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Pavlik P, Jost P, Rehulka P, Vozandychova V, Link M, Spidlova P. Epigallocatechin gallate inhibits Francisella tularensis growth and suppresses the function of DNA-binding protein HU. Microb Pathog 2023; 176:105999. [PMID: 36702369 DOI: 10.1016/j.micpath.2023.105999] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Revised: 01/11/2023] [Accepted: 01/18/2023] [Indexed: 01/25/2023]
Abstract
Francisella tularensis is a highly infectious intracellular bacterium causing tularemia disease and is regarded as a potential biological weapon. The development of a vaccine, effective treatment, or prophylactic substances targeted against tularemia is in the forefront of interest and could help to prevent or mitigate possible malevolent acts by bioterrorism utilizing F. tularensis. The viability of F. tularensis, and thus of a tularemia disease outbreak, might potentially be suppressed by simple commonly available natural substances. Epigallocatechin gallate (EGCG) is contained in green tea and its antimicrobial effect has been described. Here, we show that EGCG can suppress F. tularensis growth and is able to reduce the bacterium's ability to replicate inside mouse bone marrow-derived macrophages (BMMs) without side effects on BMMs' own viability. We suggest one (but not the only) mechanism of EGCG action. We demonstrate that EGCG can block the main functions of HU protein, the important regulator of F. tularensis virulence, leading to overall attenuation of F. tularensis viability. EGCG can delay death of mice infected by F. tularensis and can be used as a prophylactic agent against tularemia disease. Postponing death by up to 2 days can provide sufficient opportunity to administer another treatment agent.
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Affiliation(s)
- Pavla Pavlik
- Department of Molecular Pathology and Biology, Faculty of Military Health Sciences, University of Defence, Trebesska 1575, 500 01, Hradec Kralove, Czech Republic.
| | - Petr Jost
- Department of Toxicology and Military Pharmacy, Faculty of Military Health Sciences, University of Defence, Trebesska 1575, 500 01, Hradec Kralove, Czech Republic.
| | - Pavel Rehulka
- Department of Molecular Pathology and Biology, Faculty of Military Health Sciences, University of Defence, Trebesska 1575, 500 01, Hradec Kralove, Czech Republic.
| | - Vera Vozandychova
- Department of Molecular Pathology and Biology, Faculty of Military Health Sciences, University of Defence, Trebesska 1575, 500 01, Hradec Kralove, Czech Republic.
| | - Marek Link
- Department of Molecular Pathology and Biology, Faculty of Military Health Sciences, University of Defence, Trebesska 1575, 500 01, Hradec Kralove, Czech Republic.
| | - Petra Spidlova
- Department of Molecular Pathology and Biology, Faculty of Military Health Sciences, University of Defence, Trebesska 1575, 500 01, Hradec Kralove, Czech Republic.
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Yue Y, Puniya BL, Helikar T, Girardo B, Hinrichs SH, Larson MA. Arginine Catabolism and Polyamine Biosynthesis Pathway Disparities Within Francisella tularensis Subpopulations. Front Microbiol 2022; 13:890856. [PMID: 35794913 PMCID: PMC9251427 DOI: 10.3389/fmicb.2022.890856] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2022] [Accepted: 05/27/2022] [Indexed: 11/13/2022] Open
Abstract
Francisella tularensis is a highly infectious zoonotic pathogen with as few as 10 organisms causing tularemia, a disease that is fatal if untreated. Although F. tularensis subspecies tularensis (type A) and subspecies holarctica (type B) share over 99.5% average nucleotide identity, notable differences exist in genomic organization and pathogenicity. The type A clade has been further divided into subtypes A.I and A.II, with A.I strains being recognized as some of the most virulent bacterial pathogens known. In this study, we report on major disparities that exist between the F. tularensis subpopulations in arginine catabolism and subsequent polyamine biosynthesis. The genes involved in these pathways include the speHEA and aguAB operons, along with metK. In the hypervirulent F. tularensis A.I clade, such as the A.I prototype strain SCHU S4, these genes were found to be intact and highly transcribed. In contrast, both subtype A.II and type B strains have a truncated speA gene, while the type B clade also has a disrupted aguA and truncated aguB. Ablation of the chromosomal speE gene that encodes a spermidine synthase reduced subtype A.I SCHU S4 growth rate, whereas the growth rate of type B LVS was enhanced. These results demonstrate that spermine synthase SpeE promotes faster replication in the F. tularensis A.I clade, whereas type B strains do not rely on this enzyme for in vitro fitness. Our ongoing studies on amino acid and polyamine flux within hypervirulent A.I strains should provide a better understanding of the factors that contribute to F. tularensis pathogenicity.
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Affiliation(s)
- Yinshi Yue
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, NE, United States
| | - Bhanwar Lal Puniya
- Department of Biochemistry, University of Nebraska–Lincoln, Lincoln, NE, United States
| | - Tomáš Helikar
- Department of Biochemistry, University of Nebraska–Lincoln, Lincoln, NE, United States
| | - Benjamin Girardo
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, NE, United States
| | - Steven H. Hinrichs
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, NE, United States
| | - Marilynn A. Larson
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, NE, United States
- *Correspondence: Marilynn A. Larson,
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Neubert K, Zuchantke E, Leidenfrost RM, Wünschiers R, Grützke J, Malorny B, Brendebach H, Al Dahouk S, Homeier T, Hotzel H, Reinert K, Tomaso H, Busch A. Testing assembly strategies of Francisella tularensis genomes to infer an evolutionary conservation analysis of genomic structures. BMC Genomics 2021; 22:822. [PMID: 34773979 PMCID: PMC8590783 DOI: 10.1186/s12864-021-08115-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Accepted: 10/12/2021] [Indexed: 02/08/2023] Open
Abstract
Background We benchmarked sequencing technology and assembly strategies for short-read, long-read, and hybrid assemblers in respect to correctness, contiguity, and completeness of assemblies in genomes of Francisella tularensis. Benchmarking allowed in-depth analyses of genomic structures of the Francisella pathogenicity islands and insertion sequences. Five major high-throughput sequencing technologies were applied, including next-generation “short-read” and third-generation “long-read” sequencing methods. Results We focused on short-read assemblers, hybrid assemblers, and analysis of the genomic structure with particular emphasis on insertion sequences and the Francisella pathogenicity island. The A5-miseq pipeline performed best for MiSeq data, Mira for Ion Torrent data, and ABySS for HiSeq data from eight short-read assembly methods. Two approaches were applied to benchmark long-read and hybrid assembly strategies: long-read-first assembly followed by correction with short reads (Canu/Pilon, Flye/Pilon) and short-read-first assembly along with scaffolding based on long reads (Unicyler, SPAdes). Hybrid assembly can resolve large repetitive regions best with a “long-read first” approach. Conclusions Genomic structures of the Francisella pathogenicity islands frequently showed misassembly. Insertion sequences (IS) could be used to perform an evolutionary conservation analysis. A phylogenetic structure of insertion sequences and the evolution within the clades elucidated the clade structure of the highly conservative F. tularensis. Supplementary Information The online version contains supplementary material available at 10.1186/s12864-021-08115-x.
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Affiliation(s)
- Kerstin Neubert
- Department of Mathematics and Computer Science, Algorithmic Bioinformatics, Freie Universität Berlin, Institute of Computer Science, Takustr. 9, 14195, Berlin, Germany.,German Federal Institute for Risk Assessment, Diedersdorfer Weg 1, 12277, Berlin, Germany
| | - Eric Zuchantke
- Friedrich-Loeffler-Institut, Institute of Bacterial Infections and Zoonoses, Naumburger Str. 96a, 07749, Jena, Germany
| | - Robert Maximilian Leidenfrost
- Department of Biotechnology and Chemistry, Mittweida University of Applied Sciences, Technikumplatz 17a, 09648, Mittweida, Germany
| | - Röbbe Wünschiers
- Department of Biotechnology and Chemistry, Mittweida University of Applied Sciences, Technikumplatz 17a, 09648, Mittweida, Germany
| | - Josephine Grützke
- German Federal Institute for Risk Assessment, Diedersdorfer Weg 1, 12277, Berlin, Germany
| | - Burkhard Malorny
- German Federal Institute for Risk Assessment, Diedersdorfer Weg 1, 12277, Berlin, Germany
| | - Holger Brendebach
- German Federal Institute for Risk Assessment, Diedersdorfer Weg 1, 12277, Berlin, Germany
| | - Sascha Al Dahouk
- German Federal Institute for Risk Assessment, Diedersdorfer Weg 1, 12277, Berlin, Germany
| | - Timo Homeier
- Friedrich-Loeffler-Institut, Institute of Epidemiology, Südufer, 10 17493, Greifswald, Insel Riems, Germany
| | - Helmut Hotzel
- Friedrich-Loeffler-Institut, Institute of Bacterial Infections and Zoonoses, Naumburger Str. 96a, 07749, Jena, Germany
| | - Knut Reinert
- Department of Mathematics and Computer Science, Algorithmic Bioinformatics, Freie Universität Berlin, Institute of Computer Science, Takustr. 9, 14195, Berlin, Germany
| | - Herbert Tomaso
- Friedrich-Loeffler-Institut, Institute of Bacterial Infections and Zoonoses, Naumburger Str. 96a, 07749, Jena, Germany
| | - Anne Busch
- Friedrich-Loeffler-Institut, Institute of Bacterial Infections and Zoonoses, Naumburger Str. 96a, 07749, Jena, Germany. .,Department of Anaesthesiology and Intensive Care Medicine, University Hospital Jena, Jena, Germany.
