1
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Mertens-Scholz K, Moawad AA, Liebler-Tenorio EM, Helming A, Andrack J, Miethe P, Neubauer H, Pletz MW, Richter IG. Ultraviolet C inactivation of Coxiella burnetii for production of a structurally preserved whole cell vaccine antigen. BMC Microbiol 2024; 24:118. [PMID: 38575865 PMCID: PMC10993581 DOI: 10.1186/s12866-024-03246-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Accepted: 03/03/2024] [Indexed: 04/06/2024] Open
Abstract
Q fever, a worldwide-occurring zoonotic disease, can cause economic losses for public and veterinary health systems. Vaccines are not yet available worldwide and currently under development. In this regard, it is important to produce a whole cell antigen, with preserved structural and antigenic properties and free of chemical modifications. Thus, inactivation of Coxiella burnetii with ultraviolet light C (UVC) was evaluated. C. burnetii Nine Mile phase I (NMI) and phase II (NMII) were exposed to decreasing intensities in a time-dependent manner and viability was tested by rescue cultivation in axenic medium or cell culture. Effects on the cell structure were visualized by transmission electron microscopy and antigenicity of UVC-treated NMI was studied by immunization of rabbits. NMI and NMII were inactivated at UVC intensities of 250 µW/cm2 for 5 min or 100 µW/cm2 for 20 min. Reactivation by DNA repair was considered to be unlikely. No morphological changes were observed directly after UVC inactivation by transmission electron microscopy, but severe swelling and membrane degradation of bacteria with increasing severity occurred after 24 and 48 h. Immunization of rabbits resulted in a pronounced antibody response. UVC inactivation of C. burnetii resulted in a structural preserved, safe whole cell antigen and might be useful as antigen for diagnostic purposes or as vaccine candidate.
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Affiliation(s)
- Katja Mertens-Scholz
- Friedrich-Loeffler-Institut, Institute of Bacterial Infections and Zoonoses, Jena, Germany.
- Institute for Infectious Diseases and Infection Control and Center for Sepsis Care and Control (CSCC), Jena University Hospital, Jena, Germany.
| | - Amira A Moawad
- Friedrich-Loeffler-Institut, Institute of Bacterial Infections and Zoonoses, Jena, Germany
| | | | - Andrea Helming
- Department of In Vitro Diagnostics Development, Research Centre of Medical Technology and Biotechnology, Erfurt, Germany
| | - Jennifer Andrack
- Friedrich-Loeffler-Institut, Institute of Bacterial Infections and Zoonoses, Jena, Germany
| | - Peter Miethe
- Research Centre of Medical Technology and Biotechnology, Bad Langensalza, Germany
| | - Heinrich Neubauer
- Friedrich-Loeffler-Institut, Institute of Bacterial Infections and Zoonoses, Jena, Germany
| | - Mathias W Pletz
- Institute for Infectious Diseases and Infection Control and Center for Sepsis Care and Control (CSCC), Jena University Hospital, Jena, Germany
| | - Ina-Gabriele Richter
- Research Centre of Medical Technology and Biotechnology, Bad Langensalza, Germany
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2
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Long CM, Beare PA, Cockrell D, Binette P, Tesfamariam M, Richards C, Anderson M, McCormick-Ell J, Brose M, Anderson R, Omsland A, Pearson T, Heinzen RA. Natural reversion promotes LPS elongation in an attenuated Coxiella burnetii strain. Nat Commun 2024; 15:697. [PMID: 38267444 PMCID: PMC10808227 DOI: 10.1038/s41467-023-43972-y] [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: 07/27/2023] [Accepted: 11/24/2023] [Indexed: 01/26/2024] Open
Abstract
Lipopolysaccharide (LPS) phase variation is a critical aspect of virulence in many Gram-negative bacteria. It is of particular importance to Coxiella burnetii, the biothreat pathogen that causes Q fever, as in vitro propagation of this organism leads to LPS truncation, which is associated with an attenuated and exempted from select agent status (Nine Mile II, NMII). Here, we demonstrate that NMII was recovered from the spleens of infected guinea pigs. Moreover, these strains exhibit a previously unrecognized form of elongated LPS and display increased virulence in comparison with the initial NMII strain. The reversion of a 3-bp mutation in the gene cbu0533 directly leads to LPS elongation. To address potential safety concerns, we introduce a modified NMII strain unable to produce elongated LPS.
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Affiliation(s)
- Carrie M Long
- Laboratory of Bacteriology, Division of Intramural Research, National Institute of Allergy and Infectious Disease, National Institutes of Health, Hamilton, MT, 59840, USA.
| | - Paul A Beare
- Laboratory of Bacteriology, Division of Intramural Research, National Institute of Allergy and Infectious Disease, National Institutes of Health, Hamilton, MT, 59840, USA
| | - Diane Cockrell
- Laboratory of Bacteriology, Division of Intramural Research, National Institute of Allergy and Infectious Disease, National Institutes of Health, Hamilton, MT, 59840, USA
| | - Picabo Binette
- Laboratory of Bacteriology, Division of Intramural Research, National Institute of Allergy and Infectious Disease, National Institutes of Health, Hamilton, MT, 59840, USA
| | - Mahelat Tesfamariam
- Laboratory of Bacteriology, Division of Intramural Research, National Institute of Allergy and Infectious Disease, National Institutes of Health, Hamilton, MT, 59840, USA
| | - Crystal Richards
- Laboratory of Bacteriology, Division of Intramural Research, National Institute of Allergy and Infectious Disease, National Institutes of Health, Hamilton, MT, 59840, USA
| | - Matthew Anderson
- Laboratory of Bacteriology, Division of Intramural Research, National Institute of Allergy and Infectious Disease, National Institutes of Health, Hamilton, MT, 59840, USA
| | - Jessica McCormick-Ell
- Office of the Director, Office of Research Services, Division of Occupational Health and Safety, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Megan Brose
- Office of the Director, Office of Research Services, Division of Occupational Health and Safety, National Institutes of Health, Hamilton, 59840, USA
| | - Rebecca Anderson
- Office of the Director, Office of Research Services, Division of Occupational Health and Safety, National Institutes of Health, Hamilton, 59840, USA
| | - Anders Omsland
- Paul G. Allen School for Global Health, College of Veterinary Medicine, Washington State University, Pullman, WA, 99164, USA
