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Harbeoui H, Di Martino P, Mayot G. A new killing assay with the Caenorhabditis elegans PX627 mutant to assess the virulence of uropathogenic Escherichia coli strains. J Microbiol Methods 2023; 214:106823. [PMID: 37716412 DOI: 10.1016/j.mimet.2023.106823] [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: 07/19/2023] [Revised: 09/13/2023] [Accepted: 09/13/2023] [Indexed: 09/18/2023]
Abstract
The nematode Caenorhabditis elegans (C. elegans) is a prime invertebrate host model for studying uropathogenic Escherichia coli (UPEC) pathogenesis. The aim of this work was to develop a new C. elegans killing assay based on feeding bacteria by the nematode throughout its life from the egg. With this model, the lifespan of C. elegans rrf-3, temperature-sterile, mutant, and PX627, auxin-inducible infertile, mutant fed UPEC strains, was compared. The behavior of three clinical UPEC strains and the non-pathogenic Escherichia coli OP50 strain was analyzed. Survival curves were generated by the Kaplan-Meier method and compared by the log-rank test over 10 days of follow-up. There was no significant difference between the survival curves obtained with each of the two C. elegans mutants (PX627 and rrf-3) fed with each of the strains of E. coli (OP50, G1722, G1473 or ER41). The UPEC strains were classified according to their virulence in vivo in the C. elegans PX627 mutant. The most virulent strain was ER41 which harbored the virulence genes fimA, papC and hlyA, expressed hemolysis in vitro and showed no antibiotic resistance. The least virulent strain was G1722 which only harbored the two adhesion factor genes, was not hemolytic and was resistant to multiple antibiotics. The C. elegans PX627 mutant fed with UPEC bacteria from the egg stage is a simple and inexpensive invertebrate animal model for assessing the in vivo virulence of different strains. The early exposure of C. elegans to pathogenic bacteria at the egg stage, without the need to change the incubation temperature, is an advantage over previously described C. elegans killing assays.
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Affiliation(s)
- Hela Harbeoui
- ERRMECe, CY Cergy Paris University, F-95000 Neuville-Sur-Oise, France
| | | | - Gilles Mayot
- ERRMECe, CY Cergy Paris University, F-95000 Neuville-Sur-Oise, France.
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2
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Hu C, Garey KW. Nonmammalian models to study Clostridioides difficile infection; a systematic review. Anaerobe 2023; 79:102694. [PMID: 36626950 PMCID: PMC9975065 DOI: 10.1016/j.anaerobe.2023.102694] [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] [Received: 10/11/2022] [Revised: 01/05/2023] [Accepted: 01/06/2023] [Indexed: 01/09/2023]
Abstract
Clostridioide difficile is the leading cause of diarrhea disease worldwide and is a CDC-designated urgent threat level pathogen. Mammalian models are commonly utilized as gold standard to study the pathogenesis of C. difficile infection (CDI); however, alternatives are needed due to cost, higher throughput ability, and mammalian animal ethics. Nonmammalian models such as great wax worm, nematode, fruit fly, and zebrafish have been used as CDI models. This review provides a comprehensive summary of nonmammalian models used to study CDI. Multiple studies were identified using these models to study C. difficile infection, pathogenicity, colonization, host immunity, and therapy. Translational outcomes and strength and weakness of each nonmammalian model are discussed.
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Affiliation(s)
- Chenlin Hu
- University of Houston College of Pharmacy, Houston, TX, 77204, USA
| | - Kevin W Garey
- University of Houston College of Pharmacy, Houston, TX, 77204, USA.
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3
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Shaw CL, Kennedy DA. Developing an empirical model for spillover and emergence: Orsay virus host range in Caenorhabditis. Proc Biol Sci 2022; 289:20221165. [PMID: 36126684 PMCID: PMC9489279 DOI: 10.1098/rspb.2022.1165] [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: 06/15/2022] [Accepted: 08/24/2022] [Indexed: 11/20/2022] Open
Abstract
A lack of tractable experimental systems in which to test hypotheses about the ecological and evolutionary drivers of disease spillover and emergence has limited our understanding of these processes. Here we introduce a promising system: Caenorhabditis hosts and Orsay virus, a positive-sense single-stranded RNA virus that naturally infects C. elegans. We assayed species across the Caenorhabditis tree and found Orsay virus susceptibility in 21 of 84 wild strains belonging to 14 of 44 species. Confirming patterns documented in other systems, we detected effects of host phylogeny on susceptibility. We then tested whether susceptible strains were capable of transmitting Orsay virus by transplanting exposed hosts and determining whether they transmitted infection to conspecifics during serial passage. We found no evidence of transmission in 10 strains (virus undetectable after passaging in all replicates), evidence of low-level transmission in 5 strains (virus lost between passage 1 and 5 in at least one replicate) and evidence of sustained transmission in 6 strains (including all three experimental C. elegans strains) in at least one replicate. Transmission was strongly associated with viral amplification in exposed populations. Variation in Orsay virus susceptibility and transmission among Caenorhabditis strains suggests that the system could be powerful for studying spillover and emergence.
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Affiliation(s)
- Clara L. Shaw
- Department of Biology, The Pennsylvania State University, University Park, PA 16802, USA
| | - David A. Kennedy
- Department of Biology, The Pennsylvania State University, University Park, PA 16802, USA
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4
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Yoo YJ, Chung IY, Jalde SS, Choi HK, Cho YH. An iron-chelating sulfonamide identified from Drosophila-based screening for antipathogenic discovery. Virulence 2022; 13:833-843. [PMID: 35521696 PMCID: PMC9090290 DOI: 10.1080/21505594.2022.2069325] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
Abstract
We exploited bacterial infection assays using the fruit fly Drosophila melanogaster to identify anti-infective compounds that abrogate the pathological consequences in the infected hosts. Here, we demonstrated that a pyridine-3-N-sulfonylpiperidine derivative (4a) protects Drosophila from the acute infections caused by bacterial pathogens including Pseudomonas aeruginosa. 4a did not inhibit the growth of P. aeruginosa in vitro, but inhibited the production of secreted toxins such as pyocyanin and hydrogen cyanide, while enhancing the production of pyoverdine and pyochelin, indicative of iron deprivation. Based on its catechol moiety, 4a displayed iron-chelating activity in vitro toward both iron (II) and iron (III), more efficiently than the approved iron-chelating drugs such as deferoxamine and deferiprone, concomitant with more potent antibacterial efficacy in Drosophila infections and unique transcriptome profile. Taken together, these results delineate a Drosophila-based strategy to screen for antipathogenic compounds, which interfere with iron uptake crucial for bacterial virulence and survival in host tissues.