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4
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Golovliov I, Bäckman S, Granberg M, Salomonsson E, Lundmark E, Näslund J, Busch JD, Birdsell D, Sahl JW, Wagner DM, Johansson A, Forsman M, Thelaus J. Long-Term Survival of Virulent Tularemia Pathogens outside a Host in Conditions That Mimic Natural Aquatic Environments. Appl Environ Microbiol 2021; 87:e02713-20. [PMID: 33397692 PMCID: PMC8104992 DOI: 10.1128/aem.02713-20] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Accepted: 12/17/2020] [Indexed: 01/22/2023] Open
Abstract
Francisella tularensis, the causative agent of the zoonotic disease tularemia, can cause seasonal outbreaks of acute febrile illness in humans with disease peaks in late summer to autumn. Interestingly, its mechanisms for environmental persistence between outbreaks are poorly understood. One hypothesis is that F. tularensis forms biofilms in aquatic environments. We utilized two fully virulent wild-type strains: FSC200 (Francisella tularensis subsp. holarctica) and Schu S4 (Francisella tularensis subsp. tularensis) and three control strains, the attenuated live vaccine strain (LVS; F. tularensis subsp. holarctica), a Schu S4 ΔwbtI mutant that is documented to form biofilms, and the low-virulence strain U112 of the closely related species Francisella novicida Strains were incubated in saline solution (0.9% NaCl) microcosms for 24 weeks at both 4°C and 20°C, whereupon viability and biofilm formation were measured. These temperatures were selected to approximate winter and summer temperatures of fresh water in Scandinavia, respectively. U112 and Schu S4 ΔwbtI formed biofilms, but F. tularensis strains FSC200 and Schu S4 and the LVS did not. All strains exhibited prolonged viability at 4°C compared to 20°C. U112 and FSC200 displayed remarkable long-term persistence at 4°C, with only 1- and 2-fold log reductions, respectively, of viable cells after 24 weeks. Schu S4 exhibited lower survival, yielding no viable cells by week 20. At 24 weeks, cells from FSC200, but not from Schu S4, were still fully virulent in mice. Taken together, these results demonstrate biofilm-independent, long-term survival of pathogenic F. tularensis subsp. holarctica in conditions that mimic overwinter survival in aquatic environments.IMPORTANCE Tularemia, a disease caused by the environmental bacterium Francisella tularensis, is characterized by acute febrile illness. F. tularensis is highly infectious: as few as 10 organisms can cause human disease. Tularemia is not known to be spread from person to person. Rather, all human infections are independently acquired from the environment via the bite of blood-feeding arthropods, ingestion of infected food or water, or inhalation of aerosolized bacteria. Despite the environmental origins of human disease events, the ecological factors governing the long-term persistence of F. tularensis in nature between seasonal human outbreaks are poorly understood. The significance of our research is in identifying conditions that promote long-term survival of fully virulent F. tularensis outside a mammalian host or insect vector. These conditions are similar to those found in natural aquatic environments in winter and provide important new insights on how F. tularensis may persist long-term in the environment.
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Affiliation(s)
- Igor Golovliov
- Department of Clinical Microbiology, Umeå University, Umeå, Sweden
- Laboratory for Molecular Infection Medicine Sweden, Umeå University, Umeå, Sweden
| | - Stina Bäckman
- Division of CBRN Defence and Security, Swedish Defence Research Agency FOI, Umeå, Sweden
| | - Malin Granberg
- Division of CBRN Defence and Security, Swedish Defence Research Agency FOI, Umeå, Sweden
| | - Emelie Salomonsson
- Division of CBRN Defence and Security, Swedish Defence Research Agency FOI, Umeå, Sweden
| | - Eva Lundmark
- Division of CBRN Defence and Security, Swedish Defence Research Agency FOI, Umeå, Sweden
| | - Jonas Näslund
- Division of CBRN Defence and Security, Swedish Defence Research Agency FOI, Umeå, Sweden
| | - Joseph D Busch
- Pathogen and Microbiome Institute, Northern Arizona University, Flagstaff, Arizona, USA
| | - Dawn Birdsell
- Pathogen and Microbiome Institute, Northern Arizona University, Flagstaff, Arizona, USA
| | - Jason W Sahl
- Pathogen and Microbiome Institute, Northern Arizona University, Flagstaff, Arizona, USA
| | - David M Wagner
- Pathogen and Microbiome Institute, Northern Arizona University, Flagstaff, Arizona, USA
| | - Anders Johansson
- Department of Clinical Microbiology, Umeå University, Umeå, Sweden
- Laboratory for Molecular Infection Medicine Sweden, Umeå University, Umeå, Sweden
| | - Mats Forsman
- Division of CBRN Defence and Security, Swedish Defence Research Agency FOI, Umeå, Sweden
| | - Johanna Thelaus
- Division of CBRN Defence and Security, Swedish Defence Research Agency FOI, Umeå, Sweden
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5
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Klimentova J, Rehulka P, Pavkova I, Kubelkova K, Bavlovic J, Stulik J. Cross-Species Proteomic Comparison of Outer Membrane Vesicles and Membranes of Francisella tularensis subsp. tularensis versus subsp. holarctica. J Proteome Res 2021; 20:1716-1732. [PMID: 33543941 DOI: 10.1021/acs.jproteome.0c00917] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Release of outer membrane vesicles (OMV) is an important phenomenon in Gram-negative bacteria playing multiple roles in their lifestyle, including in relation to virulence and host-pathogen interaction. Francisella tularensis, unlike other bacteria, releases unusually shaped, tubular OMV. We present a proteomic comparison of OMV and membrane fractions from two F. tularensis strains: moderately virulent subsp. holarctica strain FSC200 and highly virulent subsp. tularensis strain SchuS4. Proteomic comparison studies routinely evaluate samples from the same proteome, but sometimes we must compare samples from closely related organisms. This raises quantification issues. We propose a novel approach to cross-species proteomic comparison based on an intersection protein database from the individual single-species databases. This is less prone to quantification errors arising from differences in the sequences. Consecutively comparing subproteomes of OMV and membranes of the two strains allows distinguishing differences in relative protein amounts caused by global expression changes from those caused by preferential protein packing to OMV or membranes. Among the proteins most differently packed into OMV between the two strains, we detected proteins involved in biosynthesis and metabolism of bacterial envelope components like O-antigen, lipid A, phospholipids, and fatty acids, as well as some major structural outer membrane proteins. The data are available via ProteomeXchange with identifier PXD022406.
