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Ma Z, Yu L, Zhou H, Liu T, Xu B, Ma F, Peng J, Fan H. Identification of novel genes expressed during host infection in Streptococcus equi ssp. zooepidemicus ATCC35246. Microb Pathog 2015; 79:31-40. [PMID: 25595678 DOI: 10.1016/j.micpath.2015.01.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2014] [Revised: 01/08/2015] [Accepted: 01/12/2015] [Indexed: 10/24/2022]
Abstract
Infection with Streptococcus equi ssp. zooepidemicus (Streptococcus zooepidemicus, SEZ) can cause septicemia, meningitis, and mastitis in domesticated species. Identification of this organism's virulence factors is an effective way of clarifying its pathogenic mechanism. We employed in vivo-induced antigen technology (IVIAT) to find bacterial genes that were only expressed or upregulated in an infected host (IVI genes). Convalescent-phase sera from pigs infected with SEZ were pooled, adsorbed against in vitro antigens, and used to screen SEZ genomic expression libraries. This analysis identified 43 genes as IVI genes. Six of these 43 genes were verified via real-time PCR. Following the analysis, we were able to assign a putative function to 36 of the 43 proteins. These proteins included those involved in virulence and adaptation; formation of intermediary products; gene replication, transcription and expression; energy metabolism; transport and also various proteins of unknown function. The relationship between sagD gene and bacterial virulence was confirmed. This study provides new molecular data for the study of streptococcal disease in swine and is important for identifying the pathogenic mechanisms of SEZ.
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Affiliation(s)
- Zhe Ma
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China; Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou 225009, China
| | - Lei Yu
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China
| | - Hong Zhou
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China
| | - Tingting Liu
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China
| | - Bin Xu
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China
| | - Fang Ma
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China
| | - Jie Peng
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China
| | - Hongjie Fan
- College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China; Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou 225009, China.
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Bober M, Mörgelin M, Olin AI, von Pawel-Rammingen U, Collin M. The membrane bound LRR lipoprotein Slr, and the cell wall-anchored M1 protein from Streptococcus pyogenes both interact with type I collagen. PLoS One 2011; 6:e20345. [PMID: 21655249 PMCID: PMC3105044 DOI: 10.1371/journal.pone.0020345] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2011] [Accepted: 04/29/2011] [Indexed: 11/28/2022] Open
Abstract
Streptococcus pyogenes is an important human pathogen and surface structures allow it to adhere to, colonize and invade the human host. Proteins containing leucine rich repeats (LRR) have been indentified in mammals, viruses, archaea and several bacterial species. The LRRs are often involved in protein-protein interaction, are typically 20–30 amino acids long and the defining feature of the LRR motif is an 11-residue sequence LxxLxLxxNxL (x being any amino acid). The streptococcal leucine rich (Slr) protein is a hypothetical lipoprotein that has been shown to be involved in virulence, but at present no ligands for Slr have been identified. We could establish that Slr is a membrane attached horseshoe shaped lipoprotein by homology modeling, signal peptidase II inhibition, electron microscopy (of bacteria and purified protein) and immunoblotting. Based on our previous knowledge of LRR proteins we hypothesized that Slr could mediate binding to collagen. We could show by surface plasmon resonance that recombinant Slr and purified M1 protein bind with high affinity to collagen I. Isogenic slr mutant strain (MB1) and emm1 mutant strain (MC25) had reduced binding to collagen type I as shown by slot blot and surface plasmon resonance. Electron microscopy using gold labeled Slr showed multiple binding sites to collagen I, both to the monomeric and the fibrillar structure, and most binding occurred in the overlap region of the collagen I fibril. In conclusion, we show that Slr is an abundant membrane bound lipoprotein that is co-expressed on the surface with M1, and that both these proteins are involved in recruiting collagen type I to the bacterial surface. This underlines the importance of S. pyogenes interaction with extracellular matrix molecules, especially since both Slr and M1 have been shown to be virulence factors.
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Affiliation(s)
- Marta Bober
- Division of Infection Medicine, Department of Clinical Sciences, Biomedical Center, Lund University, Lund, Sweden.