| | - Talima Pearson
- Department of Biological Sciences, Center for Microbial Genetics and Genomics, Northern Arizona University, Flagstaff, AZ, 86011, USA
| | - Robert A Heinzen
- Laboratory of Bacteriology, Division of Intramural Research, National Institute of Allergy and Infectious Disease, National Institutes of Health, Hamilton, MT, 59840, USA
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3
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Wachter S, Larson CL, Virtaneva K, Kanakabandi K, Darwitz B, Crews B, Storrud K, Heinzen RA, Beare PA. A Survey of Two-Component Systems in Coxiella burnetii Reveals Redundant Regulatory Schemes and a Requirement for an Atypical PhoBR System in Mammalian Cell Infection. J Bacteriol 2023; 205:e0041622. [PMID: 36847507 PMCID: PMC10029714 DOI: 10.1128/jb.00416-22] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Accepted: 12/20/2022] [Indexed: 03/01/2023] Open
Abstract
Coxiella burnetii is an obligate intracellular bacterium and the etiological agent of Q fever in humans. C. burnetii transitions between a replicative, metabolically active large-cell variant (LCV) and a spore-like, quiescent small-cell variant (SCV) as a likely mechanism to ensure survival between host cells and mammalian hosts. C. burnetii encodes three canonical two-component systems, four orphan hybrid histidine kinases, five orphan response regulators, and a histidine phosphotransfer protein, which have been speculated to play roles in the signaling required for C. burnetii morphogenesis and virulence. However, very few of these systems have been characterized. By employing a CRISPR interference system for genetic manipulation of C. burnetii, we created single- and multigene transcriptional knockdown strains targeting most of these signaling genes. Through this, we revealed a role for the C. burnetii PhoBR canonical two-component system in virulence, regulation of [Pi] maintenance, and Pi transport. We also outline a novel mechanism by which PhoBR function may be regulated by an atypical PhoU-like protein. We also determined that the GacA.2/GacA.3/GacA.4/GacS orphan response regulators coordinately and disparately regulate expression of SCV-associated genes in C. burnetii LCVs. These foundational results will inform future studies on the role of C. burnetii two-component systems in virulence and morphogenesis. IMPORTANCE C. burnetii is an obligate intracellular bacterium with a spore-like stability allowing it to survive long periods of time in the environment. This stability is likely due to its biphasic developmental cycle, whereby it can transition from an environmentally stable small-cell variant (SCV) to a metabolically active large-cell variant (LCV). Here, we define the role of two-component phosphorelay systems (TCS) in C. burnetii's ability to survive within the harsh environment contained in the phagolysosome of host cells. We show that the canonical PhoBR TCS has an important role in C. burnetii virulence and phosphate sensing. Further examination of the regulons controlled by orphan regulators indicated a role in modulating gene expression of SCV-associated genes, including genes essential for cell wall remodeling.
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Affiliation(s)
- Shaun Wachter
- Coxiella Pathogenesis Section, Laboratory of Bacteriology, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana, USA
- Vaccine and Infectious Disease Organization, Saskatoon, Saskatchewan, Canada
| | - Charles L. Larson
- Coxiella Pathogenesis Section, Laboratory of Bacteriology, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana, USA
| | - Kimmo Virtaneva
- Research Technologies Branch, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, Hamilton, Montana, USA
| | - Kishore Kanakabandi
- Research Technologies Branch, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, Hamilton, Montana, USA
| | - Benjamin Darwitz
- Department of Microbiology and Immunology, University of North Carolina, Chapel Hill, North Carolina, USA
| | - Ben Crews
- Research Technologies Branch, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, Hamilton, Montana, USA
| | - Keelee Storrud
- Research Technologies Branch, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, Hamilton, Montana, USA
| | - Robert A. Heinzen
- Coxiella Pathogenesis Section, Laboratory of Bacteriology, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana, USA
| | - Paul A. Beare
- Coxiella Pathogenesis Section, Laboratory of Bacteriology, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana, USA
- Research Technologies Branch, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, Hamilton, Montana, USA
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4
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Metters G, Hemsley C, Norville I, Titball R. Identification of essential genes in Coxiella burnetii. Microb Genom 2023; 9:mgen000944. [PMID: 36723494 PMCID: PMC9997736 DOI: 10.1099/mgen.0.000944] [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: 02/02/2023] Open
Abstract
Coxiella burnetii is an intracellular pathogen responsible for causing Q fever in humans, a disease with varied presentations ranging from a mild flu-like sickness to a debilitating illness that can result in endocarditis. The intracellular lifestyle of C. burnetii is unique, residing in an acidic phagolysosome-like compartment within host cells. An understanding of the core molecular biology of C. burnetii will greatly increase our understanding of C. burnetii growth, survival and pathogenesis. We used transposon-directed insertion site sequencing (TraDIS) to reveal C. burnetii Nine Mile Phase II genes fundamental for growth and in vitro survival. Screening a transposon library containing >10 000 unique transposon mutants revealed 512 predicted essential genes. Essential routes of synthesis were identified for the mevalonate pathway, as well as peptidoglycan and biotin synthesis. Some essential genes identified (e.g. predicted type IV secretion system effector genes) are typically considered to be associated with C. burnetii virulence, a caveat concerning the axenic media used in the study. Investigation into the conservation of the essential genes identified revealed that 78 % are conserved across all C. burnetii strains sequenced to date, which probably play critical functions. This is the first report of a whole genome transposon screen in C. burnetii that has been undertaken for the identification of essential genes.