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Affiliation(s)
- Jana Klimentova
- Faculty of Military Health Sciences, Department of Molecular Pathology and Biology, University of Defence, Hradec Kralove 500 01, Czech Republic
| | - Pavel Rehulka
- Faculty of Military Health Sciences, Department of Molecular Pathology and Biology, University of Defence, Hradec Kralove 500 01, Czech Republic
| | - Ivona Pavkova
- Faculty of Military Health Sciences, Department of Molecular Pathology and Biology, University of Defence, Hradec Kralove 500 01, Czech Republic
| | - Klara Kubelkova
- Faculty of Military Health Sciences, Department of Molecular Pathology and Biology, University of Defence, Hradec Kralove 500 01, Czech Republic
| | - Jan Bavlovic
- Faculty of Military Health Sciences, Department of Molecular Pathology and Biology, University of Defence, Hradec Kralove 500 01, Czech Republic
| | - Jiri Stulik
- Faculty of Military Health Sciences, Department of Molecular Pathology and Biology, University of Defence, Hradec Kralove 500 01, Czech Republic
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6
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Öhrman C, Sahl JW, Sjödin A, Uneklint I, Ballard R, Karlsson L, McDonough RF, Sundell D, Soria K, Bäckman S, Chase K, Brindefalk B, Sozhamannan S, Vallesi A, Hägglund E, Ramirez-Paredes JG, Thelaus J, Colquhoun D, Myrtennäs K, Birdsell D, Johansson A, Wagner DM, Forsman M. Reorganized Genomic Taxonomy of Francisellaceae Enables Design of Robust Environmental PCR Assays for Detection of Francisella tularensis. Microorganisms 2021; 9:146. [PMID: 33440900 PMCID: PMC7826819 DOI: 10.3390/microorganisms9010146] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Revised: 01/01/2021] [Accepted: 01/04/2021] [Indexed: 12/21/2022] Open
Abstract
In recent years, an increasing diversity of species has been recognized within the family Francisellaceae. Unfortunately, novel isolates are sometimes misnamed in initial publications or multiple sources propose different nomenclature for genetically highly similar isolates. Thus, unstructured and occasionally incorrect information can lead to confusion in the scientific community. Historically, detection of Francisella tularensis in environmental samples has been challenging due to the considerable and unknown genetic diversity within the family, which can result in false positive results. We have assembled a comprehensive collection of genome sequences representing most known Francisellaceae species/strains and restructured them according to a taxonomy that is based on phylogenetic structure. From this structured dataset, we identified a small number of genomic regions unique to F. tularensis that are putatively suitable for specific detection of this pathogen in environmental samples. We designed and validated specific PCR assays based on these genetic regions that can be used for the detection of F. tularensis in environmental samples, such as water and air filters.
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Affiliation(s)
- Caroline Öhrman
- CBRN Defence and Security, Swedish Defence Research Agency, FOI, SE 901 82 Umeå, Sweden; (C.Ö.); (A.S.); (I.U.); (L.K.); (D.S.); (S.B.); (B.B.); (E.H.); (J.T.); (K.M.)
| | - Jason W. Sahl
- Pathogen and Microbiome Institute, Northern Arizona University, Flagstaff, AZ 86011, USA; (J.W.S.); (R.B.); (R.F.M.); (K.S.); (D.B.); (D.M.W.)
| | - Andreas Sjödin
- CBRN Defence and Security, Swedish Defence Research Agency, FOI, SE 901 82 Umeå, Sweden; (C.Ö.); (A.S.); (I.U.); (L.K.); (D.S.); (S.B.); (B.B.); (E.H.); (J.T.); (K.M.)
| | - Ingrid Uneklint
- CBRN Defence and Security, Swedish Defence Research Agency, FOI, SE 901 82 Umeå, Sweden; (C.Ö.); (A.S.); (I.U.); (L.K.); (D.S.); (S.B.); (B.B.); (E.H.); (J.T.); (K.M.)
| | - Rebecca Ballard
- Pathogen and Microbiome Institute, Northern Arizona University, Flagstaff, AZ 86011, USA; (J.W.S.); (R.B.); (R.F.M.); (K.S.); (D.B.); (D.M.W.)
| | - Linda Karlsson
- CBRN Defence and Security, Swedish Defence Research Agency, FOI, SE 901 82 Umeå, Sweden; (C.Ö.); (A.S.); (I.U.); (L.K.); (D.S.); (S.B.); (B.B.); (E.H.); (J.T.); (K.M.)
| | - Ryelan F. McDonough
- Pathogen and Microbiome Institute, Northern Arizona University, Flagstaff, AZ 86011, USA; (J.W.S.); (R.B.); (R.F.M.); (K.S.); (D.B.); (D.M.W.)
| | - David Sundell
- CBRN Defence and Security, Swedish Defence Research Agency, FOI, SE 901 82 Umeå, Sweden; (C.Ö.); (A.S.); (I.U.); (L.K.); (D.S.); (S.B.); (B.B.); (E.H.); (J.T.); (K.M.)
| | - Kathleen Soria
- Pathogen and Microbiome Institute, Northern Arizona University, Flagstaff, AZ 86011, USA; (J.W.S.); (R.B.); (R.F.M.); (K.S.); (D.B.); (D.M.W.)
| | - Stina Bäckman
- CBRN Defence and Security, Swedish Defence Research Agency, FOI, SE 901 82 Umeå, Sweden; (C.Ö.); (A.S.); (I.U.); (L.K.); (D.S.); (S.B.); (B.B.); (E.H.); (J.T.); (K.M.)
| | - Kitty Chase
- US Army Medical Research Institute, Fort Detrick, MD 21702, USA;
| | - Björn Brindefalk
- CBRN Defence and Security, Swedish Defence Research Agency, FOI, SE 901 82 Umeå, Sweden; (C.Ö.); (A.S.); (I.U.); (L.K.); (D.S.); (S.B.); (B.B.); (E.H.); (J.T.); (K.M.)
| | - Shanmuga Sozhamannan
- Logistics Management Institute supporting Defense Biological Product Assurance Office (DBPAO) Joint Project Lead, CBRND Enabling Biotechnologies (JPL CBRND EB), Frederick, MD 21702, USA;
| | - Adriana Vallesi
- School of Biosciences and Veterinary Medicine, University of Camerino, 62032 Camerino, Italy;
| | - Emil Hägglund
- CBRN Defence and Security, Swedish Defence Research Agency, FOI, SE 901 82 Umeå, Sweden; (C.Ö.); (A.S.); (I.U.); (L.K.); (D.S.); (S.B.); (B.B.); (E.H.); (J.T.); (K.M.)
| | - Jose Gustavo Ramirez-Paredes
- Ridgeway Biologicals Limited a Ceva Santé Animale Company, Units 1-3 Old Station Business Park, Compton, Berkshire, England RG20 6NE, UK;
| | - Johanna Thelaus
- CBRN Defence and Security, Swedish Defence Research Agency, FOI, SE 901 82 Umeå, Sweden; (C.Ö.); (A.S.); (I.U.); (L.K.); (D.S.); (S.B.); (B.B.); (E.H.); (J.T.); (K.M.)
| | - Duncan Colquhoun
- Fish Health Research Group, Norwegian Veterinary Institute, Oslo, Pb 750 Sentrum, 23 N-0106 Oslo, Norway;
| | - Kerstin Myrtennäs
- CBRN Defence and Security, Swedish Defence Research Agency, FOI, SE 901 82 Umeå, Sweden; (C.Ö.); (A.S.); (I.U.); (L.K.); (D.S.); (S.B.); (B.B.); (E.H.); (J.T.); (K.M.)
| | - Dawn Birdsell
- Pathogen and Microbiome Institute, Northern Arizona University, Flagstaff, AZ 86011, USA; (J.W.S.); (R.B.); (R.F.M.); (K.S.); (D.B.); (D.M.W.)
| | - Anders Johansson
- Department of Clinical Microbiology, Clinical Bacteriology, and Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå University, SE-901 85 Umeå, Sweden;
| | - David M. Wagner
- Pathogen and Microbiome Institute, Northern Arizona University, Flagstaff, AZ 86011, USA; (J.W.S.); (R.B.); (R.F.M.); (K.S.); (D.B.); (D.M.W.)
| | - Mats Forsman
- CBRN Defence and Security, Swedish Defence Research Agency, FOI, SE 901 82 Umeå, Sweden; (C.Ö.); (A.S.); (I.U.); (L.K.); (D.S.); (S.B.); (B.B.); (E.H.); (J.T.); (K.M.)
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7
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Linde J, Homeier-Bachmann T, Dangel A, Riehm JM, Sundell D, Öhrman C, Forsman M, Tomaso H. Genotyping of Francisella tularensis subsp. holarctica from Hares in Germany. Microorganisms 2020; 8:microorganisms8121932. [PMID: 33291395 PMCID: PMC7761992 DOI: 10.3390/microorganisms8121932] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Revised: 11/26/2020] [Accepted: 12/02/2020] [Indexed: 02/04/2023] Open
Abstract
Francisella tularensis is the causative agent of the zoonotic disease tularemia. In Germany, most human infections are caused by contact with infected hares. The aim of this study was to characterize Francisella tularensis subsp. holarctica strains isolated from hares in Germany and to develop bioinformatics tools to analyze their genetic relatedness. In total, 257 German isolates-obtained mainly from hares (n = 233), other vertebrate animals, and ticks, but also from humans (n = 3)-were analyzed within this study. Publically available sequence data from 49 isolates were used to put our isolates into an epidemiological context and to compare isolates from natural foci and humans. Whole-genome sequences were analyzed using core-genome Multi-Locus-Sequence-Typing, canonical Single Nucleotide Polymorphism (SNP) typing and whole-genome SNP typing. An overall conformity of genotype clustering between the typing methods was found, albeit with a lower resolution for canonical single SNP typing. The subclade distribution, both on local and national levels, among strains from humans and hares was similar, suggesting circulation of the same genotypes both in animals and humans. Whilst close to identical isolates of the same subclade were found distributed over large areas, small geographical foci often harbored members of different subclades. In conclusion, although genomic high-resolution typing was shown to be robust, reproducible and allowed the identification of highly closely related strains, genetic profiling alone is not always conclusive for epidemiological linkage of F. tularensis strains.
