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Cantlay S, Garrison NL, Patterson R, Wagner K, Kirk Z, Fan J, Primerano DA, Sullivan MLG, Franks JM, Stolz DB, Horzempa J. Phenotypic and transcriptional characterization of F. tularensis LVS during transition into a viable but non-culturable state. Front Microbiol 2024; 15:1347488. [PMID: 38380104 PMCID: PMC10877056 DOI: 10.3389/fmicb.2024.1347488] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Accepted: 01/15/2024] [Indexed: 02/22/2024] Open
Abstract
Francisella tularensis is a gram-negative, intracellular pathogen which can cause serious, potentially fatal, illness in humans. Species of F. tularensis are found across the Northern Hemisphere and can infect a broad range of host species, including humans. Factors affecting the persistence of F. tularensis in the environment and its epidemiology are not well understood, however, the ability of F. tularensis to enter a viable but non-culturable state (VBNC) may be important. A broad range of bacteria, including many pathogens, have been observed to enter the VBNC state in response to stressful environmental conditions, such as nutrient limitation, osmotic or oxidative stress or low temperature. To investigate the transition into the VBNC state for F. tularensis, we analyzed the attenuated live vaccine strain, F. tularensis LVS grown under standard laboratory conditions. We found that F. tularensis LVS rapidly and spontaneously enters a VBNC state in broth culture at 37°C and that this transition coincides with morphological differentiation of the cells. The VBNC bacteria retained an ability to interact with both murine macrophages and human erythrocytes in in vitro assays and were insensitive to treatment with gentamicin. Finally, we present the first transcriptomic analysis of VBNC F. tularensis, which revealed clear differences in gene expression, and we identify sets of differentially regulated genes which are specific to the VBNC state. Identification of these VBNC specific genes will pave the way for future research aimed at dissecting the molecular mechanisms driving entry into the VBNC state.
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Affiliation(s)
- Stuart Cantlay
- Department of Biomedical Sciences, West Liberty University, West Liberty, WV, United States
| | - Nicole L. Garrison
- Department of Biomedical Sciences, West Liberty University, West Liberty, WV, United States
| | - Rachelle Patterson
- Department of Biomedical Sciences, West Liberty University, West Liberty, WV, United States
| | - Kassey Wagner
- Department of Biomedical Sciences, West Liberty University, West Liberty, WV, United States
| | - Zoei Kirk
- Department of Biomedical Sciences, West Liberty University, West Liberty, WV, United States
| | - Jun Fan
- Department of Biomedical Sciences, Joan C. Edwards School of Medicine, Marshall University, Huntington, WV, United States
| | - Donald A. Primerano
- Department of Biomedical Sciences, Joan C. Edwards School of Medicine, Marshall University, Huntington, WV, United States
| | - Mara L. G. Sullivan
- Department of Cell Biology, Center for Biologic Imaging, University of Pittsburgh, Pittsburgh, PA, United States
| | - Jonathan M. Franks
- Department of Cell Biology, Center for Biologic Imaging, University of Pittsburgh, Pittsburgh, PA, United States
| | - Donna B. Stolz
- Department of Cell Biology, Center for Biologic Imaging, University of Pittsburgh, Pittsburgh, PA, United States
| | - Joseph Horzempa
- Department of Biomedical Sciences, West Liberty University, West Liberty, WV, United States
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2
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Ahmad F, Javed K, Tahir A, Khan MUG, Abbas M, Rabbani M, Shabbir MZ. Identifying key soil characteristics for Francisella tularensis classification with optimized Machine learning models. Sci Rep 2024; 14:1743. [PMID: 38242908 PMCID: PMC10799052 DOI: 10.1038/s41598-024-51502-z] [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: 02/15/2023] [Accepted: 01/05/2024] [Indexed: 01/21/2024] Open
Abstract
Francisella tularensis (Ft) poses a significant threat to both animal and human populations, given its potential as a bioweapon. Current research on the classification of this pathogen and its relationship with soil physical-chemical characteristics often relies on traditional statistical methods. In this study, we leverage advanced machine learning models to enhance the prediction of epidemiological models for soil-based microbes. Our model employs a two-stage feature ranking process to identify crucial soil attributes and hyperparameter optimization for accurate pathogen classification using a unique soil attribute dataset. Optimization involves various classification algorithms, including Support Vector Machines (SVM), Ensemble Models (EM), and Neural Networks (NN), utilizing Bayesian and Random search techniques. Results indicate the significance of soil features such as clay, nitrogen, soluble salts, silt, organic matter, and zinc , while identifying the least significant ones as potassium, calcium, copper, sodium, iron, and phosphorus. Bayesian optimization yields the best results, achieving an accuracy of 86.5% for SVM, 81.8% for EM, and 83.8% for NN. Notably, SVM emerges as the top-performing classifier, with an accuracy of 86.5% for both Bayesian and Random Search optimizations. The insights gained from employing machine learning techniques enhance our understanding of the environmental factors influencing Ft's persistence in soil. This, in turn, reduces the risk of false classifications, contributing to better pandemic control and mitigating socio-economic impacts on communities.
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Affiliation(s)
- Fareed Ahmad
- Department of Computer Science, University of Engineering and Technology, Lahore, Pakistan.