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Affiliation(s)
- Georgie Metters
- Department of Biosciences, College of Life and Environmental Sciences, University of Exeter, Exeter EX4 4QD, UK.,Defence Science and Technology Laboratories, CBR Division, Porton Down, Salisbury SP4 0JQ, UK
| | - Claudia Hemsley
- Department of Biosciences, College of Life and Environmental Sciences, University of Exeter, Exeter EX4 4QD, UK.,Present address: Molecular Microbiology Division, School of Life Sciences, University of Dundee, Dundee, DD1 5AA, UK
| | - Isobel Norville
- Department of Biosciences, College of Life and Environmental Sciences, University of Exeter, Exeter EX4 4QD, UK.,Defence Science and Technology Laboratories, CBR Division, Porton Down, Salisbury SP4 0JQ, UK
| | - Richard Titball
- Department of Biosciences, College of Life and Environmental Sciences, University of Exeter, Exeter EX4 4QD, UK
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5
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Tesfamariam M, Binette P, Cockrell D, Beare PA, Heinzen RA, Shaia C, Long CM. Characterization of Coxiella burnetii Dugway Strain Host-Pathogen Interactions In Vivo. Microorganisms 2022; 10:2261. [PMID: 36422331 PMCID: PMC9692954 DOI: 10.3390/microorganisms10112261] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2022] [Revised: 11/09/2022] [Accepted: 11/10/2022] [Indexed: 12/12/2023] Open
Abstract
Coxiella burnetii is a Gram-negative, intracellular bacterium that causes the zoonosis Q fever. Among the many natural isolates of C. burnetii recovered from various sources, the Dugway group exhibits unique genetic characteristics, including the largest C. burnetii genomes. These strains were isolated during 1954-1958 from wild rodents from the Utah, USA desert. Despite retaining phase I lipopolysaccharide and the type 4B secretion system, two critical virulence factors, avirulence has been reported in a guinea pig infection model. Using guinea pig models, we evaluated the virulence, whole-cell vaccine (WCV) efficacy, and post-vaccination hypersensitivity (PVH) potential of a representative Dugway strain. Consistent with prior reports, Dugway appeared to be highly attenuated compared to a virulent strain. Indeed, Dugway-infected animals showed similarly low levels of fever, body weight loss, and splenomegaly like Nine Mile II-infected animals. When compared to a human Q fever vaccine, QVax®, Dugway WCV exhibited analogous protection against a heterologous Nine Mile I challenge. PVH was investigated in a skin-testing model which revealed significantly decreased maximum erythema in Dugway Δdot/icm WCV-skin-tested animals compared to that of QVax®. These data provide insight into this unique bacterial strain and implicate its potential use as a mutated WCV candidate.
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Affiliation(s)
- Mahelat Tesfamariam
- Laboratory of Bacteriology, Division of Intramural Research, National Institute of Allergy and Infectious Disease, National Institutes of Health, Hamilton, MT 59840, USA
| | - Picabo Binette
- Laboratory of Bacteriology, Division of Intramural Research, National Institute of Allergy and Infectious Disease, National Institutes of Health, Hamilton, MT 59840, USA
| | - Diane Cockrell
- Laboratory of Bacteriology, Division of Intramural Research, National Institute of Allergy and Infectious Disease, National Institutes of Health, Hamilton, MT 59840, USA
| | - Paul A. Beare
- Laboratory of Bacteriology, Division of Intramural Research, National Institute of Allergy and Infectious Disease, National Institutes of Health, Hamilton, MT 59840, USA
| | - Robert A. Heinzen
- Laboratory of Bacteriology, Division of Intramural Research, National Institute of Allergy and Infectious Disease, National Institutes of Health, Hamilton, MT 59840, USA
| | - Carl Shaia
- Rocky Mountain Veterinary Branch, Division of Intramural Research, National Institute of Allergy and Infectious Disease, National Institutes of Health, Hamilton, MT 59840, USA
| | - Carrie Mae Long
- Laboratory of Bacteriology, Division of Intramural Research, National Institute of Allergy and Infectious Disease, National Institutes of Health, Hamilton, MT 59840, USA
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6
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Unger N, Eiserloh S, Nowak F, Zuchantke S, Liebler-Tenorio E, Sobotta K, Schnee C, Berens C, Neugebauer U. Looking Inside Non-Destructively: Label-Free, Raman-Based Visualization of Intracellular Coxiella burnetii. Anal Chem 2022; 94:4988-4996. [PMID: 35302749 PMCID: PMC8974703 DOI: 10.1021/acs.analchem.1c04754] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Accepted: 02/08/2022] [Indexed: 11/30/2022]
Abstract
The life cycle of intracellular pathogens is often complex and can include different morphoforms. Treatment of intracellular infections and unperturbed studying of the pathogen inside the host cell are frequently challenging. Here, we present a Raman-based, label-free, non-invasive, and non-destructive method to localize, visualize, and even quantify intracellular bacteria in 3D within intact host cells in a Coxiella burnetii infection model. C. burnetii is a zoonotic obligate intracellular pathogen that causes infections in ruminant livestock and humans with an acute disease known as Q fever. Using statistical data analysis, no isolation is necessary to gain detailed information on the intracellular pathogen's metabolic state. High-quality false color image stacks with diffraction-limited spatial resolution enable a 3D spatially resolved single host cell analysis that shows excellent agreement with results from transmission electron microscopy. Quantitative analysis at different time points post infection allows to follow the infection cycle with the transition from the large cell variant (LCV) to the small cell variant (SCV) at around day 6 and a gradual change in the lipid composition during vacuole maturation. Spectral characteristics of intracellular LCV and SCV reveal a higher lipid content of the metabolically active LCV.
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Affiliation(s)
- Nancy Unger
- Center
for Sepsis Control and Care, Jena University
Hospital, 07747 Jena, Germany
- Leibniz
Institute of Photonic Technology, 07745 Jena, Germany
| | - Simone Eiserloh
- Center
for Sepsis Control and Care, Jena University
Hospital, 07747 Jena, Germany
- Leibniz
Institute of Photonic Technology, 07745 Jena, Germany
| | - Frauke Nowak
- Institute
of Molecular Pathogenesis, Friedrich-Loeffler-Institut—Federal
Research Institute for Animal Health (FLI), 07743 Jena, Germany
| | - Sara Zuchantke
- Institute
of Molecular Pathogenesis, Friedrich-Loeffler-Institut—Federal
Research Institute for Animal Health (FLI), 07743 Jena, Germany
| | - Elisabeth Liebler-Tenorio
- Institute
of Molecular Pathogenesis, Friedrich-Loeffler-Institut—Federal
Research Institute for Animal Health (FLI), 07743 Jena, Germany
| | - Katharina Sobotta
- Institute
of Medical Microbiology, Jena University
Hospital, 07747 Jena, Germany
| | - Christiane Schnee
- Institute
of Molecular Pathogenesis, Friedrich-Loeffler-Institut—Federal
Research Institute for Animal Health (FLI), 07743 Jena, Germany
| | - Christian Berens
- Institute
of Molecular Pathogenesis, Friedrich-Loeffler-Institut—Federal
Research Institute for Animal Health (FLI), 07743 Jena, Germany
| | - Ute Neugebauer
- Center
for Sepsis Control and Care, Jena University
Hospital, 07747 Jena, Germany
- Leibniz
Institute of Photonic Technology, 07745 Jena, Germany
- Institute
of Physical Chemistry and Abbe Center of Photonics, Friedrich Schiller University Jena, 07743 Jena, Germany
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7
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Coxiella burnetii Virulent Phase I and avirulent Phase II Variants Differentially Manipulate Autophagy pathway in Neutrophils. Infect Immun 2022; 90:e0053421. [PMID: 35100012 DOI: 10.1128/iai.00534-21] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Coxiella burnetii is an obligate intracellular gram-negative bacterium that causes Q fever in humans. Virulent C. burnetii Nine Mile Phase I (NMI) strain causes disease in animal models, while avirulent NM phase II (NMII) strain does not. In this study, we found that NMI infection induces severe splenomegaly and bacterial burden in the spleen in BALB/c mice, while NMII infection does not. Compared to NMII-infected mice, a significantly higher number of CD11b+Ly6g+ neutrophils accumulated in the liver, lung and spleen of NMI-infected mice. Thus, neutrophil accumulation correlates with NMI and NMII infection induced inflammatory response. In vitro studies also demonstrated that although NMII exhibited a higher infection rate than NMI in mouse bone-marrow neutrophils (BMNs), NMI-infected BMNs survive longer than NMII-infected BMNs. These results suggest that the differential interactions of NMI and NMII with neutrophils may be related to their ability to cause disease in animals. To understand the molecular mechanism underlying the differential interactions of NMI and NMII with neutrophils, the global transcriptomic gene expressions were compared between NMI- and NMII-infected-BMNs by RNA-seq analysis. Interestingly, several genes involved in autophagy related pathways, particularly the membrane-trafficking and lipid metabolism are upregulated in NMII-infected BMNs but downregulated in NMI-infected BMNs. Immunofluorescence and immunoblot analysis indicate that compared to NMI-infected BMNs, vacuoles in NMII-infected-BMNs exhibit increased autophagic flux along with phosphatidylserine translocation in cell membrane. Similar to neutrophils, NMII activated LC3-mediated autophagy in human macrophage. These findings suggest that NMI and NMII's differential manipulation of autophagy may relate to their pathogenesis.