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Affiliation(s)
- Jörg Linde
- Institute of Bacterial Infections and Zoonoses, Friedrich-Loeffler-Institut, 07743 Jena, Germany;
- Correspondence: ; Tel.: +49-3641-804-2320
| | - Timo Homeier-Bachmann
- Institute of Epidemiology, Friedrich-Loeffler-Institut, 17493 Greifswald-Insel Riems, Germany;
| | - Alexandra Dangel
- Bayerisches Landesamt für Gesundheit und Lebensmittelsicherheit, 85764 Oberschleißheim, Germany; (A.D.); (J.M.R.)
| | - Julia M. Riehm
- Bayerisches Landesamt für Gesundheit und Lebensmittelsicherheit, 85764 Oberschleißheim, Germany; (A.D.); (J.M.R.)
| | - David Sundell
- CBRN Defence and Security, Swedish Defence Research Agency (FOI), SE-901 82 Umeå, Sweden; (D.S.); (C.Ö.); (M.F.)
| | - Caroline Öhrman
- CBRN Defence and Security, Swedish Defence Research Agency (FOI), SE-901 82 Umeå, Sweden; (D.S.); (C.Ö.); (M.F.)
| | - Mats Forsman
- CBRN Defence and Security, Swedish Defence Research Agency (FOI), SE-901 82 Umeå, Sweden; (D.S.); (C.Ö.); (M.F.)
| | - Herbert Tomaso
- Institute of Bacterial Infections and Zoonoses, Friedrich-Loeffler-Institut, 07743 Jena, Germany;
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8
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Complete Genome Sequence of Francisella tularensis subsp. holarctica Strain A271_1 (FDC408), Isolated from a Eurasian Beaver (Castor fiber). Microbiol Resour Announc 2020; 9:9/45/e00738-20. [PMID: 33153998 PMCID: PMC7645653 DOI: 10.1128/mra.00738-20] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Here, we report the complete genome sequence of Francisella tularensis subsp. holarctica strain A271_1, isolated from a Eurasian beaver (Castor fiber) in 2012 in the Berlin/Brandenburg region, Germany. Here, we report the complete genome sequence of Francisella tularensis subsp. holarctica strain A271_1, isolated from a Eurasian beaver (Castor fiber) in 2012 in the Berlin/Brandenburg region, Germany.
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Larson MA, Abdalhamid B, Puniya BL, Helikar T, Kelley DW, Iwen PC. Differences in Blood-derived Francisella tularensis Type B Strains from Clinical Cases of Tularemia. Microorganisms 2020; 8:microorganisms8101515. [PMID: 33019689 PMCID: PMC7600085 DOI: 10.3390/microorganisms8101515] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Revised: 09/26/2020] [Accepted: 09/30/2020] [Indexed: 11/16/2022] Open
Abstract
Francisella tularensis can cause the zoonotic disease tularemia and is partitioned into subspecies due to differences in chromosomal organization and virulence. The subspecies holarctica (type B) is generally considered more clonal than the other subpopulations with moderate virulence compared to the hypervirulent A.I clade. We performed whole genome sequencing (WGS) on six type B strains isolated from the blood of patients with tularemia within a one-year period from the same United States region, to better understand the associated pathogenicity. The WGS data were compared to the prototype strain for this subspecies, specifically FSC200, which was isolated from a patient with tularemia in Europe. These findings revealed 520–528 single nucleotide polymorphisms (SNPs) between the six United States type B strains compared to FSC200, with slightly higher A+T content in the latter strain. In contrast, comparisons between the six type B isolates showed that five of the six type B isolates had only 4–22 SNPs, while one of the strains had 47–53 SNPs. Analysis of SNPs in the core genome for the six United States type B isolates and the FSC200 strain gave similar results, suggesting that some of these mutations may have been nonsynonymous, resulting in altered protein function and pathogenicity.
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Affiliation(s)
- Marilynn A. Larson
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, NE 68198, USA; (B.A.); (D.W.K.); (P.C.I.)
- Correspondence: ; Tel.: +1-402-559-9115
| | - Baha Abdalhamid
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, NE 68198, USA; (B.A.); (D.W.K.); (P.C.I.)
| | - Bhanwar Lal Puniya
- Department of Biochemistry, University of Nebraska-Lincoln, Lincoln, NE 68588, USA; (B.L.P.); (T.H.)
| | - Tomáš Helikar
- Department of Biochemistry, University of Nebraska-Lincoln, Lincoln, NE 68588, USA; (B.L.P.); (T.H.)
| | - David W. Kelley
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, NE 68198, USA; (B.A.); (D.W.K.); (P.C.I.)
| | - Peter C. Iwen
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, NE 68198, USA; (B.A.); (D.W.K.); (P.C.I.)
- Nebraska Public Health Laboratory, Omaha, NE 68198, USA
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10
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Appelt S, Köppen K, Radonić A, Drechsel O, Jacob D, Grunow R, Heuner K. Genetic Diversity and Spatial Segregation of Francisella tularensis Subspecies holarctica in Germany. Front Cell Infect Microbiol 2019; 9:376. [PMID: 31781515 PMCID: PMC6851236 DOI: 10.3389/fcimb.2019.00376] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2019] [Accepted: 10/17/2019] [Indexed: 01/28/2023] Open
Abstract
Francisella tularensis is an intracellular pleomorphic bacterium and the causative agent of tularemia, a zoonotic disease with a wide host range. Among the F. tularensis subspecies, especially F. tularensis subsp. holarctica is of clinical relevance for European countries. The study presented herein focuses namely on genetic diversity and spatial segregation of F. tularensis subsp. holarctica in Germany, as still limited information is available. The investigation is based on the analysis of 34 F. tularensis subsp. holarctica isolates and one draft genome from an outbreak strain. The isolates were cultured from sample material being that of primarily human patients (n = 25) and free-living animals (n = 9). For six of 25 human isolates, epidemiological links between disease onset and tick bites could be established, confirming the importance of arthropod linked transmission of tularemia in Germany. The strains were assigned to three of four major F. tularensis subsp. holarctica clades: B.4, B.6, and B.12. Thereby, B.6 and B.12 clade members were predominantly found; only one human isolate was assigned to clade B.4. Also, it turned out that eight isolates which caused pneumonia in patients clustered into the B.6 clade. Altogether, eight different final subclades were assigned to clade B.6 (biovar I, erythromycin sensitive) and six to B.12 (biovar II, erythromycin resistant) in addition to one new final B.12 subclade. Moreover, for 13 human and 3 animal isolates, final subclade subdivisions were not assigned (B.12 subdivisions B.33 and B.34, and B.6 subdivision B.45) because official nomenclatures are not available yet. This gives credit to the genetic variability of F. tularensis subsp. holarctica strains in Germany. The results clearly point out that the given genetic diversity in Germany seems to be comparably high to that found in other European countries including Scandinavian regions. A spatial segregation of B.6 and B.12 strains was found and statistically confirmed, and B.12 clade members were predominantly found in eastern parts and B.6 members more in western to southern parts of Germany. The portion of B.12 clade members in northeastern parts of Germany was 78.5% and in southwestern parts 1.9%.