- Quality Operations Laboratory, Institute of Microbiology, University of Veterinary and Animal Sciences, Lahore, Pakistan.
| | - Kashif Javed
- Department of Electrical Engineering, University of Engineering and Technology, Lahore, Pakistan
| | - Ahsen Tahir
- Department of Electrical Engineering, University of Engineering and Technology, Lahore, Pakistan
| | | | - Mateen Abbas
- Quality Operations Laboratory, Institute of Microbiology, University of Veterinary and Animal Sciences, Lahore, Pakistan
| | - Masood Rabbani
- Institute of Microbiology, University of Veterinary and Animal Sciences, Lahore, Pakistan
| | - Muhammad Zubair Shabbir
- Quality Operations Laboratory, Institute of Microbiology, University of Veterinary and Animal Sciences, Lahore, Pakistan
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3
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Schaudinn C, Rydzewski K, Meister B, Grunow R, Heuner K. Francisella tularensis subsp. holarctica wild-type is able to colonize natural aquatic ex vivo biofilms. Front Microbiol 2023; 14:1113412. [PMID: 36860486 PMCID: PMC9969146 DOI: 10.3389/fmicb.2023.1113412] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Accepted: 01/16/2023] [Indexed: 02/15/2023] Open
Abstract
Biofilms are a matrix-associated lifestyle of microbial communities, often enabling survivability and persistence of such bacteria. The objective of this study was to investigate the survival of the wild-type strain A-271 of Francisella tularensis subsp. holarctica (Fth) in a natural aquatic ex vivo biofilm. To that purpose, we allowed Fth A-271 to produce its own biofilm on solid surfaces but also to colonize naturally formed biofilms from aquatic habitats, which were infected with Francisella in the laboratory. The survival rates of the bacteria in biofilms were compared to those of planktonic bacteria as a function of the employed culture condition. It could be shown by light- and electron microscopy that Fth is able to form a complex, matrix-associated biofilm. The biofilm form of Francisella showed longer cultivability on agar plates in natural water when compared to planktonic (free-living) bacteria. Be it as a part of the existing ex vivo biofilm or free-floating above as planktonic bacteria, more than 80% of Francisella were not only able to survive under these conditions for 28 days, but even managed to establish microcolonies and areas with their own exclusive biofilm architecture within the ex vivo biofilm. Here, we can demonstrate for the first time that a Francisella tularensis wild-type strain (Type B) is able to successfully colonize an aquatic multi-species ex vivo biofilm. It is worthwhile to speculate that Fth might become more persistent in the environment when it forms its own biofilm or integrates in an existing one. Multi-species biofilms have been shown to be more resistant against stress compared to single-species biofilms. This may have an important impact on the long-term survival of Francisella in aquatic habitats and infection cycles in nature.
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Affiliation(s)
- Christoph Schaudinn
- Centre for Biological Threats and Special Pathogens, Advanced Light and Electron Microscopy (ZBS 4), 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,Centre for Biological Threats and Special Pathogens, Highly Pathogenic Microorganisms (ZBS 2), Robert Koch Institute, Berlin, Germany
| | - Beate Meister
- Centre for Biological Threats and Special Pathogens, Highly Pathogenic Microorganisms (ZBS 2), Robert Koch Institute, Berlin, Germany
| | - Roland Grunow
- 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,*Correspondence: Klaus Heuner, ✉
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4
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Two phase feature-ranking for new soil dataset for Coxiella burnetii persistence and classification using machine learning models. Sci Rep 2023; 13:29. [PMID: 36593267 PMCID: PMC9807593 DOI: 10.1038/s41598-022-26956-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Accepted: 12/22/2022] [Indexed: 01/03/2023] Open
Abstract
Coxiella burnetii (Cb) is a hardy, stealth bacterial pathogen lethal for humans and animals. Its tremendous resistance to the environment, ease of propagation, and incredibly low infectious dosage make it an attractive organism for biowarfare. Current research on the classification of Coxiella and features influencing its presence in the soil is generally confined to statistical techniques. Machine learning other than traditional approaches can help us better predict epidemiological modeling for this soil-based pathogen of public significance. We developed a two-phase feature-ranking technique for the pathogen on a new soil feature dataset. The feature ranking applies methods such as ReliefF (RLF), OneR (ONR), and correlation (CR) for the first phase and a combination of techniques utilizing weighted scores to determine the final soil attribute ranks in the second phase. Different classification methods such as Support Vector Machine (SVM), Linear Discriminant Analysis (LDA), Logistic Regression (LR), and Multi-Layer Perceptron (MLP) have been utilized for the classification of soil attribute dataset for Coxiella positive and negative soils. The feature-ranking methods established that potassium, chromium, cadmium, nitrogen, organic matter, and soluble salts are the most significant attributes. At the same time, manganese, clay, phosphorous, copper, and lead are the least contributing soil features for the prevalence of the bacteria. However, potassium is the most influential feature, and manganese is the least significant soil feature. The attribute ranking using RLF generates the most promising results among the ranking methods by generating an accuracy of 80.85% for MLP, 79.79% for LR, and 79.8% for LDA. Overall, SVM and MLP are the best-performing classifiers, where SVM yields an accuracy of 82.98% and 81.91% for attribute ranking by CR and RLF; and MLP generates an accuracy of 76.60% for ONR. Thus, machine models can help us better understand the environment, assisting in the prevalence of bacteria and decreasing the chances of false classification. Subsequently, this can assist in controlling epidemics and alleviating the devastating effect on the socio-economics of society.
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5
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Mlynek KD, Lopez CT, Fetterer DP, Williams JA, Bozue JA. Phase Variation of LPS and Capsule Is Responsible for Stochastic Biofilm Formation in Francisella tularensis. Front Cell Infect Microbiol 2022; 11:808550. [PMID: 35096655 PMCID: PMC8795689 DOI: 10.3389/fcimb.2021.808550] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Accepted: 12/22/2021] [Indexed: 11/24/2022] Open
Abstract
Biofilms have been established as an important lifestyle for bacteria in nature as these structured communities often enable survivability and persistence in a multitude of environments. Francisella tularensis is a facultative intracellular Gram-negative bacterium found throughout much of the northern hemisphere. However, biofilm formation remains understudied and poorly understood in F. tularensis as non-substantial biofilms are typically observed in vitro by the clinically relevant subspecies F. tularensis subsp. tularensis and F. tularensis subsp. holarctica (Type A and B, respectively). Herein, we report conditions under which robust biofilm development was observed in a stochastic, but reproducible manner in Type A and B isolates. The frequency at which biofilm was observed increased temporally and appeared switch-like as progeny from the initial biofilm quickly formed biofilm in a predictable manner regardless of time or propagation with fresh media. The Type B isolates used for this study were found to more readily switch on biofilm formation than Type A isolates. Additionally, pH was found to function as an environmental checkpoint for biofilm initiation independently of the heritable cellular switch. Multiple colony morphologies were observed in biofilm positive cultures leading to the identification of a particular subset of grey variants that constitutively produce biofilm. Further, we found that constitutive biofilm forming isolates delay the onset of a viable non-culturable state. In this study, we demonstrate that a robust biofilm can be developed by clinically relevant F. tularensis isolates, provide a mechanism for biofilm initiation and examine the potential role of biofilm formation.