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8
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Gregory AE, van Schaik EJ, Fratzke AP, Russell-Lodrigue KE, Farris CM, Samuel JE. Soluble antigens derived from Coxiella burnetii elicit protective immunity in three animal models without inducing hypersensitivity. Cell Rep Med 2021; 2:100461. [PMID: 35028605 PMCID: PMC8714860 DOI: 10.1016/j.xcrm.2021.100461] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Revised: 09/27/2021] [Accepted: 11/10/2021] [Indexed: 11/25/2022]
Abstract
Q fever is caused by the intracellular bacterium Coxiella burnetii, for which there is no approved vaccine in the United States. A formalin-inactivated whole-cell vaccine (WCV) from virulent C. burnetii NMI provides single-dose long-lived protection, but concerns remain over vaccine reactogenicity. We therefore sought an alternate approach by purifying native C. burnetii antigens from the clonally derived avirulent NMII strain. A soluble bacterial extract, termed Sol II, elicits high-titer, high-avidity antibodies and induces a CD4 T cell response that confers protection in naive mice. In addition, Sol II protects against pulmonary C. burnetii challenge in three animal models without inducing hypersensitivity. An NMI-derived extract, Sol I, enhances protection further and outperforms the WCV gold standard. Collectively, these data represent a promising approach to design highly effective, non-reactogenic Q fever vaccines.
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Affiliation(s)
- Anthony E. Gregory
- Department of Microbial Pathogenesis and Immunology, College of Medicine, Texas A&M University, Medical Research and Education Building, Bryan, TX 77807, USA
- Department of Physiology and Biophysics, School of Medicine, University of California, Irvine, Irvine, CA 92617, USA
| | - Erin J. van Schaik
- Department of Microbial Pathogenesis and Immunology, College of Medicine, Texas A&M University, Medical Research and Education Building, Bryan, TX 77807, USA
| | - Alycia P. Fratzke
- Department of Microbial Pathogenesis and Immunology, College of Medicine, Texas A&M University, Medical Research and Education Building, Bryan, TX 77807, USA
| | - Kasi E. Russell-Lodrigue
- Tulane University, School of Medicine, Tulane National Primate Research Center, Covington, LA 70433, USA
| | - Christina M. Farris
- Department of Microbial Pathogenesis and Immunology, College of Medicine, Texas A&M University, Medical Research and Education Building, Bryan, TX 77807, USA
| | - James E. Samuel
- Department of Microbial Pathogenesis and Immunology, College of Medicine, Texas A&M University, Medical Research and Education Building, Bryan, TX 77807, USA
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9
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Kumaresan V, Alam S, Zhang Y, Zhang G. The Feasibility of Using Coxiella burnetii Avirulent Nine Mile Phase II Viable Bacteria as a Live Attenuated Vaccine Against Q fever. Front Immunol 2021; 12:754690. [PMID: 34795669 PMCID: PMC8594375 DOI: 10.3389/fimmu.2021.754690] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Accepted: 10/04/2021] [Indexed: 11/13/2022] Open
Abstract
This study aimed to explore if viable C. burnetii avirulent Nine Mile phase II (NMII) can elicit protective immunity against virulent NM phase I (NMI) infection. Interestingly, mice immunized with viable NMII elicited significant protection against NMI infection at different time points post-immunization. Viable NMII induced a dose-dependent NMI-specific IgG response in mice, but all doses of NMII-immunized mice conferred a similar level of protection. Comparing different routes of immunization indicated that intranasally immunized mice showed significantly higher levels of protection than other immunization routes. The observation that viable NMII induced a similar level of long-term protection against NMI challenge as the formalin-inactivated NMI vaccine (PIV) suggests that viable NMII bacteria can induce a similar level of long-term protection against virulent NMI challenge as the PIV. Viable NMII also induced significant protection against challenge with virulent Priscilla and Scurry strains, suggesting that viable NMII can elicit broad protection. Immune sera and splenocytes from viable NMII-immunized mice are protective against NMI infection, but immune serum-receiving mice did not control NMI replication. Additionally, viable NMII conferred a comparable level of protection in wild-type, CD4+ T cell-deficient, and CD8+ T cell-deficient mice, and partial protection in B cell-deficient mice. However, NMII-immunized T cell-deficient mice were unable to prevent C. burnetii replication. Thus, both B cells and T cells are required for viable NMII-induced protective immunity but T cells may play a critical role. Collectively, this study demonstrates the feasibility of using avirulent NMII as a live attenuated vaccine against human Q fever.
