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Herron ICT, Laws TR, Nelson M. Marmosets as models of infectious diseases. Front Cell Infect Microbiol 2024; 14:1340017. [PMID: 38465237 PMCID: PMC10921895 DOI: 10.3389/fcimb.2024.1340017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2023] [Accepted: 01/29/2024] [Indexed: 03/12/2024] Open
Abstract
Animal models of infectious disease often serve a crucial purpose in obtaining licensure of therapeutics and medical countermeasures, particularly in situations where human trials are not feasible, i.e., for those diseases that occur infrequently in the human population. The common marmoset (Callithrix jacchus), a Neotropical new-world (platyrrhines) non-human primate, has gained increasing attention as an animal model for a number of diseases given its small size, availability and evolutionary proximity to humans. This review aims to (i) discuss the pros and cons of the common marmoset as an animal model by providing a brief snapshot of how marmosets are currently utilized in biomedical research, (ii) summarize and evaluate relevant aspects of the marmoset immune system to the study of infectious diseases, (iii) provide a historical backdrop, outlining the significance of infectious diseases and the importance of developing reliable animal models to test novel therapeutics, and (iv) provide a summary of infectious diseases for which a marmoset model exists, followed by an in-depth discussion of the marmoset models of two studied bacterial infectious diseases (tularemia and melioidosis) and one viral infectious disease (viral hepatitis C).
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Affiliation(s)
- Ian C. T. Herron
- CBR Division, Defence Science and Technology Laboratory (Dstl), Salisbury, United Kingdom
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2
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Köppen K, Rydzewski K, Doellinger J, Myrtennäs K, Forsman M, Appelt S, Scholz H, Heuner K. Phenotypic and genotypic discrimination of Francisella tularensis ssp. holarctica clades. Int J Med Microbiol 2023; 313:151583. [PMID: 37331050 DOI: 10.1016/j.ijmm.2023.151583] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2022] [Revised: 06/12/2023] [Accepted: 06/13/2023] [Indexed: 06/20/2023] Open
Abstract
Francisella tularensis is the causative agent of tularemia, a zoonotic disease with a wide host range. F. tularensis ssp. holarctica (Fth) is of clinical relevance for European countries, including Germany. Whole genome sequencing methods, including canonical Single Nucleotide Polymorphism (canSNP) typing and whole genome SNP typing, have revealed that European Fth strains belong to a few monophyletic populations. The majority of German Fth isolates belong to two basal phylogenetic clades B.6 (biovar I) and B.12 (biovar II). Strains of B.6 and B.12 seem to differ in their pathogenicity, and it has been shown that strains of biovar II are resistant against erythromycin. In this study, we present data corroborating our previous data demonstrating that basal clade B.12 can be divided into clades B.71 and B.72. By applying phylogenetic whole genome analysis as well as proteome analysis, we could verify that strains of these two clades are distinct from one another. This was confirmed by measuring the intensity of backscatter light on bacteria grown in liquid media. Strains belonging to clades B.6, B.71 or B.72 showed clade-specific backscatter growth curves. Furthermore, we present the whole genome sequence of strain A-1341, as a reference genome of clade B.71, and whole proteomes comparison of Fth strains belonging to clades B.6, B.71 and B.72. Further research is necessary to investigate phenotypes and putative differences in pathogenicity of the investigated different clades of Fth to better understand the relationship between observed phenotypes, pathogenicity and distribution of Fth strains.
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Affiliation(s)
- Kristin Köppen
- Working group: Cellular Interactions of Bacterial Pathogens, Centre for Biological Threats and Special Pathogens, Highly Pathogenic Microorganisms (ZBS 2), Robert Koch Institute, Berlin, Germany
| | - Kerstin Rydzewski
- Working group: Cellular Interactions of Bacterial Pathogens, Centre for Biological Threats and Special Pathogens, Highly Pathogenic Microorganisms (ZBS 2), Robert Koch Institute, Berlin, Germany
| | - Joerg Doellinger
- Centre for Biological Threats and Special Pathogens, Proteomics and Spectroscopy (ZBS 6), Robert Koch Institute, Berlin, Germany
| | - Kerstin Myrtennäs
- Division of CBRN Defence and Security, Swedish Defence Research Agency (FOI), Umeå, Sweden
| | - Mats Forsman
- Division of CBRN Defence and Security, Swedish Defence Research Agency (FOI), Umeå, Sweden
| | - Sandra Appelt
- Centre for Biological Threats and Special Pathogens, Highly Pathogenic Microorganisms (ZBS 2), Robert Koch Institute, Berlin, Germany
| | - Holger Scholz
- Centre for Biological Threats and Special Pathogens, Highly Pathogenic Microorganisms (ZBS 2), Robert Koch Institute, Berlin, Germany
| | - Klaus Heuner
- Working group: Cellular Interactions of Bacterial Pathogens, Centre for Biological Threats and Special Pathogens, Highly Pathogenic Microorganisms (ZBS 2), Robert Koch Institute, Berlin, Germany; Centre for Biological Threats and Special Pathogens, Highly Pathogenic Microorganisms (ZBS 2), Robert Koch Institute, Berlin, Germany.
