1
|
Nolan LM, Turnbull L, Katrib M, Osvath SR, Losa D, Lazenby JJ, Whitchurch CB. Pseudomonas aeruginosa is capable of natural transformation in biofilms. Microbiology (Reading) 2020; 166:995-1003. [PMID: 32749953 PMCID: PMC7660920 DOI: 10.1099/mic.0.000956] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Accepted: 07/11/2020] [Indexed: 12/28/2022]
Abstract
Natural transformation is a mechanism that enables competent bacteria to acquire naked, exogenous DNA from the environment. It is a key process that facilitates the dissemination of antibiotic resistance and virulence determinants throughout bacterial populations. Pseudomonas aeruginosa is an opportunistic Gram-negative pathogen that produces large quantities of extracellular DNA (eDNA) that is required for biofilm formation. P. aeruginosa has a remarkable level of genome plasticity and diversity that suggests a high degree of horizontal gene transfer and recombination but is thought to be incapable of natural transformation. Here we show that P. aeruginosa possesses homologues of all proteins known to be involved in natural transformation in other bacterial species. We found that P. aeruginosa in biofilms is competent for natural transformation of both genomic and plasmid DNA. Furthermore, we demonstrate that type-IV pili (T4P) facilitate but are not absolutely essential for natural transformation in P. aeruginosa.
Collapse
Affiliation(s)
- Laura M. Nolan
- The ithree institute, University of Technology Sydney, Ultimo, New South Wales, 2007, Australia
- National Heart and Lung Institute, Imperial College London, London, SW3 6LR, UK
| | - Lynne Turnbull
- The ithree institute, University of Technology Sydney, Ultimo, New South Wales, 2007, Australia
| | - Marilyn Katrib
- The ithree institute, University of Technology Sydney, Ultimo, New South Wales, 2007, Australia
| | - Sarah R. Osvath
- The ithree institute, University of Technology Sydney, Ultimo, New South Wales, 2007, Australia
| | - Davide Losa
- The ithree institute, University of Technology Sydney, Ultimo, New South Wales, 2007, Australia
- Present address: Department of Cellular, Computational and Integrative Biology (CIBIO), University of Trento, Trento, TN 38123, Italy
| | - James J. Lazenby
- Microbes in the Food Chain Programme, Quadram Institute Bioscience, Norwich Research Park, Norwich, NR4 7UQ, UK
| | - Cynthia B. Whitchurch
- The ithree institute, University of Technology Sydney, Ultimo, New South Wales, 2007, Australia
- Microbes in the Food Chain Programme, Quadram Institute Bioscience, Norwich Research Park, Norwich, NR4 7UQ, UK
- School of Biological Sciences, University of East Anglia, Norwich, NR4 7TJ, UK
| |
Collapse
|
2
|
Nolan LM, Whitchurch CB, Barquist L, Katrib M, Boinett CJ, Mayho M, Goulding D, Charles IG, Filloux A, Parkhill J, Cain AK. A global genomic approach uncovers novel components for twitching motility-mediated biofilm expansion in Pseudomonas aeruginosa. Microb Genom 2018; 4. [PMID: 30383525 PMCID: PMC6321873 DOI: 10.1099/mgen.0.000229] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Pseudomonas aeruginosa is an extremely successful pathogen able to cause both acute and chronic infections in a range of hosts, utilizing a diverse arsenal of cell-associated and secreted virulence factors. A major cell-associated virulence factor, the Type IV pilus (T4P), is required for epithelial cell adherence and mediates a form of surface translocation termed twitching motility, which is necessary to establish a mature biofilm and actively expand these biofilms. P. aeruginosa twitching motility-mediated biofilm expansion is a coordinated, multicellular behaviour, allowing cells to rapidly colonize surfaces, including implanted medical devices. Although at least 44 proteins are known to be involved in the biogenesis, assembly and regulation of the T4P, with additional regulatory components and pathways implicated, it is unclear how these components and pathways interact to control these processes. In the current study, we used a global genomics-based random-mutagenesis technique, transposon directed insertion-site sequencing (TraDIS), coupled with a physical segregation approach, to identify all genes implicated in twitching motility-mediated biofilm expansion in P. aeruginosa. Our approach allowed identification of both known and novel genes, providing new insight into the complex molecular network that regulates this process in P. aeruginosa. Additionally, our data suggest that the flagellum-associated gene products have a differential effect on twitching motility, based on whether components are intra- or extracellular. Overall the success of our TraDIS approach supports the use of this global genomic technique for investigating virulence genes in bacterial pathogens.