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Affiliation(s)
- Sandra Appelt
- Centre for Biological Threats and Special Pathogens (ZBS2), Robert Koch Institute, Berlin, Germany
| | - Kristin Köppen
- Working Group Cellular Interactions of Bacterial Pathogens, ZBS2, Robert Koch Institute, Berlin, Germany
| | - Aleksandar Radonić
- Methodology and Research Infrastructure Genome Sequencing (MF2), Robert Koch Institute, Berlin, Germany
| | - Oliver Drechsel
- Bioinformatics (MF1), Robert Koch Institute, Berlin, Germany
| | - Daniela Jacob
- Centre for Biological Threats and Special Pathogens (ZBS2), Robert Koch Institute, Berlin, Germany
| | - Roland Grunow
- Centre for Biological Threats and Special Pathogens (ZBS2), Robert Koch Institute, Berlin, Germany
| | - Klaus Heuner
- Working Group Cellular Interactions of Bacterial Pathogens, ZBS2, Robert Koch Institute, Berlin, Germany
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11
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Svensson D, Sjögren R, Sundell D, Sjödin A, Trygg J. doepipeline: a systematic approach to optimizing multi-level and multi-step data processing workflows. BMC Bioinformatics 2019; 20:498. [PMID: 31615395 PMCID: PMC6794737 DOI: 10.1186/s12859-019-3091-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Accepted: 09/10/2019] [Indexed: 12/30/2022] Open
Abstract
BACKGROUND Selecting the proper parameter settings for bioinformatic software tools is challenging. Not only will each parameter have an individual effect on the outcome, but there are also potential interaction effects between parameters. Both of these effects may be difficult to predict. To make the situation even more complex, multiple tools may be run in a sequential pipeline where the final output depends on the parameter configuration for each tool in the pipeline. Because of the complexity and difficulty of predicting outcomes, in practice parameters are often left at default settings or set based on personal or peer experience obtained in a trial and error fashion. To allow for the reliable and efficient selection of parameters for bioinformatic pipelines, a systematic approach is needed. RESULTS We present doepipeline, a novel approach to optimizing bioinformatic software parameters, based on core concepts of the Design of Experiments methodology and recent advances in subset designs. Optimal parameter settings are first approximated in a screening phase using a subset design that efficiently spans the entire search space, then optimized in the subsequent phase using response surface designs and OLS modeling. Doepipeline was used to optimize parameters in four use cases; 1) de-novo assembly, 2) scaffolding of a fragmented genome assembly, 3) k-mer taxonomic classification of Oxford Nanopore Technologies MinION reads, and 4) genetic variant calling. In all four cases, doepipeline found parameter settings that produced a better outcome with respect to the characteristic measured when compared to using default values. Our approach is implemented and available in the Python package doepipeline. CONCLUSIONS Our proposed methodology provides a systematic and robust framework for optimizing software parameter settings, in contrast to labor- and time-intensive manual parameter tweaking. Implementation in doepipeline makes our methodology accessible and user-friendly, and allows for automatic optimization of tools in a wide range of cases. The source code of doepipeline is available at https://github.com/clicumu/doepipeline and it can be installed through conda-forge.
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Affiliation(s)
- Daniel Svensson
- Department of Chemistry, Computational Life Science Cluster (CLiC), Umeå University, Umeå, Sweden
| | - Rickard Sjögren
- Department of Chemistry, Computational Life Science Cluster (CLiC), Umeå University, Umeå, Sweden
- Corporate Research, Sartorius AG, Umeå, Sweden
| | - David Sundell
- Division of CBRN Security and Defence, FOI - Swedish Defence Research Agency, Umeå, Sweden
| | - Andreas Sjödin
- Division of CBRN Security and Defence, FOI - Swedish Defence Research Agency, Umeå, Sweden
| | - Johan Trygg
- Department of Chemistry, Computational Life Science Cluster (CLiC), Umeå University, Umeå, Sweden.
- Corporate Research, Sartorius AG, Umeå, Sweden.
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12
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Thelaus J, Lundmark E, Lindgren P, Sjödin A, Forsman M. Galleria mellonella Reveals Niche Differences Between Highly Pathogenic and Closely Related Strains of Francisella spp. Front Cell Infect Microbiol 2018; 8:188. [PMID: 29922601 PMCID: PMC5996057 DOI: 10.3389/fcimb.2018.00188] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2018] [Accepted: 05/15/2018] [Indexed: 11/13/2022] Open
Abstract
Francisella tularensis, a highly virulent bacteria that causes the zoonotic disease tularemia, is considered a potential agent of biological warfare and bioterrorism. Although the host range for several species within the Francisella is known, little is known about the natural reservoirs of various Francisella species. The lack of knowledge regarding the environmental fates of these pathogens greatly reduces the possibilities for microbial risk assessments. The greater wax moth (Galleria mellonella) is an insect of the order Lepidoptera that has been used as an alternative model to study microbial infection during recent years. The aim of this study was to evaluate G. mellonella as a model system for studies of human pathogenic and closely related opportunistic and non-pathogenic strains within the Francisella genus. The employed G. mellonella larvae model demonstrated differences in lethality between human pathogenic and human non-pathogenic or opportunistic Francisella species. The F. novicida, F. hispaniensis and F. philomiragia strains were significantly more virulent in the G. mellonella model than the strains of human pathogens F. t. holarctica and F. t. tularensis. Our data show that G. mellonella is a possible in vivo model of insect immunity for studies of both opportunistic and virulent lineages of Francisella spp., that produces inverse results regarding lethality in G. mellonella and incapacitating disease in humans. The results provide insight into the potential host specificity of F. tularensis and closely related members of the same genus, thus increasing our present understanding of Francisella spp. ecology.
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13
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Busch A, Thomas P, Zuchantke E, Brendebach H, Neubert K, Gruetzke J, Al Dahouk S, Peters M, Hotzel H, Neubauer H, Tomaso H. Revisiting Francisella tularensis subsp. holarctica, Causative Agent of Tularemia in Germany With Bioinformatics: New Insights in Genome Structure, DNA Methylation and Comparative Phylogenetic Analysis. Front Microbiol 2018; 9:344. [PMID: 29593661 PMCID: PMC5859110 DOI: 10.3389/fmicb.2018.00344] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2017] [Accepted: 02/12/2018] [Indexed: 12/30/2022] Open
Abstract
Francisella (F.) tularensis is a highly virulent, Gram-negative bacterial pathogen and the causative agent of the zoonotic disease tularemia. Here, we generated, analyzed and characterized a high quality circular genome sequence of the F. tularensis subsp. holarctica strain 12T0050 that caused fatal tularemia in a hare. Besides the genomic structure, we focused on the analysis of oriC, unique to the Francisella genus and regulating replication in and outside hosts and the first report on genomic DNA methylation of a Francisella strain. The high quality genome was used to establish and evaluate a diagnostic whole genome sequencing pipeline. A genotyping strategy for F. tularensis was developed using various bioinformatics tools for genotyping. Additionally, whole genome sequences of F. tularensis subsp. holarctica isolates isolated in the years 2008–2015 in Germany were generated. A phylogenetic analysis allowed to determine the genetic relatedness of these isolates and confirmed the highly conserved nature of F. tularensis subsp. holarctica.
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Affiliation(s)
- Anne Busch
- Institute of Bacterial Infections and Zoonoses, Friedrich-Loeffler-Institut, Jena, Germany
| | - Prasad Thomas
- Institute of Bacterial Infections and Zoonoses, Friedrich-Loeffler-Institut, Jena, Germany
| | - Eric Zuchantke
- Institute of Bacterial Infections and Zoonoses, Friedrich-Loeffler-Institut, Jena, Germany
| | - Holger Brendebach
- Department of Biological Safety, German Federal Institute for Risk Assessment, Berlin, Germany
| | - Kerstin Neubert
- Algorithmic Bioinformatics, Department of Mathematics and Computer Science, Institute of Computer Science, Freie Universität Berlin, Berlin, Germany
| | - Josephine Gruetzke
- Department of Biological Safety, German Federal Institute for Risk Assessment, Berlin, Germany
| | - Sascha Al Dahouk
- Department of Biological Safety, German Federal Institute for Risk Assessment, Berlin, Germany
| | - Martin Peters
- Standort Arnsberg, Chemisches und Veterinäruntersuchungsamt Westfalen, Arnsberg, Germany
| | - Helmut Hotzel
- Institute of Bacterial Infections and Zoonoses, Friedrich-Loeffler-Institut, Jena, Germany
| | - Heinrich Neubauer
- Institute of Bacterial Infections and Zoonoses, Friedrich-Loeffler-Institut, Jena, Germany
| | - Herbert Tomaso
- Institute of Bacterial Infections and Zoonoses, Friedrich-Loeffler-Institut, Jena, Germany
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14
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Whole-Genome Relationships among Francisella Bacteria of Diverse Origins Define New Species and Provide Specific Regions for Detection. Appl Environ Microbiol 2017; 83:AEM.02589-16. [PMID: 27881415 DOI: 10.1128/aem.02589-16] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2016] [Accepted: 11/16/2016] [Indexed: 02/06/2023] Open
Abstract
Francisella tularensis is a highly virulent zoonotic pathogen that causes tularemia and, because of weaponization efforts in past world wars, is considered a tier 1 biothreat agent. Detection and surveillance of F. tularensis may be confounded by the presence of uncharacterized, closely related organisms. Through DNA-based diagnostics and environmental surveys, novel clinical and environmental Francisella isolates have been obtained in recent years. Here we present 7 new Francisella genomes and a comparison of their characteristics to each other and to 24 publicly available genomes as well as a comparative analysis of 16S rRNA and sdhA genes from over 90 Francisella strains. Delineation of new species in bacteria is challenging, especially when isolates having very close genomic characteristics exhibit different physiological features-for example, when some are virulent pathogens in humans and animals while others are nonpathogenic or are opportunistic pathogens. Species resolution within Francisella varies with analyses of single genes, multiple gene or protein sets, or whole-genome comparisons of nucleic acid and amino acid sequences. Analyses focusing on single genes (16S rRNA, sdhA), multiple gene sets (virulence genes, lipopolysaccharide [LPS] biosynthesis genes, pathogenicity island), and whole-genome comparisons (nucleotide and protein) gave congruent results, but with different levels of discrimination confidence. We designate four new species within the genus; Francisella opportunistica sp. nov. (MA06-7296), Francisella salina sp. nov. (TX07-7308), Francisella uliginis sp. nov. (TX07-7310), and Francisella frigiditurris sp. nov. (CA97-1460). This study provides a robust comparative framework to discern species and virulence features of newly detected Francisella bacteria. IMPORTANCE DNA-based detection and sequencing methods have identified thousands of new bacteria in the human body and the environment. In most cases, there are no cultured isolates that correspond to these sequences. While DNA-based approaches are highly sensitive, accurately assigning species is difficult without known near relatives for comparison. This ambiguity poses challenges for clinical cases, disease epidemics, and environmental surveillance, for which response times must be short. Many new Francisella isolates have been identified globally. However, their species designations and potential for causing human disease remain ambiguous. Through detailed genome comparisons, we identified features that differentiate F. tularensis from clinical and environmental Francisella isolates and provide a knowledge base for future comparison of Francisella organisms identified in clinical samples or environmental surveys.
