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Yap ZL, Rahman ASMZ, Hogan AM, Levin DB, Cardona ST. A CRISPR-Cas-associated transposon system for genome editing in Burkholderia cepacia complex species. Appl Environ Microbiol 2024:e0069924. [PMID: 38869300 DOI: 10.1128/aem.00699-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2024] [Accepted: 05/20/2024] [Indexed: 06/14/2024] Open
Abstract
Genome editing in non-model bacteria is important to understand gene-to-function links that may differ from those of model microorganisms. Although species of the Burkholderia cepacia complex (Bcc) have great biotechnological capacities, the limited genetic tools available to understand and mitigate their pathogenic potential hamper their utilization in industrial applications. To broaden the genetic tools available for Bcc species, we developed RhaCAST, a targeted DNA insertion platform based on a CRISPR-associated transposase driven by a rhamnose-inducible promoter. We demonstrated the utility of the system for targeted insertional mutagenesis in the Bcc strains B. cenocepacia K56-2 and Burkholderia multivorans ATCC17616. We showed that the RhaCAST system can be used for loss- and gain-of-function applications. Importantly, the selection marker could be excised and reused to allow iterative genetic manipulation. The RhaCAST system is faster, easier, and more adaptable than previous insertional mutagenesis tools available for Bcc species and may be used to disrupt pathogenicity elements and insert relevant genetic modules, enabling Bcc biotechnological applications. IMPORTANCE Species of the Burkholderia cepacia complex (Bcc) have great biotechnological potential but are also opportunistic pathogens. Genetic manipulation of Bcc species is necessary to understand gene-to-function links. However, limited genetic tools are available to manipulate Bcc, hindering our understanding of their pathogenic traits and their potential in biotechnological applications. We developed a genetic tool based on CRISPR-associated transposase to increase the genetic tools available for Bcc species. The genetic tool we developed in this study can be used for loss and gain of function in Bcc species. The significance of our work is in expanding currently available tools to manipulate Bcc.
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Affiliation(s)
- Zhong Ling Yap
- Department of Microbiology, University of Manitoba, Winnipeg, Manitoba, Canada
| | | | - Andrew M Hogan
- Department of Microbiology, University of Manitoba, Winnipeg, Manitoba, Canada
| | - David B Levin
- Department of Biosystems Engineering, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Silvia T Cardona
- Department of Microbiology, University of Manitoba, Winnipeg, Manitoba, Canada
- Department of Medical Microbiology and Infectious Diseases, University of Manitoba, Winnipeg, Manitoba, Canada
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2
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Touré H, Herrmann JL, Szuplewski S, Girard-Misguich F. Drosophila melanogaster as an organism model for studying cystic fibrosis and its major associated microbial infections. Infect Immun 2023; 91:e0024023. [PMID: 37847031 PMCID: PMC10652941 DOI: 10.1128/iai.00240-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2023] Open
Abstract
Cystic fibrosis (CF) is a human genetic disease caused by mutations in the cystic fibrosis transmembrane conductance regulator gene that encodes a chloride channel. The most severe clinical manifestation is associated with chronic pulmonary infections by pathogenic and opportunistic microbes. Drosophila melanogaster has become the invertebrate model of choice for modeling microbial infections and studying the induced innate immune response. Here, we review its contribution to the understanding of infections with six major pathogens associated with CF (Staphylococcus aureus, Pseudomonas aeruginosa, Burkholderia cepacia, Mycobacterium abscessus, Streptococcus pneumoniae, and Aspergillus fumigatus) together with the perspectives opened by the recent availability of two CF models in this model organism.
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Affiliation(s)
- Hamadoun Touré
- Université Paris-Saclay, UVSQ, INSERM, Infection et Inflammation, Montigny-le-Bretonneux, France
| | - Jean-Louis Herrmann
- Université Paris-Saclay, UVSQ, INSERM, Infection et Inflammation, Montigny-le-Bretonneux, France
- Assistance Publique-Hôpitaux de Paris, Hôpitaux Universitaires Ile-de-France Ouest, GHU Paris-Saclay, Hôpital Raymond Poincaré, Garches, France
| | - Sébastien Szuplewski
- Université Paris-Saclay, UVSQ, Laboratoire de Génétique et Biologie Cellulaire, Montigny-le-Bretonneux, France
| | - Fabienne Girard-Misguich
- Université Paris-Saclay, UVSQ, INSERM, Infection et Inflammation, Montigny-le-Bretonneux, France
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3
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Methodological tools to study species of the genus Burkholderia. Appl Microbiol Biotechnol 2021; 105:9019-9034. [PMID: 34755214 PMCID: PMC8578011 DOI: 10.1007/s00253-021-11667-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Revised: 10/25/2021] [Accepted: 10/26/2021] [Indexed: 11/26/2022]
Abstract
Bacteria belonging to the Burkholderia genus are extremely versatile and diverse. They can be environmental isolates, opportunistic pathogens in cystic fibrosis, immunocompromised or chronic granulomatous disease patients, or cause disease in healthy people (e.g., Burkholderia pseudomallei) or animals (as in the case of Burkholderia mallei). Since the genus was separated from the Pseudomonas one in the 1990s, the methodological tools to study and characterize these bacteria are evolving fast. Here we reviewed the techniques used in the last few years to update the taxonomy of the genus, to study gene functions and regulations, to deepen the knowledge on the drug resistance which characterizes these bacteria, and to elucidate their mechanisms to establish infections. The availability of these tools significantly impacts the quality of research on Burkholderia and the choice of the most appropriated is fundamental for a precise characterization of the species of interest. Key points • Updated techniques to study the genus Burkholderia were reviewed. • Taxonomy, genomics, assays, and animal models were described. • A comprehensive overview on recent advances in Burkholderia studies was made.
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Functional Analysis of Phenazine Biosynthesis Genes in Burkholderia spp. Appl Environ Microbiol 2021; 87:AEM.02348-20. [PMID: 33741619 DOI: 10.1128/aem.02348-20] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Accepted: 03/09/2021] [Indexed: 01/15/2023] Open
Abstract
Burkholderia encompasses a group of ubiquitous Gram-negative bacteria that includes numerous saprophytes as well as species that cause infections in animals, immunocompromised patients, and plants. Some species of Burkholderia produce colored, redox-active secondary metabolites called phenazines. Phenazines contribute to competitiveness, biofilm formation, and virulence in the opportunistic pathogen Pseudomonas aeruginosa, but knowledge of their diversity, biosynthesis, and biological functions in Burkholderia is lacking. In this study, we screened publicly accessible genome sequence databases and identified phenazine biosynthesis genes in multiple strains of the Burkholderia cepacia complex, some isolates of the B. pseudomallei clade, and the plant pathogen B. glumae We then focused on B. lata ATCC 17760 to reveal the organization and function of genes involved in the production of dimethyl 4,9-dihydroxy-1,6-phenazinedicarboxylate. Using a combination of isogenic mutants and plasmids carrying different segments of the phz locus, we characterized three novel genes involved in the modification of the phenazine tricycle. Our functional studies revealed a connection between the presence and amount of phenazines and the dynamics of biofilm growth in flow cell and static experimental systems but at the same time failed to link the production of phenazines with the capacity of Burkholderia to kill fruit flies and rot onions.IMPORTANCE Although the production of phenazines in Burkholderia was first reported almost 70 years ago, the role these metabolites play in the biology of these economically important microorganisms remains poorly understood. Our results revealed that the phenazine biosynthetic pathway in Burkholderia has a complex evolutionary history, which likely involved horizontal gene transfers among several distantly related groups of organisms. The contribution of phenazines to the formation of biofilms suggests that Burkholderia, like fluorescent pseudomonads, may benefit from the unique redox-cycling properties of these versatile secondary metabolites.
