow State Technical University, 105005, 2nd Baumanskaya Str. 5, Moscow, Russian Federation
| | - Natalya V Kobets
- Gamaleya Center of Epidemiology and Microbiology, Ministry of Health Russian Federation, 123098, Gamaleya Str. 18, Moscow, Russian Federation
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30
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Hanski L, Ausbacher D, Tiirola TM, Strøm MB, Vuorela PM. Amphipathic β2,2-Amino Acid Derivatives Suppress Infectivity and Disrupt the Intracellular Replication Cycle of Chlamydia pneumoniae. PLoS One 2016; 11:e0157306. [PMID: 27280777 PMCID: PMC4900588 DOI: 10.1371/journal.pone.0157306] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2016] [Accepted: 05/29/2016] [Indexed: 12/27/2022] Open
Abstract
We demonstrate in the current work that small cationic antimicrobial β2,2-amino acid derivatives (Mw < 500 Da) are highly potent against Chlamydia pneumoniae at clinical relevant concentrations (< 5 μM, i.e. < 3.4 μg/mL). C. pneumoniae is an atypical respiratory pathogen associated with frequent treatment failures and persistent infections. This gram-negative bacterium has a biphasic life cycle as infectious elementary bodies and proliferating reticulate bodies, and efficient treatment is challenging because of its long and obligate intracellular replication cycle within specialized inclusion vacuoles. Chlamydicidal effect of the β2,2-amino acid derivatives in infected human epithelial cells was confirmed by transmission electron microscopy. Images of infected host cells treated with our lead derivative A2 revealed affected chlamydial inclusion vacuoles 24 hours post infection. Only remnants of elementary and reticulate bodies were detected at later time points. Neither the EM studies nor resazurin-based cell viability assays showed toxic effects on uninfected host cells or cell organelles after A2 treatment. Besides the effects on early intracellular inclusion vacuoles, the ability of these β2,2-amino acid derivatives to suppress Chlamydia pneumoniae infectivity upon treatment of elementary bodies suggested also a direct interaction with bacterial membranes. Synthetic β2,2-amino acid derivatives that target C. pneumoniae represent promising lead molecules for development of antimicrobial agents against this hard-to-treat intracellular pathogen.
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Affiliation(s)
- Leena Hanski
- Pharmaceutical Design and Discovery Research Group, Division of Pharmaceutical Biosciences, Faculty of Pharmacy, University of Helsinki (UHEL), Helsinki, Finland
| | - Dominik Ausbacher
- Natural Products and Medicinal Chemistry Research Group, Department of Pharmacy, Faculty of Health Sciences, UiT – The Arctic University of Norway, Tromsø, Norway
| | - Terttu M. Tiirola
- Pharmaceutical Design and Discovery Research Group, Division of Pharmaceutical Biosciences, Faculty of Pharmacy, University of Helsinki (UHEL), Helsinki, Finland
| | - Morten B. Strøm
- Natural Products and Medicinal Chemistry Research Group, Department of Pharmacy, Faculty of Health Sciences, UiT – The Arctic University of Norway, Tromsø, Norway
| | - Pia M. Vuorela
- Pharmaceutical Design and Discovery Research Group, Division of Pharmaceutical Biosciences, Faculty of Pharmacy, University of Helsinki (UHEL), Helsinki, Finland
- * E-mail:
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31
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Quantitative Proteomics of the Infectious and Replicative Forms of Chlamydia trachomatis. PLoS One 2016; 11:e0149011. [PMID: 26871455 PMCID: PMC4752267 DOI: 10.1371/journal.pone.0149011] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2015] [Accepted: 01/26/2016] [Indexed: 12/24/2022] Open
Abstract
The obligate intracellular developmental cycle of Chlamydia trachomatis presents significant challenges in defining its proteome. In this study we have applied quantitative proteomics to both the intracellular reticulate body (RB) and the extracellular elementary body (EB) from C. trachomatis. We used C. trachomatis L2 as a model chlamydial isolate for our study since it has a high infectivity:particle ratio and there is an excellent quality genome sequence. EBs and RBs (>99% pure) were quantified by chromosomal and plasmid copy number using PCR, from which the concentrations of chlamydial proteins per bacterial cell/genome were determined. RBs harvested at 15h post infection (PI) were purified by three successive rounds of gradient centrifugation. This is the earliest possible time to obtain purified RBs, free from host cell components in quantity, within the constraints of the technology. EBs were purified at 48h PI. We then used two-dimensional reverse phase UPLC to fractionate RB or EB peptides before mass spectroscopic analysis, providing absolute amount estimates of chlamydial proteins. The ability to express the data as molecules per cell gave ranking in both abundance and energy requirements for synthesis, allowing meaningful identification of rate-limiting components. The study assigned 562 proteins with high confidence and provided absolute estimates of protein concentration for 489 proteins. Interestingly, the data showed an increase in TTS capacity at 15h PI. Most of the enzymes involved in peptidoglycan biosynthesis were detected along with high levels of muramidase (in EBs) suggesting breakdown of peptidoglycan occurs in the non-dividing form of the microorganism. All the genome-encoded enzymes for glycolysis, pentose phosphate pathway and tricarboxylic acid cycle were identified and quantified; these data supported the observation that the EB is metabolically active. The availability of detailed, accurate quantitative proteomic data will be invaluable for investigations into gene regulation and function.
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32
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Abstract
Chlamydia spp. are ubiquitous, obligate, intracellular Gram-negative bacterial pathogens that undergo a unique biphasic developmental cycle transitioning between the infectious, extracellular elementary body and the replicative, intracellular reticulate body. The primary Chlamydia species associated with human disease are C. trachomatis, which is the leading cause of both reportable bacterial sexually transmitted infections and preventable blindness, and C. pneumoniae, which infects the respiratory tract and is associated with cardiovascular disease. Collectively, these pathogens are a significant source of morbidity and pose a substantial financial burden on the global economy. Past efforts to elucidate virulence mechanisms of these unique and important pathogens were largely hindered by an absence of genetic methods. Watershed studies in 2011 and 2012 demonstrated that forward and reverse genetic approaches were feasible with Chlamydia and that shuttle vectors could be selected and maintained within the bacterium. While these breakthroughs have led to a steady expansion of the chlamydial genetic tool kit, there are still roads left to be traveled. This minireview provides a synopsis of the currently available genetic methods for Chlamydia along with a comparison to the methods used in other obligate intracellular bacteria. Limitations and advantages of these techniques will be discussed with an eye toward the methods still needed, and how the current state of the art for genetics in obligate intracellular bacteria could direct future technological advances for Chlamydia.
