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Sholeh M, Moradkasani S, Esmaeili S. Epidemiology of tularemia in the countries of the WHO Eastern Mediterranean Region (EMRO): A systematic review and meta-analysis. PLoS Negl Trop Dis 2024; 18:e0012141. [PMID: 38728365 PMCID: PMC11086863 DOI: 10.1371/journal.pntd.0012141] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Accepted: 04/08/2024] [Indexed: 05/12/2024] Open
Abstract
BACKGROUND Francisella tularensis, the bacterium that causes tularemia, has been a persistent and widespread pathogen in various regions of the world for centuries. Francisella tularensis can affect humans and various domestic and wild animals. The current study aimed to determine the epidemiological status of tularemia in countries of the WHO Eastern Mediterranean Region (EMRO) through a systematic review and meta-analysis. METHODS All included studies were identified through a systematic search of online databases, including Scopus, PubMed, Web of Science, and EMBASE, through July 26, 2022, using keywords and suitable combinations. We focused on cross-sectional studies investigating the prevalence of F. tularensis. The weighted pooled prevalence was calculated using a random-effects model. RESULTS A total of 206 studies were identified, of which 20 were finally included in the analysis. The human seroprevalence of tularemia in WHO-EMRO countries was 6.2% (95% CI, 4.2 9.2). In the subgroup analysis, anti-F. tularensis antibodies were found in 6.92% and 5.5% of the high-risk individuals and Iran, respectively. The pooled prevalence of F. tularensis in environmental samples (water and soil) from the WHO-EMRO countries was 5.8% (9.4% by PCR and 0.5% by culture). In addition, 2.5% (95% CI, 0.2 0.22.7) of ticks in WHO-EMRO countries were positive for F. tularensis. The pooled prevalence of F. tularensis in rodents is 2.0% (1.1% by PCR and 3.7% by serology). In addition, 0.6% of domestic ruminants (0.4% by PCR and 2.4% by serology) were positive for F. tularensis in WHO-EMRO countries. CONCLUSION According to the results of the present study, tularemia is an endemic but neglected disease in the WHO-EMRO region. However, most studies on tularemia are limited to a few countries in this region. Studies on tularemia in human populations, reservoirs, and vectors have been conducted in all countries in the WHO-EMRO region to obtain more detailed information about the epidemiology of tularemia in these regions.
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Affiliation(s)
- Mohammad Sholeh
- Department of Bacteriology, Pasteur Institute of Iran, Tehran, Iran
| | - Safoura Moradkasani
- Department of Epidemiology and Biostatistics, Research Center for Emerging and Reemerging Infectious Diseases, Pasteur Institute of Iran, Tehran, Iran
| | - Saber Esmaeili
- Department of Epidemiology and Biostatistics, Research Center for Emerging and Reemerging Infectious Diseases, Pasteur Institute of Iran, Tehran, Iran
- National Reference Laboratory for Plague, Tularemia and Q Fever, Research Centre for Emerging and Reemerging Infectious Diseases, Pasteur Institute of Iran, Akanlu, KabudarAhang, Hamadan, Iran
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2
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Pavlov V, Vakhrameeva G, Mokrievich A, Platonov ME, Titareva G, Mironova R, Kombarova T, Gapelchenkova T, Dyatlov I. Development and Properties of Francisella tularensis Subsp. holarctica 15 NIIEG Vaccine Strain without the recD Gene. Vaccines (Basel) 2022; 10:108. [PMID: 35062769 PMCID: PMC8778684 DOI: 10.3390/vaccines10010108] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2021] [Revised: 12/23/2021] [Accepted: 12/28/2021] [Indexed: 02/04/2023] Open
Abstract
The genomic analysis of all subspecies F. tularensis, as found in Gen Bank NCBI, reveals the presence of genes encoding proteins like to the multifunctional RecBCD enzyme complex in E. coli and other bacteria. To date, the role of the recD gene in F. tularensis, which encodes the alpha chain of exonuclease V, in DNA metabolism processes, has not been studied either in vitro or in vivo. F. tularensis subsp. holarctica 15 NIIEG, a vaccine strain, served as the basis to create the F. tularensis 15D strain with recD deletion. The lack of the recD gene suppresses the integration of suicide plasmids with F. tularensis genome fragments into the chromosome. The modified strain showed reduced growth in vitro and in vivo. This study shows that such deletion significantly reduces the virulence of the strain in BALB/c mice.
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Affiliation(s)
- Vitaly Pavlov
- State Research Center for Applied Microbiology and Biotechnology (SRCAMB), 142279 Obolensk, Russia; (G.V.); (A.M.); (M.E.P.); (G.T.); (R.M.); (T.K.); (T.G.); (I.D.)
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3
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Optimisation of External Factors for the Growth of Francisella novicida within Dictyostelium discoideum. BIOMED RESEARCH INTERNATIONAL 2020; 2020:6826983. [PMID: 32090107 PMCID: PMC6996686 DOI: 10.1155/2020/6826983] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/09/2019] [Accepted: 01/04/2020] [Indexed: 02/06/2023]
Abstract
The amoeba Dictyostelium discoideum has been used as a model organism to study host-pathogen interaction in many intracellular bacteria. Francisella tularensis is a Gram-negative, highly infectious bacterium that causes the zoonotic disease tularemia. The bacterium is able to replicate in different phagocytic and nonphagocytic cells including mammalian, amoebae, and arthropod cells. The aim of this study was to determine the optimal temperature and infection dose in the interaction of Francisella novicida with D. discoideum in order to establish a model of Francisella infection in the social amoeba. The amoeba cells were infected with a different multiplicity of infection (5, 10, and 100) and incubated at different temperatures (22, 25, 27, 30, and 37°C). The number of intracellular bacteria within D. discoideum, as well as cytotoxicity, was determined at 2, 4, 24, 48, and 72 hours after infection. Our results showed that the optimal temperature for Francisella intracellular replication within amoeba is 30°C with the MOI of 10. We can conclude that this MOI and temperature induced the optimal growth of bacteria in Dictyostelium with low cytotoxicity.