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Affiliation(s)
- Venkatesh Kumaresan
- Department of Molecular Microbiology and Immunology, University of Texas at San Antonio, San Antonio, TX, United States
| | - Shawkat Alam
- Department of Molecular Microbiology and Immunology, University of Texas at San Antonio, San Antonio, TX, United States
| | - Yan Zhang
- Department of Molecular Microbiology and Immunology, University of Texas at San Antonio, San Antonio, TX, United States
| | - Guoquan Zhang
- Department of Molecular Microbiology and Immunology, University of Texas at San Antonio, San Antonio, TX, United States
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10
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Viana F, O'Kane CM, Schroeder GN. Precision-cut lung slices: A powerful ex vivo model to investigate respiratory infectious diseases. Mol Microbiol 2021; 117:578-588. [PMID: 34570407 PMCID: PMC9298270 DOI: 10.1111/mmi.14817] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2021] [Accepted: 09/23/2021] [Indexed: 11/30/2022]
Abstract
Respiratory infections are a leading cause of mortality worldwide. Most of the research on the underlying disease mechanisms is based on cell culture, organoid, or surrogate animal models. Although these provide important insights, they have limitations. Cell culture models fail to recapitulate cellular interactions in the lung and animal models often do not permit high‐throughput analysis of drugs or pathogen isolates; hence, there is a need for improved, scalable models. Precision‐cut lung slices (PCLS), small, uniform tissue slices generated from animal or human lungs are increasingly recognized and employed as an ex vivo organotypic model. PCLS retain remarkable cellular complexity and the architecture of the lung, providing a platform to investigate respiratory pathogens in a near‐native environment. Here, we review the generation and features of PCLS, their use to investigate the pathogenesis of viral and bacterial pathogens, and highlight their potential to advance respiratory infection research in the future.
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Affiliation(s)
- Flávia Viana
- Wellcome-Wolfson Institute for Experimental Medicine, School of Medicine, Dentistry and Biomedical Sciences, Queen's University Belfast, Belfast, UK
| | - Cecilia M O'Kane
- Wellcome-Wolfson Institute for Experimental Medicine, School of Medicine, Dentistry and Biomedical Sciences, Queen's University Belfast, Belfast, UK
| | - Gunnar N Schroeder
- Wellcome-Wolfson Institute for Experimental Medicine, School of Medicine, Dentistry and Biomedical Sciences, Queen's University Belfast, Belfast, UK
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11
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Perry MJ, Conlon MA, Egan CT. Utilization of Standard Method Performance Requirements for the Detection of Coxiella burnetii in Environmental Samples. J AOAC Int 2021; 104:795-801. [PMID: 33822974 DOI: 10.1093/jaoacint/qsaa101] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2019] [Revised: 07/15/2020] [Accepted: 07/16/2020] [Indexed: 11/13/2022]
Abstract
BACKGROUND Coxiella burnetii, the causative agent of Q fever, is a long-standing public health problem. Infected animals shed the organism, resulting in aerosol transmission to humans. This organism can potentially be used as a bioterrorism weapon and is on the Department of Health and Human Service Select Agent List. Assay development for detecting C. burnetii in environmental samples has been limited. OBJECTIVE We describe the use of Standard Method Performance Requirements (SMPR®) 2015.011 to detect Coxiella in air filters and liquids to validate additional environmental samples. METHOD SMPR 2015.011 was used to validate a real-time polymerase chain reaction (rtPCR) assay developed to detect C. burnetii DNA in powder samples submitted to the public health laboratory for biothreat analysis. RESULTS Our laboratory developed an assay to detect the icd gene of C. burnetii. The LOD for the assay was 33 gene copies per rtPCR reaction in buffer and 260 in each of the three separate powdered samples. CONCLUSIONS The SMPR 2015.011 allowed validation of an assay to detect Coxiella nucleic acid in an environmental sample. The assay was sensitive, robust, specific, and able to detect this select agent in powders. HIGHLIGHTS Development of detection assays for agents that are difficult to culture and have limited validation material available can be problematic for manufacturers. Using the SMPR 2015.011 developed for the detection of Coxiella as well as the SMPR 2016.012 for the detection of Variola, we demonstrated that assays can be appropriately validated using alternative approaches.
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Affiliation(s)
- Michael J Perry
- Wadsworth Center, New York State Department of Health, 120 New Scotland Ave, Albany, NY 12208, USA
| | - Maureen A Conlon
- Wadsworth Center, New York State Department of Health, 120 New Scotland Ave, Albany, NY 12208, USA
| | - Christina T Egan
- Wadsworth Center, New York State Department of Health, 120 New Scotland Ave, Albany, NY 12208, USA
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12
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Long CM, Beare PA, Cockrell DC, Fintzi J, Tesfamariam M, Shaia CI, Heinzen RA. Contributions of lipopolysaccharide and the type IVB secretion system to Coxiella burnetii vaccine efficacy and reactogenicity. NPJ Vaccines 2021; 6:38. [PMID: 33741986 PMCID: PMC7979919 DOI: 10.1038/s41541-021-00296-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Accepted: 02/12/2021] [Indexed: 12/15/2022] Open
Abstract
Coxiella burnetii is the bacterial causative agent of the zoonosis Q fever. The current human Q fever vaccine, Q-VAX®, is a fixed, whole cell vaccine (WCV) licensed solely for use in Australia. C. burnetii WCV administration is associated with a dermal hypersensitivity reaction in people with pre-existing immunity to C. burnetii, limiting wider use. Consequently, a less reactogenic vaccine is needed. Here, we investigated contributions of the C. burnetii Dot/Icm type IVB secretion system (T4BSS) and lipopolysaccharide (LPS) in protection and reactogenicity of fixed WCVs. A 32.5 kb region containing 23 dot/icm genes was deleted in the virulent Nine Mile phase I (NMI) strain and the resulting mutant was evaluated in guinea pig models of C. burnetii infection, vaccination-challenge, and post-vaccination hypersensitivity. The NMI ∆dot/icm strain was avirulent, protective as a WCV against a robust C. burnetii challenge, and displayed potentially altered reactogenicity compared to NMI. Nine Mile phase II (NMII) strains of C. burnetii that produce rough LPS, were similarly tested. NMI was significantly more protective than NMII as a WCV; however, both vaccines exhibited similar reactogenicity. Collectively, our results indicate that, like phase I LPS, the T4BSS is required for full virulence by C. burnetii. Conversely, unlike phase I LPS, the T4BSS is not required for vaccine-induced protection. LPS length does not appear to contribute to reactogenicity while the T4BSS may contribute to this response. NMI ∆dot/icm represents an avirulent phase I strain with full vaccine efficacy, illustrating the potential of genetically modified C. burnetii as improved WCVs.