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Affiliation(s)
- Kevin D. Mlynek
- Bacteriology Division, U.S. Army Medical Research Institute of Infectious Diseases (USAMRIID), Frederick, MD, United States
| | - Christopher T. Lopez
- Bacteriology Division, U.S. Army Medical Research Institute of Infectious Diseases (USAMRIID), Frederick, MD, United States
| | - David P. Fetterer
- Division of Biostatistics, U.S. Army Medical Research Institute of Infectious Diseases (USAMRIID), Frederick, MD, United States
| | - Janice A. Williams
- Pathology Division, U.S. Army Medical Research Institute of Infectious Diseases (USAMRIID), Frederick, MD, United States
| | - Joel A. Bozue
- Bacteriology Division, U.S. Army Medical Research Institute of Infectious Diseases (USAMRIID), Frederick, MD, United States
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6
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Brunet CD, Hennebique A, Peyroux J, Pelloux I, Caspar Y, Maurin M. Presence of Francisella tularensis subsp. holarctica DNA in the Aquatic Environment in France. Microorganisms 2021; 9:microorganisms9071398. [PMID: 34203503 PMCID: PMC8306966 DOI: 10.3390/microorganisms9071398] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Revised: 06/24/2021] [Accepted: 06/25/2021] [Indexed: 01/08/2023] Open
Abstract
In 2018, the incidence of tularemia increased twofold in the west of France, with many pneumonic forms, suggesting environmental sources of infection. We investigated the presence of Francisellatularensis subsp. holarctica and other Francisella species DNA in the natural aquatic environment of this geographic area. Two sampling campaigns, in July 2019 and January 2020, allowed the collection of 87 water samples. Using a combination of real-time PCR assays, we tested the presence of either Francisella sp., F. tularensis/F. novicida, and F. tularensis subsp. holarctica, the latter being the only tularemia agent in Europe. Among 57 water samples of the first campaign, 15 (26.3%) were positive for Francisella sp., nine (15.8%) for F. tularensis and/or F. novicida, and four (7.0%) for F. tularensis subsp. holarctica. Ratios were 25/30 (83.3%), 24/30 (80.0%), and 4/30 (13.3%) for the second campaign. Among the thirty sites sampled during the two campaigns, nine were positive both times for Francisella sp., seven for F. tularensis and/or F. novicida, and one for F. tularensis subsp. holarctica. Altogether, our study reveals a high prevalence of Francisella sp. DNA (including the tularemia agent) in the studied aquatic environment. This aquatic environment could therefore participate in the endemicity of tularemia in the west of France.
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Affiliation(s)
- Camille D. Brunet
- Centre National de la Recherche Scientifique, Université Grenoble Alpes, TIMC, UMR5525, 38000 Grenoble, France; (C.D.B.); (A.H.); (J.P.); (Y.C.)
| | - Aurélie Hennebique
- Centre National de la Recherche Scientifique, Université Grenoble Alpes, TIMC, UMR5525, 38000 Grenoble, France; (C.D.B.); (A.H.); (J.P.); (Y.C.)
- Centre National de Référence des Francisella, Centre Hospitalier Universitaire Grenoble Alpes, 38000 Grenoble, France;
| | - Julien Peyroux
- Centre National de la Recherche Scientifique, Université Grenoble Alpes, TIMC, UMR5525, 38000 Grenoble, France; (C.D.B.); (A.H.); (J.P.); (Y.C.)
| | - Isabelle Pelloux
- Centre National de Référence des Francisella, Centre Hospitalier Universitaire Grenoble Alpes, 38000 Grenoble, France;
| | - Yvan Caspar
- Centre National de la Recherche Scientifique, Université Grenoble Alpes, TIMC, UMR5525, 38000 Grenoble, France; (C.D.B.); (A.H.); (J.P.); (Y.C.)
- Centre National de Référence des Francisella, Centre Hospitalier Universitaire Grenoble Alpes, 38000 Grenoble, France;
| | - Max Maurin
- Centre National de la Recherche Scientifique, Université Grenoble Alpes, TIMC, UMR5525, 38000 Grenoble, France; (C.D.B.); (A.H.); (J.P.); (Y.C.)
- Centre National de Référence des Francisella, Centre Hospitalier Universitaire Grenoble Alpes, 38000 Grenoble, France;
- Correspondence:
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7
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The Important Role of Metal Ions for Survival of Francisella in Water within Amoeba Environment. BIOMED RESEARCH INTERNATIONAL 2021. [DOI: 10.1155/2021/6673642] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Francisella tularensis is a gram-negative facultative intracellular bacterium that resists harsh environments. Several outbreaks of tularemia are linked to the consumption and contact with spring water. The number of F. tularensis in some waters is high, while in others, this bacterium does not survive. Except organic compounds, metals could be important for the survival of F. tularensis in water. Some Francisella strains showed the association with amoeba, which may act as the environmental reservoir. This study was aimed at following the role of metal ions and/or amoeba in the existence and replication of F. novicida in spring waters by growth kinetics, acquisition of metals, and ultrastructural analyses of bacteria. The bacteria showed a longer survival in water with higher initial concentrations of Mn and Zn. Although Mn and Zn were necessary for the survival of F. novicida, the results also showed that the bacterium does not grow in water with high levels of Zn. In contrast, high levels of Mn did not have such a negative effect on the survival of this bacterium in water. In addition, while F. novicida benefits presence of amoeba in spring water, the number of amoebae is decreasing in a coculture model with F. novicida.