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Klimentova J, Pavkova I, Horcickova L, Bavlovic J, Kofronova O, Benada O, Stulik J. Francisella tularensis subsp. holarctica Releases Differentially Loaded Outer Membrane Vesicles Under Various Stress Conditions. Front Microbiol 2019; 10:2304. [PMID: 31649645 PMCID: PMC6795709 DOI: 10.3389/fmicb.2019.02304] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2019] [Accepted: 09/20/2019] [Indexed: 11/16/2022] Open
Abstract
Francisella tularensis is a Gram-negative, facultative intracellular bacterium, causing a severe disease called tularemia. It secretes unusually shaped nanotubular outer membrane vesicles (OMV) loaded with a number of virulence factors and immunoreactive proteins. In the present study, the vesicles were purified from a clinical isolate of subsp. holarctica strain FSC200. We here provide a comprehensive proteomic characterization of OMV using a novel approach in which a comparison of OMV and membrane fraction is performed in order to find proteins selectively enriched in OMV vs. membrane. Only these proteins were further considered to be really involved in the OMV function and/or their exceptional structure. OMV were also isolated from bacteria cultured under various cultivation conditions simulating the diverse environments of F. tularensis life cycle. These included conditions mimicking the milieu inside the mammalian host during inflammation: oxidative stress, low pH, and high temperature (42°C); and in contrast, low temperature (25°C). We observed several-fold increase in vesiculation rate and significant protein cargo changes for high temperature and low pH. Further proteomic characterization of stress-derived OMV gave us an insight how the bacterium responds to the hostile environment of a mammalian host through the release of differentially loaded OMV. Among the proteins preferentially and selectively packed into OMV during stressful cultivations, the previously described virulence factors connected to the unique intracellular trafficking of Francisella were detected. Considerable changes were also observed in a number of proteins involved in the biosynthesis and metabolism of the bacterial envelope components like O-antigen, lipid A, phospholipids, and fatty acids. Data are available via ProteomeXchange with identifier PXD013074.
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Affiliation(s)
- Jana Klimentova
- Department of Molecular Pathology and Biology, Faculty of Military Health Sciences, University of Defense, Hradec Kralove, Czechia
| | - Ivona Pavkova
- Department of Molecular Pathology and Biology, Faculty of Military Health Sciences, University of Defense, Hradec Kralove, Czechia
| | - Lenka Horcickova
- Department of Molecular Pathology and Biology, Faculty of Military Health Sciences, University of Defense, Hradec Kralove, Czechia
| | - Jan Bavlovic
- Department of Molecular Pathology and Biology, Faculty of Military Health Sciences, University of Defense, Hradec Kralove, Czechia
| | - Olga Kofronova
- Institute of Microbiology of the Czech Academy of Sciences, Prague, Czechia
| | - Oldrich Benada
- Institute of Microbiology of the Czech Academy of Sciences, Prague, Czechia.,Faculty of Science, Jan Evangelista Purkyně University, Ústí nad Labem, Czechia
| | - Jiri Stulik
- Department of Molecular Pathology and Biology, Faculty of Military Health Sciences, University of Defense, Hradec Kralove, Czechia
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5
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Shahin K, Thompson KD, Inglis NF, Mclean K, Ramirez-Paredes JG, Monaghan SJ, Hoare R, Fontaine M, Metselaar M, Adams A. Characterization of the outer membrane proteome of Francisella noatunensis subsp. orientalis. J Appl Microbiol 2018; 125:686-699. [PMID: 29777634 DOI: 10.1111/jam.13918] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Revised: 05/03/2018] [Accepted: 05/11/2018] [Indexed: 11/28/2022]
Abstract
AIMS The aims of the current study were to characterize the outer membrane proteins (OMPs) of Francisella noatunensis subsp. orientalis (Fno) STIR-GUS-F2f7, and identify proteins recognized by sera from tilapia, Oreochromis niloticus, (L) that survived experimental challenge with Fno. METHODS AND RESULTS The composition of the OMPs of a virulent strain of Fno (STIR-GUS-F2f7), isolated from diseased red Nile tilapia in the United Kingdom, was examined. The sarcosine-insoluble OMPs fraction was screened with tilapia hyperimmune sera by western blot analysis following separation of the proteins by 1D SDS-PAGE. Liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS) was used to identify the various proteins present in the OMP profile. Two hundred and thirty-nine proteins were identified, of which 44 were found in the immunogenic band recognized by the tilapia hyperimmune serum. In silico analysis was performed to predict the function and location of the OMPs identified by MS. CONCLUSIONS Using a powerful proteomic-based approach in conjugation with western immunoblotting, proteins comprising the outer membrane fraction of Fno STIR-GUS-F2f7 were identified, catalogued and screened for immune recognition by tilapia sera. SIGNIFICANCE AND IMPACT OF THE STUDY The current study is the first report on the characterization of Fno-OMPs. The findings here provide preliminary data on bacterial surface proteins that exist in direct contact with the host's immune defences during infection and offer an insight into the pathogenesis of Fno.