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Affiliation(s)
- Yeon-Ji Yoo
- Department of Pharmacy, College of Pharmacy and Institute of Pharmaceutical Sciences, CHA University, Seongnam, Korea
| | - In-Young Chung
- Department of Pharmacy, College of Pharmacy and Institute of Pharmaceutical Sciences, CHA University, Seongnam, Korea
| | | | | | - You-Hee Cho
- Department of Pharmacy, College of Pharmacy and Institute of Pharmaceutical Sciences, CHA University, Seongnam, Korea
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5
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Kumar M, Singh P, Murugesan S, Vetizou M, McCulloch J, Badger JH, Trinchieri G, Al Khodor S. Microbiome as an Immunological Modifier. Methods Mol Biol 2020; 2055:595-638. [PMID: 31502171 PMCID: PMC8276114 DOI: 10.1007/978-1-4939-9773-2_27] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Humans are living ecosystems composed of human cells and microbes. The microbiome is the collection of microbes (microbiota) and their genes. Recent breakthroughs in the high-throughput sequencing technologies have made it possible for us to understand the composition of the human microbiome. Launched by the National Institutes of Health in USA, the human microbiome project indicated that our bodies harbor a wide array of microbes, specific to each body site with interpersonal and intrapersonal variabilities. Numerous studies have indicated that several factors influence the development of the microbiome including genetics, diet, use of antibiotics, and lifestyle, among others. The microbiome and its mediators are in a continuous cross talk with the host immune system; hence, any imbalance on one side is reflected on the other. Dysbiosis (microbiota imbalance) was shown in many diseases and pathological conditions such as inflammatory bowel disease, celiac disease, multiple sclerosis, rheumatoid arthritis, asthma, diabetes, and cancer. The microbial composition mirrors inflammation variations in certain disease conditions, within various stages of the same disease; hence, it has the potential to be used as a biomarker.
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Affiliation(s)
- Manoj Kumar
- Division of Translational Medicine, Research Department, Sidra Medicine, Doha, Qatar
| | - Parul Singh
- Division of Translational Medicine, Research Department, Sidra Medicine, Doha, Qatar
| | - Selvasankar Murugesan
- Division of Translational Medicine, Research Department, Sidra Medicine, Doha, Qatar
| | - Marie Vetizou
- Cancer and Inflammation Program, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - John McCulloch
- Cancer and Inflammation Program, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - Jonathan H Badger
- Cancer and Inflammation Program, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - Giorgio Trinchieri
- Cancer and Inflammation Program, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - Souhaila Al Khodor
- Division of Translational Medicine, Research Department, Sidra Medicine, Doha, Qatar.
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6
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Cutuli MA, Petronio Petronio G, Vergalito F, Magnifico I, Pietrangelo L, Venditti N, Di Marco R. Galleria mellonella as a consolidated in vivo model hosts: New developments in antibacterial strategies and novel drug testing. Virulence 2019; 10:527-541. [PMID: 31142220 PMCID: PMC6550544 DOI: 10.1080/21505594.2019.1621649] [Citation(s) in RCA: 102] [Impact Index Per Article: 20.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Revised: 05/13/2019] [Accepted: 05/14/2019] [Indexed: 12/20/2022] Open
Abstract
A greater ethical conscience, new global rules and a modified perception of ethical consciousness entail a more rigorous control on utilizations of vertebrates for in vivo studies. To cope with this new scenario, numerous alternatives to rodents have been proposed. Among these, the greater wax moth Galleria mellonella had a preponderant role, especially in the microbiological field, as demonstrated by the growing number of recent scientific publications. The reasons for its success must be sought in its peculiar characteristics such as the innate immune response mechanisms and the ability to grow at a temperature of 37°C. This review aims to describe the most relevant features of G. mellonella in microbiology, highlighting the most recent and relevant research on antibacterial strategies, novel drug tests and toxicological studies. Although solutions for some limitations are required, G. mellonella has all the necessary host features to be a consolidated in vivo model host.
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Affiliation(s)
- Marco Alfio Cutuli
- Department of Medicine and Health Sciences “Vincenzo Tiberio”, Università degli Studi del Molise Italy - III Ed Polifunzionale, Campobasso, Italy
| | - Giulio Petronio Petronio
- Department of Medicine and Health Sciences “Vincenzo Tiberio”, Università degli Studi del Molise Italy - III Ed Polifunzionale, Campobasso, Italy
| | - Franca Vergalito
- Department of Medicine and Health Sciences “Vincenzo Tiberio”, Università degli Studi del Molise Italy - III Ed Polifunzionale, Campobasso, Italy
| | - Irene Magnifico
- Department of Medicine and Health Sciences “Vincenzo Tiberio”, Università degli Studi del Molise Italy - III Ed Polifunzionale, Campobasso, Italy
| | - Laura Pietrangelo
- Department of Medicine and Health Sciences “Vincenzo Tiberio”, Università degli Studi del Molise Italy - III Ed Polifunzionale, Campobasso, Italy
| | - Noemi Venditti
- Department of Medicine and Health Sciences “Vincenzo Tiberio”, Università degli Studi del Molise Italy - III Ed Polifunzionale, Campobasso, Italy
| | - Roberto Di Marco
- Department of Medicine and Health Sciences “Vincenzo Tiberio”, Università degli Studi del Molise Italy - III Ed Polifunzionale, Campobasso, Italy
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7
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Maisuria VB, Okshevsky M, Déziel E, Tufenkji N. Proanthocyanidin Interferes with Intrinsic Antibiotic Resistance Mechanisms of Gram-Negative Bacteria. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2019; 6:1802333. [PMID: 31406662 PMCID: PMC6685479 DOI: 10.1002/advs.201802333] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/25/2018] [Revised: 04/03/2019] [Indexed: 05/30/2023]
Abstract
Antibiotic resistance is spreading at an alarming rate among pathogenic bacteria in both medicine and agriculture. Interfering with the intrinsic resistance mechanisms displayed by pathogenic bacteria has the potential to make antibiotics more effective and decrease the spread of acquired antibiotic resistance. Here, it is demonstrated that cranberry proanthocyanidin (cPAC) prevents the evolution of resistance to tetracycline in Escherichia coli and Pseudomonas aeruginosa, rescues antibiotic efficacy against antibiotic-exposed cells, and represses biofilm formation. It is shown that cPAC has a potentiating effect, both in vitro and in vivo, on a broad range of antibiotic classes against pathogenic E. coli, Proteus mirabilis, and P. aeruginosa. Evidence that cPAC acts by repressing two antibiotic resistance mechanisms, selective membrane permeability and multidrug efflux pumps, is presented. Failure of cPAC to potentiate antibiotics against efflux pump-defective mutants demonstrates that efflux interference is essential for potentiation. The use of cPAC to potentiate antibiotics and mitigate the development of resistance could improve treatment outcomes and help combat the growing threat of antibiotic resistance.
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Affiliation(s)
- Vimal B. Maisuria
- Department of Chemical EngineeringMcGill University3610 University StreetMontrealQuebecH3A 0C5Canada
| | - Mira Okshevsky
- Department of Chemical EngineeringMcGill University3610 University StreetMontrealQuebecH3A 0C5Canada
| | - Eric Déziel
- INRS‐Institut Armand‐Frappier531 boul. des PrairiesLavalQuébecH7V 1B7Canada
| | - Nathalie Tufenkji
- Department of Chemical EngineeringMcGill University3610 University StreetMontrealQuebecH3A 0C5Canada
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8
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Espinal P, Pantel A, Rolo D, Marti S, López-Rojas R, Smani Y, Pachón J, Vila J, Lavigne JP. Relationship Between Different Resistance Mechanisms and Virulence in Acinetobacter baumannii. Microb Drug Resist 2019; 25:752-760. [PMID: 30632884 DOI: 10.1089/mdr.2018.0182] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Aim: This study analyzed the virulence of several Acinetobacter baumannii strains expressing different resistance mechanisms using the Caenorhabditis elegans infection model. Results: Strains susceptible/resistant to carbapenems (presenting class D (OXA-23, OXA-24), class B metallo-β-lactamase (MBL) (NDM-1), penicillin binding protein (PBP) altered and decreased expression of Omp 33-36 kDa) and isogenic A. baumannii strains susceptible/resistant to colistin (presenting loss of lipopolysaccharide (LPS) and pmrA mutations) were included to evaluate the virulence using the C. elegans infection model. The nematode killing assay, bacterial ingestion in worms, and bacterial lawn avoidance assay were performed with the Fer-15 mutant line. A. baumannii strains generally presented low virulence, showing no difference between carbapenem-resistant strains (expressing class D, MBLs, or altered PBP) and their isogenic susceptible strains. In contrast, the absence of the Omp 33-36 kDa protein in the knockout was associated with a decrease of virulence, and a significant difference was observed between colistin-resistant mutants and their susceptible counterpart when the mechanism of resistance was associated with the loss of LPS but not with its modification. Conclusions: Resistance to carbapenems in A. baumannii associated with the production of OXA-type or NDM-type enzymes does not seem to affect their virulence in the C. elegans infection model. In contrast, the presence of Omp 33-36 kDa, and high level resistance to colistin related with the loss of LPS, might contribute with the virulence profile in A. baumannii.