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8
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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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9
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Ahmad F, Farooq A, Ghani Khan MU, Shabbir MZ, Rabbani M, Hussain I. Identification of Most Relevant Features for Classification of Francisella tularensis using Machine Learning. Curr Bioinform 2021. [DOI: 10.2174/1574893615666200219113900] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Background:
Francisella tularensis is a stealth pathogen fatal for animals and humans.
Ease of its propagation, coupled with high capacity for ailment and death makes it a potential
candidate for biological weapon.
Objective:
Work related to the pathogen’s classification and factors affecting its prolonged
existence in soil is limited to statistical measures. Machine learning other than conventional
analysis methods may be applied to better predict epidemiological modeling for this soil-borne
pathogen.
Methods:
Feature-ranking algorithms namely; relief, correlation and oneR are used for soil
attribute ranking. Moreover, classification algorithms; SVM, random forest, naive bayes, logistic
regression and MLP are used for classification of the soil attribute dataset for Francisella
tularensis positive and negative soils.
Results:
Feature-ranking methods concluded that clay, nitrogen, organic matter, soluble salts, zinc,
silt and nickel are the most significant attributes while potassium, phosphorous, iron, calcium,
copper, chromium and sand are the least contributing risk factors for the persistence of the
pathogen. However, clay is the most significant and potassium is the least contributing attribute.
Data analysis suggests that feature-ranking using relief produced classification accuracy of 84.35%
for multilayer perceptron; 82.99% for linear regression; 80.27% for SVM and random forest; and
78.23% for naive bayes, which is better than other ranking methods. MLP outperforms other
classifiers by generating an accuracy of 84.35%, 82.99% and 81.63% for feature-ranking using
relief, correlation and oneR algorithms, respectively.
Conclusion:
These models can significantly improve accuracy and can minimize the risk of
incorrect classification. They further help in controlling epidemics and thereby minimizing the
socio-economic impact on the society.
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Affiliation(s)
- Fareed Ahmad
- Department of Computer Science and Engineering, Faculty of Electrical Engineering, University of Engineering and Technology, Lahore, Pakistan
| | - Amjad Farooq
- Department of Computer Science and Engineering, Faculty of Electrical Engineering, University of Engineering and Technology, Lahore, Pakistan
| | - Muhammad Usman Ghani Khan
- Department of Computer Science and Engineering, Faculty of Electrical Engineering, University of Engineering and Technology, Lahore, Pakistan
| | | | - Masood Rabbani
- Institute of Microbiology, University of Veterinary and Animal Sciences, Lahore, Pakistan
| | - Irshad Hussain
- Institute of Microbiology, University of Veterinary and Animal Sciences, Lahore, Pakistan
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10
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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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11
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Siebert C, Villers C, Pavlou G, Touquet B, Yakandawala N, Tardieux I, Renesto P. Francisella novicida and F. philomiragia biofilm features conditionning fitness in spring water and in presence of antibiotics. PLoS One 2020; 15:e0228591. [PMID: 32023304 PMCID: PMC7001994 DOI: 10.1371/journal.pone.0228591] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2019] [Accepted: 01/17/2020] [Indexed: 02/07/2023] Open
Abstract
Biofilms are currently considered as a predominant lifestyle of many bacteria in nature. While they promote survival of microbes, biofilms also potentially increase the threats to animal and public health in case of pathogenic species. They not only facilitate bacteria transmission and persistence, but also promote spreading of antibiotic resistance leading to chronic infections. In the case of Francisella tularensis, the causative agent of tularemia, biofilms have remained largely enigmatic. Here, applying live and static confocal microscopy, we report growth and ultrastructural organization of the biofilms formed in vitro by these microorganisms over the early transition from coccobacillary into coccoid shape during biofilm assembly. Using selective dispersing agents, we provided evidence for extracellular DNA (eDNA) being a major and conserved structural component of mature biofilms formed by both F. subsp. novicida and a human clinical isolate of F. philomiragia. We also observed a higher physical robustness of F. novicida biofilm as compared to F. philomiragia one, a feature likely promoted by specific polysaccharides. Further, F. novicida biofilms resisted significantly better to ciprofloxacin than their planktonic counterparts. Importantly, when grown in biofilms, both Francisella species survived longer in cold water as compared to free-living bacteria, a trait possibly associated with a gain in fitness in the natural aquatic environment. Overall, this study provides information on survival of Francisella when embedded with biofilms that should improve both the future management of biofilm-related infections and the design of effective strategies to tackle down the problematic issue of bacteria persistence in aquatic ecosystems.
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Affiliation(s)
| | - Corinne Villers
- TIMC-IMAG UMR 5525-UGA CNRS, Grenoble Cedex 9, France.,Université de Caen Normandie, EA4655 U2RM, Caen, France
| | - Georgios Pavlou
- Institute for Advanced Biosciences (IAB), Team Membrane Dynamics of Parasite-Host Cell Interactions, CNRS UMR 5309, INSERM U1209, Université Grenoble Alpes, Grenoble, France
| | - Bastien Touquet
- Institute for Advanced Biosciences (IAB), Team Membrane Dynamics of Parasite-Host Cell Interactions, CNRS UMR 5309, INSERM U1209, Université Grenoble Alpes, Grenoble, France
| | | | - Isabelle Tardieux
- Institute for Advanced Biosciences (IAB), Team Membrane Dynamics of Parasite-Host Cell Interactions, CNRS UMR 5309, INSERM U1209, Université Grenoble Alpes, Grenoble, France
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12
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Abstract
Tularemia is a Holarctic zoonosis caused by the gamma proteobacterium Francisella tularensis and is considered to be a vector-borne disease. In many regions, human risk is associated with the bites of flies, mosquitoes, or ticks. But the biology of the agent is such that risk may be fomite related, and large outbreaks can occur due to inhalation or ingestion of contaminated materials. Such well-documented human risk factors suggest a role for these risk factors in the enzootic cycle as well. Many arthropods support the growth or survival of the agent, but whether arthropods (ticks in particular) are obligately required for the perpetuation of F. tularensis remains to be demonstrated. As with most zoonoses, our knowledge of the ecology of F. tularensis has been driven with the objective of understanding human risk. In this review, we focus on the role of the arthropod in maintaining F. tularensis, particularly with respect to long-term enzootic persistence.