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Jacquier N, Viollier PH, Greub G. The role of peptidoglycan in chlamydial cell division: towards resolving the chlamydial anomaly. FEMS Microbiol Rev 2015; 39:262-75. [PMID: 25670734 DOI: 10.1093/femsre/fuv001] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Chlamydiales are obligate intracellular bacteria including some important pathogens causing trachoma, genital tract infections and pneumonia, among others. They share an atypical division mechanism, which is independent of an FtsZ homologue. However, they divide by binary fission, in a process inhibited by penicillin derivatives, causing the formation of an aberrant form of the bacteria, which is able to survive in the presence of the antibiotic. The paradox of penicillin sensitivity of chlamydial cells in the absence of detectable peptidoglycan (PG) was dubbed the chlamydial anomaly, since no PG modified by enzymes (Pbps) that are the usual target of penicillin could be detected in Chlamydiales. We review here the recent advances in this field with the first direct and indirect evidences of PG-like material in both Chlamydiaceae and Chlamydia-related bacteria. Moreover, PG biosynthesis is required for proper localization of the newly described septal proteins RodZ and NlpD. Taken together, these new results set the stage for a better understanding of the role of PG and septal proteins in the division mechanism of Chlamydiales and illuminate the long-standing chlamydial anomaly. Moreover, understanding the chlamydial division mechanism is critical for the development of new antibiotics for the treatment of chlamydial chronic infections.
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Affiliation(s)
- Nicolas Jacquier
- Institute of Microbiology, University Hospital Center and University of Lausanne, CH-1011 Lausanne, Switzerland
| | - Patrick H Viollier
- Department of Microbiology & Molecular Medicine, Institute of Genetics & Genomics in Geneva (iGE3), Faculty of Medicine / CMU, University of Geneva, CH-1211 Geneva 4, Switzerland
| | - Gilbert Greub
- Institute of Microbiology, University Hospital Center and University of Lausanne, CH-1011 Lausanne, Switzerland
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Abstract
In a screen for compounds that inhibit infectivity of the obligate intracellular pathogen Chlamydia trachomatis, we identified the 2-pyridone amide KSK120. A fluorescent KSK120 analogue was synthesized and observed to be associated with the C. trachomatis surface, suggesting that its target is bacterial. We isolated KSK120-resistant strains and determined that several resistance mutations are in genes that affect the uptake and use of glucose-6-phosphate (G-6P). Consistent with an effect on G-6P metabolism, treatment with KSK120 blocked glycogen accumulation. Interestingly, KSK120 did not affect Escherichia coli or the host cell. Thus, 2-pyridone amides may represent a class of drugs that can specifically inhibit C. trachomatis infection. Chlamydia trachomatis is a bacterial pathogen of humans that causes a common sexually transmitted disease as well as eye infections. It grows only inside cells of its host organism, within a parasitophorous vacuole termed the inclusion. Little is known, however, about what bacterial components and processes are important for C. trachomatis cellular infectivity. Here, by using a visual screen for compounds that affect bacterial distribution within the chlamydial inclusion, we identified the inhibitor KSK120. As hypothesized, the altered bacterial distribution induced by KSK120 correlated with a block in C. trachomatis infectivity. Our data suggest that the compound targets the glucose-6-phosphate (G-6P) metabolism pathway of C. trachomatis, supporting previous indications that G-6P metabolism is critical for C. trachomatis infectivity. Thus, KSK120 may be a useful tool to study chlamydial glucose metabolism and has the potential to be used in the treatment of C. trachomatis infections.
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Discovery of chlamydial peptidoglycan reveals bacteria with murein sacculi but without FtsZ. Nat Commun 2014; 4:2856. [PMID: 24292151 PMCID: PMC3847603 DOI: 10.1038/ncomms3856] [Citation(s) in RCA: 109] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2013] [Accepted: 11/01/2013] [Indexed: 11/18/2022] Open
Abstract
Chlamydiae are important pathogens and symbionts, with unique cell biology features. They lack the cell-division protein FtsZ, which functions in maintaining cell shape and orchestrating cell division in almost all other bacteria. In addition, the existence of peptidoglycan (PG) in chlamydial cell envelopes has been highly controversial. Using electron cryotomography, mass spectrometry and fluorescent labeling dyes, here we show that some environmental chlamydiae have cell-wall sacculi consisting of an unusual PG type. Treatment with fosfomycin (a PG synthesis inhibitor) leads to lower infection rates and aberrant cell shapes, suggesting that PG synthesis is crucial for the chlamydial life cycle. Our findings demonstrate for the first time the presence of PG in a member of the Chlamydiae. They also present a unique example of a bacterium with a PG sacculus but without FtsZ, challenging the current hypothesis that it is the absence of a cell wall that renders FtsZ non-essential.