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Kendall LV, Owiny JR, Dohm ED, Knapek KJ, Lee ES, Kopanke JH, Fink M, Hansen SA, Ayers JD. Replacement, Refinement, and Reduction in Animal Studies With Biohazardous Agents. ILAR J 2019; 59:177-194. [DOI: 10.1093/ilar/ily021] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2017] [Revised: 06/11/2018] [Indexed: 12/17/2022] Open
Abstract
Abstract
Animal models are critical to the advancement of our knowledge of infectious disease pathogenesis, diagnostics, therapeutics, and prevention strategies. The use of animal models requires thoughtful consideration for their well-being, as infections can significantly impact the general health of an animal and impair their welfare. Application of the 3Rs—replacement, refinement, and reduction—to animal models using biohazardous agents can improve the scientific merit and animal welfare. Replacement of animal models can use in vitro techniques such as cell culture systems, mathematical models, and engineered tissues or invertebrate animal hosts such as amoeba, worms, fruit flies, and cockroaches. Refinements can use a variety of techniques to more closely monitor the course of disease. These include the use of biomarkers, body temperature, behavioral observations, and clinical scoring systems. Reduction is possible using advanced technologies such as in vivo telemetry and imaging, allowing longitudinal assessment of animals during the course of disease. While there is no single method to universally replace, refine, or reduce animal models, the alternatives and techniques discussed are broadly applicable and they should be considered when infectious disease animal models are developed.
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Affiliation(s)
- Lon V Kendall
- Department of Microbiology, Immunology and Pathology, and Laboratory Animal Resources, Colorado State University, Fort Collins, Colorado
| | - James R Owiny
- Laboratory Animal Resources, Colorado State University, Fort Collins, Colorado
| | - Erik D Dohm
- Animal Resources Program, University of Alabama, Birmingham, Alabama
| | - Katie J Knapek
- Comparative Medicine Training Program, Colorado State University, Fort Collins, Colorado
| | - Erin S Lee
- Animal Resource Center, University of Texas Medical Branch, Galveston, Texas
| | - Jennifer H Kopanke
- Department of Microbiology, Immunology, and Pathology, Colorado State University, Fort Collins, Colorado
| | - Michael Fink
- Department of Veterinary Pathobiology, University of Missouri, Columbia, Missouri
| | - Sarah A Hansen
- Office of Animal Resources, University of Iowa, Iowa City, Iowa
| | - Jessica D Ayers
- Laboratory Animal Resources, Colorado State University, Fort Collins, Colorado
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6
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Duckweed (Lemna minor) and Alfalfa (Medicago sativa) as Bacterial Infection Model Systems. METHODS IN MOLECULAR BIOLOGY (CLIFTON, N.J.) 2018; 1898:191-198. [PMID: 30570734 DOI: 10.1007/978-1-4939-8940-9_16] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Alternative animal host models of bacterial infection have been developed which reproduce some of the disease conditions observed in higher animals. Analogously, plants are useful for modeling bacterial pathogenesis, in some cases revealing broadly conserved infection mechanisms. Similar to animals, plants have been shown to possess innate immune systems that respond to invading viruses, bacteria, and fungi. Plant infection models often yield results faster, are more convenient, and less expensive than many animal infection models. Here, we describe the use of two different plant-based infection models for the discovery of virulence genes and factors involved in bacterial pathogenesis.
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7
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Gagné-Thivierge C, Kukavica-Ibrulj I, Filion G, Dekimpe V, Tan SGE, Vincent AT, Déziel É, Levesque RC, Charette SJ. A multi-host approach to identify a transposon mutant of Pseudomonas aeruginosa LESB58 lacking full virulence. BMC Res Notes 2018; 11:198. [PMID: 29580289 PMCID: PMC5870910 DOI: 10.1186/s13104-018-3308-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2017] [Accepted: 03/20/2018] [Indexed: 11/10/2022] Open
Abstract
OBJECTIVE Pseudomonas aeruginosa is an opportunistic bacterial pathogen well known to cause chronic lung infections in individuals with cystic fibrosis (CF). Some strains adapted to this particular niche show distinct phenotypes, such as biofilm hyperproduction. It is necessary to study CF clinical P. aeruginosa isolates, such as Liverpool Epidemic Strains (LES), to acquire a better understanding of the key genes essential for in vivo maintenance and the major virulence mechanisms involved in CF lung infections. Previously, a library of 9216 mutants of the LESB58 strain were generated by signature-tagged mutagenesis (STM) and screened in the rat model of chronic lung infection, allowing the identification of 163 STM mutants showing defects in in vivo maintenance. RESULTS In the present study, these 163 mutants were successively screened in two additional surrogate host models (the amoeba and the fruit fly). The STM PALES_11731 mutant was the unique non-virulent in the three hosts. A competitive index study in rat lungs confirmed that the mutant was 20-fold less virulent than the wild-type strain. This study demonstrated the pertinence to use a multi-host approach to study the genetic determinants of P. aeruginosa strains infecting CF patients.
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Affiliation(s)
- Cynthia Gagné-Thivierge
- Institut de Biologie Intégrative et des Systèmes (IBIS), Université Laval, Quebec City, QC, Canada.,Département de biochimie, de microbiologie et de bio-informatique, Faculté des sciences et de génie, Université Laval, Quebec City, QC, Canada.,Centre de recherche de l'Institut universitaire de cardiologie et de pneumologie de Québec, Quebec City, QC, Canada
| | - Irena Kukavica-Ibrulj
- Institut de Biologie Intégrative et des Systèmes (IBIS), Université Laval, Quebec City, QC, Canada.,Département de microbiologie, infectiologie et immunologie, Faculté de Médecine, Université Laval, Quebec City, QC, Canada
| | - Geneviève Filion
- Institut de Biologie Intégrative et des Systèmes (IBIS), Université Laval, Quebec City, QC, Canada.,Département de biochimie, de microbiologie et de bio-informatique, Faculté des sciences et de génie, Université Laval, Quebec City, QC, Canada.,Centre de recherche de l'Institut universitaire de cardiologie et de pneumologie de Québec, Quebec City, QC, Canada
| | | | - Sok Gheck E Tan
- Institut de Biologie Intégrative et des Systèmes (IBIS), Université Laval, Quebec City, QC, Canada.,Département de biochimie, de microbiologie et de bio-informatique, Faculté des sciences et de génie, Université Laval, Quebec City, QC, Canada.,Centre de recherche de l'Institut universitaire de cardiologie et de pneumologie de Québec, Quebec City, QC, Canada
| | - Antony T Vincent
- Institut de Biologie Intégrative et des Systèmes (IBIS), Université Laval, Quebec City, QC, Canada.,Département de biochimie, de microbiologie et de bio-informatique, Faculté des sciences et de génie, Université Laval, Quebec City, QC, Canada.,Centre de recherche de l'Institut universitaire de cardiologie et de pneumologie de Québec, Quebec City, QC, Canada
| | - Éric Déziel
- INRS-Institut Armand Frappier, Laval, QC, Canada
| | - Roger C Levesque
- Institut de Biologie Intégrative et des Systèmes (IBIS), Université Laval, Quebec City, QC, Canada.,Département de microbiologie, infectiologie et immunologie, Faculté de Médecine, Université Laval, Quebec City, QC, Canada
| | - Steve J Charette
- Institut de Biologie Intégrative et des Systèmes (IBIS), Université Laval, Quebec City, QC, Canada. .,Département de biochimie, de microbiologie et de bio-informatique, Faculté des sciences et de génie, Université Laval, Quebec City, QC, Canada. .,Centre de recherche de l'Institut universitaire de cardiologie et de pneumologie de Québec, Quebec City, QC, Canada.
