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Wang S, Ma M, Liang Z, Zhu X, Yao H, Wang L, Wu Z. Pathogenic investigations of Streptococcus pasteurianus, an underreported zoonotic pathogen, isolated from a diseased piglet with meningitis. Transbound Emerg Dis 2022; 69:2609-2620. [PMID: 34871467 DOI: 10.1111/tbed.14413] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Revised: 11/28/2021] [Accepted: 11/28/2021] [Indexed: 01/14/2023]
Abstract
Streptococcus pasteurianus, an underreported opportunistic pathogen, is considered an increasingly recognized cause of meningitis and bacteremia in many animals and humans worldwide. However, except for some epidemiological studies, there is no report about the gene-deletion mutagenesis, virulence factors, reservoir niches or animal infection models for this pathogen. In this study, we first isolated an S. pasteurianus strain from a newly weaned piglet's brain with meningitis. The genomic sequence of this swine isolate WUSP067 shared high homology with that of two human strains. The comparative genome analysis showed that strain WUSP067 contained a fucose utilization cluster absent in human strains, and it shared 91% identity with that of an integrative and conjugative element (ICE) ICEssuZJ20091101-2 from Streptococcus suis, another important swine bacterial pathogen. Strain WUSP067 was resistant to erythromycin, tulathromycin, lincomycin, clindamycin, doxycycline and gentamycin, and ICEs are vehicles for harbouring antimicrobial resistance genes. The infection model was established using the 3-week-old newly weaned ICR mice. The 50% lethal dose value of strain WUSP067 was 4.0 × 107 colony-forming units per mouse. The infected mice showed severe signs of meningitis and pathological changes in brains. Furthermore, the capsule-deficient mutant was generated using natural transformation, and we showed that capsule was an essential virulence factor for S. pasteurianus. In addition, we found that tonsils and hilar lymph nodes of healthy pigs may be reservoir niches for this bacterium. Thus, our study provided valuable information about the pathogenetic characteristics and antimicrobial resistance of S. pasteurianus and paved the way for studying its pathogenesis.
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Affiliation(s)
- Shuoyue Wang
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China
- Key Lab of Animal Bacteriology, Ministry of Agriculture, Nanjing, China
- OIE Reference Lab for Swine Streptococcosis, Nanjing, China
| | - Miaohang Ma
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China
- Key Lab of Animal Bacteriology, Ministry of Agriculture, Nanjing, China
- OIE Reference Lab for Swine Streptococcosis, Nanjing, China
| | - Zijing Liang
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China
- Key Lab of Animal Bacteriology, Ministry of Agriculture, Nanjing, China
- OIE Reference Lab for Swine Streptococcosis, Nanjing, China
| | - Xinchi Zhu
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China
- Key Lab of Animal Bacteriology, Ministry of Agriculture, Nanjing, China
- OIE Reference Lab for Swine Streptococcosis, Nanjing, China
| | - Huochun Yao
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China
- Key Lab of Animal Bacteriology, Ministry of Agriculture, Nanjing, China
- OIE Reference Lab for Swine Streptococcosis, Nanjing, China
| | - Liping Wang
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China
| | - Zongfu Wu
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China
- Key Lab of Animal Bacteriology, Ministry of Agriculture, Nanjing, China
- OIE Reference Lab for Swine Streptococcosis, Nanjing, China
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Cao H, Chiu KHY, Chiu SS, Jiang S, Chow KH, Ho PL. Genomic investigation of a Streptococcus pneumoniae serotype 24F strain causing meningoencephalitis in Hong Kong. Int J Med Microbiol 2021; 311:151543. [PMID: 34864352 DOI: 10.1016/j.ijmm.2021.151543] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Revised: 10/25/2021] [Accepted: 11/29/2021] [Indexed: 12/13/2022] Open
Abstract
Pneumococcal conjugate vaccines (PCVs) successfully decreased the incidence of invasive pneumococcal disease in children. However, many countries have reported serotype replacement and a rebound in diseases from non-vaccine serotypes. Here, we report the genomic investigation of a Streptococcus pneumoniae strain M215 that caused severe meningoencephalitis in an infant in 2019. The strain was assigned to serotype 24F using the bioinformatic pipeline SeroBA and pneumococcal type specific anti-sera. The strain was resistant to cotrimoxazole from mutations in both folA and folP genes. It was susceptible to penicillin and other non-β-lactam antibiotics. Phylogenetically, it belongs to Global Pneumococcal Sequence Cluster (GPSC) 6 and multi-locus sequence type 162. A total of 38 virulence genes were detected in the genome of M215. Upon comparison of the profile of virulence genes, GPSC6 but not non-GPSC6 strains of serotype 24F and related serotypes were found to possess the major virulence determinant, pilus islet-1, comprising genes encoding sortases (srtB, srtC, srtD), pilus proteins (rrgA, rrgB and rrgC) and one transcriptional regulator (rlrA), which was previously described to be characteristic feature of international clones in the pre-PCV era. In our locality, this represented the first detection of serotype 24F and GPSC6/ST162 causing serious pneumococcal disease. The emergence of the non-vaccine serotype 24F GPSC6/ST162 lineage with molecular feature of high virulence is concerning and emphasizes the need for full characterization of strains causing severe disease.
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Affiliation(s)
- Huiluo Cao
- Carol Yu Center for Infection and Department of Microbiology, University of Hong Kong, Hong Kong, China
| | | | - Susan S Chiu
- Department of Paediatrics and Adolescent Medicine, University of Hong Kong, Hong Kong, China
| | - Shuo Jiang
- Carol Yu Center for Infection and Department of Microbiology, University of Hong Kong, Hong Kong, China
| | - Kin-Hung Chow
- Carol Yu Center for Infection and Department of Microbiology, University of Hong Kong, Hong Kong, China
| | - Pak-Leung Ho
- Carol Yu Center for Infection and Department of Microbiology, University of Hong Kong, Hong Kong, China; Department of Microbiology, Queen Mary Hospital, Hong Kong, China.
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Park SS, Gonzalez-Juarbe N, Riegler AN, Im H, Hale Y, Platt MP, Croney C, Briles DE, Orihuela CJ. Streptococcus pneumoniae binds to host GAPDH on dying lung epithelial cells worsening secondary infection following influenza. Cell Rep 2021; 35:109267. [PMID: 34133917 PMCID: PMC8265312 DOI: 10.1016/j.celrep.2021.109267] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Revised: 04/07/2021] [Accepted: 05/26/2021] [Indexed: 12/13/2022] Open
Abstract
Streptococcus pneumoniae (Spn) alone and during co-infection with influenza A virus (IAV) can result in severe pneumonia with mortality. Pneumococcal surface protein A (PspA) is an established virulence factor required for Spn evasion of lactoferricin and C-reactive protein-activated complement-mediated killing. Herein, we show that PspA functions as an adhesin to dying host cells. We demonstrate that PspA binds to host-derived glyceraldehyde-3-phosphate dehydrogenase (GAPDH) bound to outward-flipped phosphatidylserine residues on dying host cells. PspA-mediated adhesion was to apoptotic, pyroptotic, and necroptotic cells, but not healthy lung cells. Using isogenic mutants of Spn, we show that PspA-GAPDH-mediated binding to lung cells increases pneumococcal localization in the lower airway, and this is enhanced as a result of pneumolysin exposure or co-infection with IAV. PspA-mediated binding to GAPDH requires amino acids 230-281 in its α-helical domain with intratracheal inoculation of this PspA fragment alongside the bacteria reducing disease severity in an IAV/Spn pneumonia model.
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Affiliation(s)
- Sang-Sang Park
- Department of Microbiology, The University of Alabama at Birmingham, Birmingham, AL, USA
| | | | - Ashleigh N Riegler
- Department of Microbiology, The University of Alabama at Birmingham, Birmingham, AL, USA
| | - Hansol Im
- Department of Microbiology, The University of Alabama at Birmingham, Birmingham, AL, USA
| | - Yvette Hale
- Department of Microbiology, The University of Alabama at Birmingham, Birmingham, AL, USA
| | - Maryann P Platt
- Infectious Diseases and Genomic Medicine Group, J. Craig Venter Institute, Rockville, MD, USA
| | - Christina Croney
- Department of Microbiology, The University of Alabama at Birmingham, Birmingham, AL, USA
| | - David E Briles
- Department of Microbiology, The University of Alabama at Birmingham, Birmingham, AL, USA
| | - Carlos J Orihuela
- Department of Microbiology, The University of Alabama at Birmingham, Birmingham, AL, USA.