Collapse
Affiliation(s)
- Laura M Nolan
- 1MRC Centre for Molecular Bacteriology and Infection (CMBI), Department of Life Sciences, Imperial College London, London SW7 2AZ, UK
| | - Cynthia B Whitchurch
- 2The ithree Institute, University of Technology Sydney, Ultimo, NSW 2007, Australia
| | - Lars Barquist
- 3Institute for Molecular Infection Biology, University of Würzburg, Würzburg D-97080, Germany.,4Helmholtz Institute for RNA-based Infection Research (HIRI), Würzburg, Germany
| | - Marilyn Katrib
- 2The ithree Institute, University of Technology Sydney, Ultimo, NSW 2007, Australia
| | - Christine J Boinett
- 5Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridge, UK.,†Present address: Hospital for Tropical Diseases, Wellcome Trust Major Overseas Programme, Oxford University Clinical Research Unit, Ho Chi Minh City, Vietnam
| | - Matthew Mayho
- 5Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridge, UK
| | - David Goulding
- 5Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridge, UK
| | - Ian G Charles
- 6Quadram Institute of Bioscience, Norwich Research Park, Norwich, Norfolk NR4 7UA, UK
| | - Alain Filloux
- 1MRC Centre for Molecular Bacteriology and Infection (CMBI), Department of Life Sciences, Imperial College London, London SW7 2AZ, UK
| | - Julian Parkhill
- 5Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridge, UK
| | - Amy K Cain
- 5Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, Cambridge, UK.,‡Present address: Chemical and Biomolecular Sciences, Macquarie University, Sydney, NSW, Australia
| |
Collapse
|
3
|
Katrib M, Ikin RJ, Brossier F, Robinson M, Slapetova I, Sharman PA, Walker RA, Belli SI, Tomley FM, Smith NC. Stage-specific expression of protease genes in the apicomplexan parasite, Eimeria tenella. BMC Genomics 2012; 13:685. [PMID: 23216867 PMCID: PMC3770453 DOI: 10.1186/1471-2164-13-685] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2012] [Accepted: 12/04/2012] [Indexed: 12/28/2022] Open
Abstract
Background Proteases regulate pathogenesis in apicomplexan parasites but investigations of proteases have been largely confined to the asexual stages of Plasmodium falciparum and Toxoplasma gondii. Thus, little is known about proteases in other Apicomplexa, particularly in the sexual stages. We screened the Eimeria tenella genome database for proteases, classified these into families and determined their stage specific expression. Results Over forty protease genes were identified in the E. tenella genome. These were distributed across aspartic (three genes), cysteine (sixteen), metallo (fourteen) and serine (twelve) proteases. Expression of at least fifteen protease genes was upregulated in merozoites including homologs of genes known to be important in host cell invasion, remodelling and egress in P. falciparum and/or T. gondii. Thirteen protease genes were specifically expressed or upregulated in gametocytes; five of these were in two families of serine proteases (S1 and S8) that are over-represented in the coccidian parasites, E. tenella and T. gondii, distinctive within the Apicomplexa because of their hard-walled oocysts. Serine protease inhibitors prevented processing of EtGAM56, a protein from E. tenella gametocytes that gives rise to tyrosine-rich peptides that are incorporated into the oocyst wall. Conclusion Eimeria tenella possesses a large number of protease genes. Expression of many of these genes is upregulated in asexual stages. However, expression of almost one-third of protease genes is upregulated in, or confined to gametocytes; some of these appear to be unique to the Coccidia and may play key roles in the formation of the oocyst wall, a defining feature of this group of parasites.