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15
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Dwibedi C, Birdsell D, Lärkeryd A, Myrtennäs K, Öhrman C, Nilsson E, Karlsson E, Hochhalter C, Rivera A, Maltinsky S, Bayer B, Keim P, Scholz HC, Tomaso H, Wittwer M, Beuret C, Schuerch N, Pilo P, Hernández Pérez M, Rodriguez-Lazaro D, Escudero R, Anda P, Forsman M, Wagner DM, Larsson P, Johansson A. Long-range dispersal moved Francisella tularensis into Western Europe from the East. Microb Genom 2016; 2:e000100. [PMID: 28348839 PMCID: PMC5359409 DOI: 10.1099/mgen.0.000100] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2016] [Accepted: 11/22/2016] [Indexed: 01/31/2023] Open
Abstract
For many infections transmitting to humans from reservoirs in nature, disease dispersal patterns over space and time are largely unknown. Here, a reversed genomics approach helped us understand disease dispersal and yielded insight into evolution and biological properties of Francisella tularensis, the bacterium causing tularemia. We whole-genome sequenced 67 strains and characterized by single-nucleotide polymorphism assays 138 strains, collected from individuals infected 1947-2012 across Western Europe. We used the data for phylogenetic, population genetic and geographical network analyses. All strains (n=205) belonged to a monophyletic population of recent ancestry not found outside Western Europe. Most strains (n=195) throughout the study area were assigned to a star-like phylogenetic pattern indicating that colonization of Western Europe occurred via clonal expansion. In the East of the study area, strains were more diverse, consistent with a founder population spreading from east to west. The relationship of genetic and geographic distance within the F. tularensis population was complex and indicated multiple long-distance dispersal events. Mutation rate estimates based on year of isolation indicated null rates; in outbreak hotspots only, there was a rate of 0.4 mutations/genome/year. Patterns of nucleotide substitution showed marked AT mutational bias suggestive of genetic drift. These results demonstrate that tularemia has moved from east to west in Europe and that F. tularensis has a biology characterized by long-range geographical dispersal events and mostly slow, but variable, replication rates. The results indicate that mutation-driven evolution, a resting survival phase, genetic drift and long-distance geographical dispersal events have interacted to generate genetic diversity within this species.
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Affiliation(s)
- Chinmay Dwibedi
- Department of Clinical Microbiology and the Laboratory for Molecular Infection Medicine Sweden, Umeå University, Umeå, Sweden
- Division of CBRN Security and Defence, Swedish Defense Research Agency, Umeå, Sweden
| | - Dawn Birdsell
- Center for Microbial Genetics and Genomics, Northern Arizona University, Flagstaff AZ, USA
| | - Adrian Lärkeryd
- Division of CBRN Security and Defence, Swedish Defense Research Agency, Umeå, Sweden
| | - Kerstin Myrtennäs
- Division of CBRN Security and Defence, Swedish Defense Research Agency, Umeå, Sweden
| | - Caroline Öhrman
- Division of CBRN Security and Defence, Swedish Defense Research Agency, Umeå, Sweden
| | - Elin Nilsson
- Division of CBRN Security and Defence, Swedish Defense Research Agency, Umeå, Sweden
| | - Edvin Karlsson
- Division of CBRN Security and Defence, Swedish Defense Research Agency, Umeå, Sweden
| | - Christian Hochhalter
- Center for Microbial Genetics and Genomics, Northern Arizona University, Flagstaff AZ, USA
| | - Andrew Rivera
- Center for Microbial Genetics and Genomics, Northern Arizona University, Flagstaff AZ, USA
| | - Sara Maltinsky
- Center for Microbial Genetics and Genomics, Northern Arizona University, Flagstaff AZ, USA
| | - Brittany Bayer
- Center for Microbial Genetics and Genomics, Northern Arizona University, Flagstaff AZ, USA
| | - Paul Keim
- Center for Microbial Genetics and Genomics, Northern Arizona University, Flagstaff AZ, USA
- Translational Genomics Research Institute North, Flagstaff AZ, USA
| | | | - Herbert Tomaso
- Institute of Bacterial Infections and Zoonoses Friedrich-Loeffler, Institut Federal Research Institute for Animal Health, Jena, Germany
| | - Matthias Wittwer
- Biology Division, Spietz Laboratory, Federal Office for Civil Protection, Spietz, Switzerland
| | - Christian Beuret
- Biology Division, Spietz Laboratory, Federal Office for Civil Protection, Spietz, Switzerland
| | - Nadia Schuerch
- Biology Division, Spietz Laboratory, Federal Office for Civil Protection, Spietz, Switzerland
| | - Paola Pilo
- Institute of Veterinary Bacteriology, University of Bern, Bern, Switzerland
| | - Marta Hernández Pérez
- Laboratory of Molecular Biology and Microbiology, Instituto Tecnológico Agrario de Castilla y León, Valladolid, Spain
- Departamento de Ingeniería Agrícola y Forestal, Universidad de Valladolid, Palencia, Spain
| | | | - Raquel Escudero
- Centro Nacional de Microbiología, Instituto de Salud Carlos III, Madrid, Spain
| | - Pedro Anda
- Centro Nacional de Microbiología, Instituto de Salud Carlos III, Madrid, Spain
| | - Mats Forsman
- Division of CBRN Security and Defence, Swedish Defense Research Agency, Umeå, Sweden
| | - David M. Wagner
- Center for Microbial Genetics and Genomics, Northern Arizona University, Flagstaff AZ, USA
| | - Pär Larsson
- Division of CBRN Security and Defence, Swedish Defense Research Agency, Umeå, Sweden
| | - Anders Johansson
- Department of Clinical Microbiology and the Laboratory for Molecular Infection Medicine Sweden, Umeå University, Umeå, Sweden
- Correspondence Anders Johansson ()
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16
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Gunnell MK, Robison RA, Adams BJ. Natural Selection in Virulence Genes of Francisella tularensis. J Mol Evol 2016; 82:264-78. [PMID: 27177502 DOI: 10.1007/s00239-016-9743-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2014] [Accepted: 04/29/2016] [Indexed: 02/06/2023]
Abstract
A fundamental tenet of evolution is that alleles that are under negative selection are often deleterious and confer no evolutionary advantage. Negatively selected alleles are removed from the gene pool and are eventually extinguished from the population. Conversely, alleles under positive selection do confer an evolutionary advantage and lead to an increase in the overall fitness of the organism. These alleles increase in frequency until they eventually become fixed in the population. Francisella tularensis is a zoonotic pathogen and a potential biothreat agent. The most virulent type of F. tularensis, Type A, is distributed across North America with Type A.I occurring mainly in the east and Type A.II appearing mainly in the west. F. tularensis is thought to be a genome in decay (losing genes) because of the relatively large number of pseudogenes present in its genome. We hypothesized that the observed frequency of gene loss/pseudogenes may be an artifact of evolution in response to a changing environment, and that genes involved in virulence should be under strong positive selection. To test this hypothesis, we sequenced and compared whole genomes of Type A.I and A.II isolates. We analyzed a subset of virulence and housekeeping genes from several F. tularensis subspecies genomes to ascertain the presence and extent of positive selection. Eleven previously identified virulence genes were screened for positive selection along with 10 housekeeping genes. Analyses of selection yielded one housekeeping gene and 7 virulence genes which showed significant evidence of positive selection at loci implicated in cell surface structures and membrane proteins, metabolism and biosynthesis, transcription, translation and cell separation, and substrate binding and transport. Our results suggest that while the loss of functional genes through disuse could be accelerated by negative selection, the genome decay in Francisella could also be the byproduct of adaptive evolution driven by complex interactions between host, pathogen, and thier environment, as evidenced by several of its virulence genes which are undergoing strong, positive selection.