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Affiliation(s)
- Sam R Telford
- Department of Infectious Disease and Global Health and New England Regional Biosafety Laboratory, Cummings School of Veterinary Medicine, Tufts University, North Grafton, Massachusetts 01536, USA;
| | - Heidi K Goethert
- Department of Infectious Disease and Global Health and New England Regional Biosafety Laboratory, Cummings School of Veterinary Medicine, Tufts University, North Grafton, Massachusetts 01536, USA;
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13
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Kane SR, Shah SR, Alfaro TM. Rapid viability polymerase chain reaction method for detection of Francisella tularensis. J Microbiol Methods 2019; 166:105738. [PMID: 31626892 DOI: 10.1016/j.mimet.2019.105738] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Revised: 10/08/2019] [Accepted: 10/08/2019] [Indexed: 11/26/2022]
Abstract
Francisella tularensis, which causes potentially fatal tularemia, has been considered an attractive agent of bioterrorism and biological warfare due to its low infectious dose, reported environmental persistence, and ability to be transmitted to humans via multiple exposure routes. Due to slow growth on even selective culture media, detection of viable F. tularensis from environmental and drinking water samples, usually takes >3 days. Therefore, a rapid viability polymerase chain reaction (RV-PCR) method was developed to detect and identify viable F. tularensis cells in environmental samples. The method uses a change in PCR response during high throughput (48-well) sample incubation in Brain Heart Infusion/Vitox/Fildes/Histidine growth medium to detect viable F. tularensis presence, which is at least two times faster than the current plate culture-based method. Using the method, 101 to 102 live F. tularensis cells were detected in simulated complex sample matrices containing chemical and biological interferences.
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Affiliation(s)
- Staci R Kane
- Lawrence Livermore National Laboratory, Livermore, CA, USA
| | - Sanjiv R Shah
- National Homeland Security Research Center, Office of Research and Development, U.S. Environmental Protection Agency, Washington, DC, USA.
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14
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Clinical characteristics in a sentinel case as well as in a cluster of tularemia patients associated with grape harvest. Int J Infect Dis 2019; 84:116-120. [PMID: 31071480 DOI: 10.1016/j.ijid.2019.04.031] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Revised: 04/26/2019] [Accepted: 04/29/2019] [Indexed: 11/23/2022] Open
Abstract
BACKGROUND Tularemia is caused by Francisella tularensis and can occasionally establish foodborne transmission. METHODS Patients were identified by active case detection through contact with the treating physicians and consent for publication was obtained. Clinical data were accumulated through a review of the patient charts. Serology, culture, and PCR methods were performed for confirmation of the diagnosis. CASE CLUSTER A 46-year-old patient was hospitalised in the University Hospital Frankfurt (a tertiary care hospital) for pharyngitis and cervical lymphadenitis with abscess. A diagnosis of tularemia was made serologically, but treatment with ciprofloxacin initially failed. F. tularensis was detected in pus from the lymph node using a specific real-time PCR. The use of RD1 PCR led to the identification of the subspecies holarctica. Antibiotic therapy with high-dose ciprofloxacin and gentamicin was administered and was subsequently changed to ciprofloxacin and rifampicin. During a must-tasting, five other individuals became infected with tularemia by ingestion of contaminated must. All patients required treatment durations of more than 14 days. CONCLUSIONS Mechanically harvested agricultural products, such as wine must, can be a source of infection, probably due to contamination with animal carcasses. The clinical course of tularemia can be complicated and prolonged and requires differentiated antibiotic treatment.
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15
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Rohani M, Shahraki AH, Ghasemi A, Esmaeili S, Karadenizli A, Mostafavi E. The prevalence of Francisella spp. in different natural surface water samples collected from northwest of Iran. IRANIAN JOURNAL OF MICROBIOLOGY 2019; 11:19-24. [PMID: 30996827 PMCID: PMC6462269] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
BACKGROUND AND OBJECTIVES Francisella tularensis has a wide distribution in northern hemisphere of the world. Up to now, there was little information about the Francisella spp. situation in the environmental samples in Iran. In this study we aimed to determine the prevalence of Francisella spp. in the environmental samples in northwest of Iran. MATERIALS AND METHODS A total of 237 natural water samples from ponds, rivers, lakes, springs and other surface waters from north western provinces of Iran (Kurdistan and Western Azerbaijan) were collected from September to November 2015. All samples were cultured for Francisella and other bacterial species and Real Time TaqMan PCR was performed on the concentrated and DNA extracted samples. For detection of the presence of bacterial DNA in the samples, two different targets in the genome of Francisella, ISFtu2 and fopA were used. RESULTS Among the tested surface water samples, 40 (17.09%; 95% CI: 12.67-22.33%) and 12 (5.13%; 95%CI: 2.81-8.56%) samples were positive for ISFtu2 and fopA respectively. None of them was positive in culture. CONCLUSION The prevalence of Francisella spp. in the environmental samples in the west of Iran is high and it is comparable with Turkey, Iran's neighboring country. Use of higher copy number genes or IS like ISFtu2 could improve the detection of this organism in the environmental samples.