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Shoudy LE, Namjoshi P, Giordano G, Kumar S, Bowling JD, Gelhaus C, Barry EM, Hazlett AJ, Hazlett BA, Cooper KL, Pittman PR, Reed DS, Hazlett KRO. The O-Ag Antibody Response to Francisella Is Distinct in Rodents and Higher Animals and Can Serve as a Correlate of Protection. Pathogens 2021; 10:pathogens10121646. [PMID: 34959601 PMCID: PMC8704338 DOI: 10.3390/pathogens10121646] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Revised: 12/13/2021] [Accepted: 12/17/2021] [Indexed: 11/16/2022] Open
Abstract
Identifying correlates of protection (COPs) for vaccines against lethal human (Hu) pathogens, such as Francisella tularensis (Ft), is problematic, as clinical trials are currently untenable and the relevance of various animal models can be controversial. Previously, Hu trials with the live vaccine strain (LVS) demonstrated ~80% vaccine efficacy against low dose (~50 CFU) challenge; however, protection deteriorated with higher challenge doses (~2000 CFU of SchuS4) and no COPs were established. Here, we describe our efforts to develop clinically relevant, humoral COPs applicable to high-dose, aerosol challenge with S4. First, our serosurvey of LVS-vaccinated Hu and animals revealed that rabbits (Rbs), but not rodents, recapitulate the Hu O-Ag dependent Ab response to Ft. Next, we assayed Rbs immunized with distinct S4-based vaccine candidates (S4ΔclpB, S4ΔguaBA, and S4ΔaroD) and found that, across multiple vaccines, the %O-Ag dep Ab trended with vaccine efficacy. Among S4ΔguaBA-vaccinated Rbs, the %O-Ag dep Ab in pre-challenge plasma was significantly higher in survivors than in non-survivors; a cut-off of >70% O-Ag dep Ab predicted survival with high sensitivity and specificity. Finally, we found this COP in 80% of LVS-vaccinated Hu plasma samples as expected for a vaccine with 80% Hu efficacy. Collectively, the %O-Ag dep Ab response is a bona fide COP for S4ΔguaBA-vaccinated Rb and holds significant promise for guiding vaccine trials with higher animals.
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Affiliation(s)
- Lauren E. Shoudy
- Department of Regenerative and Cancer Cell Biology, Albany Medical College, Albany, NY 12208, USA; (L.E.S.); (G.G.)
| | - Prachi Namjoshi
- Department of Immunology and Microbial Disease, Albany Medical College, Albany, NY 12208, USA; (P.N.); (S.K.)
| | - Gabriela Giordano
- Department of Regenerative and Cancer Cell Biology, Albany Medical College, Albany, NY 12208, USA; (L.E.S.); (G.G.)
| | - Sudeep Kumar
- Department of Immunology and Microbial Disease, Albany Medical College, Albany, NY 12208, USA; (P.N.); (S.K.)
| | - Jennifer D. Bowling
- Center for Vaccine Research, University of Pittsburgh, Pittsburgh, PA 15261, USA; (J.D.B.); (D.S.R.)
| | | | - Eileen M. Barry
- Center for Vaccine Development and Global Health, University of Maryland School of Medicine, Baltimore, MD 21201, USA;
| | - Allan J. Hazlett
- Department of Philosophy, Washington University, St Louis, MO 63130, USA;
| | - Brian A. Hazlett
- Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI 48109, USA;
| | - Kristine L. Cooper
- Hillman Cancer Center, Biostatistics Facility, University of Pittsburgh, Pittsburgh, PA 15261, USA;
| | - Phillip R. Pittman
- U.S. Army Medical Research Institute of Infectious Diseases, Fort Detrick, Fredrick, MD 21702, USA;
| | - Douglas S. Reed
- Center for Vaccine Research, University of Pittsburgh, Pittsburgh, PA 15261, USA; (J.D.B.); (D.S.R.)
| | - Karsten R. O. Hazlett
- Department of Regenerative and Cancer Cell Biology, Albany Medical College, Albany, NY 12208, USA; (L.E.S.); (G.G.)