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Affiliation(s)
- Paula Espinal
- 1 Barcelona Institute for Global Health (ISGlobal) Hospital Clínic, Universitat de Barcelona, Barcelona, Spain.,2 National Institute of Health and Medical Research, U1047, Montpellier University, Nîmes, France
| | - Alix Pantel
- 2 National Institute of Health and Medical Research, U1047, Montpellier University, Nîmes, France.,3 Department of Microbiology, University Hospital Nîmes, Nîmes, France
| | - Dora Rolo
- 1 Barcelona Institute for Global Health (ISGlobal) Hospital Clínic, Universitat de Barcelona, Barcelona, Spain
| | - Sara Marti
- 4 Microbiology Department, Hospital Universitari Bellvitge, Barcelona, Spain.,5 Research Network for Respiratory Diseases (CIBERES), ISCIII, Madrid, Spain
| | - Rafael López-Rojas
- 6 Clinic Unit of Infectious Diseases, Microbiology and Preventive Medicine, Institute of Biomedicine of Seville, IBiS, University Hospital Virgen del Rocío/CSIC/University of Seville, Seville, Spain
| | - Younes Smani
- 6 Clinic Unit of Infectious Diseases, Microbiology and Preventive Medicine, Institute of Biomedicine of Seville, IBiS, University Hospital Virgen del Rocío/CSIC/University of Seville, Seville, Spain
| | - Jerónimo Pachón
- 6 Clinic Unit of Infectious Diseases, Microbiology and Preventive Medicine, Institute of Biomedicine of Seville, IBiS, University Hospital Virgen del Rocío/CSIC/University of Seville, Seville, Spain
| | - Jordi Vila
- 1 Barcelona Institute for Global Health (ISGlobal) Hospital Clínic, Universitat de Barcelona, Barcelona, Spain
| | - Jean-Philippe Lavigne
- 2 National Institute of Health and Medical Research, U1047, Montpellier University, Nîmes, France.,3 Department of Microbiology, University Hospital Nîmes, Nîmes, France
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9
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Saha SS, Suzuki J, Uda A, Watanabe K, Shimizu T, Watarai M. Silkworm model for Francisella novicida infection. Microb Pathog 2017; 113:94-101. [PMID: 29066381 DOI: 10.1016/j.micpath.2017.10.036] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2017] [Revised: 10/17/2017] [Accepted: 10/20/2017] [Indexed: 11/16/2022]
Abstract
Understanding the virulence and pathogenesis of human pathogens using insect models is an increasingly popular method. Francisella novicida, which is virulent in mice but non-pathogenic to immunocompetent humans, is widely used as an ideal candidate for Francisella research. In this study, we developed a silkworm (Bombyx mori) infection model for F. novicida by inoculating the hemocoels of silkworms with F. novicida. We found that silkworms died within 3-7 days of F. novicida infection. However, the deletion mutant of DotU, the core part of type VI secretion systems, failed to kill silkworm. In whole silkworm bodies, the bacterial load of the DotU deletion mutant was significantly less than that of the wild-type strain. Approximately 10-fold increase in bacterial load was recorded in hemolymph and subcutaneous tissues compared with that in the silk gland, Malpighian tubule, and reproductive organs. The CFU count of the DotU deletion mutant in all organs was similar results to the whole body CFU count. Confocal microscopy further confirmed the arrested growth of the mutant strain within hemocytes. The intracellular growth of F. novicida strains was also analyzed using the silkworm ovary-derived cell line BmN4. In BmN4, both CFU count assay and confocal microscopy revealed extensive growth of the wild-type strain compared with that of the mutant strain. Francisella DotU has already been proven as a virulence factor in mammals, and it was also found to be an essential virulence factor in our silkworm infection model. Therefore, this silkworm infection model is suitable for identifying new virulence factors of Francisella.
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Affiliation(s)
- Shib Shankar Saha
- The United Graduate School of Veterinary Science, Yamaguchi University, 1677-1, Yoshida, Yamaguchi 753-8515, Japan; Department of Pathology and Parasitology, Patuakhali Science and Technology University, Babugonj, Barisal 8210, Bangladesh
| | - Jin Suzuki
- The United Graduate School of Veterinary Science, Yamaguchi University, 1677-1, Yoshida, Yamaguchi 753-8515, Japan
| | - Akihiko Uda
- Department of Veterinary Science, National Institute of Infectious Diseases, Shinjuku, Tokyo 162-8640, Japan
| | - Kenta Watanabe
- The United Graduate School of Veterinary Science, Yamaguchi University, 1677-1, Yoshida, Yamaguchi 753-8515, Japan
| | - Takashi Shimizu
- The United Graduate School of Veterinary Science, Yamaguchi University, 1677-1, Yoshida, Yamaguchi 753-8515, Japan
| | - Masahisa Watarai
- The United Graduate School of Veterinary Science, Yamaguchi University, 1677-1, Yoshida, Yamaguchi 753-8515, Japan.
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10
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Abstract
Vibrio cholerae is the etiological agent of cholera, an acute intestinal infection in humans characterized by voluminous watery diarrhea. Cholera is spread through ingestion of contaminated food or water, primarily in developing countries that lack the proper infrastructure for proper water and sewage treatment. Vibrio cholerae is an aquatic bacterium that inhabits coastal and estuarine areas, and it is known to have several environmental reservoirs, including fish. Our laboratory has recently described the use of the zebrafish as a new animal model for the study of V. cholerae intestinal colonization, pathogenesis, and transmission. As early as 6 h after exposure to V. cholerae, zebrafish develop diarrhea. Prior work in our laboratory has shown that this is not due to the action of cholera toxin. We hypothesize that accessory toxins produced by V. cholerae are the cause of diarrhea in infected zebrafish. In order to assess the effects of accessory toxins in the zebrafish, it was necessary to develop a method of quantifying diarrheal volume as a measure of pathogenesis. Here, we have adapted cell density, protein, and mucin assays, along with enumeration of V. cholerae in the zebrafish intestinal tract and in the infection water, to achieve this goal. Combined, these assays should help us determine which toxins have the greatest diarrheagenic effect in fish and, consequently, which toxins may play a role in environmental transmission.IMPORTANCE Identification of the accessory toxins that cause diarrhea in zebrafish can help us understand more about the role of fish in the wild as aquatic reservoirs for V. cholerae It is plausible that accessory toxins can act to prolong colonization and subsequent shedding of V. cholerae back into the environment, thus perpetuating and facilitating transmission during an outbreak. It is also possible that accessory toxins help to maintain low levels of intestinal colonization in fish, giving V. cholerae an advantage when environmental conditions are not optimal for survival in the water. Studies such as this one are critical because fish could be an overlooked source of cholera transmission in the environment.