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3
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Sarabia F, Chammaa S, García-Ruiz C. Solid Phase Synthesis of Globomycin and SF-1902 A5. J Org Chem 2011; 76:2132-44. [DOI: 10.1021/jo1025145] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Francisco Sarabia
- Department of Organic Chemistry, Faculty of Sciences, University of Malaga, Campus de Teatinos s/n 29071, Malaga, Spain
| | - Samy Chammaa
- Department of Organic Chemistry, Faculty of Sciences, University of Malaga, Campus de Teatinos s/n 29071, Malaga, Spain
| | - Cristina García-Ruiz
- Department of Organic Chemistry, Faculty of Sciences, University of Malaga, Campus de Teatinos s/n 29071, Malaga, Spain
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Expression of MPB83 from Mycobacterium bovis in Brucella abortus S19 induces specific cellular immune response against the recombinant antigen in BALB/c mice. Microbes Infect 2010; 12:1236-43. [PMID: 20888425 DOI: 10.1016/j.micinf.2010.09.009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2010] [Revised: 09/07/2010] [Accepted: 09/14/2010] [Indexed: 11/20/2022]
Abstract
Immunodominant MPB83 antigen from Mycobacterium bovis was expressed as a chimeric protein fused to either β-galactosidase, outer membrane lipoprotein OMP19 or periplasmic protein BP26 in gram-negative Brucella abortus S19, in all cases driven by each gene's own promoter. All fusion proteins were successfully expressed and localized in the expected subcellular fraction. Moreover, OMP19-MPB83 was processed as a lipoprotein when expressed in B. abortus. Splenocytes from BALB/c mice immunized with the recombinant S19 strains carrying the genes coding for the heterologous antigens in replicative plasmids, showed equally specific INF-γ production in response to MPB83 stimulation. Association to the lipid moiety of OMP19 presented no advantage in terms of immunogenicity for MPB83. In contrast, fusion to BP26, which was encoded by an integrative plasmid, resulted in a weaker immune response. None of the constructions affected the survival rate or the infection pattern of Brucella. We concluded that B. abortus S19 is an appropriate candidate for the expression of M. bovis antigens both associated to the membrane or cytosolic fraction and may provide the basis for a future combined vaccine for bovine brucellosis and tuberculosis.
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Florindo H, Pandit S, Gonçalves L, Alpar H, Almeida A. New approach on the development of a mucosal vaccine against strangles: Systemic and mucosal immune responses in a mouse model. Vaccine 2009; 27:1230-41. [DOI: 10.1016/j.vaccine.2008.12.004] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2008] [Revised: 12/02/2008] [Accepted: 12/09/2008] [Indexed: 11/26/2022]
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Guglielmetti S, Tamagnini I, Mora D, Minuzzo M, Scarafoni A, Arioli S, Hellman J, Karp M, Parini C. Implication of an outer surface lipoprotein in adhesion of Bifidobacterium bifidum to Caco-2 cells. Appl Environ Microbiol 2008; 74:4695-702. [PMID: 18539800 PMCID: PMC2519326 DOI: 10.1128/aem.00124-08] [Citation(s) in RCA: 96] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2008] [Accepted: 03/11/2008] [Indexed: 12/23/2022] Open
Abstract
We found that the human intestinal isolate Bifidobacterium bifidum MIMBb75 strongly adhered to Caco-2 cells. Proteinase K and lithium chloride treatments showed that proteins play a key role in MIMBb75 adhesion to Caco-2 cells. By studying the cell wall-associated proteins, we identified a surface protein, which we labeled BopA. We purified the protein chromatographically and found that it functioned as an adhesion promoter on Caco-2 cells. In silico analysis of the gene coding for this protein and globomycin experiments showed that BopA is a cysteine-anchored lipoprotein expressed as a precursor polypeptide. A database search indicated that BopA appears to function biologically as an oligopeptide/tripeptide-solute-binding protein in the ABC transport system. We discovered a protein corresponding to BopA and its gene in eight other highly adherent B. bifidum strains. Finally, we found that B. bifidum MIMBb75 and BopA affected the production of interleukin-8 in Caco-2 epithelial cells. BopA is the first protein described to date to be directly involved in the adhesion of bifidobacteria to Caco-2 cells and to show immunomodulatory activity.