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Affiliation(s)
- Carrie M Long
- Coxiella Pathogenesis Section, Laboratory of Bacteriology, Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT, USA.
| | - Paul A Beare
- Coxiella Pathogenesis Section, Laboratory of Bacteriology, Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT, USA
| | - Diane C Cockrell
- Coxiella Pathogenesis Section, Laboratory of Bacteriology, Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT, USA
| | - Jonathan Fintzi
- Biostatistics Research Branch, Division of Clinical Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD, USA
| | - Mahelat Tesfamariam
- Coxiella Pathogenesis Section, Laboratory of Bacteriology, Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT, USA
| | - Carl I Shaia
- Rocky Mountain Veterinary Branch, Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT, USA
| | - Robert A Heinzen
- Coxiella Pathogenesis Section, Laboratory of Bacteriology, Division of Intramural Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, MT, USA
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13
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Miller CN, Khan M, Ahmed SA, Kota K, Panchal RG, Hale ML. Development of a Coxiella burnetii culture method for high-throughput assay to identify host-directed therapeutics. J Microbiol Methods 2019; 169:105813. [PMID: 31862458 DOI: 10.1016/j.mimet.2019.105813] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2019] [Revised: 12/16/2019] [Accepted: 12/16/2019] [Indexed: 10/25/2022]
Abstract
The intracellular Gram-negative bacterium, Coxiella burnetii, is a worldwide zoonotic pathogen and the causative agent of Q fever. The standard of care for C. burnetii infections involves extended periods of antibiotic treatment and the development of doxycycline-resistant strains stress the need for new treatment strategies. A previously developed axenic medium has facilitated in vitro growth of the organism. In this study, we have developed a simple culture method that is inexpensive, reliable and utilizes a modular hypoxic chamber system for either small or large scale production of bacteria without the need of a tri-gas incubator. This method provides consistent growth and yields sufficient viable bacteria within four days of culture and can be used for high-throughput screening. The viable bacteria were quantified by counting colony forming units and total bacteria were enumerated using a genomic equivalent method. The characterized bacterial inoculum was then used to optimize cell-based high-throughput immunofluorescence assays with a goal to quantify intracellular bacteria and then screen and identify compounds that inhibit early stages of C. burnetii infection in macrophages.
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Affiliation(s)
- Cheryl N Miller
- Countermeasures Division, United States Army Medical Research Institute of Infectious Diseases, Frederick, MD 21702, United States.
| | - Maisha Khan
- Countermeasures Division, United States Army Medical Research Institute of Infectious Diseases, Frederick, MD 21702, United States; Department of Chemistry and Physics, Hood College, 401 Rosemont Ave, Frederick, MD 21701, United States
| | - S Ashraf Ahmed
- Systems and Structural Biology, United States Army Medical Research Institute of Infectious Diseases, Frederick, MD 21702, United States
| | - Krishna Kota
- Countermeasures Division, United States Army Medical Research Institute of Infectious Diseases, Frederick, MD 21702, United States
| | - Rekha G Panchal
- Countermeasures Division, United States Army Medical Research Institute of Infectious Diseases, Frederick, MD 21702, United States
| | - Martha L Hale
- Countermeasures Division, United States Army Medical Research Institute of Infectious Diseases, Frederick, MD 21702, United States
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14
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Metters G, Norville IH, Titball RW, Hemsley CM. From cell culture to cynomolgus macaque: infection models show lineage-specific virulence potential of Coxiella burnetii. J Med Microbiol 2019; 68:1419-1430. [PMID: 31424378 DOI: 10.1099/jmm.0.001064] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Coxiella burnetii is an obligate intracellular pathogen that causes the zoonotic disease Q fever in humans, which can occur in either an acute or a chronic form with serious complications. The bacterium has a wide host range, including unicellular organisms, invertebrates, birds and mammals, with livestock representing the most significant reservoir for human infections. Cell culture models have been used to decipher the intracellular lifestyle of C. burnetii, and several infection models, including invertebrates, rodents and non-human primates, are being used to investigate host-pathogen interactions and to identify bacterial virulence factors and vaccine candidates. However, none of the models replicate all aspects of human disease. Furthermore, it is becoming evident that C. burnetii isolates belonging to different lineages exhibit differences in their virulence in these models. Here, we compare the advantages and disadvantages of commonly used infection models and summarize currently available data for lineage-specific virulence.
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Affiliation(s)
- Georgina Metters
- College of Life and Environmental Sciences - Biosciences, University of Exeter, Exeter, UK
| | - Isobel H Norville
- Defence Science and Technology Laboratory, Porton Down, Salisbury, UK
| | - Richard W Titball
- College of Life and Environmental Sciences - Biosciences, University of Exeter, Exeter, UK
| | - Claudia M Hemsley
- College of Life and Environmental Sciences - Biosciences, University of Exeter, Exeter, UK
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15
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Dresler J, Klimentova J, Pajer P, Salovska B, Fucikova AM, Chmel M, Schmoock G, Neubauer H, Mertens-Scholz K. Quantitative Proteome Profiling of Coxiella burnetii Reveals Major Metabolic and Stress Differences Under Axenic and Cell Culture Cultivation. Front Microbiol 2019; 10:2022. [PMID: 31620097 PMCID: PMC6759588 DOI: 10.3389/fmicb.2019.02022] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Accepted: 08/19/2019] [Indexed: 12/14/2022] Open
Abstract
Coxiella burnetii is the causative agent of the zoonotic disease Q fever. To date, the lipopolysaccharide (LPS) is the only defined and characterized virulence determinant of C. burnetii. In this study, proteome profiles of C. burnetii Nine Mile phase I (RSA 493, NMI) and its isogenic Nine Mile phase II (RSA 439 NMII) isolate with a deep rough LPS were compared on L-929 mouse fibroblasts and in complex (ACCM-2), and defined (ACCM-D) media. Whole proteome extracts were analyzed using a label-free quantification approach. Between 659 and 1,046 C. burnetii proteins of the 2,132 annotated coding sequences (CDS) were identified in any particular experiment. Proteome profiles clustered according to the cultivation conditions used, indicating different regulation patterns. NMI proteome profiles compared to NMII in ACCM-D indicate transition from an exponential to a stationary phase. The levels of regulatory proteins such as RpoS, CsrA2, UspA1, and UspA2 were increased. Comparison of the oxidative stress response of NMI and NMII indicated that ACCM-2 represents a high oxidative stress environment. Expression of peroxidases, superoxide dismutases, as well as thioredoxins was increased for NMI. In contrast, in ACCM-D, only osmoregulation seems to be necessary. Proteome profiles of NMII do not differ and indicate that both axenic media represent similar oxidative stress environments. Deep rough LPS causes changes of the outer membrane stability and fluidity. This might be one reason for the observed differences. Proteins associated with the T4SS and Sec translocon as well as several effector proteins were detectable under all three conditions. Interestingly, none of these putatively secreted proteins are upregulated in ACCM-2 compared to ACCM-D, and L-929 mouse fibroblasts. Curiously, a higher similarity of proteomic patterns (overlapping up- and downregulated proteins) of ACCM-D and bacteria grown in cell culture was observed. Particularly, the proteins involved in a better adaptation or homeostasis in response to the harsh environment of the parasitophorous vacuole were demonstrated for NMI. This semi-quantitative proteomic analysis of C. burnetii compared axenically grown bacteria to those propagated in cell culture.