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Romero A, Saraceni PR, Merino S, Figueras A, Tomás JM, Novoa B. The Animal Model Determines the Results of Aeromonas Virulence Factors. Front Microbiol 2016; 7:1574. [PMID: 27757107 PMCID: PMC5048442 DOI: 10.3389/fmicb.2016.01574] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2016] [Accepted: 09/20/2016] [Indexed: 12/19/2022] Open
Abstract
The selection of an experimental animal model is of great importance in the study of bacterial virulence factors. Here, a bath infection of zebrafish larvae is proposed as an alternative model to study the virulence factors of Aeromonas hydrophila. Intraperitoneal infections in mice and trout were compared with bath infections in zebrafish larvae using specific mutants. The great advantage of this model is that bath immersion mimics the natural route of infection, and injury to the tail also provides a natural portal of entry for the bacteria. The implication of T3SS in the virulence of A. hydrophila was analyzed using the AH-1::aopB mutant. This mutant was less virulent than the wild-type strain when inoculated into zebrafish larvae, as described in other vertebrates. However, the zebrafish model exhibited slight differences in mortality kinetics only observed using invertebrate models. Infections using the mutant AH-1ΔvapA lacking the gene coding for the surface S-layer suggested that this protein was not totally necessary to the bacteria once it was inside the host, but it contributed to the inflammatory response. Only when healthy zebrafish larvae were infected did the mutant produce less mortality than the wild-type. Variations between models were evidenced using the AH-1ΔrmlB, which lacks the O-antigen lipopolysaccharide (LPS), and the AH-1ΔwahD, which lacks the O-antigen LPS and part of the LPS outer-core. Both mutants showed decreased mortality in all of the animal models, but the differences between them were only observed in injured zebrafish larvae, suggesting that residues from the LPS outer core must be important for virulence. The greatest differences were observed using the AH-1ΔFlaB-J (lacking polar flagella and unable to swim) and the AH-1::motX (non-motile but producing flagella). They were as pathogenic as the wild-type strain when injected into mice and trout, but no mortalities were registered in zebrafish larvae. This study demonstrates that zebrafish larvae can be used as a host model to assess the virulence factors of A. hydrophila. This model revealed more differences in pathogenicity than the in vitro models and enabled the detection of slight variations in pathogenesis not observed using intraperitoneal injections of mice or fish.
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Affiliation(s)
- Alejandro Romero
- Department of Immunology and Genomics, Marine Research Institute-Consejo Superior de Investigaciones Científicas, Vigo Spain
| | - Paolo R Saraceni
- Department of Immunology and Genomics, Marine Research Institute-Consejo Superior de Investigaciones Científicas, Vigo Spain
| | - Susana Merino
- Department of Microbiology, Faculty of Biology, University of Barcelona, Barcelona Spain
| | - Antonio Figueras
- Department of Immunology and Genomics, Marine Research Institute-Consejo Superior de Investigaciones Científicas, Vigo Spain
| | - Juan M Tomás
- Department of Microbiology, Faculty of Biology, University of Barcelona, Barcelona Spain
| | - Beatriz Novoa
- Department of Immunology and Genomics, Marine Research Institute-Consejo Superior de Investigaciones Científicas, Vigo Spain
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12
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Castillo Y, Suzuki J, Watanabe K, Shimizu T, Watarai M. Effect of Vitamin A on Listeria monocytogenes Infection in a Silkworm Model. PLoS One 2016; 11:e0163747. [PMID: 27669511 PMCID: PMC5036829 DOI: 10.1371/journal.pone.0163747] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2016] [Accepted: 09/13/2016] [Indexed: 11/18/2022] Open
Abstract
Insect infection models have been used increasingly to study various pathogenic agents in evaluations of pathogenicity and drug efficacy. In this study, we demonstrated that larvae of the silkworm Bombyx mori are useful for studying Listeria monocytogenes infections in insects. Infection with the L. monocytogenes wild-type strain induced silkworm death. Infection by a listeriolysin O (LLO) deletion mutant also induced silkworm death, but the bacterial numbers in silkworms were lower than those of the wild-type strain. Intracellular growth was observed when the silkworm ovary-derived cell line BmN4 was infected with the wild-type strain. Explosive replication was not observed in BmN4 cells infected with the LLO mutant and the bacterial numbers of the LLO mutant were lower than those of the wild-type strain. Pretreatment with vitamin A did not affect silkworm mortality after bacterial infection, but the efficiency of infecting the hemocytes and BmN4 cells was decreased with vitamin A treatment. Our results indicate that silkworm larvae are a useful insect infection model for L. monocytogenes and that vitamin A has protective effects against bacterial infection in silkworms.
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Affiliation(s)
- Yussaira Castillo
- The United Graduate School of Veterinary Science, Yamaguchi University, 1677-1 Yoshida, Yamaguchi 753-8515, Japan
| | - Jin Suzuki
- The United Graduate School of Veterinary Science, Yamaguchi University, 1677-1 Yoshida, Yamaguchi 753-8515, Japan
| | - Kenta Watanabe
- The United Graduate School of Veterinary Science, Yamaguchi University, 1677-1 Yoshida, Yamaguchi 753-8515, Japan
| | - Takashi Shimizu
- The United Graduate School of Veterinary Science, Yamaguchi University, 1677-1 Yoshida, Yamaguchi 753-8515, Japan
| | - Masahisa Watarai
- The United Graduate School of Veterinary Science, Yamaguchi University, 1677-1 Yoshida, Yamaguchi 753-8515, Japan
- * E-mail:
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Saralahti A, Rämet M. Zebrafish and Streptococcal Infections. Scand J Immunol 2015; 82:174-83. [PMID: 26095827 DOI: 10.1111/sji.12320] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2015] [Accepted: 04/28/2015] [Indexed: 12/11/2022]
Abstract
Streptococcal bacteria are a versatile group of gram-positive bacteria capable of infecting several host organisms, including humans and fish. Streptococcal species are common colonizers of the human respiratory and gastrointestinal tract, but they also cause some of the most common life-threatening, invasive infections in humans and aquaculture. With its unique characteristics and efficient tools for genetic and imaging applications, the zebrafish (Danio rerio) has emerged as a powerful vertebrate model for infectious diseases. Several zebrafish models introduced so far have shown that zebrafish are suitable models for both zoonotic and human-specific infections. Recently, several zebrafish models mimicking human streptococcal infections have also been developed. These models show great potential in providing novel information about the pathogenic mechanisms and host responses associated with human streptococcal infections. Here, we review the zebrafish infection models for the most relevant streptococcal species: the human-specific Streptococcus pneumoniae and Streptococcus pyogenes, and the zoonotic Streptococcus iniae and Streptococcus agalactiae. The recent success and the future potential of these models for the study of host-pathogen interactions in streptococcal infections are also discussed.