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Affiliation(s)
- K Shahin
- Faculty of Natural Sciences, Institute of Aquaculture, University of Stirling, Stirling, Scotland, UK.,Aquatic Animals Diseases Lab, Aquaculture Division, National Institute of Oceanography and Fisheries, Suez, Egypt
| | - K D Thompson
- Moredun Research Institute, Pentlands Science Park, Penicuik, Midlothian, UK
| | - N F Inglis
- Moredun Research Institute, Pentlands Science Park, Penicuik, Midlothian, UK
| | - K Mclean
- Moredun Research Institute, Pentlands Science Park, Penicuik, Midlothian, UK
| | - J G Ramirez-Paredes
- Faculty of Natural Sciences, Institute of Aquaculture, University of Stirling, Stirling, Scotland, UK
| | - S J Monaghan
- Faculty of Natural Sciences, Institute of Aquaculture, University of Stirling, Stirling, Scotland, UK
| | - R Hoare
- Faculty of Natural Sciences, Institute of Aquaculture, University of Stirling, Stirling, Scotland, UK
| | - M Fontaine
- Benchmark Animal Health, Bush House, Edinburgh Technopole, Edinburgh, Midlothian, UK
| | - M Metselaar
- Benchmark Animal Health, Bush House, Edinburgh Technopole, Edinburgh, Midlothian, UK
| | - A Adams
- Faculty of Natural Sciences, Institute of Aquaculture, University of Stirling, Stirling, Scotland, UK
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Complement C3 as a Prompt for Human Macrophage Death during Infection with Francisella tularensis Strain SCHU S4. Infect Immun 2017; 85:IAI.00424-17. [PMID: 28739830 DOI: 10.1128/iai.00424-17] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2017] [Accepted: 07/18/2017] [Indexed: 02/06/2023] Open
Abstract
Tularemia is caused by the Gram-negative bacterial pathogen Francisella tularensis Infection of macrophages and their subsequent death are believed to play important roles in the progression of disease. Because complement is a particularly effective opsonin for Francisella, we asked whether complement-dependent uptake of F. tularensis strain SCHU S4 affects the survival of primary human macrophages during infection. Complement component C3 was found to be an essential opsonin in human serum not only for greatly increased uptake of SCHU S4 but also for the induction of macrophage death. Single-cell analysis also revealed that macrophage death did not require a high intracellular bacterial burden. In the presence of C3, macrophage death was observed at 24 h postinfection in a quarter of the macrophages that contained only 1 to 5 bacterial cells. Macrophages infected in the absence of C3 rarely underwent cell death, even when they contained large numbers of bacteria. The need for C3, but not extensive replication of the pathogen, was confirmed by infections with SCHU S4 ΔpurMCD, a mutant capable of phagosome escape but of only limited cytosolic replication. C3-dependent Francisella uptake alone was insufficient to induce macrophage death, as evidenced by the failure of the phagosome escape-deficient mutant SCHU S4 ΔfevR to induce cell death despite opsonization with C3. Together, these findings indicate that recognition of C3-opsonized F. tularensis, but not extensive cytosolic replication, plays an important role in regulating macrophage viability during intracellular infections with type A F. tularensis.
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Brenz Y, Winther-Larsen HC, Hagedorn M. Expanding Francisella models: Pairing up the soil amoeba Dictyostelium with aquatic Francisella. Int J Med Microbiol 2017; 308:32-40. [PMID: 28843671 DOI: 10.1016/j.ijmm.2017.08.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2017] [Revised: 07/31/2017] [Accepted: 08/04/2017] [Indexed: 12/19/2022] Open
Abstract
The bacterial genus Francisella comprises highly pathogenic species that infect mammals, arthropods, fish and protists. Understanding virulence and host defense mechanisms of Francisella infection relies on multiple animal and cellular model systems. In this review, we want to summarize the most commonly used Francisella host model platforms and highlight novel, alternative model systems using aquatic Francisella species. Established mouse and macrophage models contributed extensively to our understanding of Francisella infection. However, murine and human cells display significant differences in their response to Francisella infection. The zebrafish and the amoeba Dictyostelium are well-established model systems for host-pathogen interactions and open up opportunities to investigate bacterial virulence and host defense. Comparisons between model systems using human and fish pathogenic Francisella species revealed shared virulence strategies and pathology between them. Hence, zebrafish and Dictyostelium might complement current model systems to find new vaccine candidates and contribute to our understanding of Francisella infection.
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Affiliation(s)
- Yannick Brenz
- Department of Parasitology, Bernhard Nocht Institute for Tropical Medicine, Bernhard-Nocht-Straße 74, 20359 Hamburg, Germany.
| | - Hanne C Winther-Larsen
- Centre for Integrative Microbial Evolution (CIME) and Department of Pharmaceutical Biosciences, University of Oslo, Sem Sælands vei 3, 0371 Oslo, Norway.
| | - Monica Hagedorn
- Department of Life Sciences and Chemistry, Jacobs University, Campus Ring 1, 28759 Bremen, Germany.