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Golgi fragmentation and sphingomyelin transport to Chlamydia trachomatis during penicillin-induced persistence do not depend on the cytosolic presence of the chlamydial protease CPAF. PLoS One 2014; 9:e103220. [PMID: 25068694 PMCID: PMC4113379 DOI: 10.1371/journal.pone.0103220] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2014] [Accepted: 06/30/2014] [Indexed: 11/24/2022] Open
Abstract
Chlamydia grows inside a cytosolic vacuole (the inclusion) that is supplied with nutrients by the host through vesicular and non-vesicular transport. It is unclear in many respects how Chlamydia organizes this transport. One model posits that the Chlamydia-induced fragmentation of the Golgi-apparatus is required for normal transport processes to the inclusion and for chlamydial development, and the chlamydial protease CPAF has been controversially implicated in Golgi-fragmentation. We here use a model of penicillin-induced persistence of infection with Chlamydia trachomatis to test this link. Under penicillin-treatment the inclusion grew in size for the first 24 h but after that growth was severely reduced. Penicillin did not reduce the number of infected cells with fragmented Golgi-apparatus, and normal Golgi-fragmentation was found in a CPAF-deficient mutant. Surprisingly, sphingomyelin transport into the inclusion and into the bacteria, as measured by fluorescence accumulation upon addition of labelled ceramide, was not reduced during penicillin-treatment. Thus, both Golgi-fragmentation and transport of sphingomyelin to C. trachomatis still occurred in this model of persistence. The portion of cells in which CPAF was detected in the cytosol, either by immunofluorescence or by immune-electron microscopy, was drastically reduced in cells cultured in the presence of penicillin. These data argue against an essential role of cytosolic CPAF for Golgi-fragmentation or for sphingomyelin transport in chlamydial infection.
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Klöckner A, Otten C, Derouaux A, Vollmer W, Bühl H, De Benedetti S, Münch D, Josten M, Mölleken K, Sahl HG, Henrichfreise B. AmiA is a penicillin target enzyme with dual activity in the intracellular pathogen Chlamydia pneumoniae. Nat Commun 2014; 5:4201. [PMID: 24953137 PMCID: PMC4083426 DOI: 10.1038/ncomms5201] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2013] [Accepted: 05/22/2014] [Indexed: 11/09/2022] Open
Abstract
Intracellular Chlamydiaceae do not need to resist osmotic challenges and a functional cell wall was not detected in these pathogens. Nevertheless, a recent study revealed evidence for circular peptidoglycan-like structures in Chlamydiaceae and penicillin inhibits cytokinesis, a phenomenon known as the chlamydial anomaly. Here, by characterizing a cell wall precursor-processing enzyme, we provide insights into the mechanisms underlying this mystery. We show that AmiA from Chlamydia pneumoniae separates daughter cells in an Escherichia coli amidase mutant. Contrary to homologues from free-living bacteria, chlamydial AmiA uses lipid II as a substrate and has dual activity, acting as an amidase and a carboxypeptidase. The latter function is penicillin sensitive and assigned to a penicillin-binding protein motif. Consistent with the lack of a regulatory domain in AmiA, chlamydial CPn0902, annotated as NlpD, is a carboxypeptidase, rather than an amidase activator, which is the case for E. coli NlpD. Functional conservation of AmiA implicates a role in cytokinesis and host response modulation. Penicillin inhibits growth of chlamydial pathogens despite their lack of a conventional peptidoglycan cell wall. Here the authors report that the chlamydial amidase, AmiA, which can rescue cell division defects of an E. coli amiA mutant, has dual activity as a penicillin sensitive, lipid II-targetting carboxypeptidase.
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Affiliation(s)
- Anna Klöckner
- 1] Institute for Medical Microbiology, Immunology and Parasitology (IMMIP), Pharmaceutical Microbiology, University of Bonn, 53115 Bonn, Germany [2]
| | - Christian Otten
- 1] Institute for Medical Microbiology, Immunology and Parasitology (IMMIP), Pharmaceutical Microbiology, University of Bonn, 53115 Bonn, Germany [2]
| | - Adeline Derouaux
- 1] The Centre for Bacterial Cell Biology, Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle upon Tyne, NE2 4AX, UK [2]
| | - Waldemar Vollmer
- The Centre for Bacterial Cell Biology, Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle upon Tyne, NE2 4AX, UK
| | - Henrike Bühl
- Institute for Medical Microbiology, Immunology and Parasitology (IMMIP), Pharmaceutical Microbiology, University of Bonn, 53115 Bonn, Germany
| | - Stefania De Benedetti
- Institute for Medical Microbiology, Immunology and Parasitology (IMMIP), Pharmaceutical Microbiology, University of Bonn, 53115 Bonn, Germany
| | - Daniela Münch
- Institute for Medical Microbiology, Immunology and Parasitology (IMMIP), Pharmaceutical Microbiology, University of Bonn, 53115 Bonn, Germany
| | - Michaele Josten
- Institute for Medical Microbiology, Immunology and Parasitology (IMMIP), Pharmaceutical Microbiology, University of Bonn, 53115 Bonn, Germany
| | - Katja Mölleken
- Institute of Functional Microbial Genomics, University of Düsseldorf, 40225 Düsseldorf, Germany
| | - Hans-Georg Sahl
- Institute for Medical Microbiology, Immunology and Parasitology (IMMIP), Pharmaceutical Microbiology, University of Bonn, 53115 Bonn, Germany
| | - Beate Henrichfreise
- Institute for Medical Microbiology, Immunology and Parasitology (IMMIP), Pharmaceutical Microbiology, University of Bonn, 53115 Bonn, Germany
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Lewis ME, Belland RJ, AbdelRahman YM, Beatty WL, Aiyar AA, Zea AH, Greene SJ, Marrero L, Buckner LR, Tate DJ, McGowin CL, Kozlowski PA, O'Brien M, Lillis RA, Martin DH, Quayle AJ. Morphologic and molecular evaluation of Chlamydia trachomatis growth in human endocervix reveals distinct growth patterns. Front Cell Infect Microbiol 2014; 4:71. [PMID: 24959423 PMCID: PMC4050528 DOI: 10.3389/fcimb.2014.00071] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2014] [Accepted: 05/15/2014] [Indexed: 11/13/2022] Open
Abstract
In vitro models of Chlamydia trachomatis growth have long been studied to predict growth in vivo. Alternative or persistent growth modes in vitro have been shown to occur under the influence of numerous stressors but have not been studied in vivo. Here, we report the development of methods for sampling human infections from the endocervix in a manner that permits a multifaceted analysis of the bacteria, host and the endocervical environment. Our approach permits evaluating total bacterial load, transcriptional patterns, morphology by immunofluorescence and electron microscopy, and levels of cytokines and nutrients in the infection microenvironment. By applying this approach to two pilot patients with disparate infections, we have determined that their contrasting growth patterns correlate with strikingly distinct transcriptional biomarkers, and are associated with differences in local levels of IFNγ. Our multifaceted approach will be useful to dissect infections in the human host and be useful in identifying patients at risk for chronic disease. Importantly, the molecular and morphological analyses described here indicate that persistent growth forms can be isolated from the human endocervix when the infection microenvironment resembles the in vitro model of IFNγ-induced persistence.