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Affiliation(s)
- Mahdi Rohani
- Department of Microbiology, 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, Kabudar Ahang, Hamadan, Iran
| | - Abdolrazagh Hashemi Shahraki
- National Reference Laboratory for Plague, Tularemia and Q Fever, Research Centre for Emerging and Reemerging Infectious Diseases, Pasteur Institute of Iran, Akanlu, Kabudar Ahang, Hamadan, Iran,Department of Epidemiology and Biostatistics, Research Centre for Emerging and Reemerging Infectious Diseases, Pasteur Institute of Iran, Tehran, Iran
| | - Ahmad Ghasemi
- National Reference Laboratory for Plague, Tularemia and Q Fever, Research Centre for Emerging and Reemerging Infectious Diseases, Pasteur Institute of Iran, Akanlu, Kabudar Ahang, Hamadan, Iran,Department of Epidemiology and Biostatistics, Research Centre for Emerging and Reemerging Infectious Diseases, Pasteur Institute of Iran, Tehran, Iran,Department of Bacteriology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Saber Esmaeili
- National Reference Laboratory for Plague, Tularemia and Q Fever, Research Centre for Emerging and Reemerging Infectious Diseases, Pasteur Institute of Iran, Akanlu, Kabudar Ahang, Hamadan, Iran,Department of Epidemiology and Biostatistics, Research Centre for Emerging and Reemerging Infectious Diseases, Pasteur Institute of Iran, Tehran, Iran,Department of Bacteriology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Aynur Karadenizli
- Department of Medical Microbiology, Kocaeli University Medical School, Kocaeli, Turkey
| | - Ehsan Mostafavi
- National Reference Laboratory for Plague, Tularemia and Q Fever, Research Centre for Emerging and Reemerging Infectious Diseases, Pasteur Institute of Iran, Akanlu, Kabudar Ahang, Hamadan, Iran,Department of Epidemiology and Biostatistics, Research Centre for Emerging and Reemerging Infectious Diseases, Pasteur Institute of Iran, Tehran, Iran,Corresponding author: Ehsan Mostafavi, Ph.D, National Reference Laboratory for Plague, Tularemia and Q Fever, Research Centre for Emerging and Reemerging Infectious Diseases, Pasteur Institute of Iran, Akanlu, Kabudar Ahang, Hamadan, Iran; Department of Epidemiology and Biostatistics, Research Centre for Emerging and Reemerging Infectious Diseases, Pasteur Institute of Iran, Tehran, Iran. Tel: +98-21-6411212, Fax: +98-21-89776655,
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16
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Cross AR, Baldwin VM, Roy S, Essex-Lopresti AE, Prior JL, Harmer NJ. Zoonoses under our noses. Microbes Infect 2019; 21:10-19. [PMID: 29913297 PMCID: PMC6386771 DOI: 10.1016/j.micinf.2018.06.001] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2018] [Revised: 06/06/2018] [Accepted: 06/07/2018] [Indexed: 11/22/2022]
Abstract
One Health is an effective approach for the management of zoonotic disease in humans, animals and environments. Examples of the management of bacterial zoonoses in Europe and across the globe demonstrate that One Health approaches of international surveillance, information-sharing and appropriate intervention methods are required to successfully prevent and control disease outbreaks in both endemic and non-endemic regions. Additionally, a One Health approach enables effective preparation and response to bioterrorism threats.
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Affiliation(s)
- Alice R Cross
- Living Systems Institute, College of Life and Environmental Sciences, University of Exeter, Exeter EX4 4QD United Kingdom.
| | - Victoria M Baldwin
- Defence Science and Technology Laboratory, Porton Down, Salisbury SP4 0JQ United Kingdom
| | - Sumita Roy
- Living Systems Institute, College of Life and Environmental Sciences, University of Exeter, Exeter EX4 4QD United Kingdom
| | | | - Joann L Prior
- Living Systems Institute, College of Life and Environmental Sciences, University of Exeter, Exeter EX4 4QD United Kingdom; Defence Science and Technology Laboratory, Porton Down, Salisbury SP4 0JQ United Kingdom; London School of Hygiene & Tropical Medicine, Kepple Street, London WC1E 7HT United Kingdom
| | - Nicholas J Harmer
- Living Systems Institute, College of Life and Environmental Sciences, University of Exeter, Exeter EX4 4QD United Kingdom
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17
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Hennebique A, Boisset S, Maurin M. Tularemia as a waterborne disease: a review. Emerg Microbes Infect 2019; 8:1027-1042. [PMID: 31287787 PMCID: PMC6691783 DOI: 10.1080/22221751.2019.1638734] [Citation(s) in RCA: 62] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2019] [Accepted: 06/27/2019] [Indexed: 12/20/2022]
Abstract
Francisella tularensis is a Gram-negative, intracellular bacterium causing the zoonosis tularemia. This highly infectious microorganism is considered a potential biological threat agent. Humans are usually infected through direct contact with the animal reservoir and tick bites. However, tularemia cases also occur after contact with a contaminated hydro-telluric environment. Water-borne tularemia outbreaks and sporadic cases have occurred worldwide in the last decades, with specific clinical and epidemiological traits. These infections represent a major public health and military challenge. Human contaminations have occurred through consumption or use of F. tularensis-contaminated water, and various aquatic activities such as swimming, canyoning and fishing. In addition, in Sweden and Finland, mosquitoes are primary vectors of tularemia due to infection of mosquito larvae in contaminated aquatic environments. The mechanisms of F. tularensis survival in water may include the formation of biofilms, interactions with free-living amoebae, and the transition to a 'viable but nonculturable' state, but the relative contribution of these possible mechanisms remains unknown. Many new aquatic species of Francisella have been characterized in recent years. F. tularensis likely shares with these species an ability of long-term survival in the aquatic environment, which has to be considered in terms of tularemia surveillance and control.