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8
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Kumar S, Sunagar R, Pham G, Franz BJ, Rosa SJ, Hazlett KRO, Gosselin EJ. Differential Cultivation of Francisella tularensis Induces Changes in the Immune Response to and Protective Efficacy of Whole Cell-Based Inactivated Vaccines. Front Immunol 2017; 7:677. [PMID: 28119692 PMCID: PMC5222797 DOI: 10.3389/fimmu.2016.00677] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2016] [Accepted: 12/21/2016] [Indexed: 01/06/2023] Open
Abstract
Francisella tularensis (Ft) is a category A biothreat agent for which there is no Food and Drug Administration-approved vaccine. Ft can survive in a variety of habitats with a remarkable ability to adapt to changing environmental conditions. Furthermore, Ft expresses distinct sets of antigens (Ags) when inside of macrophages (its in vivo host) as compared to those grown in vitro with Mueller Hinton Broth (MHB). However, in contrast to MHB-grown Ft, Ft grown in Brain-Heart Infusion (BHI) more closely mimics the antigenic profile of macrophage-grown Ft. Thus, we anticipated that when used as a vaccine, BHI-grown Ft would provide better protection compared to MHB-grown Ft, primarily due to its greater antigenic similarity to Ft circulating inside the host (macrophages) during natural infection. Our investigation, however, revealed that inactivated Ft (iFt) grown in MHB (iFt-MHB) exhibited superior protective activity when used as a vaccine, as compared to iFt grown in BHI (iFt-BHI). The superior protection afforded by iFt-MHB compared to that of iFt-BHI was associated with significantly lower bacterial burden and inflammation in the lungs and spleens of vaccinated mice. Moreover, iFt-MHB also induced increased levels of Ft-specific IgG. Further evaluation of early immunological cues also revealed that iFt-MHB exhibits increased engagement of Ag-presenting cells including increased iFt binding to dendritic cells, increased expression of costimulatory markers, and increased secretion of pro-inflammatory cytokines. Importantly, these studies directly demonstrate that Ft growth conditions strongly impact Ft vaccine efficacy and that the growth medium used to produce whole cell vaccines to Ft must be a key consideration in the development of a tularemia vaccine.
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Affiliation(s)
- Sudeep Kumar
- Center for Immunology and Microbial Diseases, Albany Medical College , Albany, NY , USA
| | - Raju Sunagar
- Center for Immunology and Microbial Diseases, Albany Medical College , Albany, NY , USA
| | - Giang Pham
- Center for Immunology and Microbial Diseases, Albany Medical College , Albany, NY , USA
| | - Brian J Franz
- Center for Immunology and Microbial Diseases, Albany Medical College , Albany, NY , USA
| | - Sarah J Rosa
- Center for Immunology and Microbial Diseases, Albany Medical College , Albany, NY , USA
| | - Karsten R O Hazlett
- Center for Immunology and Microbial Diseases, Albany Medical College , Albany, NY , USA
| | - Edmund J Gosselin
- Center for Immunology and Microbial Diseases, Albany Medical College , Albany, NY , USA
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Bröms JE, Meyer L, Sjöstedt A. A mutagenesis-based approach identifies amino acids in the N-terminal part of Francisella tularensis IglE that critically control Type VI system-mediated secretion. Virulence 2016; 8:821-847. [PMID: 27830989 PMCID: PMC5626337 DOI: 10.1080/21505594.2016.1258507] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
The Gram-negative bacterium Francisella tularensis is the etiological agent of the zoonotic disease tularemia. Its life cycle is characterized by an ability to survive within phagocytic cells through phagosomal escape and replication in the cytosol, ultimately causing inflammasome activation and host cell death. Required for these processes is the Francisella Pathogenicity Island (FPI), which encodes a Type VI secretion system (T6SS) that is active during intracellular infection. In this study, we analyzed the role of the FPI-component IglE, a lipoprotein which we previously have shown to be secreted in a T6SS-dependent manner. We demonstrate that in F. tularensis LVS, IglE is an outer membrane protein. Upon infection of J774 cells, an ΔiglE mutant failed to escape from phagosomes, and subsequently, to multiply and cause cytopathogenicity. Moreover, ΔiglE was unable to activate the inflammasome, to inhibit LPS-stimulated secretion of TNF-α, and showed marked attenuation in the mouse model. In F. novicida, IglE was required for in vitro secretion of IglC and VgrG. A mutagenesis-based approach involving frameshift mutations and alanine substitution mutations within the first ∼ 38 residues of IglE revealed that drastic changes in the sequence of the extreme N-terminus (residues 2-6) were well tolerated and, intriguingly, caused hyper-secretion of IglE during intracellular infection, while even subtle mutations further downstream lead to impaired protein function. Taken together, this study highlights the importance of IglE in F. tularensis pathogenicity, and the contribution of the N-terminus for all of the above mentioned processes.
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Affiliation(s)
- Jeanette E Bröms
- a Department of Clinical Microbiology , Clinical Bacteriology and Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå University , Umeå , Sweden
| | - Lena Meyer
- a Department of Clinical Microbiology , Clinical Bacteriology and Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå University , Umeå , Sweden
| | - Anders Sjöstedt
- a Department of Clinical Microbiology , Clinical Bacteriology and Laboratory for Molecular Infection Medicine Sweden (MIMS), Umeå University , Umeå , Sweden
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Liu JN, Yu ZJ, Liu LM, Li NX, Wang RR, Zhang CM, Liu JZ. Identification, Distribution and Population Dynamics of Francisella-like Endosymbiont in Haemaphysalis doenitzi (Acari: Ixodidae). Sci Rep 2016; 6:35178. [PMID: 27731377 PMCID: PMC5059625 DOI: 10.1038/srep35178] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2016] [Accepted: 09/26/2016] [Indexed: 12/04/2022] Open
Abstract
Francisella-like endosymbionts (FLEs) with significant homology to Francisella tularensis (γ-proteobacteria) have been characterized in several tick species, whereas knowledge on their distribution and population dynamics in ticks remains meager. Hence, in the current study, we identified a novel Francisella-like endosymbiont (FLEs-Hd) from the tick Haemaphysalis doenitzi and evaluated the putative functions of this symbiont. Results indicated that FLEs-Hd had 100% infection rate and a perfect vertical transmission in H. doenitzi, and that it is distributed in ovaries, malpighian tubules, salivary glands and midguts of the ticks, suggesting that FLEs-Hd presumably is a crucial symbiont of the host without specific tissue tropism. To further explore the function of the symbiont, the population dynamics of FLEs-Hd at each developmental stage of ticks and in tissues at different reproductive statuses were determined by real-time quantitative polymerase chain reaction (real-time qPCR). Results showed that the high density and regular population dynamics of FLEs-Hd appeared in female ovaries, suggesting that the symbiont may provide necessary nutrients or regulators to ensure normal ovary development of ticks.