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Park SS, Gonzalez-Juarbe N, Martínez E, Hale JY, Lin YH, Huffines JT, Kruckow KL, Briles DE, Orihuela CJ. Streptococcus pneumoniae Binds to Host Lactate Dehydrogenase via PspA and PspC To Enhance Virulence. mBio 2021; 12:e00673-21. [PMID: 33947761 PMCID: PMC8437407 DOI: 10.1128/mbio.00673-21] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Accepted: 03/22/2021] [Indexed: 02/06/2023] Open
Abstract
Pneumococcal surface protein A (PspA) and pneumococcal surface protein C (PspC, also called CbpA) are major virulence factors of Streptococcus pneumoniae (Spn). These surface-exposed choline-binding proteins (CBPs) function independently to inhibit opsonization, neutralize antimicrobial factors, or serve as adhesins. PspA and PspC both carry a proline-rich domain (PRD) whose role, other than serving as a flexible connector between the N-terminal and C-terminal domains, was up to this point unknown. Herein, we demonstrate that PspA binds to lactate dehydrogenase (LDH) released from dying host cells during infection. Using recombinant versions of PspA and isogenic mutants lacking PspA or specific domains of PspA, this property was mapped to a conserved 22-amino-acid nonproline block (NPB) found within the PRD of most PspAs and PspCs. The NPB of PspA had specific affinity for LDH-A, which converts pyruvate to lactate. In a mouse model of pneumonia, preincubation of Spn carrying NPB-bearing PspA with LDH-A resulted in increased bacterial titers in the lungs. In contrast, incubation of Spn carrying a version of PspA lacking the NPB with LDH-A or incubation of wild-type Spn with enzymatically inactive LDH-A did not enhance virulence. Preincubation of NPB-bearing Spn with lactate alone enhanced virulence in a pneumonia model, indicating exogenous lactate production by Spn-bound LDH-A had an important role in pneumococcal pathogenesis. Our observations show that lung LDH, released during the infection, is an important binding target for Spn via PspA/PspC and that pneumococci utilize LDH-A derived lactate for their benefit in vivoIMPORTANCEStreptococcus pneumoniae (Spn) is the leading cause of community-acquired pneumonia. PspA and PspC are among its most important virulence factors, and these surface proteins carry the proline-rich domain (PRD), whose role was unknown until now. Herein, we show that a conserved 22-amino-acid nonproline block (NPB) found within most versions of the PRD binds to host-derived lactate dehydrogenase A (LDH-A), a metabolic enzyme which converts pyruvate to lactate. PspA-mediated binding of LDH-A increased Spn titers in the lungs and this required LDH-A enzymatic activity. Enhanced virulence was also observed when Spn was preincubated with lactate, suggesting LDH-A-derived lactate is a vital food source. Our findings define a role for the NPB of the PRD and show that Spn co-opts host enzymes for its benefit. They advance our understanding of pneumococcal pathogenesis and have key implications on the susceptibility of individuals with preexisting airway damage that results in LDH-A release.
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Affiliation(s)
- Sang-Sang Park
- Department of Microbiology, The University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Norberto Gonzalez-Juarbe
- Infectious Diseases and Genomic Medicine Group, J Craig Venter Institute, Rockville, Maryland, USA
| | - Eriel Martínez
- Department of Microbiology, The University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Joanetha Yvette Hale
- Department of Microbiology, The University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Yi-Han Lin
- Infectious Diseases and Genomic Medicine Group, J Craig Venter Institute, Rockville, Maryland, USA
| | - Joshua T Huffines
- Department of Microbiology, The University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Katherine L Kruckow
- Department of Microbiology, The University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - David E Briles
- Department of Microbiology, The University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Carlos J Orihuela
- Department of Microbiology, The University of Alabama at Birmingham, Birmingham, Alabama, USA
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Hemoglobin Induces Early and Robust Biofilm Development in Streptococcus pneumoniae by a Pathway That Involves comC but Not the Cognate comDE Two-Component System. Infect Immun 2021; 89:IAI.00779-20. [PMID: 33397818 DOI: 10.1128/iai.00779-20] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Accepted: 12/15/2020] [Indexed: 11/20/2022] Open
Abstract
Streptococcus pneumoniae grows in biofilms during both asymptomatic colonization and infection. Pneumococcal biofilms on abiotic surfaces exhibit delayed growth and lower biomass and lack the structures seen on epithelial cells or during nasopharyngeal carriage. We show here that adding hemoglobin to the medium activated unusually early and vigorous biofilm growth in multiple S. pneumoniae serotypes grown in batch cultures on abiotic surfaces. Human blood (but not serum, heme, or iron) also stimulated biofilms, and the pore-forming pneumolysin, ply, was required for this induction. S. pneumoniae transitioning from planktonic into sessile growth in the presence of hemoglobin displayed an extensive transcriptome remodeling within 1 and 2 h. Differentially expressed genes included those involved in the metabolism of carbohydrates, nucleotides, amino acid, and lipids. The switch into adherent states also influenced the expression of several regulatory systems, including the comCDE genes. Inactivation of comC resulted in 67% reduction in biofilm formation, while the deletion of comD or comE had limited or no effect, respectively. These observations suggest a novel route for CSP-1 signaling independent of the cognate ComDE two-component system. Biofilm induction and the associated transcriptome remodeling suggest hemoglobin serves as a signal for host colonization in pneumococcus.
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Identification of Virulence-Associated Properties by Comparative Genome Analysis of Streptococcus pneumoniae, S. pseudopneumoniae, S. mitis, Three S. oralis Subspecies, and S. infantis. mBio 2019; 10:mBio.01985-19. [PMID: 31481387 PMCID: PMC6722419 DOI: 10.1128/mbio.01985-19] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Streptococcus pneumoniae is one of the most important human pathogens but is closely related to Streptococcus mitis, with which humans live in harmony. The fact that the two species evolved from a common ancestor provides a unique basis for studies of both infection-associated properties and properties important for harmonious coexistence with the host. By detailed comparisons of genomes of the two species and other related streptococci, we identified 224 genes associated with virulence and 25 genes unique to the mutualistic species. The exclusive presence of the virulence factors in S. pneumoniae enhances their potential as vaccine components, as a direct impact on beneficial members of the commensal microbiota can be excluded. Successful adaptation of S. mitis and other commensal streptococci to a harmonious relationship with the host relied on genetic stability and properties facilitating life in biofilms. From a common ancestor, Streptococcus pneumoniae and Streptococcus mitis evolved in parallel into one of the most important pathogens and a mutualistic colonizer of humans, respectively. This evolutionary scenario provides a unique basis for studies of both infection-associated properties and properties important for harmonious coexistence with the host. We performed detailed comparisons of 60 genomes of S. pneumoniae, S. mitis, Streptococcus pseudopneumoniae, the three Streptococcus oralis subspecies oralis, tigurinus, and dentisani, and Streptococcus infantis. Nonfunctional remnants of ancestral genes in both S. pneumoniae and in S. mitis support the evolutionary model and the concept that evolutionary changes on both sides were required to reach their present relationship to the host. Confirmed by screening of >7,500 genomes, we identified 224 genes associated with virulence. The striking difference to commensal streptococci was the diversity of regulatory mechanisms, including regulation of capsule production, a significantly larger arsenal of enzymes involved in carbohydrate hydrolysis, and proteins known to interfere with innate immune factors. The exclusive presence of the virulence factors in S. pneumoniae enhances their potential as vaccine components, as a direct impact on beneficial members of the commensal microbiota can be excluded. In addition to loss of these virulence-associated genes, adaptation of S. mitis to a mutualistic relationship with the host apparently required preservation or acquisition of 25 genes lost or absent from S. pneumoniae. Successful adaptation of S. mitis and other commensal streptococci to a harmonious relationship with the host relied on genetic stability and properties facilitating life in biofilms.
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Hobbs JK, Pluvinage B, Robb M, Smith SP, Boraston AB. Two complementary α-fucosidases from Streptococcus pneumoniae promote complete degradation of host-derived carbohydrate antigens. J Biol Chem 2019; 294:12670-12682. [PMID: 31266803 DOI: 10.1074/jbc.ra119.009368] [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] [Received: 05/14/2019] [Revised: 06/24/2019] [Indexed: 12/13/2022] Open
Abstract
An important aspect of the interaction between the opportunistic bacterial pathogen Streptococcus pneumoniae and its human host is its ability to harvest host glycans. The pneumococcus can degrade a variety of complex glycans, including N- and O-linked glycans, glycosaminoglycans, and carbohydrate antigens, an ability that is tightly linked to the virulence of S. pneumoniae Although S. pneumoniae is known to use a sophisticated enzyme machinery to attack the human glycome, how it copes with fucosylated glycans, which are primarily histo-blood group antigens, is largely unknown. Here, we identified two pneumococcal enzymes, SpGH29C and SpGH95C, that target α-(1→3/4) and α-(1→2) fucosidic linkages, respectively. X-ray crystallography studies combined with functional assays revealed that SpGH29C is specific for the LewisA and LewisX antigen motifs and that SpGH95C is specific for the H(O)-antigen motif. Together, these enzymes could defucosylate LewisY and LewisB antigens in a complementary fashion. In vitro reconstruction of glycan degradation cascades disclosed that the individual or combined activities of these enzymes expose the underlying glycan structure, promoting the complete deconstruction of a glycan that would otherwise be resistant to pneumococcal enzymes. These experiments expand our understanding of the extensive capacity of S. pneumoniae to process host glycans and the likely roles of α-fucosidases in this. Overall, given the importance of enzymes that initiate glycan breakdown in pneumococcal virulence, such as the neuraminidase NanA and the mannosidase SpGH92, we anticipate that the α-fucosidases identified here will be important factors in developing more refined models of the S. pneumoniae-host interaction.