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Affiliation(s)
- A Saralahti
- BioMediTech, University of Tampere, Tampere, Finland
| | - M Rämet
- BioMediTech, University of Tampere, Tampere, Finland.,Department of Pediatrics, Tampere University Hospital, Tampere, Finland.,Department of Children and Adolescents, Oulu University Hospital, Oulu, Finland.,PEDEGO Research Center, Medical Research Center Oulu, University of Oulu, Oulu, Finland
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14
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Wiles S. All models are wrong, but some are useful: Averting the 'microbial apocalypse'. Virulence 2015; 6:730-2. [PMID: 26315720 DOI: 10.1080/21505594.2014.1001238] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
Affiliation(s)
- Siouxsie Wiles
- a Bioluminescent Superbugs Group ; Molecular Medicine and Pathology; University of Auckland ; Auckland , New Zealand
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15
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Abstract
Glycosaminoglycans (GAGs) have been shown to bind to a wide variety of microbial pathogens, including viruses, bacteria, parasites, and fungi in vitro. GAGs are thought to promote pathogenesis by facilitating pathogen attachment, invasion, or evasion of host defense mechanisms. However, the role of GAGs in infectious disease has not been extensively studied in vivo and therefore their pathophysiological significance and functions are largely unknown. Here we describe methods to directly investigate the role of GAGs in infections in vivo using mouse models of bacterial lung and corneal infection. The overall experimental strategy is to establish the importance and specificity of GAGs, define the essential structural features of GAGs, and identify a biological activity of GAGs that promotes pathogenesis.
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Affiliation(s)
- Akiko Jinno
- Division of Respiratory Diseases, Children's Hospital, Harvard Medical School, 320 Longwood Avenue, Enders-461, Boston, MA, 02115, USA,
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16
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Steenackers H, Dubey A, Robijns S, Ermolat'ev D, Delattin N, Dovgan B, Girandon L, Fröhlich M, De Brucker K, Cammue BPA, Thevissen K, Balzarini J, Van der Eycken EV, Vanderleyden J. Evaluation of the toxicity of 5-aryl-2-aminoimidazole-based biofilm inhibitors against eukaryotic cell lines, bone cells and the nematode Caenorhabditis elegans. Molecules 2014; 19:16707-23. [PMID: 25325155 PMCID: PMC6271933 DOI: 10.3390/molecules191016707] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2014] [Revised: 08/22/2014] [Accepted: 09/15/2014] [Indexed: 01/19/2023] Open
Abstract
Previously, we have synthesized several series of compounds based on the 5-aryl-2-aminoimidazole scaffold, which showed a preventive activity against microbial biofilms. We here studied the cytotoxicity of the most active compounds of each series. First, the cytostatic activity was investigated against a number of tumor cell lines (L1210, CEM and HeLa). A subset of monosubstituted 5-aryl-2-aminoimidazoles showed a moderate safety window, with therapeutic indices (TIs) ranging between 3 and 20. Whereas introduction of a (cyclo-)alkyl chain at the N1-position strongly reduced the TI, introduction of a (cyclo-)alkyl chain or a triazole moiety at the 2N-position increased the TI up to 370. Since a promising application of preventive anti-biofilm agents is their use in anti-biofilm coatings for orthopedic implants, their effects on cell viability and functional behavior of human osteoblasts and bone marrow derived mesenchymal stem cells were tested. The 2N-substituted 5-aryl-2-aminoimidazoles consistently showed the lowest toxicity and allowed survival of the bone cells for up to 4 weeks. Moreover they did not negatively affect the osteogenic differentiation potential of the bone cells. Finally, we examined the effect of the compounds on the survival of Caenorhabditis elegans, which confirmed the higher safety window of 2N-substituted 5-aryl-2-aminoimidazoles.
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Affiliation(s)
- Hans Steenackers
- Centre of Microbial and Plant Genetics (CMPG), Department of Microbial and Molecular Systems, KU Leuven, Kasteelpark Arenberg 20, Box 2460, B-3001 Leuven, Belgium.
| | - Akanksha Dubey
- Centre of Microbial and Plant Genetics (CMPG), Department of Microbial and Molecular Systems, KU Leuven, Kasteelpark Arenberg 20, Box 2460, B-3001 Leuven, Belgium
| | - Stijn Robijns
- Centre of Microbial and Plant Genetics (CMPG), Department of Microbial and Molecular Systems, KU Leuven, Kasteelpark Arenberg 20, Box 2460, B-3001 Leuven, Belgium
| | - Denis Ermolat'ev
- Laboratory for Organic & Microwave-Assisted Chemistry (LOMAC), Department of Chemistry, KU Leuven, Celestijnenlaan 200F, B-3001 Leuven, Belgium
| | - Nicolas Delattin
- Centre of Microbial and Plant Genetics (CMPG), Department of Microbial and Molecular Systems, KU Leuven, Kasteelpark Arenberg 20, Box 2460, B-3001 Leuven, Belgium
| | | | | | | | - Katrijn De Brucker
- Centre of Microbial and Plant Genetics (CMPG), Department of Microbial and Molecular Systems, KU Leuven, Kasteelpark Arenberg 20, Box 2460, B-3001 Leuven, Belgium
| | - Bruno P A Cammue
- Centre of Microbial and Plant Genetics (CMPG), Department of Microbial and Molecular Systems, KU Leuven, Kasteelpark Arenberg 20, Box 2460, B-3001 Leuven, Belgium
| | - Karin Thevissen
- Centre of Microbial and Plant Genetics (CMPG), Department of Microbial and Molecular Systems, KU Leuven, Kasteelpark Arenberg 20, Box 2460, B-3001 Leuven, Belgium
| | - Jan Balzarini
- Laboratory of Virology and Chemotherapy, Rega Institute for Medical Research, Department of Microbiology and Immunology, KU Leuven, Minderbroedersstraat 10, B-3000 Leuven, Belgium
| | - Erik V Van der Eycken
- Laboratory for Organic & Microwave-Assisted Chemistry (LOMAC), Department of Chemistry, KU Leuven, Celestijnenlaan 200F, B-3001 Leuven, Belgium
| | - Jozef Vanderleyden
- Centre of Microbial and Plant Genetics (CMPG), Department of Microbial and Molecular Systems, KU Leuven, Kasteelpark Arenberg 20, Box 2460, B-3001 Leuven, Belgium
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17
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Bolhuis A, Aldrich-Wright JR. DNA as a target for antimicrobials. Bioorg Chem 2014; 55:51-9. [DOI: 10.1016/j.bioorg.2014.03.009] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2014] [Revised: 03/22/2014] [Accepted: 03/24/2014] [Indexed: 11/28/2022]
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18
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Martinez E, Cantet F, Fava L, Norville I, Bonazzi M. Identification of OmpA, a Coxiella burnetii protein involved in host cell invasion, by multi-phenotypic high-content screening. PLoS Pathog 2014; 10:e1004013. [PMID: 24651569 PMCID: PMC3961360 DOI: 10.1371/journal.ppat.1004013] [Citation(s) in RCA: 95] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2013] [Accepted: 02/04/2014] [Indexed: 01/22/2023] Open
Abstract
Coxiella burnetii is the agent of the emerging zoonosis Q fever. This pathogen invades phagocytic and non-phagocytic cells and uses a Dot/Icm secretion system to co-opt the endocytic pathway for the biogenesis of an acidic parasitophorous vacuole where Coxiella replicates in large numbers. The study of the cell biology of Coxiella infections has been severely hampered by the obligate intracellular nature of this microbe, and Coxiella factors involved in host/pathogen interactions remain to date largely uncharacterized. Here we focus on the large-scale identification of Coxiella virulence determinants using transposon mutagenesis coupled to high-content multi-phenotypic screening. We have isolated over 3000 Coxiella mutants, 1082 of which have been sequenced, annotated and screened. We have identified bacterial factors that regulate key steps of Coxiella infections: 1) internalization within host cells, 2) vacuole biogenesis/intracellular replication, and 3) protection of infected cells from apoptosis. Among these, we have investigated the role of Dot/Icm core proteins, determined the role of candidate Coxiella Dot/Icm substrates previously identified in silico and identified additional factors that play a relevant role in Coxiella pathogenesis. Importantly, we have identified CBU_1260 (OmpA) as the first Coxiella invasin. Mutations in ompA strongly decreased Coxiella internalization and replication within host cells; OmpA-coated beads adhered to and were internalized by non-phagocytic cells and the ectopic expression of OmpA in E. coli triggered its internalization within cells. Importantly, Coxiella internalization was efficiently inhibited by pretreating host cells with purified OmpA or by incubating Coxiella with a specific anti-OmpA antibody prior to host cell infection, suggesting the presence of a cognate receptor at the surface of host cells. In summary, we have developed multi-phenotypic assays for the study of host/pathogen interactions. By applying our methods to Coxiella burnetii, we have identified the first Coxiella protein involved in host cell invasion. Infectious diseases are among the major causes of mortality worldwide. Pathogens‚ invasion, colonization and persistence within their hosts depend on a tightly orchestrated cascade of events that are commonly referred to as host/pathogen interactions. These interactions are extremely diversified and every pathogen is characterized by its unique way of co-opting and manipulating host functions to its advantage. Understanding host/pathogen interactions is the key to face the threats imposed by infectious diseases and find alternative strategies to fight the emergence of multi-drug resistant pathogens. In this study, we have setup and validated a protocol for the rapid and unbiased identification of bacterial factors that regulate host/pathogen interactions. We have applied this method to the study of Coxiella burnetii, the etiological agent of the emerging zoonosis Q fever. We have isolated, sequenced and screened over 1000 bacterial mutations and identified genes important for Coxiella invasion and replication within host cells. Ultimately, we have characterized the first Coxiella invasin, which mediates bacterial internalization within non-phagocytic cells. Most importantly, our finding may lead to the development of a synthetic vaccine against Q fever.