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Affiliation(s)
- Jian-Nan Liu
- Key Laboratory of Animal Physiology, Biochemistry and Molecular Biology of Hebei Province, College of Life Sciences, Hebei Normal University, No. 20 Nanerhuan Eastern Road, Shijiazhuang, Hebei, 050024, P. R. China
| | - Zhi-Jun Yu
- Key Laboratory of Animal Physiology, Biochemistry and Molecular Biology of Hebei Province, College of Life Sciences, Hebei Normal University, No. 20 Nanerhuan Eastern Road, Shijiazhuang, Hebei, 050024, P. R. China
| | - Li-Meng Liu
- Department of Integrative Biology, University of California, Berkeley, Valley Life Sciences Building, Room 5155A, Berkeley, CA, 94720-3140, USA
| | - Ning-Xin Li
- Key Laboratory of Animal Physiology, Biochemistry and Molecular Biology of Hebei Province, College of Life Sciences, Hebei Normal University, No. 20 Nanerhuan Eastern Road, Shijiazhuang, Hebei, 050024, P. R. China
| | - Rong-Rong Wang
- Key Laboratory of Animal Physiology, Biochemistry and Molecular Biology of Hebei Province, College of Life Sciences, Hebei Normal University, No. 20 Nanerhuan Eastern Road, Shijiazhuang, Hebei, 050024, P. R. China
| | - Chun-Mian Zhang
- Key Laboratory of Animal Physiology, Biochemistry and Molecular Biology of Hebei Province, College of Life Sciences, Hebei Normal University, No. 20 Nanerhuan Eastern Road, Shijiazhuang, Hebei, 050024, P. R. China
| | - Jing-Ze Liu
- Key Laboratory of Animal Physiology, Biochemistry and Molecular Biology of Hebei Province, College of Life Sciences, Hebei Normal University, No. 20 Nanerhuan Eastern Road, Shijiazhuang, Hebei, 050024, P. R. China
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Duzlu O, Yildirim A, Inci A, Gumussoy KS, Ciloglu A, Onder Z. Molecular Investigation ofFrancisella-Like Endosymbiont in Ticks andFrancisella tularensisin Ixodid Ticks and Mosquitoes in Turkey. Vector Borne Zoonotic Dis 2016; 16:26-32. [DOI: 10.1089/vbz.2015.1818] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
Affiliation(s)
- Onder Duzlu
- Department of Parasitology, Faculty of Veterinary Medicine, Erciyes University, Kayseri, Turkey
- Vectors and Vector-Borne Diseases Implementation and Research Center, Erciyes University, Kayseri, Turkey
| | - Alparslan Yildirim
- Department of Parasitology, Faculty of Veterinary Medicine, Erciyes University, Kayseri, Turkey
- Vectors and Vector-Borne Diseases Implementation and Research Center, Erciyes University, Kayseri, Turkey
| | - Abdullah Inci
- Department of Parasitology, Faculty of Veterinary Medicine, Erciyes University, Kayseri, Turkey
- Vectors and Vector-Borne Diseases Implementation and Research Center, Erciyes University, Kayseri, Turkey
| | - Kadir Semih Gumussoy
- Vectors and Vector-Borne Diseases Implementation and Research Center, Erciyes University, Kayseri, Turkey
- Department of Microbiology, Faculty of Veterinary Medicine, Erciyes University, Kayseri, Turkey
| | - Arif Ciloglu
- Department of Parasitology, Faculty of Veterinary Medicine, Erciyes University, Kayseri, Turkey
- Vectors and Vector-Borne Diseases Implementation and Research Center, Erciyes University, Kayseri, Turkey
| | - Zuhal Onder
- Department of Parasitology, Faculty of Veterinary Medicine, Erciyes University, Kayseri, Turkey
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Brudal E, Winther-Larsen HC, Colquhoun DJ, Duodu S. Evaluation of reference genes for reverse transcription quantitative PCR analyses of fish-pathogenic Francisella strains exposed to different growth conditions. BMC Res Notes 2013; 6:76. [PMID: 23452832 PMCID: PMC3599356 DOI: 10.1186/1756-0500-6-76] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2012] [Accepted: 02/27/2013] [Indexed: 12/20/2022] Open
Abstract
Background Reverse transcription quantitative PCR has become a powerful technique to monitor mRNA transcription in response to different environmental conditions in many bacterial species. However, correct evaluation of data requires accurate and reliable use of reference genes whose transcription does not change during the course of the experiment. In the present study exposure to different growth conditions was used to validate the transcription stability of eight reference gene candidates in three strains from two subspecies of Francisella noatunensis, a pathogen causing disease in both warm and cold water fish species. Results Relative transcription levels for genes encoding DNA gyrase (gyrA), RNA polymerase beta subunit (rpoB), DNA polymerase I (polA), cell division protein (ftsZ), outer membrane protein (fopA), riboflavin biosynthesis protein (ribC), 16S ribosomal RNA (16S rRNA) and DNA helicases (uvrD) were quantified under exponential, stationary and iron-restricted growth conditions. The suitability of selected reference genes for reliable interpretation of gene expression data was tested using the virulence-associated intracellular growth locus subunit C (iglC) gene. Conclusion Although the transcription stability of the reference genes was slightly different in the three strains studied, fopA, ftsZ and polA proved to be the most stable and suitable for normalization of gene transcription in Francisella noatunensis ssp.