- Department of Immunology and Microbial Disease, Albany Medical College, Albany, NY 12208, USA; (P.N.); (S.K.)
- Correspondence: ; Tel.: +1-518-262-2338
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Appelt S, Faber M, Köppen K, Jacob D, Grunow R, Heuner K. Francisella tularensis Subspecies holarctica and Tularemia in Germany. Microorganisms 2020; 8:microorganisms8091448. [PMID: 32971773 PMCID: PMC7564102 DOI: 10.3390/microorganisms8091448] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Revised: 09/16/2020] [Accepted: 09/18/2020] [Indexed: 12/26/2022] Open
Abstract
Tularemia is a zoonotic disease caused by Francisella tularensis a small, pleomorphic, facultative intracellular bacterium. In Europe, infections in animals and humans are caused mainly by Francisella tularensis subspecies holarctica. Humans can be exposed to the pathogen directly and indirectly through contact with sick animals, carcasses, mosquitoes and ticks, environmental sources such as contaminated water or soil, and food. So far, F. tularensis subsp. holarctica is the only Francisella species known to cause tularemia in Germany. On the basis of surveillance data, outbreak investigations, and literature, we review herein the epidemiological situation-noteworthy clinical cases next to genetic diversity of F. tularensis subsp. holarctica strains isolated from patients. In the last 15 years, the yearly number of notified cases of tularemia has increased steadily in Germany, suggesting that the disease is re-emerging. By sequencing F. tularensis subsp. holarctica genomes, knowledge has been added to recent findings, completing the picture of genotypic diversity and geographical segregation of Francisella clades in Germany. Here, we also shortly summarize the current knowledge about a new Francisella species (Francisella sp. strain W12-1067) that has been recently identified in Germany. This species is the second Francisella species discovered in Germany.
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Affiliation(s)
- Sandra Appelt
- Centre for Biological Threats and Special Pathogens (ZBS 2), Robert Koch Institute, 13353 Berlin, Germany; (S.A.); (D.J.); (R.G.)
| | - Mirko Faber
- Gastrointestinal Infections, Zoonoses and Tropical Infections (Division 35), Department for Infectious Disease Epidemiology, Robert Koch Institute, 13353 Berlin, Germany;
| | - Kristin Köppen
- Cellular Interactions of Bacterial Pathogens, ZBS 2, Robert Koch Institute, 13353 Berlin, Germany;
| | - Daniela Jacob
- Centre for Biological Threats and Special Pathogens (ZBS 2), Robert Koch Institute, 13353 Berlin, Germany; (S.A.); (D.J.); (R.G.)
| | - Roland Grunow
- Centre for Biological Threats and Special Pathogens (ZBS 2), Robert Koch Institute, 13353 Berlin, Germany; (S.A.); (D.J.); (R.G.)