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Affiliation(s)
- Eric Martinez
- CNRS, UMR5236, CPBS, Montpellier, France
- Université Montpellier 1, CPBS, Montpellier, France
- Université Montpellier 2, CPBS, Montpellier, France
| | - Franck Cantet
- CNRS, UMR5236, CPBS, Montpellier, France
- Université Montpellier 1, CPBS, Montpellier, France
- Université Montpellier 2, CPBS, Montpellier, France
| | - Laura Fava
- CNRS, UMR5236, CPBS, Montpellier, France
- Université Montpellier 1, CPBS, Montpellier, France
- Université Montpellier 2, CPBS, Montpellier, France
| | - Isobel Norville
- Defence Science and Technology Laboratory, Porton Down, United Kingdom
| | - Matteo Bonazzi
- CNRS, UMR5236, CPBS, Montpellier, France
- Université Montpellier 1, CPBS, Montpellier, France
- Université Montpellier 2, CPBS, Montpellier, France
- * E-mail:
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19
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Meijer AH, van der Vaart M, Spaink HP. Real-time imaging and genetic dissection of host-microbe interactions in zebrafish. Cell Microbiol 2013; 16:39-49. [DOI: 10.1111/cmi.12236] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2013] [Revised: 10/15/2013] [Accepted: 10/16/2013] [Indexed: 12/29/2022]
Affiliation(s)
- Annemarie H. Meijer
- Institute of Biology; Leiden University; Einsteinweg 55, 2333 CC Leiden The Netherlands
| | - Michiel van der Vaart
- Institute of Biology; Leiden University; Einsteinweg 55, 2333 CC Leiden The Netherlands
| | - Herman P. Spaink
- Institute of Biology; Leiden University; Einsteinweg 55, 2333 CC Leiden The Netherlands
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20
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Model casting. Microbes Infect 2013; 15:535-9. [DOI: 10.1016/j.micinf.2013.06.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2013] [Accepted: 06/05/2013] [Indexed: 11/23/2022]
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21
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Lavigne JP, Audibert S, Molinari N, O'Callaghan D, Keriel A. Influence of a high-glucose diet on the sensitivity of Caenorhabditis elegans towards Escherichia coli and Staphylococcus aureus strains. Microbes Infect 2013; 15:540-9. [PMID: 23639525 DOI: 10.1016/j.micinf.2013.04.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2012] [Revised: 04/17/2013] [Accepted: 04/18/2013] [Indexed: 11/17/2022]
Abstract
It was recently observed that a glucose-enriched diet activates the insulin-like pathway in Caenorhabditis elegans, resulting in an inhibition of the FOXO transcription factor DAF-16. Because this signalling pathway is highly conserved from invertebrates to mammals and DAF-16 is a key player in innate immunity, we wondered whether a high-glucose diet, resembling the hyperglycaemic conditions in diabetic patients, would affect the susceptibility of C. elegans to bacterial pathogens isolated from different clinical situations (urinary tract or diabetic foot infections). We confirmed previous reports showing that such a diet decreases the lifespan of C. elegans fed with an avirulent Escherichia coli strain. However, glucose-fed nematodes appeared to be more resistant to most clinical isolates tested, showing that this invertebrate model does not mimic infections encountered in human diabetes, where patients show increased susceptibility to bacterial infections. This study also suggests that modulation of innate immunity in C. elegans, upon activation of the IGF1/insulin-like pathway by glucose, is not exclusively mediated by DAF-16, but also involves an additional factor that requires DAF-16 activity.
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Affiliation(s)
- Jean-Philippe Lavigne
- Inserm U1047, UFR Médecine, 186 Chemin de Carreau de Lanes, 30908 Nîmes Cedex 2, France
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22
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Abstract
The animal and bacterial kingdoms have coevolved and coadapted in response to environmental selective pressures over hundreds of millions of years. The meta'omics revolution in both sequencing and its analytic pipelines is fostering an explosion of interest in how the gut microbiome impacts physiology and propensity to disease. Gut microbiome studies are inherently interdisciplinary, drawing on approaches and technical skill sets from the biomedical sciences, ecology, and computational biology. Central to unraveling the complex biology of environment, genetics, and microbiome interaction in human health and disease is a deeper understanding of the symbiosis between animals and bacteria. Experimental model systems, including mice, fish, insects, and the Hawaiian bobtail squid, continue to provide critical insight into how host-microbiota homeostasis is constructed and maintained. Here we consider how model systems are influencing current understanding of host-microbiota interactions and explore recent human microbiome studies.