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Affiliation(s)
- Maria E Lewis
- Department of Microbiology, Immunology and Parasitology, Louisiana State University Health Sciences Center New Orleans, LA, USA
| | - Robert J Belland
- Department of Microbiology, Immunology and Biochemistry, University of Tennessee Health Sciences Center Memphis, TN, USA
| | - Yasser M AbdelRahman
- Department of Microbiology, Immunology and Biochemistry, University of Tennessee Health Sciences Center Memphis, TN, USA ; Department of Microbiology and Immunology, Faculty of Pharmacy, Cairo University Cairo, Egypt
| | - Wandy L Beatty
- Department of Molecular Microbiology, Washington University School of Medicine St. Louis, MO, USA
| | - Ashok A Aiyar
- Department of Microbiology, Immunology and Parasitology, Louisiana State University Health Sciences Center New Orleans, LA, USA
| | - Arnold H Zea
- Department of Microbiology, Immunology and Parasitology, Louisiana State University Health Sciences Center New Orleans, LA, USA
| | - Sheila J Greene
- Department of Microbiology, Immunology and Parasitology, Louisiana State University Health Sciences Center New Orleans, LA, USA
| | - Luis Marrero
- Department of Microbiology, Immunology and Parasitology, Louisiana State University Health Sciences Center New Orleans, LA, USA
| | - Lyndsey R Buckner
- Department of Microbiology, Immunology and Parasitology, Louisiana State University Health Sciences Center New Orleans, LA, USA
| | - David J Tate
- Department of Microbiology, Immunology and Parasitology, Louisiana State University Health Sciences Center New Orleans, LA, USA
| | - Chris L McGowin
- Department of Microbiology, Immunology and Parasitology, Louisiana State University Health Sciences Center New Orleans, LA, USA
| | - Pamela A Kozlowski
- Department of Microbiology, Immunology and Parasitology, Louisiana State University Health Sciences Center New Orleans, LA, USA
| | - Michelle O'Brien
- Section of Infectious Diseases, Department of Medicine, Louisiana State University Health Sciences Center New Orleans, LA, USA
| | - Rebecca A Lillis
- Section of Infectious Diseases, Department of Medicine, Louisiana State University Health Sciences Center New Orleans, LA, USA
| | - David H Martin
- Section of Infectious Diseases, Department of Medicine, Louisiana State University Health Sciences Center New Orleans, LA, USA
| | - Alison J Quayle
- Department of Microbiology, Immunology and Parasitology, Louisiana State University Health Sciences Center New Orleans, LA, USA
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Aiyar A, Quayle AJ, Buckner LR, Sherchand SP, Chang TL, Zea AH, Martin DH, Belland RJ. Influence of the tryptophan-indole-IFNγ axis on human genital Chlamydia trachomatis infection: role of vaginal co-infections. Front Cell Infect Microbiol 2014; 4:72. [PMID: 24918090 PMCID: PMC4042155 DOI: 10.3389/fcimb.2014.00072] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2014] [Accepted: 05/15/2014] [Indexed: 11/13/2022] Open
Abstract
The natural history of genital Chlamydia trachomatis infections can vary widely; infections can spontaneously resolve but can also last from months to years, potentially progressing to cause significant pathology. The host and bacterial factors underlying this wide variation are not completely understood, but emphasize the bacterium's capacity to evade/adapt to the genital immune response, and/or exploit local environmental conditions to survive this immune response. IFNγ is considered to be a primary host protective cytokine against endocervical C.trachomatis infections. IFNγ acts by inducing the host enzyme indoleamine 2,3-dioxgenase, which catabolizes tryptophan, thereby depriving the bacterium of this essential amino acid. In vitro studies have revealed that tryptophan deprivation causes Chlamydia to enter a viable but non-infectious growth pattern that is termed a persistent growth form, characterized by a unique morphology and gene expression pattern. Provision of tryptophan can reactivate the bacterium to the normal developmental cycle. There is a significant difference in the capacity of ocular and genital C. trachomatis serovars to counter tryptophan deprivation. The latter uniquely encode a functional tryptophan synthase to synthesize tryptophan via indole salvage, should indole be available in the infection microenvironment. In vitro studies have confirmed the capacity of indole to mitigate the effects of IFNγ; it has been suggested that a perturbed vaginal microbiome may provide a source of indole in vivo. Consistent with this hypothesis, the microbiome associated with bacterial vaginosis includes species that encode a tryptophanase to produce indole. In this review, we discuss the natural history of genital chlamydial infections, morphological and molecular changes imposed by IFNγ on Chlamydia, and finally, the microenvironmental conditions associated with vaginal co-infections that can ameliorate the effects of IFNγ on C. trachomatis.