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Affiliation(s)
- Joanne K Hobbs
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia V8P 5C2, Canada
| | - Benjamin Pluvinage
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia V8P 5C2, Canada
| | - Melissa Robb
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia V8P 5C2, Canada
| | - Steven P Smith
- Department of Biomedical and Molecular Sciences, Queen's University, Kingston, Ontario K7L 3N6, Canada
| | - Alisdair B Boraston
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia V8P 5C2, Canada
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Hobbs JK, Pluvinage B, Boraston AB. Glycan-metabolizing enzymes in microbe-host interactions: the Streptococcus pneumoniae paradigm. FEBS Lett 2018; 592:3865-3897. [PMID: 29608212 DOI: 10.1002/1873-3468.13045] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2018] [Revised: 03/21/2018] [Accepted: 03/22/2018] [Indexed: 12/31/2022]
Abstract
Streptococcus pneumoniae is a frequent colonizer of the upper airways; however, it is also an accomplished pathogen capable of causing life-threatening diseases. To colonize and cause invasive disease, this bacterium relies on a complex array of factors to mediate the host-bacterium interaction. The respiratory tract is rich in functionally important glycoconjugates that display a vast range of glycans, and, thus, a key component of the pneumococcus-host interaction involves an arsenal of bacterial carbohydrate-active enzymes to depolymerize these glycans and carbohydrate transporters to import the products. Through the destruction of host glycans, the glycan-specific metabolic machinery deployed by S. pneumoniae plays a variety of roles in the host-pathogen interaction. Here, we review the processing and metabolism of the major host-derived glycans, including N- and O-linked glycans, Lewis and blood group antigens, proteoglycans, and glycogen, as well as some dietary glycans. We discuss the role of these metabolic pathways in the S. pneumoniae-host interaction, speculate on the potential of key enzymes within these pathways as therapeutic targets, and relate S. pneumoniae as a model system to glycan processing in other microbial pathogens.
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Affiliation(s)
- Joanne K Hobbs
- Department of Biochemistry and Microbiology, University of Victoria, British Columbia, Canada
| | - Benjamin Pluvinage
- Department of Biochemistry and Microbiology, University of Victoria, British Columbia, Canada
| | - Alisdair B Boraston
- Department of Biochemistry and Microbiology, University of Victoria, British Columbia, Canada
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Shenoy AT, Brissac T, Gilley RP, Kumar N, Wang Y, Gonzalez-Juarbe N, Hinkle WS, Daugherty SC, Shetty AC, Ott S, Tallon LJ, Deshane J, Tettelin H, Orihuela CJ. Streptococcus pneumoniae in the heart subvert the host response through biofilm-mediated resident macrophage killing. PLoS Pathog 2017; 13:e1006582. [PMID: 28841717 PMCID: PMC5589263 DOI: 10.1371/journal.ppat.1006582] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2017] [Revised: 09/07/2017] [Accepted: 08/15/2017] [Indexed: 11/18/2022] Open
Abstract
For over 130 years, invasive pneumococcal disease has been associated with the presence of extracellular planktonic pneumococci, i.e. diplococci or short chains in affected tissues. Herein, we show that Streptococcus pneumoniae that invade the myocardium instead replicate within cellular vesicles and transition into non-purulent biofilms. Pneumococci within mature cardiac microlesions exhibited salient biofilm features including intrinsic resistance to antibiotic killing and the presence of an extracellular matrix. Dual RNA-seq and subsequent principal component analyses of heart- and blood-isolated pneumococci confirmed the biofilm phenotype in vivo and revealed stark anatomical site-specific differences in virulence gene expression; the latter having major implications on future vaccine antigen selection. Our RNA-seq approach also identified three genomic islands as exclusively expressed in vivo. Deletion of one such island, Region of Diversity 12, resulted in a biofilm-deficient and highly inflammogenic phenotype within the heart; indicating a possible link between the biofilm phenotype and a dampened host-response. We subsequently determined that biofilm pneumococci released greater amounts of the toxin pneumolysin than did planktonic or RD12 deficient pneumococci. This allowed heart-invaded wildtype pneumococci to kill resident cardiac macrophages and subsequently subvert cytokine/chemokine production and neutrophil infiltration into the myocardium. This is the first report for pneumococcal biofilm formation in an invasive disease setting. We show that biofilm pneumococci actively suppress the host response through pneumolysin-mediated immune cell killing. As such, our findings contradict the emerging notion that biofilm pneumococci are passively immunoquiescent.
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Affiliation(s)
- Anukul T. Shenoy
- Department of Microbiology, The University of Alabama at Birmingham, Birmingham, AL, United States of America
- Department of Microbiology, Immunology, and Molecular Genetics, The University of Texas Health San Antonio, San Antonio, TX, United States of America
| | - Terry Brissac
- Department of Microbiology, The University of Alabama at Birmingham, Birmingham, AL, United States of America
| | - Ryan P. Gilley
- Department of Microbiology, Immunology, and Molecular Genetics, The University of Texas Health San Antonio, San Antonio, TX, United States of America
| | - Nikhil Kumar
- Department of Microbiology and Immunology, Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD, United States of America
| | - Yong Wang
- Division of Pulmonary, Allergy & Critical Care Medicine, The University of Alabama at Birmingham, Birmingham, AL, United States of America
| | - Norberto Gonzalez-Juarbe
- Department of Microbiology, The University of Alabama at Birmingham, Birmingham, AL, United States of America
| | - Whitney S. Hinkle
- Department of Microbiology, The University of Alabama at Birmingham, Birmingham, AL, United States of America
| | - Sean C. Daugherty
- Department of Microbiology and Immunology, Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD, United States of America
| | - Amol C. Shetty
- Department of Microbiology and Immunology, Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD, United States of America
| | - Sandra Ott
- Department of Microbiology and Immunology, Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD, United States of America
| | - Luke J. Tallon
- Department of Microbiology and Immunology, Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD, United States of America
| | - Jessy Deshane
- Division of Pulmonary, Allergy & Critical Care Medicine, The University of Alabama at Birmingham, Birmingham, AL, United States of America
| | - Hervé Tettelin
- Department of Microbiology and Immunology, Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD, United States of America
| | - Carlos J. Orihuela
- Department of Microbiology, The University of Alabama at Birmingham, Birmingham, AL, United States of America
- Department of Microbiology, Immunology, and Molecular Genetics, The University of Texas Health San Antonio, San Antonio, TX, United States of America
- * E-mail:
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Lizcano A, Akula Suresh Babu R, Shenoy AT, Saville AM, Kumar N, D'Mello A, Hinojosa CA, Gilley RP, Segovia J, Mitchell TJ, Tettelin H, Orihuela CJ. Transcriptional organization of pneumococcal psrP-secY2A2 and impact of GtfA and GtfB deletion on PsrP-associated virulence properties. Microbes Infect 2017; 19:323-333. [PMID: 28408270 PMCID: PMC5581956 DOI: 10.1016/j.micinf.2017.04.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2016] [Revised: 03/10/2017] [Accepted: 04/03/2017] [Indexed: 01/08/2023]
Abstract
Pneumococcal serine-rich repeat protein (PsrP) is a glycoprotein that mediates Streptococcus pneumoniae attachment to lung cells and promotes biofilm formation. Herein, we investigated the transcriptional organization of psrP-secY2A2, the 37-kbp pathogenicity island encoding PsrP and its accessory genes. PCR amplification of cDNA and RNA-seq analysis found psrP-secY2A2 to be minimally composed of three operons: psrP-glyA, glyB, and glyC-asp5. Transcription of all three operons was greatest during biofilm growth and immunoblot analyses confirmed increased PsrP production by biofilm pneumococci. Using gas chromatography-mass spectrometry we identified monomeric N-acetylglucosamine as the primary glycoconjugate present on a recombinant intracellular version of PsrP, i.e. PsrP1-734. This finding was validated by immunoblot using lectins with known carbohydrate specificities. We subsequently deleted gtfA and gtfB, the GTFs thought to be responsible for addition of O-linked N-acetylglucosamine, and tested for PsrP and its associated virulence properties. These deletions negatively affected our ability to detect PsrP1-734 in bacterial whole cell lysates. Moreover, S. pneumoniae mutants lacking these genes pheno-copied the psrP mutant and were attenuated for: biofilm formation, adhesion to lung epithelial cells, and pneumonia in mice. Our studies identify the transcriptional organization of psrP-secY2A2 and show the indispensable role of GtfA and GtfB on PsrP-mediated pneumococcal virulence.