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8
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Schmid N, Suppiger A, Steiner E, Pessi G, Kaever V, Fazli M, Tolker-Nielsen T, Jenal U, Eberl L. High intracellular c-di-GMP levels antagonize quorum sensing and virulence gene expression in Burkholderia cenocepacia H111. MICROBIOLOGY-SGM 2017; 163:754-764. [PMID: 28463102 DOI: 10.1099/mic.0.000452] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The opportunistic human pathogen Burkholderia cenocepacia H111 uses two chemically distinct signal molecules for controlling gene expression in a cell density-dependent manner: N-acyl-homoserine lactones (AHLs) and cis-2-dodecenoic acid (BDSF). Binding of BDSF to its cognate receptor RpfR lowers the intracellular c-di-GMP level, which in turn leads to differential expression of target genes. In this study we analysed the transcriptional profile of B. cenocepacia H111 upon artificially altering the cellular c-di-GMP level. One hundred and eleven genes were shown to be differentially expressed, 96 of which were downregulated at a high c-di-GMP concentration. Our analysis revealed that the BDSF, AHL and c-di-GMP regulons overlap for the regulation of 24 genes and that a high c-di-GMP level suppresses expression of AHL-regulated genes. Phenotypic analyses confirmed changes in the expression of virulence factors, the production of AHL signal molecules and the biosynthesis of different biofilm matrix components upon altered c-di-GMP levels. We also demonstrate that the intracellular c-di-GMP level determines the virulence of B. cenocepacia to Caenorhabditis elegans and Galleria mellonella.
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Affiliation(s)
- Nadine Schmid
- Institute of Plant and Microbial Biology, University of Zurich, Zurich, Switzerland
| | - Angela Suppiger
- Institute of Plant and Microbial Biology, University of Zurich, Zurich, Switzerland
| | - Elisabeth Steiner
- Institute of Plant and Microbial Biology, University of Zurich, Zurich, Switzerland
| | - Gabriella Pessi
- Institute of Plant and Microbial Biology, University of Zurich, Zurich, Switzerland
| | - Volkhard Kaever
- Research Core Unit Metabolomics, Hannover Medical School, Hannover, Germany
| | - Mustafa Fazli
- Department of Biology, Faculty of Science, University of Copenhagen, Copenhagen, Denmark
| | - Tim Tolker-Nielsen
- Costerton Biofilm Center, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Urs Jenal
- Focal Area of Infection Biology, Biozentrum, University of Basel, Basel, Switzerland
| | - Leo Eberl
- Institute of Plant and Microbial Biology, University of Zurich, Zurich, Switzerland
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9
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Bergman P, Seyedoleslami Esfahani S, Engström Y. Drosophila as a Model for Human Diseases—Focus on Innate Immunity in Barrier Epithelia. Curr Top Dev Biol 2017; 121:29-81. [DOI: 10.1016/bs.ctdb.2016.07.002] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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10
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Pradenas GA, Ross BN, Torres AG. Burkholderia cepacia Complex Vaccines: Where Do We Go from here? Vaccines (Basel) 2016; 4:vaccines4020010. [PMID: 27092530 PMCID: PMC4931627 DOI: 10.3390/vaccines4020010] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2016] [Revised: 04/07/2016] [Accepted: 04/08/2016] [Indexed: 01/15/2023] Open
Abstract
Burkholderia comprises a wide variety of environmental Gram-negative bacteria. Burkholderia cepacia complex (Bcc) includes several Burkholderia species that pose a health hazard as they are able to cause respiratory infections in patients with chronic granulomatous disease and cystic fibrosis. Due to the intrinsic resistance to a wide array of antibiotics and naturally occurring immune evasion strategies, treatment of Bcc infections often proves to be unsuccessful. To date, limited work related to vaccine development has been performed for Bcc pathogens. In this review, we have gathered key aspects of Bcc research that have been reported in recent years related to vaccine efforts, virulence, immune responses, and animal models, and use this information to inform the research community of areas of opportunity toward development of a viable Bcc vaccine.
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Affiliation(s)
- Gonzalo A Pradenas
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX 77555, USA.
| | - Brittany N Ross
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX 77555, USA.
| | - Alfredo G Torres
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX 77555, USA.
- Sealy Center for Vaccine Development, University of Texas Medical Branch, Galveston, TX 77555, USA.
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11
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Allen VW, O'Connor RM, Ulgherait M, Zhou CG, Stone EF, Hill VM, Murphy KR, Canman JC, Ja WW, Shirasu-Hiza MM. period-Regulated Feeding Behavior and TOR Signaling Modulate Survival of Infection. Curr Biol 2015; 26:184-194. [PMID: 26748856 DOI: 10.1016/j.cub.2015.11.051] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2014] [Revised: 10/16/2015] [Accepted: 11/23/2015] [Indexed: 12/23/2022]
Abstract
Most metazoans undergo dynamic, circadian-regulated changes in behavior and physiology. Currently, it is unknown how circadian-regulated behavior impacts immunity against infection. Two broad categories of defense against bacterial infection are resistance, control of microbial growth, and tolerance, control of the pathogenic effects of infection. Our study of behaviorally arrhythmic Drosophila circadian period mutants identified a novel link between nutrient intake and tolerance of infection with B. cepacia, a bacterial pathogen of rising importance in hospital-acquired infections. We found that infection tolerance in wild-type animals is stimulated by acute exposure to dietary glucose and amino acids. Glucose-stimulated tolerance was induced by feeding or direct injection; injections revealed a narrow window for glucose-stimulated tolerance. In contrast, amino acids stimulated tolerance only when ingested. We investigated the role of a known amino-acid-sensing pathway, the TOR (Target of Rapamycin) pathway, in immunity. TORC1 is circadian regulated and inhibition of TORC1 decreased resistance, as in vertebrates. Surprisingly, inhibition of the less well-characterized TOR complex 2 (TORC2) dramatically increased survival, through both resistance and tolerance mechanisms. This work suggests that dietary intake on the day of infection by B. cepacia can make a significant difference in long-term survival. We further demonstrate that TOR signaling mediates both resistance and tolerance of infection and identify TORC2 as a novel potential therapeutic target for increasing survival of infection.