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Affiliation(s)
- Espen Brudal
- Section for Microbiology, Immunology and Parasitology, Department of Food Safety and Infection Biology, Norwegian School of Veterinary Science, PO Box 8146 Dep, Oslo 0033, Norway
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Michelet L, Bonnet S, Madani N, Moutailler S. Discriminating Francisella tularensis and Francisella-like endosymbionts in Dermacentor reticulatus ticks: evaluation of current molecular techniques. Vet Microbiol 2013; 163:399-403. [PMID: 23415475 DOI: 10.1016/j.vetmic.2013.01.014] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2012] [Revised: 01/17/2013] [Accepted: 01/18/2013] [Indexed: 11/28/2022]
Abstract
Francisella tularensis, the causative agent of tularemia, is commonly transmitted by ticks. To ensure accurate F. tularensis reporting rates in epidemiological surveys, specific discrimination between F. tularensis and Francisella-like tick endosymbionts (FLEs) is absolutely critical. Four molecular available techniques capable of distinguishing Francisella spp. were compared here for the first time in French Dermacentor reticulatus ticks in order to estimate their specificity as well as their ease and speed of use. Results showed that tul4 and fopA real-time PCR assays can easily and effectively discriminate between F. tularensis and FLEs in D. reticulatus. In addition, a high prevalence of FLEs in D. reticulatus collected in France was reported by the use of fopA real-time PCR assay (79%). Finally, phylogenetic analysis showed that FLEs isolated from D. reticulatus correspond to a well-defined group compared to FLEs originating from various tick species.
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Affiliation(s)
- Lorraine Michelet
- USC BIPAR, Animal Health Laboratory, ANSES, INRA, ENVA, UPEC, 23 Avenue du Général de Gaulle, 94706 Maisons Alfort cedex, France.
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Sridhar S, Sharma A, Kongshaug H, Nilsen F, Jonassen I. Whole genome sequencing of the fish pathogen Francisella noatunensis subsp. orientalis Toba04 gives novel insights into Francisella evolution and pathogenecity. BMC Genomics 2012; 13:598. [PMID: 23131096 PMCID: PMC3532336 DOI: 10.1186/1471-2164-13-598] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2012] [Accepted: 10/31/2012] [Indexed: 01/23/2023] Open
Abstract
BACKGROUND Francisella is a genus of gram-negative bacterium highly virulent in fishes and human where F. tularensis is causing the serious disease tularaemia in human. Recently Francisella species have been reported to cause mortality in aquaculture species like Atlantic cod and tilapia. We have completed the sequencing and draft assembly of the Francisella noatunensis subsp. orientalisToba04 strain isolated from farmed Tilapia. Compared to other available Francisella genomes, it is most similar to the genome of Francisella philomiragia subsp. philomiragia, a free-living bacterium not virulent to human. RESULTS The genome is rearranged compared to the available Francisella genomes even though we found no IS-elements in the genome. Nearly 16% percent of the predicted ORFs are pseudogenes. Computational pathway analysis indicates that a number of the metabolic pathways are disrupted due to pseudogenes. Comparing the novel genome with other available Francisella genomes, we found around 2.5% of unique genes present in Francisella noatunensis subsp. orientalis Toba04 and a list of genes uniquely present in the human-pathogenic Francisella subspecies. Most of these genes might have transferred from bacterial species through horizontal gene transfer. Comparative analysis between human and fish pathogen also provide insights into genes responsible for pathogenecity. Our analysis of pseudogenes indicates that the evolution of Francisella subspecies's pseudogenes from Tilapia is old with large number of pseudogenes having more than one inactivating mutation. CONCLUSIONS The fish pathogen has lost non-essential genes some time ago. Evolutionary analysis of the Francisella genomes, strongly suggests that human and fish pathogenic Francisella species have evolved independently from free-living metabolically competent Francisella species. These findings will contribute to understanding the evolution of Francisella species and pathogenesis.