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Affiliation(s)
- Aurélie Hennebique
- Centre National de Référence des Francisella, Institut de Biologie et de Pathologie, Centre Hospitalier Universitaire Grenoble Alpes, Grenoble, France
- Université Grenoble Alpes, Centre National de la Recherche Scientifique, TIMC-IMAG, Grenoble, France
| | - Sandrine Boisset
- Centre National de Référence des Francisella, Institut de Biologie et de Pathologie, Centre Hospitalier Universitaire Grenoble Alpes, Grenoble, France
- Université Grenoble Alpes, Centre National de la Recherche Scientifique, TIMC-IMAG, Grenoble, France
| | - Max Maurin
- Centre National de Référence des Francisella, Institut de Biologie et de Pathologie, Centre Hospitalier Universitaire Grenoble Alpes, Grenoble, France
- Université Grenoble Alpes, Centre National de la Recherche Scientifique, TIMC-IMAG, Grenoble, France
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18
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A Single Mechanosensitive Channel Protects Francisella tularensis subsp. holarctica from Hypoosmotic Shock and Promotes Survival in the Aquatic Environment. Appl Environ Microbiol 2018; 84:AEM.02203-17. [PMID: 29269496 DOI: 10.1128/aem.02203-17] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2017] [Accepted: 12/15/2017] [Indexed: 01/01/2023] Open
Abstract
Francisella tularensis subsp. holarctica is found in North America and much of Europe and causes the disease tularemia in humans and animals. An aquatic cycle has been described for this subspecies, which has caused waterborne outbreaks of tularemia in at least 10 countries. In this study, we sought to identify the mechanosensitive channel(s) required for the bacterium to survive the transition from mammalian hosts to freshwater, which is likely essential for the transmission of the bacterium between susceptible hosts. A single 165-amino-acid MscS-type mechanosensitive channel (FtMscS) was found to protect F. tularensis subsp. holarctica from hypoosmotic shock, despite lacking much of the cytoplasmic vestibule domain found in well-characterized MscS proteins from other organisms. The deletion of this channel did not affect virulence within the mammalian host; however, FtMscS was required to survive the transition from the host niche to freshwater. The deletion of FtMscS did not alter the sensitivity of F. tularensis subsp. holarctica to detergents, H2O2, or antibiotics, suggesting that the role of FtMscS is specific to protection from hypoosmotic shock. The deletion of FtMscS also led to a reduced average cell size without altering gross cell morphology. The mechanosensitive channel identified and characterized in this study likely contributes to the transmission of tularemia between hosts by allowing the bacterium to survive the transition from mammalian hosts to freshwater.IMPORTANCE The contamination of freshwater by Francisella tularensis subsp. holarctica has resulted in a number of outbreaks of tularemia. Invariably, the contamination originates from the carcasses or excreta of infected animals and thus involves an abrupt osmotic downshock as the bacteria enter freshwater. How F. tularensis survives this drastic change in osmolarity has not been clear, but here we report that a single mechanosensitive channel protects the bacterium from osmotic downshock. This channel is functional despite lacking much of the cytoplasmic vestibule domain that is present in better-studied organisms such as Escherichia coli; this report builds on previous studies that have suggested that parts of this domain are dispensable for downshock protection. These findings extend our understanding of the aquatic cycle and ecological persistence of F. tularensis, with further implications for mechanosensitive channel biology.
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19
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Buse HY, Schaefer III FW, Rice EW. Enhanced survival but not amplification of Francisella spp. in the presence of free-living amoebae. Acta Microbiol Immunol Hung 2017; 64:17-36. [PMID: 27929353 DOI: 10.1556/030.63.2016.015] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Transmission of Francisella tularensis, the etiologic agent of tularemia, has been associated with various water sources. Survival of many waterborne pathogens within free-living amoeba (FLA) is well documented; however, the role of amoebae in the environmental persistence of F. tularensis is unclear. In this study, axenic FLA cultures of Acanthamoeba castellanii, Acanthamoeba polyphaga, and Vermamoeba vermiformis were each inoculated with virulent strains of F. tularensis (Types A and B), the attenuated live vaccine strain, and Francisella novicida. Experimental parameters included low and high multiplicity of infection and incubation temperatures of 25 and 30 °C for 0-10 days. Francisella spp. survival was enhanced by the presence of FLA; however, bacterial growth and protozoa infectivity were not observed. In contrast, co-infections of A. polyphaga and Legionella pneumophila, used as an amoeba pathogen control, resulted in bacterial proliferation, cytopathic effects, and amoebal lysis. Collectively, even though short-term incubation with FLA was beneficial, the long-term effects on Francisella survival are unknown, especially given the expenditure of available amoebal derived nutrients and the fastidious nature of Francisella spp. These factors have clear implications for the role of FLA in Francisella environmental persistence.
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Affiliation(s)
- Helen Y. Buse
- 1 National Homeland Security Research Center, US Environmental Protection Agency, Cincinnati, OH, USA
| | - Frank W. Schaefer III
- 1 National Homeland Security Research Center, US Environmental Protection Agency, Cincinnati, OH, USA
| | - Eugene W. Rice
- 1 National Homeland Security Research Center, US Environmental Protection Agency, Cincinnati, OH, USA
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20
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Stephens MD, Yodsanit N, Melander C. Potentiation of the Fosmidomycin analogue FR 900098 with substituted 2-oxazolines against Francisella novicida. MEDCHEMCOMM 2016; 7:1952-1956. [PMID: 28154750 PMCID: PMC5279706 DOI: 10.1039/c6md00365f] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
A library of 33 compounds was screened for potentiation of the antibiotic FR 900098 against the Francisella tularensis surrogate Francisella novicida. From the screen a highly potent 2-oxazoline adjuvant was discovered capable of potentiating FR 900098 with a 1000-fold reduction in MIC against the Francisella sub-species F. novicida and F. philomiragia.