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Affiliation(s)
- Mark K Gunnell
- Department of Microbiology and Molecular Biology, Brigham Young University, Provo, UT, 84602, USA. .,Microbiology Branch, Life Sciences Division, Dugway Proving Ground, Dugway, UT, 84022, USA.
| | - Richard A Robison
- Department of Microbiology and Molecular Biology, Brigham Young University, Provo, UT, 84602, USA
| | - Byron J Adams
- Department of Biology, Brigham Young University, Provo, UT, 84602, USA
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17
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Dankova V, Balonova L, Link M, Straskova A, Sheshko V, Stulik J. Inactivation of Francisella tularensis Gene Encoding Putative ABC Transporter Has a Pleiotropic Effect upon Production of Various Glycoconjugates. J Proteome Res 2016; 15:510-24. [DOI: 10.1021/acs.jproteome.5b00864] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Affiliation(s)
- Vera Dankova
- Department
of Molecular Pathology and Biology, Faculty of Military Health Sciences, University of Defence, Hradec Kralove 500 01, Czech Republic
| | - Lucie Balonova
- Department
of Molecular Pathology and Biology, Faculty of Military Health Sciences, University of Defence, Hradec Kralove 500 01, Czech Republic
| | - Marek Link
- Department
of Molecular Pathology and Biology, Faculty of Military Health Sciences, University of Defence, Hradec Kralove 500 01, Czech Republic
| | - Adela Straskova
- Department
of Phototrophic Microorganisms, Institute of Microbiology, The Academy of Sciences of The Czech Republic, Trebon 379 81, Czech Republic
| | - Valeria Sheshko
- Department
of Molecular Pathology and Biology, Faculty of Military Health Sciences, University of Defence, Hradec Kralove 500 01, Czech Republic
| | - Jiri Stulik
- Department
of Molecular Pathology and Biology, Faculty of Military Health Sciences, University of Defence, Hradec Kralove 500 01, Czech Republic
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18
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Karadenizli A, Forsman M, Şimşek H, Taner M, Öhrman C, Myrtennäs K, Lärkeryd A, Johansson A, Özdemir L, Sjödin A. Genomic analyses of Francisella tularensis strains confirm disease transmission from drinking water sources, Turkey, 2008, 2009 and 2012. ACTA ACUST UNITED AC 2015; 20. [PMID: 26062561 DOI: 10.2807/1560-7917.es2015.20.21.21136] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Waterborne epidemics of tularaemia caused by Francisella tularensis are increasingly reported in Turkey. We have used whole genome sequencing to investigate if F. tularensis isolated from patients could be traced back to drinking water sources. Tonsil swabs from 33 patients diagnosed with oropharyngeal tularaemia in three outbreaks and 140 water specimens were analysed. F. tularensis subsp. holarctica was confirmed by microagglutination and PCR in 12 patients and five water specimens. Genomic analysis of three pairs of patient and water isolates from outbreaks in Sivas, Çorum, and Kocaeli showed the isolates to belong to two new clusters of the F. tularensis B.12 genetic clade. The clusters were defined by 19 and 15 single nucleotide polymorphisms (SNPs) in a multiple alignment based on 507 F. tularensis genomes. One synonymous SNP was chosen as a new canonical SNP (canSNP) for each cluster for future use in diagnostic assays. No SNP was identified between the genomes from the patient–water pair of isolates from Kocaeli, one SNP between the pair of isolates from Sivas, whereas the pair from Çorum differed at seven SNPs. These results illustrate the power of whole genome sequencing for tracing F. tularensis patient isolates back to their environmental source.
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Affiliation(s)
- A Karadenizli
- Department of Medical Microbiology, Kocaeli University, Kocaeli, Turkey
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19
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Afset JE, Larssen KW, Bergh K, Sjödin A, Lärkeryd A, Johansson A, Forsman M. Phylogeographical pattern of Francisella tularensis in a nationwide outbreak of tularaemia in Norway, 2011. Euro Surveill 2015. [DOI: 10.2807/1560-7917.es2015.20.19.21125] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In 2011, a nationwide outbreak of tularaemia occurred in Norway with 180 recorded cases. It was associated with the largest peak in lemming density seen in 40 years. Francisella tularensis was isolated from 18 patients. To study the geographical distribution of F. tularensis genotypes in Norway and correlate genotype with epidemiology and clinical presentation, we performed whole genome sequencing of patient isolates. All 18 genomes from the outbreak carried genetic signatures of F. tularensis subsp. holarctica and were assigned to genetic clades using canonical single nucleotide polymorphisms. Ten isolates were assigned to major genetic clade B.6 (subclade B.7), seven to clade B.12, and one to clade B.4. The B.6 subclade B.7 was most common in southern and central Norway, while clade B.12 was evenly distributed between the southern, central and northern parts of the country. There was no association between genotype and clinical presentation of tularaemia, time of year or specimen type. We found extensive sequence similarity with F. tularensis subsp. holarctica genomes from high-endemic tularaemia areas in Sweden. Finding nearly identical genomes across large geographical distances in Norway and Sweden imply a life cycle of the bacterium without replication between the outbreaks and raise new questions about long-range migration mechanisms.
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Affiliation(s)
- J E Afset
- Department of Laboratory Medicine, Children’s and Women’s Health, Faculty of Medicine, Norwegian University of Science and Technology, Trondheim, Norway
- Department of Medical Microbiology, St. Olavs Hospital, University Hospital, Trondheim, Norway
| | - K W Larssen
- Department of Medical Microbiology, St. Olavs Hospital, University Hospital, Trondheim, Norway
| | - K Bergh
- Department of Medical Microbiology, St. Olavs Hospital, University Hospital, Trondheim, Norway
- Department of Laboratory Medicine, Children’s and Women’s Health, Faculty of Medicine, Norwegian University of Science and Technology, Trondheim, Norway
| | - A Sjödin
- Division of CBRN Security and Defence, FOI - Swedish Defence Research Agency, Umeå, Sweden
| | - A Lärkeryd
- Division of CBRN Security and Defence, FOI - Swedish Defence Research Agency, Umeå, Sweden
| | - A Johansson
- Department of Clinical Microbiology, The Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå University, Umeå, Sweden
| | - M Forsman
- Division of CBRN Security and Defence, FOI - Swedish Defence Research Agency, Umeå, Sweden
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Bäckman S, Näslund J, Forsman M, Thelaus J. Transmission of tularemia from a water source by transstadial maintenance in a mosquito vector. Sci Rep 2015; 5:7793. [PMID: 25609657 PMCID: PMC4302321 DOI: 10.1038/srep07793] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2014] [Accepted: 12/16/2014] [Indexed: 01/26/2023] Open
Abstract
Mosquitoes are thought to function as mechanical vectors of Francisella tularensis subspecies holarctica (F. t. holarctica) causing tularemia in humans. We investigated the clinical relevance of transstadially maintained F. t. holarctica in mosquitoes. Aedes egypti larvae exposed to a fully virulent F. t. holarctica strain for 24 hours, were allowed to develop into adults when they were individually homogenized. Approximately 24% of the homogenates tested positive for F. t. DNA in PCR. Mice injected with the mosquito homogenates acquired tularemia within 5 days. This novel finding demonstrates the possibility of transmission of bacteria by adult mosquitoes having acquired the pathogen from their aquatic larval habitats.