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Affiliation(s)
- Settu Sridhar
- Department of Informatics, University of Bergen, Norway
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Silva MT, Pestana NTS. The in vivo extracellular life of facultative intracellular bacterial parasites: role in pathogenesis. Immunobiology 2012; 218:325-37. [PMID: 22795971 DOI: 10.1016/j.imbio.2012.05.011] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2012] [Revised: 03/23/2012] [Accepted: 05/16/2012] [Indexed: 01/14/2023]
Abstract
Classically labeled facultative intracellular pathogens are characterized by the ability to have an intracellular phase in the host, which is required for pathogenicity, while capable of extracellular growth in vitro. The ability of these bacteria to replicate in cell-free conditions is usually assessed by culture in artificial bacteriological media. However, the extracellular growth ability of these pathogens may also be expressed by a phase of extracellular infection in the natural setting of the host with pathologic consequences, an ability that adds to the pathogenic potential of the infectious agent. This infective capability to grow in the extracellular sites of the host represents an additional virulence attribute of those pathogens which may lead to severe outcomes. Here we discuss examples of infectious diseases where the in vivo infective extracellular life is well documented, including infections by Francisella tularensis, Yersinia pestis, Burkholderia pseudomallei, Burkholderia cenocepacia, Salmonella enterica serovar Typhimurium and Edwardsiella tarda. The occurrence of a phase of systemic dissemination with extracellular multiplication during progressive infections by facultative intracellular bacterial pathogens has been underappreciated, with most studies exclusively centered on the intracellular phase of the infections. The investigation of the occurrence of a dual lifestyle in the host among bacterial pathogens in general should be extended and likely will reveal more cases of infectious diseases with a dual infective intracellular/extracellular pattern.
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Affiliation(s)
- Manuel T Silva
- Institute for Molecular and Cell Biology, University of Porto, Porto, Portugal
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Li Y, Powell DA, Shaffer SA, Rasko DA, Pelletier MR, Leszyk JD, Scott AJ, Masoudi A, Goodlett DR, Wang X, Raetz CRH, Ernst RK. LPS remodeling is an evolved survival strategy for bacteria. Proc Natl Acad Sci U S A 2012; 109:8716-21. [PMID: 22586119 PMCID: PMC3365160 DOI: 10.1073/pnas.1202908109] [Citation(s) in RCA: 129] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Maintenance of membrane function is essential and regulated at the genomic, transcriptional, and translational levels. Bacterial pathogens have a variety of mechanisms to adapt their membrane in response to transmission between environment, vector, and human host. Using a well-characterized model of lipid A diversification (Francisella), we demonstrate temperature-regulated membrane remodeling directed by multiple alleles of the lipid A-modifying N-acyltransferase enzyme, LpxD. Structural analysis of the lipid A at environmental and host temperatures revealed that the LpxD1 enzyme added a 3-OH C18 acyl group at 37 °C (host), whereas the LpxD2 enzyme added a 3-OH C16 acyl group at 18 °C (environment). Mutational analysis of either of the individual Francisella lpxD genes altered outer membrane (OM) permeability, antimicrobial peptide, and antibiotic susceptibility, whereas only the lpxD1-null mutant was attenuated in mice and subsequently exhibited protection against a lethal WT challenge. Additionally, growth-temperature analysis revealed transcriptional control of the lpxD genes and posttranslational control of the LpxD1 and LpxD2 enzymatic activities. These results suggest a direct mechanism for LPS/lipid A-level modifications resulting in alterations of membrane fluidity, as well as integrity and may represent a general paradigm for bacterial membrane adaptation and virulence-state adaptation.
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Affiliation(s)
- Yanyan Li
- State Key Laboratory of Food Science and Technology, The Key Laboratory of Carbohydrate Chemistry and Biotechnology and Industrial Biotechnology of Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214211, China
- Department of Microbial Pathogenesis, University of Maryland, Baltimore, MD 21201
| | - Daniel A. Powell
- Department of Microbial Pathogenesis, University of Maryland, Baltimore, MD 21201
| | - Scott A. Shaffer
- Departments of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA 01605
| | - David A. Rasko
- Institute for Genome Sciences, Department of Microbiology and Immunology, University of Maryland, Baltimore, MD 21201
| | - Mark R. Pelletier
- Department of Microbial Pathogenesis, University of Maryland, Baltimore, MD 21201
| | - John D. Leszyk
- Departments of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, MA 01605
| | - Alison J. Scott
- Department of Microbial Pathogenesis, University of Maryland, Baltimore, MD 21201
| | - Ali Masoudi
- Department of Biochemistry, Duke University, Durham, NC 27710; and
| | - David R. Goodlett
- Department of Medicinal Chemistry, University of Washington, Seattle, WA 98195
| | - Xiaoyuan Wang
- State Key Laboratory of Food Science and Technology, The Key Laboratory of Carbohydrate Chemistry and Biotechnology and Industrial Biotechnology of Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214211, China
| | | | - Robert K. Ernst
- Department of Microbial Pathogenesis, University of Maryland, Baltimore, MD 21201
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Silva MT. Classical labeling of bacterial pathogens according to their lifestyle in the host: inconsistencies and alternatives. Front Microbiol 2012; 3:71. [PMID: 22393329 PMCID: PMC3289908 DOI: 10.3389/fmicb.2012.00071] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2012] [Accepted: 02/11/2012] [Indexed: 02/05/2023] Open
Abstract
An ample understanding of the complex interactions between host and pathogen will improve our ability to develop new prophylactic and therapeutic measures against infection. Precise classification of infectious agents in regards to their infective lifestyles in the host and corresponding pathogenic implications are required because clear concepts are essential to plan fruitful research. Classically, pathogenic bacteria are classified as extracellular, facultative intracellular, and obligate intracellular. In my opinion, this classification is inadequate because, as concluded from data here discussed, it is based on inconsistencies and hyper-valorizes the capacity of the infectious agent replicate in vitro in cell-free media. For a microbial pathogen, what matters is whether intra- or extracellularity is in the context of the in vivo life and in association with pathogenicity. When living as a pathogen in association with its host, what is relevant in microbiological terms is not the ability to grow in artificial cell-free bacteriological media or in environmental niches but whether the intracellular infectious agent, besides the phase of intracellular growth which is behind its label, also is able to live extracellularly in the natural settings of the extracellular territories of their hosts. To eliminate the inconsistencies associated with the classical labeling of bacterial pathogens, I propose that bacterial pathogens be labeled exclusive extracellular, dual intracellular/extracellular and exclusive intracellular based on their infective lifestyle in the host, not in the ability to grow in artificial bacteriological media.