| | - Klaus Heuner
- Cellular Interactions of Bacterial Pathogens, ZBS 2, Robert Koch Institute, 13353 Berlin, Germany;
- Correspondence: ; Tel.: +49-301-8754-2226
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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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Brudal E, Lampe EO, Reubsaet L, Roos N, Hegna IK, Thrane IM, Koppang EO, Winther-Larsen HC. Vaccination with outer membrane vesicles from Francisella noatunensis reduces development of francisellosis in a zebrafish model. FISH & SHELLFISH IMMUNOLOGY 2015; 42:50-57. [PMID: 25449706 DOI: 10.1016/j.fsi.2014.10.025] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2014] [Revised: 10/17/2014] [Accepted: 10/17/2014] [Indexed: 06/04/2023]
Abstract
Infection of fish with the facultative intracellular bacterium Francisella noatunensis remains an unresolved problem for aquaculture industry worldwide as it is difficult to vaccinate against without using live attenuated vaccines. Outer membrane vesicles (OMVs) are biological structures shed by Gram-negative bacteria in response to various environmental stimuli. OMVs have successfully been used to vaccinate against both intracellular and extracellular pathogens, due to an ability to stimulate innate, cell-mediated and humoral immune responses. We show by using atomic force and electron microscopy that the fish pathogenic bacterium F. noatunensis subspecies noatunensis (F.n.n.) shed OMVs both in vitro into culture medium and in vivo in a zebrafish infection model. The main protein constituents of the OMV are IglC, PdpD and PdpA, all known Francisella virulence factors, in addition to the outer membrane protein FopA and the chaperonin GroEL, as analyzed by mass spectrometry. The vesicles, when used as a vaccine, reduced proliferation of the bacterium and protected zebrafish when subsequently challenged with a high dose of F.n.n. without causing adverse effects for the host. Also granulomatous responses were reduced in F.n.n.-challenged zebrafish after OMV vaccination. Taken together, the data support the possible use of OMVs as vaccines against francisellosis in fish.
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Affiliation(s)
- Espen Brudal
- Section for Microbiology, Immunology and Parasitology, Department of Food Safety and Infection Biology, Norwegian University of Life Sciences, PO Box 8146 Dep, 0033 Oslo, Norway; Laboratory for Microbial Dynamics (LaMDa), School of Pharmacy, University of Oslo, PO Box 1068 Blindern, 0316 Oslo, Norway
| | - Elisabeth O Lampe
- Laboratory for Microbial Dynamics (LaMDa), School of Pharmacy, University of Oslo, PO Box 1068 Blindern, 0316 Oslo, Norway; Department of Pharmaceutical Biosciences, School of Pharmacy, University of Oslo, PO Box 1068 Blindern, 0316 Oslo, Norway
| | - Léon Reubsaet
- Department of Pharmaceutical Chemistry, School of Pharmacy, University of Oslo, PO Box 1068 Blindern, 0316 Oslo, Norway
| | - Norbert Roos
- Department of Biosciences, University of Oslo, PO Box 1068 Blindern, 0316 Oslo, Norway
| | - Ida K Hegna
- Laboratory for Microbial Dynamics (LaMDa), School of Pharmacy, University of Oslo, PO Box 1068 Blindern, 0316 Oslo, Norway; Department of Pharmaceutical Biosciences, School of Pharmacy, University of Oslo, PO Box 1068 Blindern, 0316 Oslo, Norway
| | - Ida Marie Thrane
- Laboratory for Microbial Dynamics (LaMDa), School of Pharmacy, University of Oslo, PO Box 1068 Blindern, 0316 Oslo, Norway; Department of Pharmaceutical Biosciences, School of Pharmacy, University of Oslo, PO Box 1068 Blindern, 0316 Oslo, Norway
| | - Erling O Koppang
- Section for Anatomy and Pathology, Department of Basic Sciences and Aquatic Medicine, Norwegian University of Life Sciences, PO Box 8146 Dep, 0033 Oslo, Norway
| | - Hanne C Winther-Larsen
- Laboratory for Microbial Dynamics (LaMDa), School of Pharmacy, University of Oslo, PO Box 1068 Blindern, 0316 Oslo, Norway; Department of Pharmaceutical Biosciences, School of Pharmacy, University of Oslo, PO Box 1068 Blindern, 0316 Oslo, Norway.
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Hu X, Compton JR, Abdulhameed MDM, Marchand CL, Robertson KL, Leary DH, Jadhav A, Hershfield JR, Wallqvist A, Friedlander AM, Legler PM. 3-substituted indole inhibitors against Francisella tularensis FabI identified by structure-based virtual screening. J Med Chem 2013; 56:5275-87. [PMID: 23815100 DOI: 10.1021/jm4001242] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
In this study, we describe novel inhibitors against Francisella tularensis SchuS4 FabI identified from structure-based in silico screening with integrated molecular dynamics simulations to account for induced fit of a flexible loop crucial for inhibitor binding. Two 3-substituted indoles, 54 and 57, preferentially bound the NAD(+) form of the enzyme and inhibited growth of F. tularensis SchuS4 at concentrations near that of their measured Ki. While 57 was species-specific, 54 showed a broader spectrum of growth inhibition against F. tularensis , Bacillus anthracis , and Staphylococcus aureus . Binding interaction analysis in conjunction with site-directed mutagenesis revealed key residues and elements that contribute to inhibitor binding and species specificity. Mutation of Arg-96, a poorly conserved residue opposite the loop, was unexpectedly found to enhance inhibitor binding in the R96G and R96M variants. This residue may affect the stability and closure of the flexible loop to enhance inhibitor (or substrate) binding.