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Affiliation(s)
- Simone Guglielmetti
- Department of Food Science and Microbiology, University of Milan, Via Celoria 2, 20133 Milan, Italy.
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Florindo HF, Pandit S, Gonçalves LMD, Alpar HO, Almeida AJ. Streptococcus equi antigens adsorbed onto surface modified poly-epsilon-caprolactone microspheres induce humoral and cellular specific immune responses. Vaccine 2008; 26:4168-77. [PMID: 18599166 DOI: 10.1016/j.vaccine.2008.05.074] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2008] [Revised: 04/29/2008] [Accepted: 05/25/2008] [Indexed: 10/21/2022]
Abstract
Streptococcus equi subsp. equi is the causative agent of Strangles, which is one of the most costly and widespread infectious diseases, affecting the respiratory tract of Equidae. In this work, polyvinyl alcohol, alginate and chitosan were used in formulations of surface modified poly-epsilon-caprolactone microspheres which were evaluated after adsorption of S.equi enzymatic extract for physicochemical characteristics and in vivo immune responses in mice. After subcutaneous immunisation, the formulations induced higher lymphokines levels, in accordance with cellular and humoral immune responses, as compared to the free antigen, successfully activating the paths leading to Th1 and Th2 cells. The obtained results highlight the role of these microspheres as an adjuvant and their use to protect animals against strangles.
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Affiliation(s)
- H F Florindo
- iMED, Universidade de Lisboa, Avenida Professor Gama Pinto, 1649-003 Lisboa, Portugal
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Abstract
Lipoproteins are a functionally diverse class of secreted bacterial proteins characterized by an N-terminal lipid moiety. The lipid moiety serves to anchor these proteins to the cell surface. Lipoproteins are synthesized as pre-prolipoproteins and mature by post-translational modifications. The post-translational modifications are directed by the lipobox motif located within the signal peptide. Enzymes involved in lipoprotein synthesis are essential in Gram-negative bacteria but not in Gram-positive bacteria. Inactivation of genes involved in lipoprotein synthesis attenuates a variety of Gram-positive pathogens, including Mycobacterium tuberculosis. The attenuated phenotype of these mutants indicates an important role of lipoproteins and lipoprotein synthesis in bacterial virulence. M. tuberculosis, the causative agent of tuberculosis, is one of the most devastating pathogens in the world. This article reviews recent findings on the synthesis, localization and function of lipoproteins in mycobacteria.
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Affiliation(s)
- Mandana Rezwan
- Institut für Medizinische Mikrobiologie, Universität Zürich, Gloriastrasse 32, CH-8006 Zürich, Switzerland
| | - Thomas Grau
- Institut für Medizinische Mikrobiologie, Universität Zürich, Gloriastrasse 32, CH-8006 Zürich, Switzerland
| | - Andreas Tschumi
- Institut für Medizinische Mikrobiologie, Universität Zürich, Gloriastrasse 32, CH-8006 Zürich, Switzerland
| | - Peter Sander
- Nationales Zentrum für Mykobakterien, Gloriastrasse 30, CH-8006 Zürich, Switzerland
- Institut für Medizinische Mikrobiologie, Universität Zürich, Gloriastrasse 32, CH-8006 Zürich, Switzerland
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Hamilton A, Robinson C, Sutcliffe IC, Slater J, Maskell DJ, Davis-Poynter N, Smith K, Waller A, Harrington DJ. Mutation of the maturase lipoprotein attenuates the virulence of Streptococcus equi to a greater extent than does loss of general lipoprotein lipidation. Infect Immun 2006; 74:6907-19. [PMID: 17015455 PMCID: PMC1698103 DOI: 10.1128/iai.01116-06] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Streptococcus equi is the causative agent of strangles, a prevalent and highly contagious disease of horses. Despite the animal suffering and economic burden associated with strangles, little is known about the molecular basis of S. equi virulence. Here we have investigated the contributions of a specific lipoprotein and the general lipoprotein processing pathway to the abilities of S. equi to colonize equine epithelial tissues in vitro and to cause disease in both a mouse model and the natural host in vivo. Colonization of air interface organ cultures after they were inoculated with a mutant strain deficient in the maturase lipoprotein (DeltaprtM(138-213), with a deletion of nucleotides 138 to 213) was significantly less than that for cultures infected with wild-type S. equi strain 4047 or a mutant strain that was unable to lipidate preprolipoproteins (Deltalgt(190-685)). Moreover, mucus production was significantly greater in both wild-type-infected and Deltalgt(190-685)-infected organ cultures. Both mutants were significantly attenuated compared with the wild-type strain in a mouse model of strangles, although 2 of 30 mice infected with the Deltalgt(190-685) mutant did still exhibit signs of disease. In contrast, only the DeltaprtM(138-213) mutant was significantly attenuated in a pony infection study, with 0 of 5 infected ponies exhibiting pathological signs of strangles compared with 4 of 4 infected with the wild-type and 3 of 5 infected with the Deltalgt(190-685) mutant. We believe that this is the first study to evaluate the contribution of lipoproteins to the virulence of a gram-positive pathogen in its natural host. These data suggest that the PrtM lipoprotein is a potential vaccine candidate, and further investigation of its activity and its substrate(s) are warranted.