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Affiliation(s)
- Manuel T Silva
- Institute for Molecular and Cell Biology, University of Porto Porto, Portugal
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O'Connell HA, Rose LJ, Shams AM, Arduino MJ, Rice EW. Chlorine disinfection of Francisella tularensis. Lett Appl Microbiol 2011; 52:84-6. [PMID: 21189486 DOI: 10.1111/j.1472-765x.2010.02971.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
AIMS To determine the range of free available chlorine (FAC) required for disinfection of the live vaccine strain (LVS) and wild-type strains of Francisella tularensis. METHODS AND RESULTS Seven strains of planktonic F. tularensis were exposed to 0·5 mg·l(-1) FAC for two pH values, 7 and 8, at 5 and 25°C. LVS was inactivated 2 to 4 times more quickly than any of the wild-type F. tularensis strains at pH 8 and 5°C. CONCLUSIONS Free available chlorine residual concentrations routinely maintained in drinking water distribution systems would require up to two hours to reduce all F. tularensis strains by 4 log10. LVS was inactivated most quickly of the tested strains. SIGNIFICANCE AND IMPACT OF THE STUDY This work provides contact time (CT) values that are useful for drinking water risk assessment and also suggests that LVS may not be a good surrogate in disinfection studies.
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Affiliation(s)
- H A O'Connell
- Centers for Disease Control and Prevention, Atlanta, GA 30333, USA.
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Asare R, Akimana C, Jones S, Abu Kwaik Y. Molecular bases of proliferation of Francisella tularensis in arthropod vectors. Environ Microbiol 2010; 12:2587-612. [PMID: 20482589 DOI: 10.1111/j.1462-2920.2010.02230.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Arthropod vectors are important vehicles for transmission of Francisella tularensis between mammals, but very little is known about the F. tularensis-arthropod vector interaction. Drosophila melanogaster has been recently developed as an arthropod vector model for F. tularensis. We have shown that intracellular trafficking of F. tularensis within human monocytes-derived macrophages and D. melanogaster-derived S2 cells is very similar. Within both evolutionarily distant host cells, the Francisella-containing phagosome matures to a late endosome-like phagosome with limited fusion to lysosomes followed by rapid bacterial escape into the cytosol where the bacterial proliferate. To decipher the molecular bases of intracellular proliferation of F. tularensis within arthropod-derived cells, we screened a comprehensive library of mutants of F. tularensis ssp. novicida for their defect in intracellular proliferation within D. melanogaster-derived S2 cells. Our data show that 394 genes, representing 22% of the genome, are required for intracellular proliferation within D. melanogaster-derived S2 cells, including many of the Francisella Pathogenicity Island (FPI) genes that are also required for proliferation within mammalian macrophages. Functional gene classes that exhibit growth defect include metabolic (25%), FPI (2%), type IV pili (1%), transport (16%) and DNA modification (5%). Among 168 most defective mutants in intracellular proliferation in S2 cells, 80 are defective in lethality and proliferation within adult D. melanogaster. The observation that only 135 of the 394 mutants that are defective in S2 cells are also defective in human macrophages indicates that F. tularensis utilize common as well as distinct mechanisms to proliferate within mammalian and arthropod cells. Our studies will facilitate deciphering the molecular aspects of F. tularensis-arthropod vector interaction and its patho-adaptation to infect mammals.
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Affiliation(s)
- Rexford Asare
- Department of Microbiology and Immunology, University of Louisville College of Medicine, Louisville, KY 40292, USA
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Global transcriptional response to spermine, a component of the intramacrophage environment, reveals regulation of Francisella gene expression through insertion sequence elements. J Bacteriol 2009; 191:6855-64. [PMID: 19749055 DOI: 10.1128/jb.00995-09] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Tularemia is caused by the category A biodefense agent Francisella tularensis. This bacterium is associated with diverse environments and a plethora of arthropod and mammalian hosts. How F. tularensis adapts to these different conditions, particularly the eukaryotic intracellular environment in which it replicates, is poorly understood. Here, we demonstrate that the polyamines spermine and spermidine are environmental signals that alter bacterial stimulation of host cells. Genomewide analysis showed that F. tularensis LVS undergoes considerable changes in gene expression in response to spermine. Unexpectedly, analysis of gene expression showed that multiple members of two classes of Francisella insertion sequence (IS) elements, ISFtu1 and ISFtu2, and the genes adjacent to these elements were induced by spermine. Spermine was sufficient to activate transcription of these IS elements and of nearby genes in broth culture and in macrophages. Importantly, the virulent strain of F. tularensis, Schu S4, exhibited similar phenotypes of cytokine induction and gene regulation in response to spermine. Distinctions in gene expression changes between Schu S4 and LVS at one orthologous locus, however, correlated with differences in IS element location. Our results indicate that spermine and spermidine are novel triggers to alert F. tularensis of its eukaryotic host environment. The results reported here also identify an unexpected mechanism of gene regulation controlled by a spermine-responsive promoter contained within IS elements. Different arrangements of these mobile genetic elements among Francisella strains may contribute to virulence by conveying new expression patterns for genes from different strains.
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