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Affiliation(s)
- Xin Hu
- Center of Bio/Molecular Science and Engineering, Naval Research Laboratories , Washington, D.C. 20375, United States
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Stundick MV, Albrecht MT, Houchens CR, Smith AP, Dreier TM, Larsen JC. Animal models for Francisella tularensis and Burkholderia species: scientific and regulatory gaps toward approval of antibiotics under the FDA Animal Rule. Vet Pathol 2013; 50:877-92. [PMID: 23628693 DOI: 10.1177/0300985813486812] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The development and regulatory approval of medical countermeasures (MCMs) for the treatment and prevention of bacterial threat agent infections will require the evaluation of products in animal models. To obtain regulatory approval, these models must accurately recapitulate aspects of human disease, including, but not necessarily limited to, route of exposure, time to disease onset, pathology, immune response, and mortality. This article focuses on the state of animal model development for 3 agents for which models are largely immature: Francisella tularensis, Burkholderia mallei, and Burkholderia pseudomallei. An overview of available models and a description of scientific and regulatory gaps are provided.
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Affiliation(s)
- M V Stundick
- US Department of Health and Human Services, Office of the Assistant Secretary for Preparedness and Response, Biomedical Advanced Research and Development Authority, 375 E. St, SW- 12th Floor, Washington, DC 20024, USA.
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Wrench AP, Gardner CL, Gonzalez CF, Lorca GL. Identification of a small molecule that modifies MglA/SspA interaction and impairs intramacrophage survival of Francisella tularensis. PLoS One 2013; 8:e54498. [PMID: 23372736 PMCID: PMC3553074 DOI: 10.1371/journal.pone.0054498] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2012] [Accepted: 12/13/2012] [Indexed: 12/26/2022] Open
Abstract
The transcription factors MglA and SspA of Francisella tularensis form a heterodimer complex and interact with the RNA polymerase to regulate the expression of the Francisella pathogenicity island (FPI) genes. These genes are essential for this pathogen’s virulence and survival within host cells. In this study, we used a small molecule screening to identify quinacrine as a thermal stabilizing compound for F. tularensis SCHU S4 MglA and SspA. A bacterial two-hybrid system was used to analyze the in vivo effect of quinacrine on the heterodimer complex. The results show that quinacrine affects the interaction between MglA and SspA, indicated by decreased β-galactosidase activity. Further in vitro analyses, using size exclusion chromatography, indicated that quinacrine does not disrupt the heterodimer formation, however, changes in the alpha helix content were confirmed by circular dichroism. Structure-guided site-directed mutagenesis experiments indicated that quinacrine makes contact with amino acid residues Y63 in MglA, and K97 in SspA, both located in the “cleft” of the interacting surfaces. In F. tularensis subsp. novicida, quinacrine decreased the transcription of the FPI genes, iglA, iglD, pdpD and pdpA. As a consequence, the intramacrophage survival capabilities of the bacteria were affected. These results support use of the MglA/SspA interacting surface, and quinacrine’s chemical scaffold, for the design of high affinity molecules that will function as therapeutics for the treatment of Tularemia.
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Affiliation(s)
- Algevis P Wrench
- Department of Microbiology and Cell Science, Institute of Food and Agricultural Sciences, University of Florida, Gainesville, Florida, United States of America
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Ireland PM, LeButt H, Thomas RM, Oyston PCF. A Francisella tularensis SCHU S4 mutant deficient in γ-glutamyltransferase activity induces protective immunity: characterization of an attenuated vaccine candidate. MICROBIOLOGY-SGM 2011; 157:3172-3179. [PMID: 21852349 DOI: 10.1099/mic.0.052902-0] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Francisella tularensis is an intracellular pathogen which causes tularaemia. There is no licensed vaccine currently available for prophylaxis. The γ-glutamyl transpeptidase (GGT) encoded by the ggt gene has been shown to be important for the intracellular survival of F. tularensis. In this study we have constructed a ggt deletion mutant in the highly virulent F. tularensis strain SCHU S4. Characterization of the mutant strain confirmed the function of ggt, and confirmed the role of GGT in cysteine acquisition. The mutant strain was highly attenuated both in vitro and in vivo using murine models of infection. Moreover, we have demonstrated that the attenuated mutant is able to induce protective immunity against an F. tularensis SCHU S4 challenge, and thus may be a candidate for the development of an attenuated vaccine.