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Affiliation(s)
- Andrea Hamilton
- University of Sunderland, Tyne and Wear SR1 3SD, United Kingdom
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Nygaard TK, Liu M, McClure MJ, Lei B. Identification and characterization of the heme-binding proteins SeShp and SeHtsA of Streptococcus equi subspecies equi. BMC Microbiol 2006; 6:82. [PMID: 17007644 PMCID: PMC1592302 DOI: 10.1186/1471-2180-6-82] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2006] [Accepted: 09/28/2006] [Indexed: 05/12/2023] Open
Abstract
Background Heme is a preferred iron source of bacterial pathogens. Streptococcus equi subspecies equi is a bacterial pathogen that causes strangles in horses. Whether S. equi has a heme acquisition transporter is unknown. Results An S. equi genome database was blasted with the heme binding proteins Shp and HtsA of Streptococcus pyogenes, and found that S. equi has the homologue of Shp (designated SeShp) and HtsA (designated SeHtsA). Tag-free recombinant SeShp and SeHtsA and 6xHis-tagged SeHtsA (SeHtsAHis) were prepared and characterized. Purified holoSeShp and holoSeHtsA bind Fe(II)-protoporphyrin IX (heme) and Fe(III)-protoporphyrin IX (hemin) in a 1:1 stoichiometry, respectively, and are designated hemoSeShp and hemiSeHtsA. HemiSeShp and hemiSeHtsAHis can be reconstituted from apoSeShp and apoSeHtsAHis and hemin. HemoSeShp is stable in air and can be oxidized to hemiSeShp by ferricyanide. HemiSeHtsA can be reduced into hemoSeHtsA, which autoxidizes readily. HemoSeShp rapidly transfers its heme to apoSeHtsAHis. In addition, hemoSeShp can also transfer its heme to apoHtsA, and hemoShp is able to donate heme to apoSeHtsAHis. Conclusion The primary structures, optical properties, oxidative stability, and in vitro heme transfer reaction of SeShp and SeHtsA are very similar to those of S. pyogenes Shp and HtsA. The data suggest that the putative cell surface protein SeShp and lipoprotein SeHtsA are part of the machinery to acquire heme in S. equi. The results also imply that the structure, function, and functional mechanism of the heme acquisition machinery are conserved in S. equi and S. pyogenes.