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Affiliation(s)
- Anel Lizcano
- Department of Microbiology and Immunology, The University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA
| | - Ramya Akula Suresh Babu
- Department of Microbiology and Immunology, The University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA
| | - Anukul T Shenoy
- Department of Microbiology and Immunology, The University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA; Department of Microbiology, The University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Alison Maren Saville
- Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow G12 8QQ, Scotland, UK
| | - Nikhil Kumar
- Department of Microbiology and Immunology, Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Adonis D'Mello
- Department of Microbiology and Immunology, Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Cecilia A Hinojosa
- Department of Microbiology and Immunology, The University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA
| | - Ryan P Gilley
- Department of Microbiology and Immunology, The University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA
| | - Jesus Segovia
- Department of Microbiology and Immunology, The University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA
| | - Timothy J Mitchell
- Institute of Infection, Immunity and Inflammation, University of Glasgow, Glasgow G12 8QQ, Scotland, UK; Institute of Microbiology and Infection, College of Medical and Dental Sciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
| | - Hervé Tettelin
- Department of Microbiology and Immunology, Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Carlos J Orihuela
- Department of Microbiology and Immunology, The University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA; Department of Microbiology, The University of Alabama at Birmingham, Birmingham, AL 35294, USA.
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11
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Blanchette KA, Shenoy AT, Milner J, Gilley RP, McClure E, Hinojosa CA, Kumar N, Daugherty SC, Tallon LJ, Ott S, King SJ, Ferreira DM, Gordon SB, Tettelin H, Orihuela CJ. Neuraminidase A-Exposed Galactose Promotes Streptococcus pneumoniae Biofilm Formation during Colonization. Infect Immun 2016; 84:2922-32. [PMID: 27481242 PMCID: PMC5038079 DOI: 10.1128/iai.00277-16] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2016] [Accepted: 07/21/2016] [Indexed: 01/26/2023] Open
Abstract
Streptococcus pneumoniae is an opportunistic pathogen that colonizes the nasopharynx. Herein we show that carbon availability is distinct between the nasopharynx and bloodstream of adult humans: glucose is absent from the nasopharynx, whereas galactose is abundant. We demonstrate that pneumococcal neuraminidase A (NanA), which cleaves terminal sialic acid residues from host glycoproteins, exposed galactose on the surface of septal epithelial cells, thereby increasing its availability during colonization. We observed that S. pneumoniae mutants deficient in NanA and β-galactosidase A (BgaA) failed to form biofilms in vivo despite normal biofilm-forming abilities in vitro Subsequently, we observed that glucose, sucrose, and fructose were inhibitory for biofilm formation, whereas galactose, lactose, and low concentrations of sialic acid were permissive. Together these findings suggested that the genes involved in biofilm formation were under some form of carbon catabolite repression (CCR), a regulatory network in which genes involved in the uptake and metabolism of less-preferred sugars are silenced during growth with preferred sugars. Supporting this notion, we observed that a mutant deficient in pyruvate oxidase, which converts pyruvate to acetyl-phosphate under non-CCR-inducing growth conditions, was unable to form biofilms. Subsequent comparative transcriptome sequencing (RNA-seq) analyses of planktonic and biofilm-grown pneumococci showed that metabolic pathways involving the conversion of pyruvate to acetyl-phosphate and subsequently leading to fatty acid biosynthesis were consistently upregulated during diverse biofilm growth conditions. We conclude that carbon availability in the nasopharynx impacts pneumococcal biofilm formation in vivo Additionally, biofilm formation involves metabolic pathways not previously appreciated to play an important role.
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Affiliation(s)
- Krystle A Blanchette
- Department of Microbiology and Immunology, The University of Texas Health Science Center at San Antonio, San Antonio, Texas, USA
| | - Anukul T Shenoy
- Department of Microbiology and Immunology, The University of Texas Health Science Center at San Antonio, San Antonio, Texas, USA Department of Microbiology, The University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Jeffrey Milner
- Department of Microbiology, The University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Ryan P Gilley
- Department of Microbiology and Immunology, The University of Texas Health Science Center at San Antonio, San Antonio, Texas, USA
| | - Erin McClure
- Department of Microbiology and Immunology, Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Cecilia A Hinojosa
- Department of Microbiology and Immunology, The University of Texas Health Science Center at San Antonio, San Antonio, Texas, USA
| | - Nikhil Kumar
- Department of Microbiology and Immunology, Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Sean C Daugherty
- Department of Microbiology and Immunology, Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Luke J Tallon
- Department of Microbiology and Immunology, Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Sandra Ott
- Department of Microbiology and Immunology, Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Samantha J King
- Center for Microbial Pathogenesis, The Research Institute at Nationwide Children's Hospital, Columbus, Ohio, USA Department of Pediatrics, The Ohio State University, Columbus, Ohio, USA
| | - Daniela M Ferreira
- Department of Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Stephen B Gordon
- Department of Clinical Sciences, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Hervé Tettelin
- Department of Microbiology and Immunology, Institute for Genome Sciences, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Carlos J Orihuela
- Department of Microbiology and Immunology, The University of Texas Health Science Center at San Antonio, San Antonio, Texas, USA Department of Microbiology, The University of Alabama at Birmingham, Birmingham, Alabama, USA
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12
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Cornick JE, Chaguza C, Harris SR, Yalcin F, Senghore M, Kiran AM, Govindpershad S, Ousmane S, Plessis MD, Pluschke G, Ebruke C, McGee L, Sigaùque B, Collard JM, Antonio M, von Gottberg A, French N, Klugman KP, Heyderman RS, Bentley SD, Everett DB, For The PAGe Consortium. Region-specific diversification of the highly virulent serotype 1 Streptococcus pneumoniae. Microb Genom 2015; 1:e000027. [PMID: 28348812 PMCID: PMC5320570 DOI: 10.1099/mgen.0.000027] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2015] [Accepted: 06/29/2015] [Indexed: 12/20/2022] Open
Abstract
Serotype 1 Streptococcus pneumoniae is a leading cause of invasive pneumococcal disease (IPD) worldwide, with the highest burden in developing countries. We report the whole-genome sequencing analysis of 448 serotype 1 isolates from 27 countries worldwide (including 11 in Africa). The global serotype 1 population shows a strong phylogeographic structure at the continental level, and within Africa there is further region-specific structure. Our results demonstrate that region-specific diversification within Africa has been driven by limited cross-region transfer events, genetic recombination and antimicrobial selective pressure. Clonal replacement of the dominant serotype 1 clones circulating within regions is uncommon; however, here we report on the accessory gene content that has contributed to a rare clonal replacement event of ST3081 with ST618 as the dominant cause of IPD in the Gambia.
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Affiliation(s)
- Jennifer E Cornick
- The Malawi-Liverpool-Wellcome Trust Clinical Research Programme, University of Malawi College of Medicine, Blantyre, Malawi.,University of Liverpool, Institute of Infection and Global Health, Liverpool, UK
| | - Chrispin Chaguza
- The Malawi-Liverpool-Wellcome Trust Clinical Research Programme, University of Malawi College of Medicine, Blantyre, Malawi.,University of Liverpool, Institute of Infection and Global Health, Liverpool, UK
| | - Simon R Harris
- The Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, UK
| | - Feyruz Yalcin
- The Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, UK
| | - Madikay Senghore
- Medical Research Council, Banjul, The Gambia.,Division of Translational and Systems Medicine, Microbiology and Infection Unit, The University of Warwick, Coventry, UK
| | - Anmol M Kiran
- The Malawi-Liverpool-Wellcome Trust Clinical Research Programme, University of Malawi College of Medicine, Blantyre, Malawi.,University of Liverpool, Institute of Infection and Global Health, Liverpool, UK
| | - Shanil Govindpershad
- National Institute for Communicable Diseases, Division of the National Health Laboratory Service; and School of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Sani Ousmane
- Centre de Recherche Médicale et Sanitaire, Niamey, Niger
| | - Mignon Du Plessis
- National Institute for Communicable Diseases, Division of the National Health Laboratory Service; and School of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Gerd Pluschke
- Swiss Tropical and Public Health Institute, Basel, Switzerland
| | - Chinelo Ebruke
- Medical Research Council, Banjul, The Gambia.,Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK
| | - Lesley McGee
- Centers for Disease Control and Prevention, Atlanta, GA, USA
| | - Beutel Sigaùque
- Centro de Investigação em Saúde da Manhiça, Maputo, Mozambique
| | | | - Martin Antonio
- Medical Research Council, Banjul, The Gambia.,Division of Translational and Systems Medicine, Microbiology and Infection Unit, The University of Warwick, Coventry, UK.,Faculty of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK
| | - Anne von Gottberg
- National Institute for Communicable Diseases, Division of the National Health Laboratory Service; and School of Pathology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Neil French
- University of Liverpool, Institute of Infection and Global Health, Liverpool, UK
| | - Keith P Klugman
- Hubert Department of Global Health, Rollins School of Public Health, Emory University, Atlanta, GA, USA
| | - Robert S Heyderman
- The Malawi-Liverpool-Wellcome Trust Clinical Research Programme, University of Malawi College of Medicine, Blantyre, Malawi
| | - Stephen D Bentley
- The Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, UK
| | - Dean B Everett
- The Malawi-Liverpool-Wellcome Trust Clinical Research Programme, University of Malawi College of Medicine, Blantyre, Malawi.,University of Liverpool, Institute of Infection and Global Health, Liverpool, UK
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13
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Manzoor I, Shafeeq S, Afzal M, Kuipers OP. Fucose-Mediated Transcriptional Activation of the fcs Operon by FcsR in Streptococcus pneumoniae. J Mol Microbiol Biotechnol 2015; 25:120-8. [DOI: 10.1159/000377724] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
In this study, we explore the impact of fucose on the transcriptome of <i>S. pneumoniae</i> D39. The expression of various genes and operons, including the fucose uptake PTS and utilization operon (<i>fcs</i> operon) was altered in the presence of fucose. By means of quantitative RT-PCR and β-galactosidase analysis, we demonstrate the role of the transcriptional regulator FcsR, present upstream of the <i>fcs</i> operon, as a transcriptional activator of the <i>fcs</i> operon. We also predict a 19-bp putative FcsR regulatory site (5′-ATTTGAACATTATTCAAGT-3′) in the promoter region of the <i>fcs</i> operon. The functionality of this predicted FcsR regulatory site was further confirmed by promoter-truncation experiments, where deletion of half of the FscR regulatory site or full deletion led to the abolition of expression of the <i>fcs</i> operon.