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Affiliation(s)
| | - Jana Klimentova
- Faculty of Military Health Sciences, University of Defence, Hradec Kralove, Czechia
| | - Petr Pajer
- Military Health Institute, Prague, Czechia
| | - Barbora Salovska
- Department of Genome Integrity, Institute of Molecular Genetics of the Czech Academy of Sciences, Prague, Czechia
| | | | - Martin Chmel
- Department of Infectious Diseases, First Faculty of Medicine, Charles University and Military University Hospital Prague, Prague, Czechia
| | - Gernot Schmoock
- Institute of Bacterial Infections and Zoonoses, Friedrich-Loeffler-Institut, Jena, Germany
| | - Heinrich Neubauer
- Institute of Bacterial Infections and Zoonoses, Friedrich-Loeffler-Institut, Jena, Germany
| | - Katja Mertens-Scholz
- Institute of Bacterial Infections and Zoonoses, Friedrich-Loeffler-Institut, Jena, Germany
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16
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Hayek I, Berens C, Lührmann A. Modulation of host cell metabolism by T4SS-encoding intracellular pathogens. Curr Opin Microbiol 2019; 47:59-65. [PMID: 30640035 DOI: 10.1016/j.mib.2018.11.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2018] [Revised: 11/22/2018] [Accepted: 11/29/2018] [Indexed: 12/26/2022]
Abstract
Intracellular bacterial pathogens intimately interact with the infected host cell to prevent elimination and to ensure survival. One group of intracellular pathogens, including Coxiella burnetii, Legionella pneumophila, Brucella spp., Anaplasma phagocytophilum, and Ehrlichia chaffeensis, utilizes a type IV secretion system (T4SS) that injects effectors to modulate host cell signalling, vesicular trafficking, autophagy, cell death and transcription to ensure survival [1]. So far, little emphasis has been directed towards understanding how these bacteria manipulate host cell metabolism. This manipulation is not only important for gaining access to nutrients, but also for regulating specific virulence programs [2,3]. Here, we will summarize recent progress made in characterizing the manipulation of host cell metabolism by C. burnetii and other intracellular pathogens utilizing a T4SS.
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Affiliation(s)
- Inaya Hayek
- Mikrobiologisches Institut-Klinische Mikrobiologie, Immunologie und Hygiene, Universitätsklinikum Erlangen, Friedrich-Alexander Universität (FAU) Erlangen-Nürnberg, Wasserturmstraße 3/5, D-91054 Erlangen, Germany
| | - Christian Berens
- Institut für molekulare Pathogenese, Friedrich-Loeffler-Institut, Naumburger Str. 96a, D-07743 Jena, Germany
| | - Anja Lührmann
- Mikrobiologisches Institut-Klinische Mikrobiologie, Immunologie und Hygiene, Universitätsklinikum Erlangen, Friedrich-Alexander Universität (FAU) Erlangen-Nürnberg, Wasserturmstraße 3/5, D-91054 Erlangen, Germany.
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17
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Boskani T, Edvinsson B, Wahab T. Development of nineteen Taqman real-time PCR assays for screening and detection of select highly pathogenic bacteria. Infect Ecol Epidemiol 2019. [DOI: 10.1080/20008686.2018.1553462] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
Affiliation(s)
- Talar Boskani
- Department of Microbiology, Public Health Agency of Sweden, Solna, Sweden
| | - Benjamin Edvinsson
- Department of Microbiology, Public Health Agency of Sweden, Solna, Sweden
- Unit of Freeze Dried and Inhalation, AstraZeneca Sweden Operations, Sweden
| | - Tara Wahab
- Department of Microbiology, Public Health Agency of Sweden, Solna, Sweden
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18
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Shpynov S, Tarasevich I, Skiba A, Pozdnichenko N, Gumenuk A. Comparison of genomes of Coxiella burnetii strains using formal order analysis. New Microbes New Infect 2018; 23:86-92. [PMID: 29692911 PMCID: PMC5913358 DOI: 10.1016/j.nmni.2018.02.011] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2017] [Revised: 01/27/2018] [Accepted: 02/06/2018] [Indexed: 12/31/2022] Open
Abstract
The Coxiella burnetii strain NL3262 was isolated during the Q fever outbreak in the Netherlands in 2007–2010. Formal-order analysis (FOA) was used to study the similarity of the genome (chromosome and plasmid) of this strain with the genomes from other strains. Chromosomes from ten C. burnetii strains and eight plasmids were studied with FOA tools such as ‘Map of genes’ and ‘Matrix of similarity.’ The ‘Map of genes’ tool showed that the chromosome of strain C. burnetii str. NL3262 distanced itself by the index of average remoteness (g) of 1.449640 (x-axis) from chromosomes of other strains (g 1.448295–1.448865). The ‘Matrix of similarity’ was used for an advanced analysis of the obtained results. The complete similarity of the components of chromosomes and plasmids was determined by pairwise comparison and the identification of nucleotides matching with them. A total of 84.90% of the chromosomal components of C. burnetii strain NL3262 coincided completely with the chromosomal components of strain Z3055. For chromosomes of other strains, this percentage varied from 12.06% to 47.14%. The plasmid of strain NL3262 had 50.0% of the components being completely coincident with the components of the plasmid of RSA 331; with RSA 493 it was 29.89%. Thus, C. burnetii str. NL3262 is the closest to str. Z3055 by the similarity of the chromosomal components, but on the index of average remoteness of the chromosome and the similarity of the plasmids' QpH1 components, it is the closest to strain RSA 331.
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Affiliation(s)
- S.N. Shpynov
- N. F. Gamaleya FRCEM, Moscow, Russia
- Corresponding author: S.N. Shpynov, 18, N.F. Gamaleya str., Moscow, 123098 Russia.