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Affiliation(s)
- Tyler K Nygaard
- Department of Veterinary Molecular Biology, Montana State University, Bozeman, Montana 59717, USA
| | - Mengyao Liu
- Department of Veterinary Molecular Biology, Montana State University, Bozeman, Montana 59717, USA
| | - Michael J McClure
- Department of Veterinary Molecular Biology, Montana State University, Bozeman, Montana 59717, USA
| | - Benfang Lei
- Department of Veterinary Molecular Biology, Montana State University, Bozeman, Montana 59717, USA
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12
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Wood JLN, Newton JR, Chanter N, Mumford JA. Association between respiratory disease and bacterial and viral infections in British racehorses. J Clin Microbiol 2005; 43:120-6. [PMID: 15634959 PMCID: PMC540098 DOI: 10.1128/jcm.43.1.120-126.2005] [Citation(s) in RCA: 106] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Respiratory disease is important in horses, particularly in young Thoroughbred racehorses, and inflammation that is detected in the trachea and bronchi (termed inflammatory airway disease [IAD]) is more significant in this population in terms of impact and frequency than other presentations of respiratory disease. IAD, which is characterized by neutrophilic inflammation, mild clinical signs, and accumulation of mucus in the trachea, may be multifactorial, possibly involving infections and environmental and immunological factors, and its etiology remains unclear. This 3-year longitudinal study of young Thoroughbred racehorses was undertaken to characterize the associations of IAD and nasal discharge with viral and bacterial infections. IAD was statistically associated with tracheal infection with Streptococcus pneumoniae (capsule type 3), Streptococcus zooepidemicus, Actinobacillus spp., and Mycoplasma equirhinis and equine herpesvirus 1 and 4 infections, after adjustment for variation between training yards, seasons, and age groups. The association with S. pneumoniae and S. zooepidemicus was independent of prior viral infection and, critically, was dependent on the numbers of organisms isolated. S. pneumoniae was significant only in horses that were 2 years old or younger. The prevalence and incidence of IAD, S. zooepidemicus, and S. pneumoniae decreased in parallel with age, consistent with increased disease resistance, perhaps by the acquisition of immunity. The study provided evidence for S. zooepidemicus and S. pneumoniae playing an important etiological role in the pathogenesis of IAD in young horses.
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Affiliation(s)
- J L N Wood
- Epidemiology Unit, Animal Health Trust, Lanwades Park, Kentford, Newmarket, Suffolk, CB8 0NG, United Kingdom.
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de Greeff A, Hamilton A, Sutcliffe IC, Buys H, van Alphen L, Smith HE. Lipoprotein signal peptidase of Streptococcus suis serotype 2. MICROBIOLOGY (READING, ENGLAND) 2003; 149:1399-1407. [PMID: 12777481 DOI: 10.1099/mic.0.26329-0] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
This paper reports the complete coding sequence for a proliprotein signal peptidase (SP-ase) of Streptococcus suis, Lsp. This is believed to be the first SP-ase described for S. suis. SP-ase II is involved in the removal of the signal peptide from glyceride-modified prolipoproteins. By using in vitro transcription/translation systems, it was shown that the lsp gene was transcribed in vitro. Functionality of Lsp in Escherichia coli was demonstrated by using an in vitro globomycin resistance assay, to show that expression of Lsp in E. coli increased the globomycin resistance. An isogenic mutant of S. suis serotype 2 unable to produce Lsp was constructed and shown to process lipoproteins incorrectly, including an S. suis homologue of the pneumococcal PsaA lipoprotein. Five piglets were inoculated with a mixture of both strains in an experimental infection, to determine the virulence of the mutant strain relative to that of the wild-type strain in a competitive challenge experiment. The data showed that both strains were equally virulent, indicating that the knockout mutant of lsp is not attenuated in vivo.