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14
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Paixão L, Oliveira J, Veríssimo A, Vinga S, Lourenço EC, Ventura MR, Kjos M, Veening JW, Fernandes VE, Andrew PW, Yesilkaya H, Neves AR. Host glycan sugar-specific pathways in Streptococcus pneumoniae: galactose as a key sugar in colonisation and infection [corrected]. PLoS One 2015; 10:e0121042. [PMID: 25826206 PMCID: PMC4380338 DOI: 10.1371/journal.pone.0121042] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2014] [Accepted: 02/12/2015] [Indexed: 01/13/2023] Open
Abstract
The human pathogen Streptococcus pneumoniae is a strictly fermentative organism that relies on glycolytic metabolism to obtain energy. In the human nasopharynx S. pneumoniae encounters glycoconjugates composed of a variety of monosaccharides, which can potentially be used as nutrients once depolymerized by glycosidases. Therefore, it is reasonable to hypothesise that the pneumococcus would rely on these glycan-derived sugars to grow. Here, we identified the sugar-specific catabolic pathways used by S. pneumoniae during growth on mucin. Transcriptome analysis of cells grown on mucin showed specific upregulation of genes likely to be involved in deglycosylation, transport and catabolism of galactose, mannose and N acetylglucosamine. In contrast to growth on mannose and N-acetylglucosamine, S. pneumoniae grown on galactose re-route their metabolic pathway from homolactic fermentation to a truly mixed acid fermentation regime. By measuring intracellular metabolites, enzymatic activities and mutant analysis, we provide an accurate map of the biochemical pathways for galactose, mannose and N-acetylglucosamine catabolism in S. pneumoniae. Intranasal mouse infection models of pneumococcal colonisation and disease showed that only mutants in galactose catabolic genes were attenuated. Our data pinpoint galactose as a key nutrient for growth in the respiratory tract and highlights the importance of central carbon metabolism for pneumococcal pathogenesis.
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Affiliation(s)
- Laura Paixão
- Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Joana Oliveira
- Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Oeiras, Portugal
| | - André Veríssimo
- Centre for Intelligent Systems, LAETA, IDMEC, Instituto Superior Técnico, Universidade de Lisboa, Lisboa, Portugal
| | - Susana Vinga
- Centre for Intelligent Systems, LAETA, IDMEC, Instituto Superior Técnico, Universidade de Lisboa, Lisboa, Portugal
| | - Eva C. Lourenço
- Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Oeiras, Portugal
| | - M. Rita Ventura
- Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Oeiras, Portugal
| | - Morten Kjos
- Molecular Genetics Group, Groningen Biomolecular Sciences and Biotechnology Institute, Centre for Synthetic Biology, University of Groningen, Groningen, The Netherlands
| | - Jan-Willem Veening
- Molecular Genetics Group, Groningen Biomolecular Sciences and Biotechnology Institute, Centre for Synthetic Biology, University of Groningen, Groningen, The Netherlands
| | - Vitor E. Fernandes
- Department of Infection, Immunity & Inflammation, University of Leicester, Leicester, United Kingdom
| | - Peter W. Andrew
- Department of Infection, Immunity & Inflammation, University of Leicester, Leicester, United Kingdom
| | - Hasan Yesilkaya
- Department of Infection, Immunity & Inflammation, University of Leicester, Leicester, United Kingdom
| | - Ana Rute Neves
- Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Oeiras, Portugal
- * E-mail:
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15
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Tavares DA, Simões AS, Bootsma HJ, Hermans PWM, de Lencastre H, Sá-Leão R. Non-typeable pneumococci circulating in Portugal are of cps type NCC2 and have genomic features typical of encapsulated isolates. BMC Genomics 2014; 15:863. [PMID: 25283442 PMCID: PMC4200197 DOI: 10.1186/1471-2164-15-863] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2014] [Accepted: 09/29/2014] [Indexed: 11/24/2022] Open
Abstract
BACKGROUND Pneumococcus is a major human pathogen and the polysaccharide capsule is considered its main virulence factor. Nevertheless, strains lacking a capsule, named non-typeable pneumococcus (NT), are maintained in nature and frequently colonise the human nasopharynx. Interest in these strains, not targeted by any of the currently available pneumococcal vaccines, has been rising as they seem to play an important role in the evolution of the species. Currently, there is a paucity of data regarding this group of pneumococci. Also, questions have been raised on whether they are true pneumococci. We aimed to obtain insights in the genetic content of NT and the mechanisms leading to non-typeability and to genetic diversity. RESULTS A collection of 52 NT isolates representative of the lineages circulating in Portugal between 1997 and 2007, as determined by pulsed-field gel electrophoresis and multilocus sequence typing, was analysed. The capsular region was sequenced and comparative genomic hybridisation (CGH) using a microarray covering the genome of 10 pneumococcal strains was carried out. The presence of mobile elements was investigated as source of intraclonal variation. NT circulating in Portugal were found to have similar capsular regions, of cps type NCC2, i.e., having aliB-like ORF1 and aliB-like ORF2 genes. The core genome of NT was essentially similar to that of encapsulated strains. Also, competence genes and most virulence genes were present. The few virulence genes absent in all NT were the capsular genes, type-I and type-II pili, choline-binding protein A (cbpA/pspC), and pneumococcal surface protein A (pspA). Intraclonal variation could not be entirely explained by the presence of prophages and other mobile elements. CONCLUSIONS NT circulating in Portugal are a homogeneous group belonging to cps type NCC2. Our observations support the theory that they are bona-fide pneumococcal isolates that do not express the capsule but are otherwise essentially similar to encapsulated pneumococci. Thus we propose that NT should be routinely identified and reported in surveillance studies.