Collapse
Affiliation(s)
- Marilyn Katrib
- Institute for the Biotechnology of Infectious Diseases, University of Technology, Sydney, Broadway, N.S.W. 2007, Australia
| | | | | | | | | | | | | | | | | | | |
Collapse
|
4
|
Rieux A, Gras S, Lecaille F, Niepceron A, Katrib M, Smith NC, Lalmanach G, Brossier F. Eimeripain, a cathepsin B-like cysteine protease, expressed throughout sporulation of the apicomplexan parasite Eimeria tenella. PLoS One 2012; 7:e31914. [PMID: 22457711 PMCID: PMC3310820 DOI: 10.1371/journal.pone.0031914] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2011] [Accepted: 01/17/2012] [Indexed: 11/29/2022] Open
Abstract
The invasion and replication of Eimeria tenella in the chicken intestine is responsible for avian coccidiosis, a disease that has major economic impacts on poultry industries worldwide. E. tenella is transmitted to naïve animals via shed unsporulated oocysts that need contact with air and humidity to form the infectious sporulated oocysts, which contain the first invasive form of the parasite, the sporozoite. Cysteine proteases (CPs) are major virulence factors expressed by protozoa. In this study, we show that E. tenella expresses five transcriptionally regulated genes encoding one cathepsin L, one cathepsin B and three cathepsin Cs. Biot-LC-LVG-CHN2, a cystatin derived probe, tagged eight polypeptides in unsporulated oocysts but only one in sporulated oocysts. CP-dependant activities were found against the fluorescent substrates, Z-FR-AMC and Z-LR-AMC, throughout the sporulation process. These activities corresponded to a cathepsin B-like enzyme since they were inhibited by CA-074, a specific cathepsin B inhibitor. A 3D model of the catalytic domain of the cathepsin B-like protease, based on its sequence homology with human cathepsin B, further confirmed its classification as a papain-like protease with similar characteristics to toxopain-1 from the related apicomplexan parasite, Toxoplasma gondii; we have, therefore, named the E. tenella cathepsin B, eimeripain. Following stable transfection of E. tenella sporozoites with a plasmid allowing the expression of eimeripain fused to the fluorescent protein mCherry, we demonstrated that eimeripain is detected throughout sporulation and has a punctate distribution in the bodies of extra- and intracellular parasites. Furthermore, CA-074 Me, the membrane-permeable derivative of CA-074, impairs invasion of epithelial MDBK cells by E. tenella sporozoites. This study represents the first characterization of CPs expressed by a parasite from the Eimeria genus. Moreover, it emphasizes the role of CPs in transmission and dissemination of exogenous stages of apicomplexan parasites.
Collapse
Affiliation(s)
- Anaïs Rieux
- INRA, UMR1282, Equipe Pathogenèse des Coccidioses, Infectiologie et Santé Publique, Nouzilly, France
- Université François Rabelais de Tours, UMR1282, Infectiologie et Santé Publique, Tours, France
| | - Simon Gras
- INRA, UMR1282, Equipe Pathogenèse des Coccidioses, Infectiologie et Santé Publique, Nouzilly, France
- Université François Rabelais de Tours, UMR1282, Infectiologie et Santé Publique, Tours, France
| | - Fabien Lecaille
- INSERM U618, Protéases et Vectorisation Pulmonaires, Université François Rabelais, Tours, France
| | - Alisson Niepceron
- INRA, UMR1282, Equipe Pathogenèse des Coccidioses, Infectiologie et Santé Publique, Nouzilly, France
- Université François Rabelais de Tours, UMR1282, Infectiologie et Santé Publique, Tours, France
| | - Marilyn Katrib
- Institute for the Biotechnology of Infectious Diseases, University of Technology, Sydney, Australia
| | - Nicholas C. Smith
- Queensland Tropical Health Alliance, Faculty of Medicine, Health and Molecular Sciences, James Cook University, Cairns, Australia
| | - Gilles Lalmanach
- INSERM U618, Protéases et Vectorisation Pulmonaires, Université François Rabelais, Tours, France
| | - Fabien Brossier
- INRA, UMR1282, Equipe Pathogenèse des Coccidioses, Infectiologie et Santé Publique, Nouzilly, France
- Université François Rabelais de Tours, UMR1282, Infectiologie et Santé Publique, Tours, France
- * E-mail:
| |
Collapse
|
5
|
Mai K, Smith NC, Feng ZP, Katrib M, Šlapeta J, Šlapetova I, Wallach MG, Luxford C, Davies MJ, Zhang X, Norton RS, Belli SI. Peroxidase catalysed cross-linking of an intrinsically unstructured protein via dityrosine bonds in the oocyst wall of the apicomplexan parasite, Eimeria maxima. Int J Parasitol 2011; 41:1157-64. [DOI: 10.1016/j.ijpara.2011.07.001] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2011] [Revised: 06/30/2011] [Accepted: 07/02/2011] [Indexed: 10/18/2022]
|
6
|
Miller CM, Zakrzewski AM, Ikin RJ, Boulter NR, Katrib M, Lees MP, Fuller SJ, Wiley JS, Smith NC. Dysregulation of the inflammatory response to the parasite, Toxoplasma gondii, in P2X7 receptor-deficient mice. Int J Parasitol 2010; 41:301-8. [PMID: 21044631 DOI: 10.1016/j.ijpara.2010.10.001] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2010] [Accepted: 10/04/2010] [Indexed: 12/18/2022]