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Affiliation(s)
- Victoria W Allen
- Department of Genetics and Development, Columbia University Medical Center, New York, NY 10032, USA
| | - Reed M O'Connor
- Department of Genetics and Development, Columbia University Medical Center, New York, NY 10032, USA
| | - Matthew Ulgherait
- Department of Genetics and Development, Columbia University Medical Center, New York, NY 10032, USA
| | - Clarice G Zhou
- Department of Genetics and Development, Columbia University Medical Center, New York, NY 10032, USA
| | - Elizabeth F Stone
- Department of Genetics and Development, Columbia University Medical Center, New York, NY 10032, USA
| | - Vanessa M Hill
- Department of Genetics and Development, Columbia University Medical Center, New York, NY 10032, USA
| | - Keith R Murphy
- Department of Metabolism and Aging, Scripps Research Institute, Jupiter, FL 33458, USA
| | - Julie C Canman
- Department of Pathology and Cell Biology, Columbia University Medical Center, New York, NY 10032, USA
| | - William W Ja
- Department of Metabolism and Aging, Scripps Research Institute, Jupiter, FL 33458, USA
| | - Mimi M Shirasu-Hiza
- Department of Genetics and Development, Columbia University Medical Center, New York, NY 10032, USA.
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12
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Abnave P, Mottola G, Gimenez G, Boucherit N, Trouplin V, Torre C, Conti F, Ben Amara A, Lepolard C, Djian B, Hamaoui D, Mettouchi A, Kumar A, Pagnotta S, Bonatti S, Lepidi H, Salvetti A, Abi-Rached L, Lemichez E, Mege JL, Ghigo E. Screening in planarians identifies MORN2 as a key component in LC3-associated phagocytosis and resistance to bacterial infection. Cell Host Microbe 2015; 16:338-50. [PMID: 25211076 DOI: 10.1016/j.chom.2014.08.002] [Citation(s) in RCA: 81] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2014] [Revised: 06/13/2014] [Accepted: 07/10/2014] [Indexed: 01/21/2023]
Abstract
Dugesia japonica planarian flatworms are naturally exposed to various microbes but typically survive this challenge. We show that planarians eliminate bacteria pathogenic to Homo sapiens, Caenorhabditis elegans, and/or Drosophila melanogaster and thus represent a model to identify innate resistance mechanisms. Whole-transcriptome analysis coupled with RNAi screening of worms infected with Staphylococcus aureus or Legionella pneumophila identified 18 resistance genes with nine human orthologs, of which we examined the function of MORN2. Human MORN2 facilitates phagocytosis-mediated restriction of Mycobacterium tuberculosis, L. pneumophila, and S. aureus in macrophages. MORN2 promotes the recruitment of LC3, an autophagy protein also involved in phagocytosis, to M. tuberculosis-containing phagosomes and subsequent maturation to degradative phagolysosomes. MORN2-driven trafficking of M. tuberculosis to single-membrane, LC3-positive compartments requires autophagy-related proteins Atg5 and Beclin-1, but not Ulk-1 and Atg13, highlighting the importance of MORN2 in LC3-associated phagocytosis. These findings underscore the value of studying planarian defenses to identify immune factors.
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Affiliation(s)
- Prasad Abnave
- CNRS UMR 7278, IRD198, INSERM U1095, Aix-Marseille Université, 27 Bd Jean Moulin 13385 Marseille Cedex 05, France; INSERM, U1065, C3M, Université de Nice Sophia-Antipolis, Equipe labellisée ligue contre le cancer, 06204 Nice Cedex 3, France
| | - Giovanna Mottola
- CNRS UMR 7278, IRD198, INSERM U1095, Aix-Marseille Université, 27 Bd Jean Moulin 13385 Marseille Cedex 05, France; Department of Molecular Medicine and Medical Biotechnology, University of Naples "Federico II," Via S. Pansini 5, 80131 Naples, Italy
| | - Gregory Gimenez
- Otago Genomics & Bioinformatics Facility, Department of Biochemistry, University of Otago, PO Box 56, 710 Cumberland Street, Dunedin 9054, New Zealand
| | - Nicolas Boucherit
- CNRS UMR 7278, IRD198, INSERM U1095, Aix-Marseille Université, 27 Bd Jean Moulin 13385 Marseille Cedex 05, France
| | - Virginie Trouplin
- CNRS UMR 7278, IRD198, INSERM U1095, Aix-Marseille Université, 27 Bd Jean Moulin 13385 Marseille Cedex 05, France
| | - Cedric Torre
- CNRS UMR 7278, IRD198, INSERM U1095, Aix-Marseille Université, 27 Bd Jean Moulin 13385 Marseille Cedex 05, France
| | - Filippo Conti
- CNRS UMR 7278, IRD198, INSERM U1095, Aix-Marseille Université, 27 Bd Jean Moulin 13385 Marseille Cedex 05, France; INSERM, U1065, C3M, Université de Nice Sophia-Antipolis, Equipe labellisée ligue contre le cancer, 06204 Nice Cedex 3, France
| | - Amira Ben Amara
- CNRS UMR 7278, IRD198, INSERM U1095, Aix-Marseille Université, 27 Bd Jean Moulin 13385 Marseille Cedex 05, France
| | - Catherine Lepolard
- CNRS UMR 7278, IRD198, INSERM U1095, Aix-Marseille Université, 27 Bd Jean Moulin 13385 Marseille Cedex 05, France
| | - Benjamin Djian
- CNRS UMR 7278, IRD198, INSERM U1095, Aix-Marseille Université, 27 Bd Jean Moulin 13385 Marseille Cedex 05, France
| | - Daniel Hamaoui
- INSERM, U1065, C3M, Université de Nice Sophia-Antipolis, Equipe labellisée ligue contre le cancer, 06204 Nice Cedex 3, France
| | - Amel Mettouchi
- INSERM, U1065, C3M, Université de Nice Sophia-Antipolis, Equipe labellisée ligue contre le cancer, 06204 Nice Cedex 3, France
| | - Atul Kumar
- CNRS UMR 7278, IRD198, INSERM U1095, Aix-Marseille Université, 27 Bd Jean Moulin 13385 Marseille Cedex 05, France; INSERM, U1065, C3M, Université de Nice Sophia-Antipolis, Equipe labellisée ligue contre le cancer, 06204 Nice Cedex 3, France
| | - Sophie Pagnotta
- Centre Commun de Microscopie Appliquée (CCMA) Université de Nice Sophia Antipolis, Faculté des Sciences, Parc Valrose, 06108 Nice Cedex 2, France
| | - Stefano Bonatti
- Department of Molecular Medicine and Medical Biotechnology, University of Naples "Federico II," Via S. Pansini 5, 80131 Naples, Italy
| | - Hubert Lepidi
- CNRS UMR 7278, IRD198, INSERM U1095, Aix-Marseille Université, 27 Bd Jean Moulin 13385 Marseille Cedex 05, France
| | - Alessandra Salvetti
- Department of Clinical and Experimental Medicine, Unity of Experimental Biology and Genetics, University of Pisa, Via Volta 4, 56126 Pisa, Italy
| | - Laurent Abi-Rached
- Centre National de la Recherche Scientifique, Laboratoire d'Analyse, Topologie, Probabilités - Unité Mixte de Recherche 7353, Equipe ATIP, Aix-Marseille Université, 13331 Marseille, France
| | - Emmanuel Lemichez
- INSERM, U1065, C3M, Université de Nice Sophia-Antipolis, Equipe labellisée ligue contre le cancer, 06204 Nice Cedex 3, France
| | - Jean-Louis Mege
- CNRS UMR 7278, IRD198, INSERM U1095, Aix-Marseille Université, 27 Bd Jean Moulin 13385 Marseille Cedex 05, France
| | - Eric Ghigo
- CNRS UMR 7278, IRD198, INSERM U1095, Aix-Marseille Université, 27 Bd Jean Moulin 13385 Marseille Cedex 05, France.