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19
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Beare PA, Jeffrey BM, Long CM, Martens CM, Heinzen RA. Genetic mechanisms of Coxiella burnetii lipopolysaccharide phase variation. PLoS Pathog 2018; 14:e1006922. [PMID: 29481553 PMCID: PMC5843353 DOI: 10.1371/journal.ppat.1006922] [Citation(s) in RCA: 54] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2018] [Revised: 03/08/2018] [Accepted: 02/05/2018] [Indexed: 12/30/2022] Open
Abstract
Coxiella burnetii is an intracellular pathogen that causes human Q fever, a disease that normally presents as a severe flu-like illness. Due to high infectivity and disease severity, the pathogen is considered a risk group 3 organism. Full-length lipopolysaccharide (LPS) is required for full virulence and disease by C. burnetii and is the only virulence factor currently defined by infection of an immunocompetent animal. Transition of virulent phase I bacteria with smooth LPS, to avirulent phase II bacteria with rough LPS, occurs during in vitro passage. Semi-rough intermediate forms are also observed. Here, the genetic basis of LPS phase conversion was investigated to obtain a more complete understanding of C. burnetii pathogenesis. Whole genome sequencing of strains producing intermediate and/or phase II LPS identified several common mutations in predicted LPS biosynthesis genes. After passage in broth culture for 30 weeks, phase I strains from different genomic groups exhibited similar phase transition kinetics and elevation of mutations in LPS biosynthesis genes. Targeted mutagenesis and genetic complementation using a new C. burnetii nutritional selection system based on lysine auxotrophy confirmed that six of the mutated genes were necessary for production of phase I LPS. Disruption of two of these genes in a C. burnetii phase I strain resulted in production of phase II LPS, suggesting inhibition of the encoded enzymes could represent a new therapeutic strategy for treatment of Q fever. Additionally, targeted mutagenesis of genes encoding LPS biosynthesis enzymes can now be used to construct new phase II strains from different genomic groups for use in pathogen-host studies at a risk group 2 level.
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Affiliation(s)
- Paul A. Beare
- Coxiella Pathogenesis Section, Laboratory of Bacteriology, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana, United States of America
| | - Brendan M. Jeffrey
- Bioinformatics and Computational Biosciences Branch, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana, United States of America
| | - Carrie M. Long
- Coxiella Pathogenesis Section, Laboratory of Bacteriology, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana, United States of America
| | - Craig M. Martens
- Research Technologies Section, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana, United States of America
| | - Robert A. Heinzen
- Coxiella Pathogenesis Section, Laboratory of Bacteriology, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Hamilton, Montana, United States of America
- * E-mail:
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20
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Pechstein J, Schulze-Luehrmann J, Lührmann A. Coxiella burnetii as a useful tool to investigate bacteria-friendly host cell compartments. Int J Med Microbiol 2017; 308:77-83. [PMID: 28935173 DOI: 10.1016/j.ijmm.2017.09.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2017] [Revised: 08/21/2017] [Accepted: 09/11/2017] [Indexed: 10/25/2022] Open
Abstract
Coxiella burnetii is an obligate intracellular and airborne pathogen which can cause the zoonotic disease Q fever. After inhalation of contaminated aerosols alveolar macrophages are taking up C. burnetii into a phagosome. This phagosome matures to a very large vacuole called the C. burnetii-containing vacuole (CCV). Host endogenous and bacterial driven processes lead to the biogenesis of this unusual compartment, which resembles partially a phagolysosome. However, there are several important differences to the classical phagolysosome, which are crucial for the ability of C. burnetii to replicate intracellularly and depend on a functional type IV secretion system (T4SS). The T4SS delivers effector proteins into the host cell cytoplasm to redirect intracellular processes, leading to the establishment of a microenvironment allowing bacterial replication. This article summarizes the current knowledge of the microenvironment permissive for C. burnetii replication.
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Affiliation(s)
- Julian Pechstein
- Mikrobiologisches Institut - Klinische Mikrobiologie, Immunologie und Hygiene, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Wasserturmstraße 3/5, D-91054 Erlangen, Germany
| | - Jan Schulze-Luehrmann
- Mikrobiologisches Institut - Klinische Mikrobiologie, Immunologie und Hygiene, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Wasserturmstraße 3/5, D-91054 Erlangen, Germany
| | - Anja Lührmann
- Mikrobiologisches Institut - Klinische Mikrobiologie, Immunologie und Hygiene, Universitätsklinikum Erlangen, Friedrich-Alexander-Universität Erlangen-Nürnberg, Wasserturmstraße 3/5, D-91054 Erlangen, Germany.
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21
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Lührmann A, Newton HJ, Bonazzi M. Beginning to Understand the Role of the Type IV Secretion System Effector Proteins in Coxiella burnetii Pathogenesis. Curr Top Microbiol Immunol 2017. [PMID: 29536362 DOI: 10.1007/978-3-319-75241-9_10] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
Abstract
Coxiella burnetii is the etiological agent of the zoonotic disease Q fever, which manifests in severe outbreaks and is associated with important health and economic burden. Moreover, C. burnetii belongs to the list of class B bioterrorism organisms, as it is an airborne and highly infective pathogen with remarkable resistance to environmental stresses. Detailed study of the host-pathogen interaction during C. burnetii infection has been hampered due to the obligate intracellular nature of this pathogen. However, the development of an axenic culture medium, together with the implementation of bioinformatics tools and high-content screening approaches, have significantly progressed C. burnetii research in the last decade. This has facilitated identification of the Dot/Icm type IV secretion system (T4SS) as an essential virulence factor. T4SS is used to deliver an arsenal of effector proteins into the cytoplasm of the host cell. These effectors mediate the survival of the host cell and the development of very large replicative compartments called Coxiella-containing vacuoles (CCVs). Biogenesis of the CCV relies on T4SS-dependent re-routing of numerous intracellular trafficking pathways to deliver membranes and nutrients that are essential for bacterial replication. This review aims to illustrate the key milestones that have contributed to ascribe C. burnetii as a model organism for the study of host/pathogen interactions as well as presenting an up-to-date description of our knowledge of the cell biology of C. burnetii infections.
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Affiliation(s)
- Anja Lührmann
- Mikrobiologisches Institut-Klinische Mikrobiologie, Immunologie und Hygiene, Universitätsklinikum Erlangen, Friedrich-Alexander Universität Erlangen-Nürnberg, Wasserturmstraße 3/5, 91054, Erlangen, Germany.
| | - Hayley J Newton
- Department of Microbiology and Immunology, University of Melbourne at the Peter Doherty Institute for Infection and Immunity, Melbourne, VIC, Australia.
| | - Matteo Bonazzi
- Institut de Recherche En Infectiologie de Montpellier (IRIM), CNRS, UMR9004, Université de Montpellier, Montpellier, France.
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