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Affiliation(s)
- Ashok Aiyar
- Department of Microbiology, Immunology, and Parasitology, Louisiana State University Health Sciences Center New Orleans, LA, USA
| | - Alison J Quayle
- Department of Microbiology, Immunology, and Parasitology, Louisiana State University Health Sciences Center New Orleans, LA, USA
| | - Lyndsey R Buckner
- Department of Microbiology, Immunology, and Parasitology, Louisiana State University Health Sciences Center New Orleans, LA, USA
| | - Shardulendra P Sherchand
- Department of Microbiology, Immunology, and Parasitology, Louisiana State University Health Sciences Center New Orleans, LA, USA
| | - Theresa L Chang
- Department of Microbiology and Molecular Genetics, Public Health Research Institute Center, New Jersey Medical School-Rutgers, The State University of New Jersey Newark, NJ, USA
| | - Arnold H Zea
- Department of Microbiology, Immunology, and Parasitology, Louisiana State University Health Sciences Center New Orleans, LA, USA
| | - David H Martin
- Section of Infectious Diseases, Department of Medicine, Louisiana State University Health Sciences Center New Orleans, LA, USA
| | - Robert J Belland
- Department of Microbiology, Immunology, and Biochemistry, University of Tennessee Health Sciences Center Memphis, TN, USA
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40
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Hanski L, Vuorela PM. Recent advances in technologies for developing drugs againstChlamydia pneumoniae. Expert Opin Drug Discov 2014; 9:791-802. [DOI: 10.1517/17460441.2014.915309] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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41
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Zhu H, Li H, Wang P, Chen M, Huang Z, Li K, Li Y, He J, Han J, Zhang Q. Persistent and acute chlamydial infections induce different structural changes in the Golgi apparatus. Int J Med Microbiol 2014; 304:577-85. [PMID: 24780199 DOI: 10.1016/j.ijmm.2014.03.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2013] [Revised: 03/20/2014] [Accepted: 03/24/2014] [Indexed: 11/15/2022] Open
Abstract
Chlamydia trachomatis causes a wide range of diseases that have a significant impact on public health. Acute chlamydial infections can cause fragmentation of the Golgi compartment ensuring the lipid transportation from the host cell. However, the changes that occur in the host cell Golgi apparatus after persistent infections are unclear. Here, we examined Golgi-associated gene (golga5) transcription and expression along with the structure of the Golgi apparatus in cells persistently infected with Chlamydia trachomatis. The results showed that persistent infections caused little fragmentation of the Golgi. The results also revealed that Golgi fragmentation might be associated with the suppression of transcription of the gene golga5.
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Affiliation(s)
- Huiling Zhu
- State Key Laboratory of Biocontrol, School of Life Sciences, Department of Dermatology in the First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Hongmei Li
- State Key Laboratory of Biocontrol, School of Life Sciences, Department of Dermatology in the First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Pu Wang
- State Key Laboratory of Biocontrol, School of Life Sciences, Department of Dermatology in the First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Mukai Chen
- State Key Laboratory of Biocontrol, School of Life Sciences, Department of Dermatology in the First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Zengwei Huang
- State Key Laboratory of Biocontrol, School of Life Sciences, Department of Dermatology in the First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China; Guangzhou Sugarcane Industry Research Institute, Guangzhou, China
| | - Kunpeng Li
- State Key Laboratory of Biocontrol, School of Life Sciences, Department of Dermatology in the First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Yinyin Li
- State Key Laboratory of Biocontrol, School of Life Sciences, Department of Dermatology in the First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Jian He
- State Key Laboratory of Biocontrol, School of Life Sciences, Department of Dermatology in the First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Jiande Han
- State Key Laboratory of Biocontrol, School of Life Sciences, Department of Dermatology in the First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China.
| | - Qinfen Zhang
- State Key Laboratory of Biocontrol, School of Life Sciences, Department of Dermatology in the First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China.
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Evolution to a chronic disease niche correlates with increased sensitivity to tryptophan availability for the obligate intracellular bacterium Chlamydia pneumoniae. J Bacteriol 2014; 196:1915-24. [PMID: 24682324 DOI: 10.1128/jb.01476-14] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
The chlamydiae are obligate intracellular parasites that have evolved specific interactions with their various hosts and host cell types to ensure their successful survival and consequential pathogenesis. The species Chlamydia pneumoniae is ubiquitous, with serological studies showing that most humans are infected at some stage in their lifetime. While most human infections are asymptomatic, C. pneumoniae can cause more-severe respiratory disease and pneumonia and has been linked to chronic diseases such as asthma, atherosclerosis, and even Alzheimer's disease. The widely dispersed animal-adapted C. pneumoniae strains cause an equally wide range of diseases in their hosts. It is emerging that the ability of C. pneumoniae to survive inside its target cells, including evasion of the host's immune attack mechanisms, is linked to the acquisition of key metabolites. Tryptophan and arginine are key checkpoint compounds in this host-parasite battle. Interestingly, the animal strains of C. pneumoniae have a slightly larger genome, enabling them to cope better with metabolite restrictions. It therefore appears that as the evolutionarily more ancient animal strains have evolved to infect humans, they have selectively become more "susceptible" to the levels of key metabolites, such as tryptophan. While this might initially appear to be a weakness, it allows these human C. pneumoniae strains to exquisitely sense host immune attack and respond by rapidly reverting to a persistent phase. During persistence, they reduce their metabolic levels, halting progression of their developmental cycle, waiting until the hostile external conditions have passed before they reemerge.
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Schoborg RV, Borel N. Porcine epidemic diarrhea virus (PEDV) co-infection induced chlamydial persistence/stress does not require viral replication. Front Cell Infect Microbiol 2014; 4:20. [PMID: 24660163 PMCID: PMC3952398 DOI: 10.3389/fcimb.2014.00020] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2013] [Accepted: 02/05/2014] [Indexed: 12/26/2022] Open
Abstract
Chlamydiae may exist at the site of infection in an alternative replicative form, called the aberrant body (AB). ABs are produced during a viable but non-infectious developmental state termed “persistence” or “chlamydial stress.” As persistent/stressed chlamydiae: (i) may contribute to chronic inflammation observed in diseases like trachoma; and (ii) are more resistant to current anti-chlamydial drugs of choice, it is critical to better understand this developmental stage. We previously demonstrated that porcine epidemic diarrhea virus (PEDV) co-infection induced Chlamydia pecorum persistence/stress in culture. One critical characteristic of persistence/stress is that the chlamydiae remain viable and can reenter the normal developmental cycle when the stressor is removed. Thus, we hypothesized that PEDV-induced persistence would be reversible if viral replication was inhibited. Therefore, we performed time course experiments in which Vero cells were C. pecorum/PEDV infected in the presence of cycloheximide (CHX), which inhibits viral but not chlamydial protein synthesis. CHX-exposure inhibited PEDV replication, but did not inhibit induction of C. pecorum persistence at 24 h post-PEDV infection, as indicated by AB formation and reduced production of infectious EBs. Interestingly, production of infectious EBs resumed when CHX-exposed, co-infected cells were incubated 48–72 h post-PEDV co-infection. These data demonstrate that PEDV co-infection-induced chlamydial persistence/stress is reversible and suggest that this induction (i) does not require viral replication in host cells; and (ii) does not require de novo host or viral protein synthesis. These data also suggest that viral binding and/or entry may be required for this effect. Because the PEDV host cell receptor (CD13 or aminopeptidase N) stimulates cellular signaling pathways in the absence of PEDV infection, we suspect that PEDV co-infection might alter CD13 function and induce the chlamydiae to enter the persistent state.