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López Hernández Y, Yero D, Pinos-Rodríguez JM, Gibert I. Animals devoid of pulmonary system as infection models in the study of lung bacterial pathogens. Front Microbiol 2015; 6:38. [PMID: 25699030 PMCID: PMC4316775 DOI: 10.3389/fmicb.2015.00038] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2014] [Accepted: 01/12/2015] [Indexed: 01/15/2023] Open
Abstract
Biological disease models can be difficult and costly to develop and use on a routine basis. Particularly, in vivo lung infection models performed to study lung pathologies use to be laborious, demand a great time and commonly are associated with ethical issues. When infections in experimental animals are used, they need to be refined, defined, and validated for their intended purpose. Therefore, alternative and easy to handle models of experimental infections are still needed to test the virulence of bacterial lung pathogens. Because non-mammalian models have less ethical and cost constraints as a subjects for experimentation, in some cases would be appropriated to include these models as valuable tools to explore host-pathogen interactions. Numerous scientific data have been argued to the more extensive use of several kinds of alternative models, such as, the vertebrate zebrafish (Danio rerio), and non-vertebrate insects and nematodes (e.g., Caenorhabditis elegans) in the study of diverse infectious agents that affect humans. Here, we review the use of these vertebrate and non-vertebrate models in the study of bacterial agents, which are considered the principal causes of lung injury. Curiously none of these animals have a respiratory system as in air-breathing vertebrates, where respiration takes place in lungs. Despite this fact, with the present review we sought to provide elements in favor of the use of these alternative animal models of infection to reveal the molecular signatures of host-pathogen interactions.
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Affiliation(s)
- Yamilé López Hernández
- Centro de Biociencias, Universidad Autónoma de San Luis Potosí San Luis de Potosí, Mexico
| | - Daniel Yero
- Institut de Biotecnologia i de Biomedicina, Universitat Autònoma de Barcelona Barcelona, Spain ; Departament de Genètica i de Microbiologia, Universitat Autònoma de Barcelona Barcelona, Spain
| | - Juan M Pinos-Rodríguez
- Centro de Biociencias, Universidad Autónoma de San Luis Potosí San Luis de Potosí, Mexico
| | - Isidre Gibert
- Institut de Biotecnologia i de Biomedicina, Universitat Autònoma de Barcelona Barcelona, Spain ; Departament de Genètica i de Microbiologia, Universitat Autònoma de Barcelona Barcelona, Spain
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14
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Fauvarque MO. Small flies to tackle big questions: assaying complex bacterial virulence mechanisms usingDrosophila melanogaster. Cell Microbiol 2014; 16:824-33. [DOI: 10.1111/cmi.12292] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2014] [Revised: 03/05/2014] [Accepted: 03/10/2014] [Indexed: 12/29/2022]
Affiliation(s)
- Marie-Odile Fauvarque
- Univ. Grenoble Alpes; iRTSV-BGE; F-38000 Grenoble France
- CEA; iRTSV-BGE; F-38000 Grenoble France
- INSERM; BGE; F-38000 Grenoble France
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15
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Suppiger A, Schmid N, Aguilar C, Pessi G, Eberl L. Two quorum sensing systems control biofilm formation and virulence in members of the Burkholderia cepacia complex. Virulence 2014; 4:400-9. [PMID: 23799665 PMCID: PMC3714132 DOI: 10.4161/viru.25338] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
The Burkholderia cepacia complex (Bcc) consists of 17 closely related species that are problematic opportunistic bacterial pathogens for cystic fibrosis patients and immunocompromised individuals. These bacteria are capable of utilizing two different chemical languages: N-acyl homoserine lactones (AHLs) and cis-2-unsaturated fatty acids. Here we summarize the current knowledge of the underlying molecular architectures of these communication systems, showing how they are interlinked and discussing how they regulate overlapping as well as specific sets of genes. A particular focus is laid on the role of these signaling systems in the formation of biofilms, which are believed to be highly important for chronic infections. We review genes that have been implicated in the sessile lifestyle of this group of bacteria. The new emerging role of the intracellular second messenger cyclic dimeric guanosine monophosphate (c-di-GMP) as a downstream regulator of the fatty acid signaling cascade and as a key factor in biofilm formation is also discussed.
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Affiliation(s)
- Angela Suppiger
- Department of Microbiology, University of Zürich, Zürich, Switzerland
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16
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Nadarasah G, Stavrinides J. Quantitative evaluation of the host-colonizing capabilities of the enteric bacterium Pantoea using plant and insect hosts. MICROBIOLOGY-SGM 2014; 160:602-615. [PMID: 24430494 DOI: 10.1099/mic.0.073452-0] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The genus Pantoea is a highly diverse group comprising free-living, and both pathogenic and non-pathogenic host-associating species. Pathogenic isolates have been found to infect insects, plants and humans, yet it is unclear whether these isolates have similar pathogenic potential to the free-living environmental populations. Using MLSA of six housekeeping genes, we evaluated the phylogenetic relationships among 115 environmental and clinical (human) isolates representing 11 Pantoea species. An overlay of the location of isolation onto the resulting tree revealed that clinical and environmental isolates are interspersed, and do not form distinctive groups. We then conducted quantitative growth assays of our isolates using maize, onion and fruit flies as hosts. Notably, most clinical isolates were able to grow in both plant hosts often comparably or even better than the environmental isolates. There were no obvious growth or host colonization patterns that could distinguish those isolates with clinical potential. Growth of an isolate in one host could not be predicted based on its performance in another host, nor could host growth be predicted by phylogeny or source of isolation. This work demonstrates that the host-colonizing capabilities of all Pantoea species groups is unpredictable, indicating a broader host range and pathogenic potential than currently assumed.