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Affiliation(s)
- Débora A Tavares
- />Laboratory of Molecular Microbiology of Human Pathogens, Instituto de Tecnologia Química e Biológica (ITQB) António Xavier, Universidade Nova de Lisboa (UNL), Oeiras, Portugal
| | - Alexandra S Simões
- />Laboratory of Molecular Microbiology of Human Pathogens, Instituto de Tecnologia Química e Biológica (ITQB) António Xavier, Universidade Nova de Lisboa (UNL), Oeiras, Portugal
| | - Hester J Bootsma
- />Laboratory of Paediatric Infectious Diseases, Radboud University Nijmegen Medical Centre, Nijmegen, the Netherlands
| | - Peter WM Hermans
- />Laboratory of Paediatric Infectious Diseases, Radboud University Nijmegen Medical Centre, Nijmegen, the Netherlands
- />Crucell – Johnson and Johnson, Leiden, the Netherlands
| | - Hermínia de Lencastre
- />Laboratory of Molecular Genetics, ITQB, UNL, Oeiras, Portugal
- />Laboratory of Microbiology and Infectious Diseases, The Rockefeller University, New York, NY USA
| | - Raquel Sá-Leão
- />Laboratory of Molecular Microbiology of Human Pathogens, Instituto de Tecnologia Química e Biológica (ITQB) António Xavier, Universidade Nova de Lisboa (UNL), Oeiras, Portugal
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16
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Higgins MA, Suits MD, Marsters C, Boraston AB. Structural and Functional Analysis of Fucose-Processing Enzymes from Streptococcus pneumoniae. J Mol Biol 2014; 426:1469-82. [DOI: 10.1016/j.jmb.2013.12.006] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2013] [Revised: 12/02/2013] [Accepted: 12/05/2013] [Indexed: 10/25/2022]
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17
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Streptococcus pneumoniae biofilm formation is strain dependent, multifactorial, and associated with reduced invasiveness and immunoreactivity during colonization. mBio 2013; 4:e00745-13. [PMID: 24129258 PMCID: PMC3812715 DOI: 10.1128/mbio.00745-13] [Citation(s) in RCA: 85] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
UNLABELLED Biofilms are thought to play an important role during colonization of the nasopharynx by Streptococcus pneumoniae, yet how they form in vivo and the determinants responsible remain unknown. Using scanning electron microscopy, we show that biofilm aggregates of increasing complexity form on murine nasal septa following intranasal inoculation. These biofilms were highly distinct from in vitro biofilms, as they were discontiguous and appeared to incorporate nonbacterial components such as intact host cells. Biofilms initially formed on the surface of ciliated epithelial cells and, as cells were sloughed off, were found on the basement membrane. The size and number of biofilm aggregates within nasal lavage fluid were digitally quantitated and revealed strain-specific capabilities that loosely correlated with the ability to form robust in vitro biofilms. We tested the ability of isogenic mutants deficient in CbpA, pneumolysin, hydrogen peroxide, LytA, LuxS, CiaR/H, and PsrP to form biofilms within the nasopharynx. This analysis revealed that CiaR/H was absolutely required for colonization, that PsrP and SpxB strongly impacted aggregate formation, and that other determinants affected aggregate morphology in a modest fashion. We determined that mice colonized with ΔpsrP mutants had greater levels of the proinflammatory cytokines tumor necrosis factor alpha (TNF-α), interleukin-6 (IL-6), IL-1β, and KC in nasal lavage fluid than did mice colonized with wild-type controls. This phenotype correlated with a diminished capacity of biofilm pneumococci to invade host cells in vitro despite enhanced attachment. Our results show that biofilms form during colonization and suggest that they may contribute to persistence through a hyperadhesive, noninvasive state that elicits a dampened cytokine response. IMPORTANCE This work demonstrates the first temporal characterization of Streptococcus pneumoniae biofilm formation in vivo. Our results show that the morphology of biofilms formed by both invasive and noninvasive clinical isolates in vivo is distinct from that of formed biofilms in vitro, yet propensity to form biofilms in vivo loosely correlates with the degree of in vitro biofilm formation on a microtiter plate. We show that host components, including intact host cells, influence the formation of in vivo structures. We also found that efficient biofilm formation in vivo requires multiple bacterial determinants. While some factors are essential for in vivo biofilm formation (CiaRH, PsrP, and SpxB), other factors are less critical (CbpA, LytA, LuxS, and pneumolysin). In comparison to their planktonic counterparts, biofilm pneumococci are hyperadhesive but less invasive and elicit a weaker proinflammatory cytokine response. These findings give insight into the requirements for and potential role of biofilms during prolonged asymptomatic colonization.
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18
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Donkor ES, Stabler RA, Hinds J, Adegbola RA, Antonio M, Wren BW. Comparative phylogenomics of Streptococcus pneumoniae isolated from invasive disease and nasopharyngeal carriage from West Africans. BMC Genomics 2012; 13:569. [PMID: 23107513 PMCID: PMC3534514 DOI: 10.1186/1471-2164-13-569] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2012] [Accepted: 10/18/2012] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND We applied comparative phylogenomics (whole genome comparisons of microbes using DNA microarrays combined with Bayesian-based phylogenies) to investigate S. pneumoniae isolates from West Africa, with the aim of providing insights into the pathogenicity and other features related to the biology of the organism. The strains investigated comprised a well defined collection of 58 invasive and carriage isolates that were sequenced typed and included eight different S. pneumoniae serotypes (1, 3, 5, 6A, 11, 14, 19 F and 23 F) of varying invasive disease potential. RESULTS The core genome of the isolates was estimated to be 38% and was mainly represented by gene functional categories associated with housekeeping functions. Comparison of the gene content of invasive and carriage isolates identified at least eleven potential genes that may be important in virulence including surface proteins, transport proteins, transcription factors and hypothetical proteins. Thirteen accessory regions (ARs) were also identified and did not show any loci association with the eleven virulence genes. Intraclonal diversity (isolates of the same serotype and MLST but expressing different patterns of ARs) was observed among some clones including ST 1233 (serotype 5), ST 3404 (serotype 5) and ST 3321 (serotype 14). A constructed phylogenetic tree of the isolates showed a high level of heterogeneity consistent with the frequent S. pneumoniae recombination. Despite this, a homogeneous clustering of all the serotype 1 strains was observed. CONCLUSIONS Comparative phylogenomics of invasive and carriage S. pneumoniae isolates identified a number of putative virulence determinants that may be important in the progression of S. pneumoniae from the carriage phase to invasive disease. Virulence determinants that contribute to S. pneumoniae pathogenicity are likely to be distributed randomly throughout its genome rather than being clustered in dedicated loci or islands. Compared to other S. pneumoniae serotypes, serotype 1 appears most genetically uniform.
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Affiliation(s)
- Eric S Donkor
- Department of Pathogen Molecular Biology, London School of Hygiene and Tropical Medicine, London WC1E 7HT, UK
- Department of Microbiology, University of Ghana Medical School, Accra, Ghana
| | - Richard A Stabler
- Department of Pathogen Molecular Biology, London School of Hygiene and Tropical Medicine, London WC1E 7HT, UK
| | - Jason Hinds
- Bacterial Microarray Group, St. George’s University of London, London, SW17 0RE, UK
| | | | - Martin Antonio
- Vaccinology Theme, Medical Research Council Unit, The Gambia
| | - Brendan W Wren
- Department of Pathogen Molecular Biology, London School of Hygiene and Tropical Medicine, London WC1E 7HT, UK
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19
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Pneumococcal carbohydrate transport: food for thought. Trends Microbiol 2012; 20:517-22. [PMID: 22959614 DOI: 10.1016/j.tim.2012.08.008] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2012] [Revised: 08/10/2012] [Accepted: 08/16/2012] [Indexed: 02/05/2023]
Abstract
Streptococcus pneumoniae relies exclusively on carbohydrates as a carbon source and devotes 30% of all transport mechanisms to carbohydrate import. Pneumococci utilize at least 32 carbohydrates in vitro. However, some proposed substrates are not human-derived, so it is unclear where they are encountered in the host niche, and other substrates remain unidentified. The majority of transporter loci are conserved, arguing against redundancy and instead for distinct roles during pathogenesis. Despite this, expression and regulation of carbohydrate transporters in vivo remain ill defined. Recent work has also demonstrated that multiple ABC transporters share an ATPase; whether this evolved for genome minimization or for transporter regulation remains unknown. Continued efforts to understand carbohydrate import may reveal novel vaccine and therapeutic targets and increase our understanding of pneumococcal pathogenesis.
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20
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Bidossi A, Mulas L, Decorosi F, Colomba L, Ricci S, Pozzi G, Deutscher J, Viti C, Oggioni MR. A functional genomics approach to establish the complement of carbohydrate transporters in Streptococcus pneumoniae. PLoS One 2012; 7:e33320. [PMID: 22428019 PMCID: PMC3302838 DOI: 10.1371/journal.pone.0033320] [Citation(s) in RCA: 134] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2011] [Accepted: 02/10/2012] [Indexed: 01/02/2023] Open
Abstract
The aerotolerant anaerobe Streptococcus pneumoniae is part of the normal nasopharyngeal microbiota of humans and one of the most important invasive pathogens. A genomic survey allowed establishing the occurrence of twenty-one phosphotransferase systems, seven carbohydrate uptake ABC transporters, one sodium:solute symporter and a permease, underlining an exceptionally high capacity for uptake of carbohydrate substrates. Despite high genomic variability, combined phenotypic and genomic analysis of twenty sequenced strains did assign the substrate specificity only to two uptake systems. Systematic analysis of mutants for most carbohydrate transporters enabled us to assign a phenotype and substrate specificity to twenty-three transport systems. For five putative transporters for galactose, pentoses, ribonucleosides and sulphated glycans activity was inferred, but not experimentally confirmed and only one transport system remains with an unknown substrate and lack of any functional annotation. Using a metabolic approach, 80% of the thirty-two fermentable carbon substrates were assigned to the corresponding transporter. The complexity and robustness of sugar uptake is underlined by the finding that many transporters have multiple substrates, and many sugars are transported by more than one system. The present work permits to draw a functional map of the complete arsenal of carbohydrate utilisation proteins of pneumococci, allows re-annotation of genomic data and might serve as a reference for related species. These data provide tools for specific investigation of the roles of the different carbon substrates on pneumococcal physiology in the host during carriage and invasive infection.