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Affiliation(s)
- Robert V Schoborg
- Department of Biomedical Sciences, Quillen College of Medicine, East Tennessee State University Johnson City, TN, USA
| | - Nicole Borel
- Department of Pathobiology, Institute of Veterinary Pathology, University of Zurich Zurich, Switzerland
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44
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Bavoil PM. What's in a word: the use, misuse, and abuse of the word "persistence" in Chlamydia biology. Front Cell Infect Microbiol 2014; 4:27. [PMID: 24624366 PMCID: PMC3940941 DOI: 10.3389/fcimb.2014.00027] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2014] [Accepted: 02/12/2014] [Indexed: 11/30/2022] Open
Abstract
The word persistence was used by Chlamydia researchers almost as soon as Chlamydia research was born to reflect the propensity of chlamydiae to cause inapparent infection in their hosts, from birds to humans. More recently, the term persistence has been used, misused, and sometimes abused amidst in vitro and in vivo studies that aim to mimick the ability of chlamydiae to emerge from the presumed inapparent state into clinically detectable infection and disease. Here, I have attempted to provide a global perspective on the state of research on chlamydial persistence, revisiting old observations that may warrant a new look, critically evaluating more recent observations and their shortcomings, and including recent developments that may help redefine chlamydiae as pathogens-or not-of both animals and humans.
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Affiliation(s)
- Patrik M. Bavoil
- Department of Microbial Pathogenesis, School of Dentistry, University of MarylandBaltimore, MD, USA
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45
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De Benedetti S, Bühl H, Gaballah A, Klöckner A, Otten C, Schneider T, Sahl HG, Henrichfreise B. Characterization of serine hydroxymethyltransferase GlyA as a potential source of D-alanine in Chlamydia pneumoniae. Front Cell Infect Microbiol 2014; 4:19. [PMID: 24616885 PMCID: PMC3935232 DOI: 10.3389/fcimb.2014.00019] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2013] [Accepted: 02/03/2014] [Indexed: 01/08/2023] Open
Abstract
For intracellular Chlamydiaceae, there is no need to withstand osmotic challenges, and a functional cell wall has not been detected in these pathogens so far. Nevertheless, penicillin inhibits cell division in Chlamydiaceae resulting in enlarged aberrant bodies, a phenomenon known as chlamydial anomaly. D-alanine is a unique and essential component in the biosynthesis of bacterial cell walls. In free-living bacteria like Escherichia coli, penicillin-binding proteins such as monofunctional transpeptidases PBP2 and PBP3, the putative targets of penicillin in Chlamydiaceae, cross-link adjacent peptidoglycan strands via meso-diaminopimelic acid and D-Ala-D-Ala moieties of pentapeptide side chains. In the absence of genes coding for alanine racemase Alr and DadX homologs, the source of D-Ala and thus the presence of substrates for PBP2 and PBP3 activity in Chlamydiaceae has puzzled researchers for years. Interestingly, Chlamydiaceae genomes encode GlyA, a serine hydroxymethyltransferase that has been shown to exhibit slow racemization of D- and L-alanine as a side reaction in E. coli. We show that GlyA from Chlamydia pneumoniae can serve as a source of D-Ala. GlyA partially reversed the D-Ala auxotrophic phenotype of an E. coli racemase double mutant. Moreover, purified chlamydial GlyA had racemase activity on L-Ala in vitro and was inhibited by D-cycloserine, identifying GlyA, besides D-Ala ligase MurC/Ddl, as an additional target of this competitive inhibitor in Chlamydiaceae. Proof of D-Ala biosynthesis in Chlamydiaceae helps to clarify the structure of cell wall precursor lipid II and the role of chlamydial penicillin-binding proteins in the development of non-dividing aberrant chlamydial bodies and persistence in the presence of penicillin.
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Affiliation(s)
- Stefania De Benedetti
- Pharmaceutical Microbiology Section, Institute for Medical Microbiology, Immunology and Parasitology, University of Bonn Bonn, Germany
| | - Henrike Bühl
- Pharmaceutical Microbiology Section, Institute for Medical Microbiology, Immunology and Parasitology, University of Bonn Bonn, Germany
| | - Ahmed Gaballah
- Pharmaceutical Microbiology Section, Institute for Medical Microbiology, Immunology and Parasitology, University of Bonn Bonn, Germany
| | - Anna Klöckner
- Pharmaceutical Microbiology Section, Institute for Medical Microbiology, Immunology and Parasitology, University of Bonn Bonn, Germany
| | - Christian Otten
- Pharmaceutical Microbiology Section, Institute for Medical Microbiology, Immunology and Parasitology, University of Bonn Bonn, Germany
| | - Tanja Schneider
- Pharmaceutical Microbiology Section, Institute for Medical Microbiology, Immunology and Parasitology, University of Bonn Bonn, Germany
| | - Hans-Georg Sahl
- Pharmaceutical Microbiology Section, Institute for Medical Microbiology, Immunology and Parasitology, University of Bonn Bonn, Germany
| | - Beate Henrichfreise
- Pharmaceutical Microbiology Section, Institute for Medical Microbiology, Immunology and Parasitology, University of Bonn Bonn, Germany
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Penicillin kills Chlamydia following the fusion of bacteria with lysosomes and prevents genital inflammatory lesions in C. muridarum-infected mice. PLoS One 2013; 8:e83511. [PMID: 24376710 PMCID: PMC3871543 DOI: 10.1371/journal.pone.0083511] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2013] [Accepted: 11/04/2013] [Indexed: 01/11/2023] Open
Abstract
The obligate intracellular bacterium Chlamydia exists as two distinct forms. Elementary bodies (EBs) are infectious and extra-cellular, whereas reticulate bodies (RBs) replicate within a specialized intracellular compartment termed an ‘inclusion’. Alternative persistent intra-cellular forms can be induced in culture by diverse stimuli such as IFNγ or adenosine/EHNA. They do not grow or divide but revive upon withdrawal of the stimulus and are implicated in several widespread human diseases through ill-defined in vivo mechanisms. β-lactam antibiotics have also been claimed to induce persistence in vitro. The present report shows that upon penicillin G (pG) treatment, inclusions grow as fast as those in infected control cells. After removal of pG, Chlamydia do not revert to RBs. These effects are independent of host cell type, serovar, biovar and species of Chlamydia. Time-course experiments demonstrated that only RBs were susceptible to pG. pG-treated bacteria lost their control over host cell apoptotic pathways and no longer expressed pre-16S rRNA, in contrast to persistent bacteria induced with adenosine/EHNA. Confocal and live-video microscopy showed that bacteria within the inclusion fused with lysosomal compartments in pG-treated cells. That leads to recruitment of cathepsin D as early as 3 h post pG treatment, an event preceding bacterial death by several hours. These data demonstrate that pG treatment of cultured cells infected with Chlamydia results in the degradation of the bacteria. In addition we show that pG is significantly more efficient than doxycycline at preventing genital inflammatory lesions in C. muridarum-C57Bl/6 infected mice. These in vivo results support the physiological relevance of our findings and their potential therapeutic applications.