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Affiliation(s)
- Geetanchaly Nadarasah
- Department of Biology, University of Regina, 3737 Wascana Parkway, Regina, Saskatchewan S4S0A2, Canada
| | - John Stavrinides
- Department of Biology, University of Regina, 3737 Wascana Parkway, Regina, Saskatchewan S4S0A2, Canada
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17
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Panayidou S, Ioannidou E, Apidianakis Y. Human pathogenic bacteria, fungi, and viruses in Drosophila: disease modeling, lessons, and shortcomings. Virulence 2014; 5:253-69. [PMID: 24398387 DOI: 10.4161/viru.27524] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Drosophila has been the invertebrate model organism of choice for the study of innate immune responses during the past few decades. Many Drosophila-microbe interaction studies have helped to define innate immunity pathways, and significant effort has been made lately to decipher mechanisms of microbial pathogenesis. Here we catalog 68 bacterial, fungal, and viral species studied in flies, 43 of which are relevant to human health. We discuss studies of human pathogens in flies revealing not only the elicitation and avoidance of immune response but also mechanisms of tolerance, host tissue homeostasis, regeneration, and predisposition to cancer. Prominent among those is the emerging pattern of intestinal regeneration as a defense response induced by pathogenic and innocuous bacteria. Immunopathology mechanisms and many microbial virulence factors have been elucidated, but their relevance to human health conventionally necessitates validation in mammalian models of infection.
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Affiliation(s)
- Stavria Panayidou
- Department of Biological Sciences; University of Cyprus; Nicosia, Cyprus
| | - Eleni Ioannidou
- Department of Biological Sciences; University of Cyprus; Nicosia, Cyprus
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18
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Abstract
In recent years the zebrafish has gained enormous attention in infection biology, and many protocols have been developed to study interaction of both human and fish pathogens, including viruses, fungi, and bacteria, with the host. Especially the extraordinary possibilities for live imaging of disease processes in the transparent embryos using fluorescent bacteria and cell-specific reporter fish combined with gene knockdown, transcriptome, and genetic studies have dramatically advanced our understanding of disease mechanisms. The zebrafish embryo is amenable to study virulence of both extracellular and facultative intracellular pathogens introduced through the technique of microinjection. Several protocols have been published that address the different sites of injection, antisense strategies, imaging, and production of transgenic fish in detail. Here we describe a protocol to study the virulence profiles, ranging from acute fatal to persistent, of bacteria belonging to the Burkholderia cepacia complex. This standard operating protocol combines simple survival assays, analysis of bacterial kinetics, analysis of the early innate immune response with qRT-PCR, and the use of transgenic reporter fish to study interactions with host phagocytes, and is also applicable to other pathogens.
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19
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Common duckweed (Lemna minor) is a versatile high-throughput infection model for the Burkholderia cepacia complex and other pathogenic bacteria. PLoS One 2013; 8:e80102. [PMID: 24223216 PMCID: PMC3819297 DOI: 10.1371/journal.pone.0080102] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2013] [Accepted: 10/07/2013] [Indexed: 01/05/2023] Open
Abstract
Members of the Burkholderia cepacia complex (Bcc) have emerged in recent decades as problematic pulmonary pathogens of cystic fibrosis (CF) patients, with severe infections progressing to acute necrotizing pneumonia and sepsis. This study presents evidence that Lemna minor (Common duckweed) is useful as a plant model for the Bcc infectious process, and has potential as a model system for bacterial pathogenesis in general. To investigate the relationship between Bcc virulence in duckweed and Galleria mellonella (Greater wax moth) larvae, a previously established Bcc infection model, a duckweed survival assay was developed and used to determine LD50 values. A strong correlation (R2 = 0.81) was found between the strains’ virulence ranks in the two infection models, suggesting conserved pathways in these vastly different hosts. To broaden the application of the duckweed model, enteropathogenic Escherichia coli (EPEC) and five isogenic mutants with previously established LD50 values in the larval model were tested against duckweed, and a strong correlation (R2 = 0.93) was found between their raw LD50 values. Potential virulence factors in B. cenocepacia K56-2 were identified using a high-throughput screen against single duckweed plants. In addition to the previously characterized antifungal compound (AFC) cluster genes, several uncharacterized genes were discovered including a novel lysR regulator, a histidine biosynthesis gene hisG, and a gene located near the gene encoding the recently characterized virulence factor SuhBBc. Finally, to demonstrate the utility of this model in therapeutic applications, duckweed was rescued from Bcc infection by treating with bacteriophage at 6-h intervals. It was observed that phage application became ineffective at a timepoint that coincided with a sharp increase in bacterial invasion of plant tissue. These results indicate that common duckweed can serve as an effective infection model for the investigation of bacterial virulence factors and therapeutic strategies to combat them.
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20
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Subramoni S, Sokol PA. Quorum sensing systems influence Burkholderia cenocepacia virulence. Future Microbiol 2013; 7:1373-87. [PMID: 23231487 DOI: 10.2217/fmb.12.118] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Burkholderia cepacia complex strains communicate using N-acyl homoserine lactones and BDSF-dependent quorum sensing (QS) systems. Burkholderia cenocepacia QS systems include CepIR, CciIR, CepR2 and BDSF. Analysis of CepR, CciIR, CepR2 and RpfF (BDSF synthase) QS regulons revealed that these QS systems both independently regulate and coregulate many target genes, often in an opposing manner. The role of QS and several QS-regulated genes in virulence has been determined using vertebrate, invertebrate and plant infection models. Virulence phenotypes are strain and model dependent, suggesting that different QS-regulated genes are important depending on the strain and type of infection. QS inhibitors in combination with antibiotics can reduce biofilm formation and virulence in infection models.
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Affiliation(s)
- Sujatha Subramoni
- Department of Microbiology, Immunology & Infectious Diseases, Faculty of Medicine, University of Calgary, 3330 Hospital Drive NW, Calgary, Alberta T2N 4N1, Canada
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21
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Chapalain A, Vial L, Laprade N, Dekimpe V, Perreault J, Déziel E. Identification of quorum sensing-controlled genes in Burkholderia ambifaria. Microbiologyopen 2013; 2:226-42. [PMID: 23382083 PMCID: PMC3633348 DOI: 10.1002/mbo3.67] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2012] [Revised: 12/18/2012] [Accepted: 12/26/2012] [Indexed: 01/23/2023] Open
Abstract
The Burkholderia cepacia complex (Bcc) comprises strains with a virulence potential toward immunocompromised patients as well as plant growth-promoting rhizobacteria (PGPR). Owing to the link between quorum sensing (QS) and virulence, most studies among Bcc species have been directed toward QS of pathogenic bacteria. We have investigated the QS of B. ambifaria, a PGPR only infrequently recovered from patients. The cepI gene, responsible for the synthesis of the main signaling molecule N-octanoylhomoserine lactone (C8 -HSL), was inactivated. Phenotypes of the B. ambifaria cepI mutant we observed, such as increased production of siderophores and decreased proteolytic and antifungal activities, are in agreement with those of other Bcc cepI mutants. The cepI mutant was then used as background strain for a whole-genome transposon-insertion mutagenesis strategy, allowing the identification of 20 QS-controlled genes, corresponding to 17 loci. The main functions identified are linked to antifungal and antimicrobial properties, as we have identified QS-controlled genes implicated in the production of pyrrolnitrin, burkholdines (occidiofungin-like molecules), and enacyloxins. This study provides insights in the QS-regulated functions of a PGPR, which could lead to beneficial potential biotechnological applications.