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Affiliation(s)
- Philip M Ireland
- Defence Science and Technology Laboratory, Porton Down, Salisbury, Wiltshire SP4 0JQ, UK
| | - Helen LeButt
- Defence Science and Technology Laboratory, Porton Down, Salisbury, Wiltshire SP4 0JQ, UK
| | - Rebecca M Thomas
- Defence Science and Technology Laboratory, Porton Down, Salisbury, Wiltshire SP4 0JQ, UK
| | - Petra C F Oyston
- Defence Science and Technology Laboratory, Porton Down, Salisbury, Wiltshire SP4 0JQ, UK
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11
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Colquhoun DJ, Duodu S. Francisella infections in farmed and wild aquatic organisms. Vet Res 2011; 42:47. [PMID: 21385413 PMCID: PMC3060124 DOI: 10.1186/1297-9716-42-47] [Citation(s) in RCA: 88] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2010] [Accepted: 03/08/2011] [Indexed: 01/08/2023] Open
Abstract
Over the last 10 years or so, infections caused by bacteria belonging to a particular branch of the genus Francisella have become increasingly recognised in farmed fish and molluscs worldwide. While the increasing incidence of diagnoses may in part be due to the development and widespread availability of molecular detection techniques, the domestication of new organisms has undoubtedly instigated emergence of clinical disease in some species. Francisellosis in fish develops in a similar fashion independent of host species and is commonly characterised by the presence of multi-organ granuloma and high morbidity, with varying associated mortality levels. A number of fish species are affected including Atlantic cod, Gadus morhua; tilapia, Oreochromis sp.; Atlantic salmon, Salmo salar; hybrid striped bass, Morone chrysops × M. saxatilis and three-lined grunt, Parapristipoma trilinineatum. The disease is highly infectious and often prevalent in affected stocks. Most, if not all strains isolated from teleost fish belong to either F. noatunensis subsp. orientalis in warm water fish species or Francisella noatunensis subsp. noatunensis in coldwater fish species. The disease is quite readily diagnosed following histological examination and identification of the aetiological bacterium by culture on cysteine rich media or PCR. The available evidence may indicate a degree of host specificity for the various Francisella strains, although this area requires further study. No effective vaccine is currently available. Investigation of the virulence mechanisms and host response shows similarity to those known from Francisella tularensis infection in mammals. However, no evidence exists for zoonotic potential amongst the fish pathogenic Francisella.
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Affiliation(s)
- Duncan J Colquhoun
- Section for Fish health, National Veterinary Institute, Postbox 750 sentrum, 0106 Oslo, Norway.
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12
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Meibom KL, Charbit A. Francisella tularensis metabolism and its relation to virulence. Front Microbiol 2010; 1:140. [PMID: 21687763 PMCID: PMC3109416 DOI: 10.3389/fmicb.2010.00140] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2010] [Accepted: 12/13/2010] [Indexed: 01/08/2023] Open
Abstract
Francisella tularensis is a Gram-negative bacterium capable of causing the zoonotic disease tularaemia in a large number of mammalian species and in arthropods. F. tularensis is a facultative intracellular bacterium that infects and replicates in vivo mainly inside macrophages. During its systemic dissemination, F. tularensis must cope with very different life conditions (such as survival in different target organs or tissues and/or survival in the blood stream…) and may thus encounter a broad variety of carbon substrates, nitrogen, phosphor, and sulfur sources, as well as very low concentrations of essential ions. The development of recent genome-wide genetic screens have led to the identification of hundreds of genes participating to variable extents to Francisella virulence. Remarkably, an important proportion of the genes identified are related to metabolic and nutritional functions. However, the relationship between nutrition and the in vivo life cycle of F. tularensis is yet poorly understood. In this review, we will address the importance of metabolism and nutrition for F. tularensis pathogenesis, focusing specifically on amino acid and carbohydrate requirements.
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