Abstract
The P2X(7) receptor (P2X(7)R) is a two transmembrane receptor that is highly expressed on the surface of immune cells. Loss of function polymorphisms in this receptor have been linked to increased susceptibility to intracellular pathogens. P2X(7)R gene knockout (P2X(7)R(-/-); on a C57Bl/6J background), C57Bl/6J and BALB/c mice were infected with the avirulent ME49 strain of the intracellular parasite, Toxoplasma gondii, and susceptibility determined by monitoring weight loss. P2X(7)R(-/-) mice lost significantly more weight than C57Bl/6J mice from day 8p.i. C57Bl/6J, in turn, lost significantly more weight than BALB/c mice. Thus, by day 10p.i., P2X(7)R(-/-) mice had lost 5.7 ± 0.7% of their weight versus 2.4 ± 0.6% for C57Bl/6J mice, whereas BALB/c mice had gained 1.9 ± 0.5%; by day 12p.i., P2X(7)R(-/-) mice had lost 15.1±0.6%, C57Bl/6J had lost 10.1±0.8% and BALB/c had lost 4.8 ± 0.8% of their weight. Neither parasite burden nor liver pathology was greater in the P2X(7)R(-/-) mice than in C57Bl/6J mice but BALB/c mice had significantly smaller numbers of parasites and less pathology in their livers than these strains. Absence of the P2X(7) receptor did not affect IFN-γ, IL-12, IL-1β, monocyte chemoattractant protein-1 (MCP-1) or TNF production. However, both P2X(7)R(-/-) and C57Bl/6J mice produced more IL-1β and TNF than BALB/c mice. There was one important point of differentiation between the P2X(7)R(-/-) and C57Bl/6J mice, namely the significantly enhanced and prolonged production of nitric oxide, accompanied by delayed production of IL-10 in the P2X(7)R-deficient mice.
Collapse
Affiliation(s)
- Catherine M Miller
- Institute for Biotechnology of Infectious Diseases, University of Technology, Sydney, Broadway, NSW 2007, Australia
| | | | | | | | | | | | | | | | | |
Collapse
|
7
|
Abstract
Eimeria species, of the Phylum Apicomplexa, cause the disease coccidiosis in poultry, resulting in severe economic losses every year. Transmission of the disease is via the faecal-oral route, and is facilitated by intensive rearing conditions in the poultry industry. Additionally, Eimeria has developed drug resistance against most anticoccidials used today, which, along with the public demand for chemical free meat, has lead to the requirement for an effective vaccine strategy. This review focuses on the history and current status of anticoccidial vaccines, and our work in developing the transmission-blocking vaccine, CoxAbic (Netanya, Israel). The vaccine is composed of affinity-purified antigens from the wall-forming bodies of macrogametocytes of Eimeria maxima, which are proteolytically processed and cross-linked via tyrosine residues to form the environmentally resistant oocyst wall. The vaccine is delivered via maternal immunization, where vaccination of laying hens leads to protection of broiler offspring. It has been extensively tested for efficacy and safety in field trials conducted in five countries and involving over 60 million offspring chickens from immunized hens and is currently the only subunit vaccine against any protozoan parasite to reach the marketplace.
Collapse
Affiliation(s)
- P A Sharman
- Institute for the Biotechnology of Infectious Diseases, University of Technology, Sydney, NSW, Australia
| | | | | | | |
Collapse
|
8
|
Mai K, Sharman PA, Walker RA, Katrib M, De Souza D, McConville MJ, Wallach MG, Belli SI, Ferguson DJP, Smith NC. Oocyst wall formation and composition in coccidian parasites. Mem Inst Oswaldo Cruz 2010; 104:281-9. [PMID: 19430654 DOI: 10.1590/s0074-02762009000200022] [Citation(s) in RCA: 83] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2008] [Accepted: 12/04/2009] [Indexed: 11/22/2022] Open
Abstract
The oocyst wall of coccidian parasites is a robust structure that is resistant to a variety of environmental and chemical insults. This resilience allows oocysts to survive for long periods, facilitating transmission from host to host. The wall is bilayered and is formed by the sequential release of the contents of two specialized organelles - wall forming body 1 and wall forming body 2 - found in the macrogametocyte stage of Coccidia. The oocyst wall is over 90% protein but few of these proteins have been studied. One group is cysteine-rich and may be presumed to crosslink via disulphide bridges, though this is yet to be investigated. Another group of wall proteins is rich in tyrosine. These proteins, which range in size from 8-31 kDa, are derived from larger precursors of 56 and 82 kDa found in the wall forming bodies. Proteases may catalyze processing of the precursors into tyrosine-rich peptides, which are then oxidatively crosslinked in a reaction catalyzed by peroxidases. In support of this hypothesis, the oocyst wall has high levels of dityrosine bonds. These dityrosine crosslinked proteins may provide a structural matrix for assembly of the oocyst wall and contribute to its resilience.