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Affiliation(s)
- Aleksandar D. Kostic
- Harvard School of Public Health, Boston, Massachusetts 02115, USA
- Harvard Medical School, Boston, Massachusetts 02115, USA
- Dana-Farber Cancer Institute, Boston, Massachusetts 02115, USA
- The Broad Institute of Harvard and Massachusetts Institute of Technology, Boston, Massachusetts 02141, USA
| | - Michael R. Howitt
- Harvard School of Public Health, Boston, Massachusetts 02115, USA
- Harvard Medical School, Boston, Massachusetts 02115, USA
- Dana-Farber Cancer Institute, Boston, Massachusetts 02115, USA
| | - Wendy S. Garrett
- Harvard School of Public Health, Boston, Massachusetts 02115, USA
- Harvard Medical School, Boston, Massachusetts 02115, USA
- Dana-Farber Cancer Institute, Boston, Massachusetts 02115, USA
- The Broad Institute of Harvard and Massachusetts Institute of Technology, Boston, Massachusetts 02141, USA
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23
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Evaluating the pathogenic potential of environmental Escherichia coli by using the Caenorhabditis elegans infection model. Appl Environ Microbiol 2013; 79:2435-45. [PMID: 23377948 DOI: 10.1128/aem.03501-12] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
The detection and abundance of Escherichia coli in water is used to monitor and mandate the quality of drinking and recreational water. Distinguishing commensal waterborne E. coli isolates from those that cause diarrhea or extraintestinal disease in humans is important for quantifying human health risk. A DNA microarray was used to evaluate the distribution of virulence genes in 148 E. coli environmental isolates from a watershed in eastern Ontario, Canada, and in eight clinical isolates. Their pathogenic potential was evaluated with Caenorhabditis elegans, and the concordance between the bioassay result and the pathotype deduced by genotyping was explored. Isolates identified as potentially pathogenic on the basis of their complement of virulence genes were significantly more likely to be pathogenic to C. elegans than those determined to be potentially nonpathogenic. A number of isolates that were identified as nonpathogenic on the basis of genotyping were pathogenic in the infection assay, suggesting that genotyping did not capture all potentially pathogenic types. The detection of the adhesin-encoding genes sfaD, focA, and focG, which encode adhesins; of iroN2, which encodes a siderophore receptor; of pic, which encodes an autotransporter protein; and of b1432, which encodes a putative transposase, was significantly associated with pathogenicity in the infection assay. Overall, E. coli isolates predicted to be pathogenic on the basis of genotyping were indeed so in the C. elegans infection assay. Furthermore, the detection of C. elegans-infective environmental isolates predicted to be nonpathogenic on the basis of genotyping suggests that there are hitherto-unrecognized virulence factors or combinations thereof that are important in the establishment of infection.
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24
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Castillo JC, Shokal U, Eleftherianos I. A novel method for infecting Drosophila adult flies with insect pathogenic nematodes. Virulence 2012; 3:339-47. [PMID: 22546901 DOI: 10.4161/viru.20244] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Drosophila has been established as an excellent genetic and genomic model to investigate host-pathogen interactions and innate immune defense mechanisms. To date, most information on the Drosophila immune response derives from studies that involve bacterial, fungal or viral pathogens. However, immune reactions to insect parasitic nematodes are still not well characterized. The nematodes Heterorhabditis bacteriophora live in symbiosis with the entomopathogenic bacteria Photorhabdus luminescens, and they are able to invade and kill insects. Interestingly, Heterorhabditis nematodes are viable in the absence of Photorhabdus. Techniques for infecting Drosophila larvae with these nematodes have been previously reported. Here, we have developed a method for infecting Drosophila adult flies with Heterorhabditis nematodes carrying (symbiotic worms) or lacking (axenic worms) their associated bacteria. The protocol we present can be readily adapted for studying parasitic strategies of other insect nematodes using Drosophila as the host infection model.
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Affiliation(s)
- Julio Cesar Castillo
- Insect Infection and Immunity Lab, Department of Biological Sciences, The George Washington University, Washington, DC, USA
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25
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Ott L, McKenzie A, Baltazar MT, Britting S, Bischof A, Burkovski A, Hoskisson PA. Evaluation of invertebrate infection models for pathogenic corynebacteria. ACTA ACUST UNITED AC 2012; 65:413-21. [PMID: 22443092 DOI: 10.1111/j.1574-695x.2012.00963.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2011] [Revised: 03/08/2012] [Accepted: 03/09/2012] [Indexed: 02/02/2023]
Abstract
For several pathogenic bacteria, model systems for host-pathogen interactions were developed, which provide the possibility of quick and cost-effective high throughput screening of mutant bacteria for genes involved in pathogenesis. A number of different model systems, including amoeba, nematodes, insects, and fish, have been introduced, and it was observed that different bacteria respond in different ways to putative surrogate hosts, and distinct model systems might be more or less suitable for a certain pathogen. The aim of this study was to develop a suitable invertebrate model for the human and animal pathogens Corynebacterium diphtheriae, Corynebacterium pseudotuberculosis, and Corynebacterium ulcerans. The results obtained in this study indicate that Acanthamoeba polyphaga is not optimal as surrogate host, while both Caenorhabtitis elegans and Galleria larvae seem to offer tractable models for rapid assessment of virulence between strains. Caenorhabtitis elegans gives more differentiated results and might be the best model system for pathogenic corynebacteria, given the tractability of bacteria and the range of mutant nematodes available to investigate the host response in combination with bacterial virulence. Nevertheless, Galleria will also be useful in respect to innate immune responses to pathogens because insects offer a more complex cell-based innate immune system compared with the simple innate immune system of C. elegans.
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Affiliation(s)
- Lisa Ott
- Lehrstuhl für Mikrobiologie, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
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26
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Lavigne JP, Vergunst AC, Goret L, Sotto A, Combescure C, Blanco J, O'Callaghan D, Nicolas-Chanoine MH. Virulence potential and genomic mapping of the worldwide clone Escherichia coli ST131. PLoS One 2012; 7:e34294. [PMID: 22457832 PMCID: PMC3311635 DOI: 10.1371/journal.pone.0034294] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2011] [Accepted: 02/27/2012] [Indexed: 11/19/2022] Open
Abstract
Recently, the worldwide propagation of clonal CTX-M-15-producing Escherichia coli isolates, namely ST131 and O25b:H4, has been reported. Like the majority of extra-intestinal pathogenic E. coli isolates, the pandemic clone ST131 belongs to phylogenetic group B2, and has recently been shown to be highly virulent in a mouse model, even though it lacks several genes encoding key virulence factors (Pap, Cnf1 and HlyA). Using two animal models, Caenorhabditis elegans and zebrafish embryos, we assessed the virulence of three E. coli ST131 strains (2 CTX-M-15- producing urine and 1 non-ESBL-producing faecal isolate), comparing them with five non-ST131 B2 and a group A uropathogenic E. coli (UPEC). In C. elegans, the three ST131 strains showed intermediate virulence between the non virulent group A isolate and the virulent non-ST131 B2 strains. In zebrafish, the CTX-M-15-producing ST131 UPEC isolates were also less virulent than the non-ST131 B2 strains, suggesting that the production of CTX-M-15 is not correlated with enhanced virulence. Amongst the non-ST131 B2 group isolates, variation in pathogenic potential in zebrafish embryos was observed ranging from intermediate to highly virulent. Interestingly, the ST131 strains were equally persistent in surviving embryos as the non-ST131-group B2 strains, suggesting similar mechanisms may account for development of persistent infection. Optical maps of the genome of the ST131 strains were compared with those of 24 reference E. coli strains. Although small differences were seen within the ST131 strains, the tree built on the optical maps showed that these strains belonged to a specific cluster (86% similarity) with only 45% similarity with the other group B2 strains and 25% with strains of group A and D. Thus, the ST131 clone has a genetic composition that differs from other group B2 strains, and appears to be less virulent than previously suspected.
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Affiliation(s)
- Jean-Philippe Lavigne
- Institut National de la Santé et de la Recherche Médicale, U1047, UFR Médecine, Université Montpellier 1, Nîmes, France.