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Affiliation(s)
- Annelise Chapalain
- INRS-Institut Armand-Frappier, 531 bd des Prairies, Laval, Quebec H7V 1B7, Canada
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22
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Utility of insects for studying human pathogens and evaluating new antimicrobial agents. ADVANCES IN BIOCHEMICAL ENGINEERING/BIOTECHNOLOGY 2013; 135:1-25. [PMID: 23604210 DOI: 10.1007/10_2013_194] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/06/2022]
Abstract
Insect models, such as Galleria mellonella and Drosophila melanogaster have significant ethical, logistical, and economic advantages over mammalian models for the studies of infectious diseases. Using these models, various pathogenic microbes have been studied and many novel virulence genes have been identified. Notably, because insects are susceptible to a wide variety of human pathogens and have immune responses similar to those of mammals, they offer the opportunity to understand innate immune responses against human pathogens better. It is important to note that insect pathosystems have also offered a simple strategy to evaluate the efficacy and toxicity of many antimicrobial agents. Overall, insect models provide a rapid, inexpensive, and reliable way as complementary hosts to conventional vertebrate animal models to study pathogenesis and antimicrobial agents.
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23
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Burkholderia thailandensis is virulent in Drosophila melanogaster. PLoS One 2012; 7:e49745. [PMID: 23209596 PMCID: PMC3507839 DOI: 10.1371/journal.pone.0049745] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2012] [Accepted: 10/16/2012] [Indexed: 11/19/2022] Open
Abstract
Melioidosis is a serious infectious disease endemic to Southeast Asia and Northern Australia. This disease is caused by the Gram-negative bacterium Burkholderia pseudomallei; Burkholderia thailandensis is a closely-related organism known to be avirulent in humans. B. thailandensis has not previously been used to infect Drosophila melanogaster. We examined the effect of B. thailandensis infection on fly survival, on antimicrobial peptide expression, and on phagocytic cells. In the fruit fly, which possesses only an innate immune system, B. thailandensis is highly virulent, causing rapid death when injected or fed. One intriguing aspect of this infection is its temperature dependence: infected flies maintained at 25°C exhibit rapid bacterial proliferation and death in a few days, while infected animals maintained at 18°C exhibit very slow bacterial proliferation and take weeks to die; this effect is due in part to differences in immune activity of the host. Death in this infection is likely due at least in part to a secreted toxin, as injection of flies with sterile B. thailandensis-conditioned medium is able to kill. B. thailandensis infection strongly induces the expression of antimicrobial peptides, but this is insufficient to inhibit bacterial proliferation in infected flies. Finally, the function of fly phagocytes is not affected by B. thailandensis infection. The high virulence of B. thailandensis in the fly suggests the possibility that this organism is a natural pathogen of one or more invertebrates.
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24
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Identification of Burkholderia cenocepacia strain H111 virulence factors using nonmammalian infection hosts. Infect Immun 2012; 81:143-53. [PMID: 23090963 DOI: 10.1128/iai.00768-12] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Burkholderia cenocepacia H111, a strain isolated from a cystic fibrosis patient, has been shown to effectively kill the nematode Caenorhabditis elegans. We used the C. elegans model of infection to screen a mini-Tn5 mutant library of B. cenocepacia H111 for attenuated virulence. Of the approximately 5,500 B. cenocepacia H111 random mini-Tn5 insertion mutants that were screened, 22 showed attenuated virulence in C. elegans. Except for the quorum-sensing regulator cepR, none of the mutated genes coded for the biosynthesis of classical virulence factors such as extracellular proteases or siderophores. Instead, the mutants contained insertions in metabolic and regulatory genes. Mutants attenuated in virulence in the C. elegans infection model were also tested in the Drosophila melanogaster pricking model, and those also attenuated in this model were further tested in Galleria mellonella. Six of the 22 mutants were attenuated in D. melanogaster, and five of these were less pathogenic in the G. mellonella model. We show that genes encoding enzymes of the purine, pyrimidine, and shikimate biosynthesis pathways are critical for virulence in multiple host models of infection.
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25
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Edwards S, Kjellerup BV. Exploring the applications of invertebrate host-pathogen models for in vivo biofilm infections. ACTA ACUST UNITED AC 2012; 65:205-14. [PMID: 22533965 DOI: 10.1111/j.1574-695x.2012.00975.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2011] [Revised: 04/13/2012] [Accepted: 04/15/2012] [Indexed: 12/26/2022]
Abstract
In the natural environment, microorganisms exist together in self-produced polymeric matrix biofilms. Often, several species, which can belong to both bacterial and fungal kingdoms, coexist and interact in ways which are not completely understood. Biofilm infections have become prevalent largely in medical settings because of the increasing use of indwelling medical devices such as catheters or prosthetics. These infections are resistant to common antimicrobial therapies because of the inherent nature of their structure. In terms of infectious biofilms, it is important to understand the microbe-microbe interactions and how the host immune system reacts in order to discover therapeutic targets. Currently, single infection immune response studies are thriving with the use of invertebrate models. This review highlights the advances in single microbial-host immune response as well as the promising aspects of polymicrobial biofilm study in five invertebrate models: Lemna minor (duckweed), Arabidopsis thaliana (thale cress), Dictyostelium discoideum (slime mold), Drosophila melanogaster (common fruit fly), and Caenorhabditis elegans (roundworm).
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Affiliation(s)
- Sarah Edwards
- Department of Biological Sciences, Goucher College, Baltimore, MD 21204, USA
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26
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Abstract
The deleterious and sometimes fatal outcomes of bacterial infectious diseases are the net result of the interactions between the pathogen and the host, and the genetically tractable fruit fly, Drosophila melanogaster, has emerged as a valuable tool for modeling the pathogen-host interactions of a wide variety of bacteria. These studies have revealed that there is a remarkable conservation of bacterial pathogenesis and host defence mechanisms between higher host organisms and Drosophila. This review presents an in-depth discussion of the Drosophila immune response, the Drosophila killing model, and the use of the model to examine bacterial-host interactions. The recent introduction of the Drosophila model into the oral microbiology field is discussed, specifically the use of the model to examine Porphyromonas gingivalis-host interactions, and finally the potential uses of this powerful model system to further elucidate oral bacterial-host interactions are addressed.
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Affiliation(s)
- Christina O Igboin
- Division of Oral Biology, College of Dentistry, The Ohio State University, Columbus, Ohio, USA
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27
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Diversity of potential pathogenicity and biofilm formation among Burkholderia cepacia complex water, clinical, and agricultural isolates in China. World J Microbiol Biotechnol 2012; 28:2113-23. [PMID: 22806034 DOI: 10.1007/s11274-012-1016-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2011] [Accepted: 01/30/2012] [Indexed: 01/31/2023]
Abstract
A collection of 70 Burkholderia cepacia complex isolates, recovered from clinical, water, and agricultural resources in China in our previous studies, were tested to assess their potential pathogenicity and association of biofilm formation with pathogenicity. The pathogenicity was tested in the alternative infection models alfalfa, detached lettuce midrib, Galleria mellonella (wax moth), rat agar bead, and lettuce intact leaves. Severe to moderate pathogenicity were observed for isolates of clinical and water origin compared to agricultural isolates, with the exception of a few clinical isolates exhibiting reduced pathogenicity. Virulent isolates persisted in rat lungs until 21 days post infection causing histopathological changes like inflammation, while in lettuce midrib tissues invasion, localization, and replication of bacteria were observed. Biofilm formation ability was also documented in high frequency among water and clinical virulent isolates compared to agricultural isolates. Although variations in pathogenicity were observed for a few isolates, results obtained from different model systems including lettuce were consistent. Our studies indicate that water and clinical isolates showed severe virulence and strong biofilm formation ability compared to agricultural isolates. The results also show lettuce as a promising infection model not only to study the pathogenicity factors used by Bcc bacteria but also for characterization the in vivo transcriptional profile for different niches adaptation of this opportunistic pathogen.