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Affiliation(s)
- Matthew D Stephens
- Department of Chemistry, North Carolina State University, 2620 Yarbrough Drive, Raleigh, NC 27695, USA
| | - Nisakorn Yodsanit
- Department of Chemistry, Mahidol University, 999 Phuttamonthon 4 Road, Salaya 73170, Thailand
| | - Christian Melander
- Department of Chemistry, North Carolina State University, 2620 Yarbrough Drive, Raleigh, NC 27695, USA
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21
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Soto E, Halliday-Simmonds I, Francis S, Kearney MT, Hansen JD. Biofilm formation of Francisella noatunensis subsp. orientalis. Vet Microbiol 2015; 181:313-7. [PMID: 26507830 DOI: 10.1016/j.vetmic.2015.10.007] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2015] [Revised: 09/29/2015] [Accepted: 10/08/2015] [Indexed: 11/25/2022]
Abstract
Francisella noatunensis subsp. orientalis (Fno) is an emergent fish pathogen in both marine and fresh water environments. The bacterium is suspected to persist in the environment even without the presence of a suitable fish host. In the present study, the influence of different abiotic factors such as salinity and temperature were used to study the biofilm formation of different isolates of Fno including intracellular growth loci C (iglC) and pathogenicity determinant protein A (pdpA) knockout strains. Finally, we compared the susceptibility of planktonic and biofilm to three disinfectants used in the aquaculture and ornamental fish industry, namely Virkon(®), bleach and hydrogen peroxide. The data indicates that Fno is capable of producing biofilms within 24 h where both salinity as well as temperature plays a role in the growth and biofilm formation of Fno. Mutations in the iglC or pdpA, both known virulence factors, do not appear to affect the capacity of Fno to produce biofilms, and the minimum inhibitory concentration, and minimum biocidal concentration for the three disinfectants were lower than the minimum biofilm eradication concentration values. This information needs to be taken into account if trying to eradicate the pathogen from aquaculture facilities or aquariums.
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Affiliation(s)
- Esteban Soto
- Department of Medicine and Epidemiology, University of California-Davis, School of Veterinary Medicine, Davis, CA 95616, USA; Department of Biomedical Sciences, Ross University School of Veterinary Medicine, P.O. Box 334, Basseterre, St. Kitts, West Indies.
| | - Iona Halliday-Simmonds
- Department of Biomedical Sciences, Ross University School of Veterinary Medicine, P.O. Box 334, Basseterre, St. Kitts, West Indies
| | - Stewart Francis
- Department of Biomedical Sciences, Ross University School of Veterinary Medicine, P.O. Box 334, Basseterre, St. Kitts, West Indies
| | - Michael T Kearney
- Department of Pathobiological Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, LA 70803, USA
| | - John D Hansen
- U.S. Geological Survey, Western Fisheries Research Center, Seattle, WA 98115, USA
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Silvestri EE, Perkins SD, Rice EW, Stone H, Schaefer FW. Review of processing and analytical methods for Francisella tularensis in soil and water. ANN MICROBIOL 2015. [DOI: 10.1007/s13213-015-1144-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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Kubelkova K, Macela A. Putting the Jigsaw Together - A Brief Insight Into the Tularemia. Open Life Sci 2015. [DOI: 10.1515/biol-2015-0013] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
AbstractTularemia is a debilitating febrile and potentially fatal zoonotic disease of humans and other vertebrates caused by the Gram-negative bacterium Francisella tularensis. The natural reservoirs are small rodents, hares, and possibly amoebas in water. The etiological agent, Francisella tularensis, is a non-spore forming, encapsulated, facultative intracellular bacterium, a member of the γ-Proteobacteria class of Gram-negative bacteria. Francisella tularensis is capable of invading and replicating within phagocytic as well as non-phagocytic cells and modulate inflammatory response. Infection by the pulmonary, dermal, or oral routes, respectively, results in pneumonic, ulceroglandular, or oropharyngeal tularemia. The highest mortality rates are associated with the pneumonic form of this disease. All members of Francisella tularensis species cause more or less severe disease Due to their abilities to be transmitted to humans via multiple routes and to be disseminated via biological aerosol that can cause the disease after inhalation of even an extremely low infectious dose, Francisella tularensis has been classified as a Category A bioterrorism agent. The current standard of care for tularemia is treatment with antibiotics, as this therapy is highly effective if used soon after infection, although it is not, however, absolutely effective in all cases.
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Abstract
Our understanding of the virulence and pathogenesis of Francisella spp. has significantly advanced in recent years, including a new understanding that this organism can form biofilms. What is known so far about Francisella spp. biofilms is summarized here and future research questions are suggested. The molecular basis of biofilm production has begun to be studied, especially the role of extracellular carbohydrates and capsule, quorum sensing and two-component signaling systems. Further work has explored the contribution of amoebae, pili, outer-membrane vesicles, chitinases, and small molecules such as c-di-GMP to Francisella spp. biofilm formation. A role for Francisella spp. biofilm in feeding mosquito larvae has been suggested. As no strong role in virulence has been found yet, Francisella spp. biofilm formation is most likely a key mechanism for environmental survival and persistence. The significance and importance of Francisella spp.’s biofilm phenotype as a critical aspect of its microbial physiology is being developed. Areas for further studies include the potential role of Francisella spp. biofilms in the infection of mammalian hosts and virulence regulation.
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Affiliation(s)
- Monique L van Hoek
- School of Systems Biology and National Center for Biodefense and Infectious Diseases; George Mason University; Manassas, VA USA
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Telford SR, Goethert HK. Toward an understanding of the perpetuation of the agent of tularemia. Front Microbiol 2011; 1:150. [PMID: 21687803 PMCID: PMC3109306 DOI: 10.3389/fmicb.2010.00150] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2010] [Accepted: 12/29/2010] [Indexed: 11/13/2022] Open
Abstract
The epidemiology of tularemia has influenced, perhaps incorrectly skewed, our views on the ecology of the agent of tularemia. In particular, the central role of lagomorphs needs to be reexamined. Diverse observations, some incidental, and some that are more generally reproducible, have not been synthesized so that the critical elements of the perpetuation of Francisella tularensis can be identified. Developing a quantitative model of the basic reproduction number of F. tularensis may require separate treatments for Type A and Type B given the fundamental differences in their ecology.
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Affiliation(s)
- Sam R Telford
- Division of Infectious Diseases, Cummings School of Veterinary Medicine, Tufts University North Grafton, MA, USA
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