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Fuchs TM, Eisenreich W, Heesemann J, Goebel W. Metabolic adaptation of human pathogenic and related nonpathogenic bacteria to extra- and intracellular habitats. FEMS Microbiol Rev 2012; 36:435-62. [DOI: 10.1111/j.1574-6976.2011.00301.x] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2010] [Accepted: 07/21/2011] [Indexed: 01/02/2023] Open
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28
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McMullan R, Anderson A, Nurrish S. Behavioral and immune responses to infection require Gαq- RhoA signaling in C. elegans. PLoS Pathog 2012; 8:e1002530. [PMID: 22359503 PMCID: PMC3280986 DOI: 10.1371/journal.ppat.1002530] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2011] [Accepted: 12/28/2011] [Indexed: 11/18/2022] Open
Abstract
Following pathogen infection the hosts' nervous and immune systems react with coordinated responses to the danger. A key question is how the neuronal and immune responses to pathogens are coordinated, are there common signaling pathways used by both responses? Using C. elegans we show that infection by pathogenic strains of M. nematophilum, but not exposure to avirulent strains, triggers behavioral and immune responses both of which require a conserved Gαq-RhoGEF Trio-Rho signaling pathway. Upon infection signaling by the Gαq pathway within cholinergic motorneurons is necessary and sufficient to increase release of the neurotransmitter acetylcholine and increase locomotion rates and these behavioral changes result in C. elegans leaving lawns of M. nematophilum. In the immune response to infection signaling by the Gαq pathway within rectal epithelial cells is necessary and sufficient to cause changes in cell morphology resulting in tail swelling that limits the infection. These Gαq mediated behavioral and immune responses to infection are separate, act in a cell autonomous fashion and activation of this pathway in the appropriate cells can trigger these responses in the absence of infection. Within the rectal epithelium the Gαq signaling pathway cooperates with a Ras signaling pathway to activate a Raf-ERK-MAPK pathway to trigger the cell morphology changes, whereas in motorneurons Gαq signaling triggers behavioral responses independent of Ras signaling. Thus, a conserved Gαq pathway cooperates with cell specific factors in the nervous and immune systems to produce appropriate responses to pathogen. Thus, our data suggests that ligands for Gq coupled receptors are likely to be part of the signals generated in response to M. nematophilum infection. Once infected by a pathogen the nervous and immune systems of many animals react with coordinated responses to the danger. A key question is what are the pathways by which responses to infection occur and to what extent are the same pathways involved in differing responses? Here we demonstrate that a Gαq-RhoA pathway is required for both behavioral and immune responses to infection in C. elegans. We show that Gαq-RhoA signaling is a late step in the response to infection and their site of action defines the cellular targets of signals generated internally in response to infection. One response is to move away from sites of pathogenic bacteria and Gαq-RhoA signaling acts in motorneurons to achieve this. A second response is an innate immune response where Gαq-RhoA signaling acts within cells close to sites of infection, the rectal epithelial cells, to cause major changes in their size and shape to mitigate the effects of infection. Our work demonstrates that ligands for Gq coupled GPCRs are likely to be required for response to infection. Identifying these ligands and the cells that release them will help define the mechanisms by which C. elegans recognizes pathogens and coordinates behavioral and immune responses to infection.
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Affiliation(s)
- Rachel McMullan
- MRC Cell Biology Unit, MRC Laboratory for Molecular Cell Biology and Department of Neuroscience, Physiology and Pharmacology, University College London, London, United Kingdom
- Division of Cell and Molecular Biology, Department of Life Sciences, Imperial College London, South Kensington Campus, London, United Kingdom
- * E-mail: (RM); (SN)
| | - Alexandra Anderson
- Division of Cell and Molecular Biology, Department of Life Sciences, Imperial College London, South Kensington Campus, London, United Kingdom
| | - Stephen Nurrish
- MRC Cell Biology Unit, MRC Laboratory for Molecular Cell Biology and Department of Neuroscience, Physiology and Pharmacology, University College London, London, United Kingdom
- * E-mail: (RM); (SN)
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Of model hosts and man: using Caenorhabditis elegans, Drosophila melanogaster and Galleria mellonella as model hosts for infectious disease research. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2012; 710:11-7. [PMID: 22127881 DOI: 10.1007/978-1-4419-5638-5_2] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The use of invertebrate model hosts has increased in popularity due to numerous advantages of invertebrates over mammalian models, including ethical, logistical and budgetary features. This review provides an introduction to three model hosts, the nematode Caenorhabditis elegans, the fruit fly Drosophila melanogaster and the larvae of Galleria mellonella, the greater wax moth. It highlights principal experimental advantages of each model, for C. elegans the ability to run high-throughput assays, for D. melanogaster the evolutionarily conserved innate immune response, and for G. mellonella the ability to conduct experiments at 37°C and easily inoculate a precise quantity of pathogen. It additionally discusses recent research that has been conducted with each host to identify pathogen virulence factors, study the immune response, and evaluate potential antimicrobial compounds, focusing principally on fungal pathogens.
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Krause-Heuer AM, Leverett P, Bolhuis A, Aldrich-Wright JR. Copper(II) and Palladium(II) Complexes with Cytotoxic and Antibacterial Activity. Aust J Chem 2012. [DOI: 10.1071/ch12058] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The synthesis of eight square pyramidal copper complexes with general structure [Cu(IL)(AL)H2O]2+, where IL represents various methylated 1,10-phenanthrolines, and AL represents either 1S,2S- or 1R,2R-diaminocyclohexane, is reported, with the complexes synthesised as both the perchlorate and chloride salts. The crystal structures of [Cu(1,10-phenanthroline)(1S,2S-diaminocyclohexane](ClO4)2·H2O and [Cu(5,6-dimethyl-1,10-phenanthroline)(1S,2S-diaminocyclohexane](ClO4)2·1.5H2O are reported. Four square planar palladium complexes with general structure [Pd(IL)(AL)]Cl2 have also been synthesised. These complexes were synthesised in order to investigate the structure–activity relationship against both cancer cell lines and bacterial cultures. The copper complexes display anticancer activity similar to cisplatin and 1,10-phenanthroline (phen) in the L1210 murine leukaemia cell line. Methylation of the phen increased the copper complex cytotoxicity by approximately four-fold, compared with the non-methylated complex. No significant difference in activity was observed by altering the chirality of the diaminocyclohexane ligand. The copper complexes demonstrated antibacterial activity against Bacillus subtilis, Staphylococcus aureus, and Escherichia coli; however, high levels of toxicity (30–60 % of death) were observed in the nematode Caenorhabditis elegans. The copper complexes have also been shown to act as DNA nucleases, with the ability to cleave plasmid DNA in the presence of hydrogen peroxide. The palladium complexes all have half maximal inhibitory concentration (IC50) values of ~10 μM in the L1210 cell line, with no significant difference in the cytotoxicity of any of the compounds tested. Minimal antibacterial activity of the palladium complexes was observed.
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Bolhuis A, Hand L, Marshall JE, Richards AD, Rodger A, Aldrich-Wright J. Antimicrobial activity of ruthenium-based intercalators. Eur J Pharm Sci 2011; 42:313-7. [DOI: 10.1016/j.ejps.2010.12.004] [Citation(s) in RCA: 97] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2010] [Revised: 12/07/2010] [Accepted: 12/12/2010] [Indexed: 10/18/2022]
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Coenye T, Nelis HJ. In vitro and in vivo model systems to study microbial biofilm formation. J Microbiol Methods 2010; 83:89-105. [DOI: 10.1016/j.mimet.2010.08.018] [Citation(s) in RCA: 251] [Impact Index Per Article: 17.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2010] [Revised: 08/19/2010] [Accepted: 08/23/2010] [Indexed: 12/23/2022]
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