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Patel KK, Webley WC. Evidence of infectious asthma phenotype: Chlamydia-induced allergy and pathogen-specific IgE in a neonatal mouse model. PLoS One 2013; 8:e83453. [PMID: 24376704 PMCID: PMC3869801 DOI: 10.1371/journal.pone.0083453] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2013] [Accepted: 11/03/2013] [Indexed: 01/09/2023] Open
Abstract
Asthma is a chronic respiratory disease whose etiology is poorly understood. Recent studies suggest that early-life respiratory infections with atypical bacteria may play an important role in the induction or exacerbation of chronic respiratory disease. The current study utilized a neonatal mouse ovalbumin (OVA) sensitization model of asthma to determine the course of early-life respiratory tract infection by Chlamydia. Neonatal (day 1) and adult (6 wks) BALB/c mice were infected intranasally with Chlamydia (MoPn) and 7 weeks later were sensitized and challenged with ovalbumin. Allergic airway disease was characterized by examination of serum and bronchoalveolar lavage fluid (BAL) cellularity, cytokine production and antibody response. The presence of Chlamydia was determined by PCR and culture. Ova-specific IgE was quantified by ELISA and Chlamydia-specific IgE was determined via Western blot analysis. Chlamydial infection in neonatal mice induced increased production of Th2 cytokines (IL-4, 5, 10, and 13) in both BAL and serum, while infected adult mice produced increased Th1 cytokines (IL-2, IFN-γ). The BAL from infected neonates contained significantly elevated levels of eosinophils compared to infected adult mice. Although adult mice cleared the infection ∼30 days post infection (pi), neonates were still infected 66 days after initial infection. Chlamydia-specific IgE was detected in both the BAL and serum of neonatal mice beginning 28 days post infection, however, infected adult mice did not produce Chlamydia-specific IgE antibodies over the course of the study. When allergic airway was induced using Ova, infected neonatal mice increased their production of IL-4, IL-5 and IL-13 by >2 fold compared to uninfected controls and infected adult groups. Our findings demonstrate that early-life Chlamydia infection induces a Th2-dominant cytokine response in the airways of neonatal mice, leading to chronic infection. More significantly, early life respiratory colonization with Chlamydia elicits pathogen-specific IgE production, which further supports an infectious asthma phenotype.
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Affiliation(s)
- Katir K. Patel
- Department of Microbiology, University of Massachusetts, Amherst, Massachusetts, United States of America
| | - Wilmore C. Webley
- Department of Microbiology, University of Massachusetts, Amherst, Massachusetts, United States of America
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Ong VA, Marsh JW, Lawrence A, Allan JA, Timms P, Huston WM. The protease inhibitor JO146 demonstrates a critical role for CtHtrA for Chlamydia trachomatis reversion from penicillin persistence. Front Cell Infect Microbiol 2013; 3:100. [PMID: 24392355 PMCID: PMC3866801 DOI: 10.3389/fcimb.2013.00100] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2013] [Accepted: 12/03/2013] [Indexed: 11/13/2022] Open
Abstract
The Chlamydia trachomatis serine protease HtrA (CtHtrA) has recently been demonstrated to be essential during the replicative phase of the chlamydial developmental cycle. A chemical inhibition strategy (serine protease inhibitor JO146) was used to demonstrate this essential role and it was found that the chlamydial inclusions diminish in size and are lost from the cell after CtHtrA inhibition without formation of viable elementary bodies. The inhibitor (JO146) was used in this study to investigate the role of CtHtrA for penicillin persistence and heat stress conditions for Chlamydia trachomatis. JO146 addition during penicillin persistence resulted in only minor reductions (~1 log) in the final viable infectious yield after persistent Chlamydia were reverted from persistence. However, JO146 treatment during the reversion and recovery from penicillin persistence was completely lethal for Chlamydia trachomatis. JO146 was completely lethal when added either during heat stress conditions, or during the recovery from heat stress conditions. These data together indicate that CtHtrA has essential roles during some stress environments (heat shock), recovery from stress environments (heat shock and penicillin persistence), as well as the previously characterized essential role during the replicative phase of the chlamydial developmental cycle. Thus, CtHtrA is an essential protease with both replicative phase and stress condition functions for Chlamydia trachomatis.