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Affiliation(s)
- Alessandro Bidossi
- Lab. Microbiologia Molecolare e Biotecnologia, Dip. Biologia Molecolare, Università di Siena, Siena, Italy
| | - Laura Mulas
- Lab. Microbiologia Molecolare e Biotecnologia, Dip. Biologia Molecolare, Università di Siena, Siena, Italy
| | - Francesca Decorosi
- Sezione Microbiologia, Dip. Biotecnologie Agrarie, Università degli Studi di Firenze, Firenze, Italy
| | - Leonarda Colomba
- Lab. Microbiologia Molecolare e Biotecnologia, Dip. Biologia Molecolare, Università di Siena, Siena, Italy
| | - Susanna Ricci
- Lab. Microbiologia Molecolare e Biotecnologia, Dip. Biologia Molecolare, Università di Siena, Siena, Italy
| | - Gianni Pozzi
- Lab. Microbiologia Molecolare e Biotecnologia, Dip. Biologia Molecolare, Università di Siena, Siena, Italy
- UOC Batteriologia, Azienda Ospedaliera Universitaria Senese, Siena, Italy
| | | | - Carlo Viti
- Sezione Microbiologia, Dip. Biotecnologie Agrarie, Università degli Studi di Firenze, Firenze, Italy
| | - Marco Rinaldo Oggioni
- Lab. Microbiologia Molecolare e Biotecnologia, Dip. Biologia Molecolare, Università di Siena, Siena, Italy
- UOC Batteriologia, Azienda Ospedaliera Universitaria Senese, Siena, Italy
- * E-mail:
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21
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McAllister LJ, Ogunniyi AD, Stroeher UH, Paton JC. Contribution of a genomic accessory region encoding a putative cellobiose phosphotransferase system to virulence of Streptococcus pneumoniae. PLoS One 2012; 7:e32385. [PMID: 22363821 PMCID: PMC3283741 DOI: 10.1371/journal.pone.0032385] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2011] [Accepted: 01/27/2012] [Indexed: 11/29/2022] Open
Abstract
Streptococcus pneumoniae (the pneumococcus) is a formidable human pathogen, responsible for massive global morbidity and mortality. The ability to utilize carbohydrates in a variety of host niches appears to be integral to pneumococcal pathogenesis. In this study we investigated a genomic island, which includes a ROK family protein, a putative cellobiose phosphotransferase system (PTS) and a putative sulfatase. This accessory region is widespread in the pneumococcus in strains of various serotypes and levels of virulence. We have performed simple bioinformatic analysis of the region and investigated its role in vivo in 2 strains with markedly different virulence profiles (WCH206 of serotype 3, ST180; Menzies5 of serotype 11A, ST662). Deleting and replacing the entire island with an antibiotic resistance cassette caused the virulent serotype 3 strain to become attenuated in a murine pneumonia/sepsis model. Further mutants were constructed and used to show that various components of the island contribute significantly to the fitness of WCH206 in a variety of niches of this model, including the nasopharynx, ears and blood, but especially in the lungs. In addition, the island conferred a competitive advantage in nasopharyngeal colonization for the serotype 11A strain, which was essentially avirulent in the pneumonia/sepsis model. The contribution of this island to both pathogenesis and colonization may explain why this accessory region is widespread in the pneumococcus.
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Affiliation(s)
| | | | | | - James C. Paton
- Research Centre for Infectious Diseases, School of Molecular and Biomedical Science, University of Adelaide, Adelaide, South Australia, Australia
- * E-mail:
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22
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Higgins MA, Boraston AB. Structure of the fucose mutarotase from Streptococcus pneumoniae in complex with L-fucose. Acta Crystallogr Sect F Struct Biol Cryst Commun 2011; 67:1524-1530. [PMID: 22139157 PMCID: PMC3232130 DOI: 10.1107/s1744309111046343] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2011] [Accepted: 11/03/2011] [Indexed: 05/31/2023]
Abstract
Streptococcus pneumoniae relies on a variety of carbohydrate-utilization pathways for both colonization of its human host and full virulence during the development of invasive disease. One such pathway is the fucose-utilization pathway, a component of which is fucose mutarotase (SpFcsU), an enzyme that performs the interconversion between α-L-fucose and β-L-fucose. This protein was crystallized and its three-dimensional structure was solved in complex with L-fucose. The structure shows a complex decameric quaternary structure with a high overall degree of structural identity to Escherichia coli FcsU (EcFcsU). Furthermore, the active-site architecture of SpFcsU is highly similar to that of EcFcsU. When considered in the context of the fucose-utilization pathway found in S. pneumoniae, SpFcsU appears to link the two halves of the pathway by enhancing the rate of conversion of the product of the final glycoside hydrolysis step, β-fucose, into the substrate for the fucose isomerase, α-fucose.
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Affiliation(s)
- Melanie A. Higgins
- Department of Biochemistry and Microbiology, University of Victoria, PO Box 3055 STN CSC, Victoria, BC V8W 3P6, Canada
| | - Alisdair B. Boraston
- Department of Biochemistry and Microbiology, University of Victoria, PO Box 3055 STN CSC, Victoria, BC V8W 3P6, Canada
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23
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McAllister LJ, Ogunniyi AD, Stroeher UH, Leach AJ, Paton JC. Contribution of serotype and genetic background to virulence of serotype 3 and serogroup 11 pneumococcal isolates. Infect Immun 2011; 79:4839-49. [PMID: 21930754 PMCID: PMC3232656 DOI: 10.1128/iai.05663-11] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2011] [Accepted: 09/12/2011] [Indexed: 11/20/2022] Open
Abstract
The capsular serotype has long been associated with the virulence of Streptococcus pneumoniae. Here we present an in-depth study of phenotypic and genetic differences between serotype 3 and serogroup 11 S. pneumoniae clinical isolates from both the general and indigenous populations of Australia. Both serotypes/groups included clonally unrelated strains with differences in well-known polymorphic virulence genes, such as nanA and pspA, as demonstrated by multilocus sequence typing and Western blot analysis. Nonetheless, the serotype 3 strains were consistently and significantly more virulent in mice than the serogroup 11 strains. Despite extensive genomic analysis, noncapsular genes common to one serotype/group but not the other were not identified. Nevertheless, following the conversion of a serotype 11A isolate to serotype 3 and subsequent analysis in an intranasal infection model, it was evident that both capsular and noncapsular factors determine the virulence phenotype in mice. However, it appears that these noncapsular factors vary from strain to strain.
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Affiliation(s)
- Lauren J. McAllister
- Research Centre for Infectious Diseases, School of Molecular and Biomedical Science, University of Adelaide, Adelaide 5005, South Australia, Australia
| | - Abiodun D. Ogunniyi
- Research Centre for Infectious Diseases, School of Molecular and Biomedical Science, University of Adelaide, Adelaide 5005, South Australia, Australia
| | - Uwe H. Stroeher
- Research Centre for Infectious Diseases, School of Molecular and Biomedical Science, University of Adelaide, Adelaide 5005, South Australia, Australia
| | - Amanda J. Leach
- Menzies School of Health Research, Charles Darwin University, Darwin, Northern Territory 0811, Australia
| | - James C. Paton
- Research Centre for Infectious Diseases, School of Molecular and Biomedical Science, University of Adelaide, Adelaide 5005, South Australia, Australia
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24
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Hyams C, Opel S, Hanage W, Yuste J, Bax K, Henriques-Normark B, Spratt BG, Brown JS. Effects of Streptococcus pneumoniae strain background on complement resistance. PLoS One 2011; 6:e24581. [PMID: 22022358 PMCID: PMC3192701 DOI: 10.1371/journal.pone.0024581] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2011] [Accepted: 08/15/2011] [Indexed: 01/04/2023] Open
Abstract
Background Immunity to infections caused by Streptococcus pneumoniae is dependent on complement. There are wide variations in sensitivity to complement between S. pneumoniae strains that could affect their ability to cause invasive infections. Although capsular serotype is one important factor causing differences in complement resistance between strains, there is also considerable other genetic variation between S. pneumoniae strains that may affect complement-mediated immunity. We have therefore investigated whether genetically distinct S. pneumoniae strains with the same capsular serotype vary in their sensitivity to complement mediated immunity. Methodology and Principal Findings C3b/iC3b deposition and neutrophil association were measured using flow cytometry assays for S. pneumoniae strains with different genetic backgrounds for each of eight capsular serotypes. For some capsular serotypes there was marked variation in C3b/iC3b deposition between different strains that was independent of capsule thickness and correlated closely to susceptibility to neutrophil association. C3b/iC3b deposition results also correlated weakly with the degree of IgG binding to each strain. However, the binding of C1q (the first component of the classical pathway) correlated more closely with C3b/iC3b deposition, and large differences remained in complement sensitivity between strains with the same capsular serotype in sera in which IgG had been cleaved with IdeS. Conclusions These data demonstrate that bacterial factors independent of the capsule and recognition by IgG have strong effects on the susceptibility of S. pneumoniae to complement, and could therefore potentially account for some of the differences in virulence between strains.