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28
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O'Grady EP, Sokol PA. Burkholderia cenocepacia differential gene expression during host-pathogen interactions and adaptation to the host environment. Front Cell Infect Microbiol 2011; 1:15. [PMID: 22919581 PMCID: PMC3417382 DOI: 10.3389/fcimb.2011.00015] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2011] [Accepted: 11/20/2011] [Indexed: 01/08/2023] Open
Abstract
Members of the Burkholderia cepacia complex (Bcc) are important in medical, biotechnological, and agricultural disciplines. These bacteria naturally occur in soil and water environments and have adapted to survive in association with plants and animals including humans. All Bcc species are opportunistic pathogens including Burkholderia cenocepacia that causes infections in cystic fibrosis and chronic granulomatous disease patients. The adaptation of B. cenocepacia to the host environment was assessed in a rat chronic respiratory infection model and compared to that of high cell-density in vitro grown cultures using transcriptomics. The distribution of genes differentially expressed on chromosomes 1, 2, and 3 was relatively proportional to the size of each genomic element, whereas the proportion of plasmid-encoded genes differentially expressed was much higher relative to its size and most genes were induced in vivo. The majority of genes encoding known virulence factors, components of types II and III secretion systems and chromosome 2-encoded type IV secretion system were similarly expressed between in vitro and in vivo environments. Lower expression in vivo was detected for genes encoding N-acyl-homoserine lactone synthase CepI, orphan LuxR homolog CepR2, zinc metalloproteases ZmpA and ZmpB, LysR-type transcriptional regulator ShvR, nematocidal protein AidA, and genes associated with flagellar motility, Flp type pilus formation, and type VI secretion. Plasmid-encoded type IV secretion genes were markedly induced in vivo. Additional genes induced in vivo included genes predicted to be involved in osmotic stress adaptation or intracellular survival, metal ion, and nutrient transport, as well as those encoding outer membrane proteins. Genes identified in this study are potentially important for virulence during host–pathogen interactions and may be associated with survival and adaptation to the host environment during chronic lung infections.
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Affiliation(s)
- Eoin P O'Grady
- Department of Microbiology, Immunology and Infectious Diseases, University of Calgary, Calgary, AB, Canada
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29
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Hu Y, Flockhart I, Vinayagam A, Bergwitz C, Berger B, Perrimon N, Mohr SE. An integrative approach to ortholog prediction for disease-focused and other functional studies. BMC Bioinformatics 2011; 12:357. [PMID: 21880147 PMCID: PMC3179972 DOI: 10.1186/1471-2105-12-357] [Citation(s) in RCA: 478] [Impact Index Per Article: 36.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2011] [Accepted: 08/31/2011] [Indexed: 12/12/2022] Open
Abstract
Background Mapping of orthologous genes among species serves an important role in functional genomics by allowing researchers to develop hypotheses about gene function in one species based on what is known about the functions of orthologs in other species. Several tools for predicting orthologous gene relationships are available. However, these tools can give different results and identification of predicted orthologs is not always straightforward. Results We report a simple but effective tool, the Drosophila RNAi Screening Center Integrative Ortholog Prediction Tool (DIOPT; http://www.flyrnai.org/diopt), for rapid identification of orthologs. DIOPT integrates existing approaches, facilitating rapid identification of orthologs among human, mouse, zebrafish, C. elegans, Drosophila, and S. cerevisiae. As compared to individual tools, DIOPT shows increased sensitivity with only a modest decrease in specificity. Moreover, the flexibility built into the DIOPT graphical user interface allows researchers with different goals to appropriately 'cast a wide net' or limit results to highest confidence predictions. DIOPT also displays protein and domain alignments, including percent amino acid identity, for predicted ortholog pairs. This helps users identify the most appropriate matches among multiple possible orthologs. To facilitate using model organisms for functional analysis of human disease-associated genes, we used DIOPT to predict high-confidence orthologs of disease genes in Online Mendelian Inheritance in Man (OMIM) and genes in genome-wide association study (GWAS) data sets. The results are accessible through the DIOPT diseases and traits query tool (DIOPT-DIST; http://www.flyrnai.org/diopt-dist). Conclusions DIOPT and DIOPT-DIST are useful resources for researchers working with model organisms, especially those who are interested in exploiting model organisms such as Drosophila to study the functions of human disease genes.
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Affiliation(s)
- Yanhui Hu
- Drosophila RNAi Screening Center, Department of Genetics, Harvard Medical School, 77 Avenue Louis Pasteur, Boston, MA 02115, USA
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Burkholderia cenocepacia ShvR-regulated genes that influence colony morphology, biofilm formation, and virulence. Infect Immun 2011; 79:2984-97. [PMID: 21690240 DOI: 10.1128/iai.00170-11] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Burkholderia cenocepacia is an opportunistic pathogen that primarily infects cystic fibrosis (CF) patients. Previously, we reported that ShvR, a LysR regulator, influences colony morphology, virulence, and biofilm formation and regulates the expression of an adjacent 24-kb genomic region encoding 24 genes. In this study, we report the functional characterization of selected genes in this region. A Tn5 mutant with shiny colony morphology was identified with a polar mutation in BCAS0208, predicted to encode an acyl-coenzyme A dehydrogenase. Mutagenesis of BCAS0208 and complementation analyses revealed that BCAS0208 is required for rough colony morphology, biofilm formation, and virulence on alfalfa seedlings. It was not possible to complement with BCAS0208 containing a mutation in the catalytic site. BCAS0201, encoding a putative flavin adenine dinucleotide (FAD)-dependent oxidoreductase, and BCAS0207, encoding a putative citrate synthase, do not influence colony morphology but are required for optimum levels of biofilm formation and virulence. Both BCAS0208 and BCAS0201 contribute to pellicle formation, although individual mutations in each of these genes had no appreciable effect on pellicle formation. A mutant with a polar insertion in BCAS0208 was significantly less virulent in a rat model of chronic lung infection as well as in the alfalfa model. Genes in this region were shown to influence utilization of branched-chain fatty acids, tricarboxylic acid cycle substrates, l-arabinose, and branched-chain amino acids. Together, our data show that the ShvR-regulated genes BCAS0208 to BCAS0201 are required for the rough colony morphotype, biofilm and pellicle formation, and virulence in B. cenocepacia.
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Slater JL, Gregson L, Denning DW, Warn PA. Pathogenicity ofAspergillus fumigatusmutants assessed inGalleria mellonellamatches that in mice. Med Mycol 2011; 49 Suppl 1:S107-13. [DOI: 10.3109/13693786.2010.523852] [Citation(s) in RCA: 101] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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