Collapse
Affiliation(s)
- Kelly Mai
- Institute for Biotechnology of Infectious Diseases, University of Technology, Sydney, Australia
| | | | | | | | | | | | | | | | | | | |
Collapse
|
9
|
Belli SI, Ferguson DJP, Katrib M, Slapetova I, Mai K, Slapeta J, Flowers SA, Miska KB, Tomley FM, Shirley MW, Wallach MG, Smith NC. Conservation of proteins involved in oocyst wall formation in Eimeria maxima, Eimeria tenella and Eimeria acervulina. Int J Parasitol 2009; 39:1063-70. [PMID: 19477178 PMCID: PMC2726925 DOI: 10.1016/j.ijpara.2009.05.004] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2009] [Revised: 05/18/2009] [Accepted: 05/18/2009] [Indexed: 11/25/2022]
Abstract
Vaccination with proteins from gametocytes of Eimeria maxima protects chickens, via transfer of maternal antibodies, against infection with several species of Eimeria. Antibodies to E. maxima gametocyte proteins recognise proteins in the wall forming bodies of macrogametocytes and oocyst walls of E. maxima, Eimeria tenella and Eimeria acervulina. Homologous genes for two major gametocyte proteins – GAM56 and GAM82 – were found in E. maxima, E. tenella and E. acervulina. Alignment of the predicted protein sequences of these genes reveals that, as well as sharing regions of tyrosine richness, strong homology exists in their amino-terminal regions, where protective antibodies bind. This study confirms the conservation of the roles of GAM56 and GAM82 in oocyst wall formation and shows that antibodies to gametocyte antigens of E. maxima cross-react with homologous proteins in other species, helping to explain cross-species maternal immunity.
Collapse
Affiliation(s)
- Sabina I Belli
- Institute for the Biotechnology of Infectious Diseases, University of Technology, Sydney, NSW 2007, Australia
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
10
|
Belli SI, Mai K, Skene CD, Gleeson MT, Witcombe DM, Katrib M, Finger A, Wallach MG, Smith NC. Characterisation of the antigenic and immunogenic properties of bacterially expressed, sexual stage antigens of the coccidian parasite, Eimeria maxima. Vaccine 2004; 22:4316-25. [PMID: 15474724 DOI: 10.1016/j.vaccine.2004.04.019] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2003] [Revised: 03/12/2004] [Accepted: 04/20/2004] [Indexed: 10/26/2022]
Abstract
Coccidiosis in poultry is caused by the intestinal parasite Eimeria; it causes significant financial losses to the commercial poultry industry worldwide. CoxAbic is the first commercially available subunit vaccine against coccidiosis. The vaccine consists of affinity purified sexual stage (gametocyte) antigens (APGA) isolated from Eimeria maxima. Production of this vaccine is time-consuming and laborious and, therefore, a recombinant subunit vaccine substitute for CoxAbic is desirable. The genes encoding the two immunodominant components of CoxAbic, gam56 and gam82, were cloned into the bacterial expression vector, pTRCHisB, and the proteins expressed and purified. Both recombinant proteins were recognised by protective chicken antibodies that were raised to APGA, by immunoblotting. In a competitive ELISA, a combination of the recombinant proteins inhibited the binding of anti-APGA antibodies to APGA by 76%, which was comparable to the inhibition of 98% observed when APGA was used as the competing protein in the assay. In two breeds of chicken (Australorp and Cobb500), the recombinant proteins alone, or in combination, elicited a dose-dependent, antibody response that recognised APGA by ELISA, and gametocytes by immunoblotting. Together, the results suggested that the development of a recombinant subunit vaccine that maintains the antigenic and immunogenic properties of the native protein vaccine, CoxAbic, is feasible.
Collapse
Affiliation(s)
- Sabina I Belli
- Institute for the Biotechnology of Infectious Diseases, University of Technology, Sydney, Gore Hill, N.S.W. 2065, Australia.
| | | | | | | | | | | | | | | | | |
Collapse
|