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Affiliation(s)
- Vanissa A Ong
- School of Biomedical Sciences, Institute of Health and Biomedical Innovation, Queensland University of Technology Brisbane, QLD, Australia
| | - James W Marsh
- School of Biomedical Sciences, Institute of Health and Biomedical Innovation, Queensland University of Technology Brisbane, QLD, Australia
| | - Amba Lawrence
- School of Biomedical Sciences, Institute of Health and Biomedical Innovation, Queensland University of Technology Brisbane, QLD, Australia
| | - John A Allan
- The Wesley Research Institute, Wesley Hospital Auchenflower, QLD, Australia ; The Wesley Reproductive Medicine and Gynaecological Surgery Unit, The Wesley Hospital Auchenflower, QLD, Australia
| | - Peter Timms
- School of Biomedical Sciences, Institute of Health and Biomedical Innovation, Queensland University of Technology Brisbane, QLD, Australia
| | - Wilhelmina M Huston
- School of Biomedical Sciences, Institute of Health and Biomedical Innovation, Queensland University of Technology Brisbane, QLD, Australia ; The Wesley Research Institute, Wesley Hospital Auchenflower, QLD, Australia
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Liechti GW, Kuru E, Hall E, Kalinda A, Brun YV, VanNieuwenhze M, Maurelli AT. A new metabolic cell-wall labelling method reveals peptidoglycan in Chlamydia trachomatis. Nature 2013; 506:507-10. [PMID: 24336210 PMCID: PMC3997218 DOI: 10.1038/nature12892] [Citation(s) in RCA: 257] [Impact Index Per Article: 23.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2013] [Accepted: 11/21/2013] [Indexed: 12/16/2022]
Abstract
Peptidoglycan (PG), an essential structure in the cell walls of the vast majority of bacteria, is critical for division and maintaining cell shape and hydrostatic pressure. Bacteria comprising the Chlamydiales were thought to be one of the few exceptions. Chlamydia harbour genes for PG biosynthesis and exhibit susceptibility to 'anti-PG' antibiotics, yet attempts to detect PG in any chlamydial species have proven unsuccessful (the 'chlamydial anomaly'). We used a novel approach to metabolically label chlamydial PG using d-amino acid dipeptide probes and click chemistry. Replicating Chlamydia trachomatis were labelled with these probes throughout their biphasic developmental life cycle, and the results of differential probe incorporation experiments conducted in the presence of ampicillin are consistent with the presence of chlamydial PG-modifying enzymes. These findings culminate 50 years of speculation and debate concerning the chlamydial anomaly and are the strongest evidence so far that chlamydial species possess functional PG.
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Affiliation(s)
- G W Liechti
- 1] Department of Microbiology and Immunology, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Bethesda, Maryland 20814-4799, USA [2]
| | - E Kuru
- 1] Interdisciplinary Biochemistry Program, Indiana University, Bloomington, Indiana 47405, USA [2]
| | - E Hall
- Department of Chemistry, Indiana University, Bloomington, Indiana 47405, USA
| | - A Kalinda
- Department of Chemistry, Indiana University, Bloomington, Indiana 47405, USA
| | - Y V Brun
- Department of Biology, Indiana University, Bloomington, Indiana 47405, USA
| | - M VanNieuwenhze
- Department of Chemistry, Indiana University, Bloomington, Indiana 47405, USA
| | - A T Maurelli
- Department of Microbiology and Immunology, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Bethesda, Maryland 20814-4799, USA
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50
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Yilma AN, Singh SR, Dixit S, Dennis VA. Anti-inflammatory effects of silver-polyvinyl pyrrolidone (Ag-PVP) nanoparticles in mouse macrophages infected with live Chlamydia trachomatis. Int J Nanomedicine 2013; 8:2421-32. [PMID: 23882139 PMCID: PMC3709643 DOI: 10.2147/ijn.s44090] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Chlamydia trachomatis is a very common sexually transmissible infection in both developing and developed countries. A hallmark of C. trachomatis infection is the induction of severe inflammatory responses which play critical roles in its pathogenesis. Antibiotics are the only treatment option currently available for controlling C. trachomatis infection; however, they are efficacious only when administered early after an infection. The objectives of this study are to explore alternative strategies in the control and regulation of inflammatory responses triggered by a C. trachomatis infection. We employed silver-polyvinyl pyrrolidone (Ag-PVP) nanoparticles, which have been shown to possess anti-inflammatory properties, as our target and the in vitro mouse J774 macrophage model of C. trachomatis infection. Our hypothesis is that small sizes of Ag-PVP nanoparticles will control inflammatory mediators triggered by a C. trachomatis infection. Cytotoxicity studies using Ag-PVP nanoparticles of 10, 20, and 80 nm sizes revealed >80% macrophage viability up to a concentration of 6.25 μg/mL, with the 10 nm size being the least toxic. All sizes of Ag-PVP nanoparticles, especially the 10 nm size, reduced the levels of the prototypic cytokines, tumor necrosis factor (TNF) and interleukin (IL)-6, as elicited from C. trachomatis infected macrophages. Additionally, Ag-PVP nanoparticles (10 nm) selectively inhibited a broad spectrum of other cytokines and chemokines produced by infected macrophages. Of significance, Ag-PVP nanoparticles (10 nm) caused perturbations in a variety of upstream (toll like receptor 2 [TLR2], nucleotide-binding oligomerization-protein 2 [NOD2], cluster of differentiation [CD]40, CD80, and CD86) and downstream (IL-1 receptor-associated kinase 3 [IRAK3] and matrix metallopeptidase 9 [MMP9]) inflammatory signaling pathways by downregulating their messenger ribonucleic acid (mRNA) gene transcript expressions as induced by C. trachomatis in macrophages. Collectively, our data provides further evidence for the anti-inflammatory properties of Ag-PVP nanoparticles, and opens new possibilities for smaller sizes of Ag-PVP nanoparticles to be employed as regulators of inflammatory responses induced by C. trachomatis.
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Affiliation(s)
- Abebayehu N Yilma
- Center for Nanobiotechnology and Life Sciences Research, Alabama State University, Montgomery, AL, USA
| | - Shree R Singh
- Center for Nanobiotechnology and Life Sciences Research, Alabama State University, Montgomery, AL, USA
| | - Saurabh Dixit
- Center for Nanobiotechnology and Life Sciences Research, Alabama State University, Montgomery, AL, USA
| | - Vida A Dennis
- Center for Nanobiotechnology and Life Sciences Research, Alabama State University, Montgomery, AL, USA
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