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Affiliation(s)
- Astrid de Greeff
- Department of Medical Microbiology, University of Amsterdam, 1100 DD Amsterdam, The Netherlands
- Division of Infectious Diseases and Food Chain Quality, Cluster of Endemic Diseases, Institute of Animal Science and Health, 8200 AB Lelystad, The Netherlands
| | - Andrea Hamilton
- Institute of Pharmacy, Chemistry and Biomedical Sciences, University of Sunderland, UK
| | - Iain C Sutcliffe
- Institute of Pharmacy, Chemistry and Biomedical Sciences, University of Sunderland, UK
| | - Herma Buys
- Division of Infectious Diseases and Food Chain Quality, Cluster of Endemic Diseases, Institute of Animal Science and Health, 8200 AB Lelystad, The Netherlands
| | - Loek van Alphen
- Laboratory for Vaccine Research, RIVM, National Institute of Public Health and the Environment, 3720 BA Bilthoven, The Netherlands
- Department of Medical Microbiology, University of Amsterdam, 1100 DD Amsterdam, The Netherlands
| | - Hilde E Smith
- Division of Infectious Diseases and Food Chain Quality, Cluster of Endemic Diseases, Institute of Animal Science and Health, 8200 AB Lelystad, The Netherlands
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Réglier-Poupet H, Pellegrini E, Charbit A, Berche P. Identification of LpeA, a PsaA-like membrane protein that promotes cell entry by Listeria monocytogenes. Infect Immun 2003; 71:474-82. [PMID: 12496198 PMCID: PMC143402 DOI: 10.1128/iai.71.1.474-482.2003] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The intracellular life of Listeria monocytogenes starts by a complex process of entry involving several bacterial ligands and eukaryotic receptors. In this work, we identified in silico from the sequence of the genome of L. monocytogenes a previously unknown gene designated lpeA (for lipoprotein promoting entry) encoding a 35-kDa protein homologous to PsaA, a lipoprotein belonging to the LraI family and implicated in the cell adherence of Streptococcus pneumoniae and related species. By constructing a mutant of L. monocytogenes in which lpeA is deleted (lpeA mutant), we show that the PsaA-like protein LpeA is not involved in bacterial adherence but is required for entry of L. monocytogenes in eukaryotic cells. In contrast to wild-type bacteria, mutant bacteria failed to invade the epithelial Caco-2 and hepatocyte TIB73 cell lines, as confirmed by confocal microscopy. The mutant bacteria rapidly penetrated in mouse bone marrow-derived macrophages. Surprisingly, lpeA mutant bacteria survive better in macrophages than do wild-type bacteria. This was correlated with a weak exacerbation of virulence of the lpeA mutant in the mouse. LpeA is therefore a novel invasin favoring the entry of L. monocytogenes into nonprofessional phagocytes but not its invasion of macrophages. This is the first report of a lipoprotein promoting cell invasion of an intracellular pathogen.
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Affiliation(s)
- Hélène Réglier-Poupet
- INSERM U570, Faculté de Médecine Necker-Enfants Malades, 75730 Paris cedex 15, France
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15
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Sutcliffe IC, Harrington DJ. Pattern searches for the identification of putative lipoprotein genes in Gram-positive bacterial genomes. MICROBIOLOGY (READING, ENGLAND) 2002; 148:2065-2077. [PMID: 12101295 DOI: 10.1099/00221287-148-7-2065] [Citation(s) in RCA: 135] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
N-terminal lipidation is a major mechanism by which bacteria can tether proteins to membranes and one which is of particular importance to Gram-positive bacteria due to the absence of a retentive outer membrane. Lipidation is directed by the presence of a cysteine-containing 'lipobox' within the lipoprotein signal peptide sequence and this feature has greatly facilitated the identification of putative lipoproteins by gene sequence analysis. The properties of lipoprotein signal peptides have been described previously by the Prosite pattern PS00013. Here, a dataset of 33 experimentally verified Gram-positive bacterial lipoproteins (excluding those from Mollicutes) has been identified by an extensive literature review. The signal peptide features of these lipoproteins have been analysed to create a refined pattern, G+LPP, which is more specific for the identification of Gram-positive bacterial lipoproteins. The ability of this pattern to identify probable lipoprotein sequences is demonstrated by a search of the genome of Streptococcus pyogenes, in comparison with sequences identified using PS00013. Greater discrimination against likely false-positives was evident from the use of G+LPP compared with PS00013. These data confirm the likely abundance of lipoproteins in Gram-positive bacterial genomes, with at least 25 probable lipoproteins identified in S. pyogenes
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Affiliation(s)
- Iain C Sutcliffe
- Fleming Building, Institute of Pharmacy, Chemistry and Biomedical Sciences, University of Sunderland, Sunderland SR2 3SD, UK1
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Harrington DJ, Sutcliffe IC, Chanter N. The molecular basis of Streptococcus equi infection and disease. Microbes Infect 2002; 4:501-10. [PMID: 11932201 DOI: 10.1016/s1286-4579(02)01565-4] [Citation(s) in RCA: 89] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Streptococcus equi is the aetiological agent of strangles, one of the most prevalent diseases of the horse. The animal suffering and economic burden associated with this disease necessitate effective treatment. Current antibiotic therapy is often ineffective and thus recent attention has focused on vaccine development. A systematic understanding of S. equi virulence, leading to the identification of targets to which protective immunity can be directed, is a prerequisite of the development of such a vaccine. Here, the virulence factors of S. equi are reviewed.