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Affiliation(s)
- Stina Bäckman
- The Swedish Defence Research Agency, FOI Division of CBRN Defence and Security SE- 901 82 Umeå, Sweden
| | - Jonas Näslund
- The Swedish Defence Research Agency, FOI Division of CBRN Defence and Security SE- 901 82 Umeå, Sweden
| | - Mats Forsman
- The Swedish Defence Research Agency, FOI Division of CBRN Defence and Security SE- 901 82 Umeå, Sweden
| | - Johanna Thelaus
- The Swedish Defence Research Agency, FOI Division of CBRN Defence and Security SE- 901 82 Umeå, Sweden
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21
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Crane DD, Bauler TJ, Wehrly TD, Bosio CM. Mitochondrial ROS potentiates indirect activation of the AIM2 inflammasome. Front Microbiol 2014; 5:438. [PMID: 25191316 PMCID: PMC4138581 DOI: 10.3389/fmicb.2014.00438] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2014] [Accepted: 08/01/2014] [Indexed: 01/06/2023] Open
Abstract
Activation of the inflammasome is important for the detection and clearance of cytosolic pathogens. In contrast to avirulent Francisella novicida (Fn), infection with virulent Francisella tularensis ssp tularensis does not trigger activation of the host AIM2 inflammasome. Here we show that differential activation of AIM2 following Francisella infection is due to sensitivity of each isolate to reactive oxygen species (ROS). ROS present at the outset of Fn infection contributes to activation of the AIM2 inflammasome, independent of NLRP3 and NADPH oxidase. Rather, mitochondrial ROS (mROS) is critical for Fn stimulation of the inflammasome. This study represents the first demonstration of the importance of mROS in the activation of the AIM2 inflammasome by bacteria. Our results also demonstrate that bacterial resistance to mROS is a mechanism of virulence for early evasion of detection by the host.
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Affiliation(s)
- Deborah D Crane
- Immunity to Pulmonary Pathogens Section, Laboratory of Intracellular Parasites, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases - National Institutes of Health Hamilton, MT, USA
| | - Timothy J Bauler
- Immunity to Pulmonary Pathogens Section, Laboratory of Intracellular Parasites, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases - National Institutes of Health Hamilton, MT, USA
| | - Tara D Wehrly
- Immunity to Pulmonary Pathogens Section, Laboratory of Intracellular Parasites, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases - National Institutes of Health Hamilton, MT, USA
| | - Catharine M Bosio
- Immunity to Pulmonary Pathogens Section, Laboratory of Intracellular Parasites, Rocky Mountain Laboratories, National Institute of Allergy and Infectious Diseases - National Institutes of Health Hamilton, MT, USA
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Kingry LC, Petersen JM. Comparative review of Francisella tularensis and Francisella novicida. Front Cell Infect Microbiol 2014; 4:35. [PMID: 24660164 PMCID: PMC3952080 DOI: 10.3389/fcimb.2014.00035] [Citation(s) in RCA: 142] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2013] [Accepted: 02/22/2014] [Indexed: 01/08/2023] Open
Abstract
Francisella tularensis is the causative agent of the acute disease tularemia. Due to its extreme infectivity and ability to cause disease upon inhalation, F. tularensis has been classified as a biothreat agent. Two subspecies of F. tularensis, tularensis and holarctica, are responsible for tularemia in humans. In comparison, the closely related species F. novicida very rarely causes human illness and cases that do occur are associated with patients who are immune compromised or have other underlying health problems. Virulence between F. tularensis and F. novicida also differs in laboratory animals. Despite this varying capacity to cause disease, the two species share ~97% nucleotide identity, with F. novicida commonly used as a laboratory surrogate for F. tularensis. As the F. novicida U112 strain is exempt from U.S. select agent regulations, research studies can be carried out in non-registered laboratories lacking specialized containment facilities required for work with virulent F. tularensis strains. This review is designed to highlight phenotypic (clinical, ecological, virulence, and pathogenic) and genomic differences between F. tularensis and F. novicida that warrant maintaining F. novicida and F. tularensis as separate species. Standardized nomenclature for F. novicida is critical for accurate interpretation of experimental results, limiting clinical confusion between F. novicida and F. tularensis and ensuring treatment efficacy studies utilize virulent F. tularensis strains.
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Affiliation(s)
- Luke C Kingry
- Division of Vector-Borne Diseases, Bacterial Diseases Branch, Centers for Disease Control and Prevention Fort Collins, CO, USA
| | - Jeannine M Petersen
- Division of Vector-Borne Diseases, Bacterial Diseases Branch, Centers for Disease Control and Prevention Fort Collins, CO, USA
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23
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Thelaus J, Andersson A, Broman T, Bäckman S, Granberg M, Karlsson L, Kuoppa K, Larsson E, Lundmark E, Lundström JO, Mathisen P, Näslund J, Schäfer M, Wahab T, Forsman M. Francisella tularensis subspecies holarctica occurs in Swedish mosquitoes, persists through the developmental stages of laboratory-infected mosquitoes and is transmissible during blood feeding. MICROBIAL ECOLOGY 2014; 67:96-107. [PMID: 24057273 PMCID: PMC3907667 DOI: 10.1007/s00248-013-0285-1] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2013] [Accepted: 08/28/2013] [Indexed: 05/29/2023]
Abstract
In Sweden, mosquitoes are considered the major vectors of the bacterium Francisella tularensis subsp. holarctica, which causes tularaemia. The aim of this study was to investigate whether mosquitoes acquire the bacterium as aquatic larvae and transmit the disease as adults. Mosquitoes sampled in a Swedish area where tularaemia is endemic (Örebro) were positive for the presence of F. tularensis deoxyribonucleic acid throughout the summer. Presence of the clinically relevant F. tularensis subsp. holarctica was confirmed in 11 out of the 14 mosquito species sampled. Experiments performed using laboratory-reared Aedes aegypti confirmed that F. tularensis subsp. holarctica was transstadially maintained from orally infected larvae to adult mosquitoes and that 25% of the adults exposed as larvae were positive for the presence of F. tularensis-specific sequences for at least 2 weeks. In addition, we found that F. tularensis subsp. holarctica was transmitted to 58% of the adult mosquitoes feeding on diseased mice. In a small-scale in vivo transmission experiment with F. tularensis subsp. holarctica-positive adult mosquitoes and susceptible mice, none of the animals developed tularaemia. However, we confirmed that there was transmission of the bacterium to blood vials by mosquitoes that had been exposed to the bacterium in the larval stage. Taken together, these results provide evidence that mosquitoes play a role in disease transmission in part of Sweden where tularaemia recurs.
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Affiliation(s)
- J Thelaus
- Division of CBRN Defence and Security, Swedish Defence Research Agency, 90182, Umea, Sweden,
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24
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Coolen JPM, Sjödin A, Maraha B, Hajer GF, Forsman M, Verspui E, Frenay HME, Notermans DW, de Vries MC, Reubsaet FAG, Paauw A, Roeselers G. Draft genome sequence of Francisella tularensis subsp. holarctica BD11-00177. Stand Genomic Sci 2013; 8:539-47. [PMID: 24501637 PMCID: PMC3910693 DOI: 10.4056/sigs.4217923] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Francisella tularensis is a facultative intracellular bacterium in the class Gammaproteobacteria. This strain is of interest because it is the etiologic agent of tularemia and a highly virulent category A biothreat agent. Here we describe the draft genome sequence and annotation of Francisella tularensis subsp. holarctica BD11-00177, isolated from the first case of indigenous tularemia detected in The Netherlands since 1953. Whole genome DNA sequence analysis assigned this isolate to the genomic group B.FTNF002–00, which previously has been exclusively reported from Spain, France, Italy, Switzerland and Germany. Automatic annotation of the 1,813,372 bp draft genome revealed 2,103 protein-coding and 46 RNA genes.
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Affiliation(s)
| | - Andreas Sjödin
- Division for CBRN Defence and Security, FOI - Swedish Defence Research Agency, Umeå, Sweden
| | - Boulos Maraha
- Department of Medical Microbiology, Beatrix Hospital, Gorinchem and Albert Schweitzer Hospital, Dordrecht, The Netherlands
| | - Gerard F Hajer
- Department of Surgery, Beatrix Hospital, Gorinchem, The Netherlands
| | - Mats Forsman
- Division for CBRN Defence and Security, FOI - Swedish Defence Research Agency, Umeå, Sweden
| | - Ellen Verspui
- Public Health Service Zuid Holland Zuid, Dordrecht, The Netherlands
| | - Hendrina M E Frenay
- Department of Medical Microbiology, Beatrix Hospital, Gorinchem and Albert Schweitzer Hospital, Dordrecht, The Netherlands
| | - Daan W Notermans
- Diagnostic Laboratory for Infectious Diseases and Perinatal Screening (LIS), Center for Infectious Disease Control, National Institute of Public Health and the Environment (RIVM), Bilthoven, The Netherlands
| | - Maaike C de Vries
- Diagnostic Laboratory for Infectious Diseases and Perinatal Screening (LIS), Center for Infectious Disease Control, National Institute of Public Health and the Environment (RIVM), Bilthoven, The Netherlands
| | - Frans A G Reubsaet
- Diagnostic Laboratory for Infectious Diseases and Perinatal Screening (LIS), Center for Infectious Disease Control, National Institute of Public Health and the Environment (RIVM), Bilthoven, The Netherlands
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