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Affiliation(s)
- Dean J Harrington
- Department of Biomedical Sciences, University of Bradford, West Yorkshire, BD7 1DP, UK.
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Kitten T, Munro CL, Wang A, Macrina FL. Vaccination with FimA from Streptococcus parasanguis protects rats from endocarditis caused by other viridans streptococci. Infect Immun 2002; 70:422-5. [PMID: 11748213 PMCID: PMC127623 DOI: 10.1128/iai.70.1.422-425.2002] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The FimA protein of Streptococcus parasanguis is a virulence factor in the rat model of endocarditis, and immunization with FimA protects rats against homologous bacterial challenge. Because FimA-like proteins are widespread among the oral streptococci, the leading cause of native valve endocarditis, we evaluated the ability of this vaccinogen to protect rats when challenged by other streptococcal species. Here we report that FimA vaccination produced antibodies that cross-reacted with and protected against challenge by the oral streptococci S. mitis, S. mutans, and S. salivarius. FimA thus has promise as a vaccinogen to control infective endocarditis caused by oral streptococci.
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Affiliation(s)
- Todd Kitten
- The Philips Institute of Oral and Craniofacial Molecular Biology, Department of Adult Health Nursing, Virginia Commonwealth University, Richmond, Virginia 23298, USA.
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Meehan M, Lynagh Y, Woods C, Owen P. The fibrinogen-binding protein (FgBP) of Streptococcus equi subsp. equi additionally binds IgG and contributes to virulence in a mouse model. MICROBIOLOGY (READING, ENGLAND) 2001; 147:3311-22. [PMID: 11739763 DOI: 10.1099/00221287-147-12-3311] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The major cell-wall-associated protein of the equine pathogen Streptococcus equi subsp. equi is an M-like fibrinogen-binding protein (FgBP) which binds equine fibrinogen (Fg) avidly, through residues located at the extreme N-terminus of the molecule. In this study, it is shown that FgBP additionally binds equine IgG-Fc. When tested against polyclonal IgG from ten other animal species, it was found that FgBP binds human, rabbit, pig and cat IgG, but does not bind mouse, rat, goat, sheep, cow or chicken IgG. Through the use of a panel of recombinant FgBP truncates containing defined deletions of sequence, it was shown that residues in the central regions of FgBP are important in IgG binding. An fbp knockout mutant which does not express FgBP on the cell surface was also constructed. Mutant cells failed to autoaggregate, bound no detectable equine Fg or IgG-Fc, were rapidly killed in horse blood, and showed greatly decreased virulence in a mouse model. Results suggest that FgBP is the major surface structure responsible for binding either Fg or IgG, that the molecule has pronounced antiphagocytic properties, and that it is a likely factor contributing to the virulence of wild-type S. equi subsp. equi.
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Affiliation(s)
- M Meehan
- Department of Microbiology, Moyne Institute of Preventive Medicine, Trinity College, Dublin 2, Ireland
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Abstract
Phylogenetic analysis of 47 extracellular putative metal binding receptors (MBRs) belonging to the newly defined cluster suggests the existence of two subclusters. The question of substrate specificity of the corresponding ATP binding cassette (ABC) permeases is discussed, based on data collected from 19 of them concerning their regulation, metal requirement of permease mutants, metal uptake and metal binding. The proposal that the two subclusters correspond to paralogous metal permeases dedicated primarily to manganese and to zinc transport is made. The question of a direct role of MBRs as adhesins of Gram-positive bacteria is then discussed and the importance of metal permeases for cellular processes and host-bacteria interactions is reviewed.
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Affiliation(s)
- J P Claverys
- Laboratoire de Microbiologie et Génétique Moléculaire UMR5 100, CNRS-Université Paul Sabatier, Toulouse, France.
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