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Affiliation(s)
- Catherine Hyams
- Centre for Respiratory Research, Department of Medicine, University College Medical School, Rayne Institute, London, United Kingdom
| | - Sophia Opel
- Centre for Respiratory Research, Department of Medicine, University College Medical School, Rayne Institute, London, United Kingdom
| | - William Hanage
- Department of Epidemiology, Harvard School of Public Health, Boston, Massachusetts, United States of America
| | - Jose Yuste
- Spanish Pneumococcal Reference Laboratory, Centro Nacional de Microbiologia, Instituto de Salud Carlos III, Majadahonda, Madrid, Spain
| | - Katie Bax
- Department of Anatomy, University College London, London, United Kingdom
| | - Birgitta Henriques-Normark
- Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet and the Swedish Institute for Infectious Disease Control, Stockholm, Sweden
| | - Brian G. Spratt
- Department of Infectious Disease Epidemiology, St. Mary's Hospital Campus, Imperial College London, London, United Kingdom
| | - Jeremy S. Brown
- Centre for Respiratory Research, Department of Medicine, University College Medical School, Rayne Institute, London, United Kingdom
- * E-mail:
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25
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Higgins MA, Ficko-Blean E, Meloncelli PJ, Lowary TL, Boraston AB. The overall architecture and receptor binding of pneumococcal carbohydrate-antigen-hydrolyzing enzymes. J Mol Biol 2011; 411:1017-36. [PMID: 21767550 DOI: 10.1016/j.jmb.2011.06.035] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2011] [Revised: 06/16/2011] [Accepted: 06/20/2011] [Indexed: 11/19/2022]
Abstract
The TIGR4 and SP3-BS71 strains of Streptococcus pneumoniae each produce family 98 glycoside hydrolases, called Sp4GH98 and Sp3GH98, respectively, which have different modular architectures and substrate specificities. Sp4GH98 degrades the Lewis(Y) antigen and possesses three C-terminal family 47 carbohydrate-binding modules (CBMs) that bind to this substrate. Sp3GH98 degrades the blood group A/B antigens and has two N-terminal family 51 CBMs that are of unknown function. Here, we examine the complex carbohydrate-binding specificity of the family 51 CBMs from Sp3GH98 (referred to as CBM51-1 and CBM51-2), the structural basis of this interaction, and the overall solution conformations of both Sp3GH98 and Sp4GH98, which are shown to be fully secreted proteins. Through glycan microarray binding analysis and isothermal titration calorimetry, CBM51-1 is found to bind specifically to the blood group A/B antigens. However, due to a series of relatively small structural rearrangements that were revealed in structures determined by X-ray crystallography, CBM51-2 appears to be incapable of binding carbohydrates. Analysis of small-angle X-ray scattering data in combination with the available high-resolution X-ray crystal structures of the Sp3GH98 and Sp4GH98 catalytic modules and their CBMs yielded models of the biological solution structures of the full-length enzymes. These studies reveal the complex architectures of the two enzymes and suggest that carbohydrate recognition by the CBMs and the activity of the catalytic modules are not directly coupled.
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Affiliation(s)
- Melanie A Higgins
- Biochemistry and Microbiology, University of Victoria, PO Box 3055 STN CSC, Victoria, BC, Canada V8W 3P6
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26
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Harvey RM, Stroeher UH, Ogunniyi AD, Smith-Vaughan HC, Leach AJ, Paton JC. A variable region within the genome of Streptococcus pneumoniae contributes to strain-strain variation in virulence. PLoS One 2011; 6:e19650. [PMID: 21573186 PMCID: PMC3088708 DOI: 10.1371/journal.pone.0019650] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2010] [Accepted: 04/08/2011] [Indexed: 01/12/2023] Open
Abstract
The bacterial factors responsible for the variation in invasive potential between different clones and serotypes of Streptococcus pneumoniae are largely unknown. Therefore, the isolation of rare serotype 1 carriage strains in Indigenous Australian communities provided a unique opportunity to compare the genomes of non-invasive and invasive isolates of the same serotype in order to identify such factors. The human virulence status of non-invasive, intermediately virulent and highly virulent serotype 1 isolates was reflected in mice and showed that whilst both human non-invasive and highly virulent isolates were able to colonize the murine nasopharynx equally, only the human highly virulent isolates were able to invade and survive in the murine lungs and blood. Genomic sequencing comparisons between these isolates identified 8 regions >1 kb in size that were specific to only the highly virulent isolates, and included a version of the pneumococcal pathogenicity island 1 variable region (PPI-1v), phage-associated adherence factors, transporters and metabolic enzymes. In particular, a phage-associated endolysin, a putative iron/lead permease and an operon within PPI-1v exhibited niche-specific changes in expression that suggest important roles for these genes in the lungs and blood. Moreover, in vivo competition between pneumococci carrying PPI-1v derivatives representing the two identified versions of the region showed that the version of PPI-1v in the highly virulent isolates was more competitive than the version from the less virulent isolates in the nasopharyngeal tissue, blood and lungs. This study is the first to perform genomic comparisons between serotype 1 isolates with distinct virulence profiles that correlate between mice and humans, and has highlighted the important role that hypervariable genomic loci, such as PPI-1v, play in pneumococcal disease. The findings of this study have important implications for understanding the processes that drive progression from colonization to invasive disease and will help direct the development of novel therapeutic strategies.
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Affiliation(s)
- Richard M. Harvey
- Research Centre for Infectious Diseases, School of Molecular and Biomedical Science, University of Adelaide, Adelaide, South Australia, Australia
| | - Uwe H. Stroeher
- Research Centre for Infectious Diseases, School of Molecular and Biomedical Science, University of Adelaide, Adelaide, South Australia, Australia
| | - Abiodun D. Ogunniyi
- Research Centre for Infectious Diseases, School of Molecular and Biomedical Science, University of Adelaide, Adelaide, South Australia, Australia
| | - Heidi C. Smith-Vaughan
- Menzies School of Health Research, Charles Darwin University, Darwin, Northern Territory, Australia
| | - Amanda J. Leach
- Menzies School of Health Research, Charles Darwin University, Darwin, Northern Territory, Australia
| | - James C. Paton
- Research Centre for Infectious Diseases, School of Molecular and Biomedical Science, University of Adelaide, Adelaide, South Australia, Australia
- * E-mail:
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27
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Everett DB, Mukaka M, Denis B, Gordon SB, Carrol ED, van Oosterhout JJ, Molyneux EM, Molyneux M, French N, Heyderman RS. Ten years of surveillance for invasive Streptococcus pneumoniae during the era of antiretroviral scale-up and cotrimoxazole prophylaxis in Malawi. PLoS One 2011; 6:e17765. [PMID: 21423577 PMCID: PMC3058053 DOI: 10.1371/journal.pone.0017765] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2010] [Accepted: 02/14/2011] [Indexed: 12/03/2022] Open
Abstract
Objective To document trends in invasive pneumococcal disease (IPD) in a central hospital in Malawi during the period of national scale-up of antiretroviral therapy (ART) and cotrimoxazole prophylaxis. Methods Between 1 January 2000 and 31 December 2009 almost 100,000 blood cultures and 40,000 cerebrospinal fluid (CSF) cultures were obtained from adults and children admitted to the Queen Elizabeth Central Hospital, Blantyre, Malawi with suspected severe bacterial infection. Results 4,445 pneumococcal isolates were obtained over the 10 year period. 1,837 were from children: 885 (19.9%) from blood and 952 (21.4%) from CSF. 2,608 were from adults: 1,813 (40.8%) from blood and 795 (17.9%) from CSF. At the start of the surveillance period cotrimoxazole resistance was 73.8% and at the end was 92.6%. Multidrug resistance (MDR) was present in almost one third of isolates and was constant over time. Free ART was introduced in Malawi in 2004. From 2005 onwards there was a decline in invasive pneumococcal infections with a negative correlation between ART scale-up and the decline in IPD (Pearson's correlation r = −0.91; p<0.001). Conclusion During 2004–2009, national ART scale-up in Malawi was associated with a downward trend in IPD at QECH. The introduction of cotrimoxazole prophylaxis in HIV-infected groups has not coincided with a further increase in pneumococcal cotrimoxazole or multidrug resistance. These data highlight the importance of surveillance for high disease burden infections such as IPD in the region, which will be vital for monitoring pneumococcal conjugate vaccine introduction into national immunisation programmes.
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Affiliation(s)
- Dean B Everett
- Malawi-Liverpool-Wellcome Trust Clinical Research Programme, College of Medicine, Chichiri, Blantyre, Malawi.
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28
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Sanchez CJ, Shivshankar P, Stol K, Trakhtenbroit S, Sullam PM, Sauer K, Hermans PWM, Orihuela CJ. The pneumococcal serine-rich repeat protein is an intra-species bacterial adhesin that promotes bacterial aggregation in vivo and in biofilms. PLoS Pathog 2010; 6:e1001044. [PMID: 20714350 PMCID: PMC2920850 DOI: 10.1371/journal.ppat.1001044] [Citation(s) in RCA: 143] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2010] [Accepted: 07/14/2010] [Indexed: 12/16/2022] Open
Abstract
The Pneumococcal serine-rich repeat protein (PsrP) is a pathogenicity island encoded adhesin that has been positively correlated with the ability of Streptococcus pneumoniae to cause invasive disease. Previous studies have shown that PsrP mediates bacterial attachment to Keratin 10 (K10) on the surface of lung cells through amino acids 273–341 located in the Basic Region (BR) domain. In this study we determined that the BR domain of PsrP also mediates an intra-species interaction that promotes the formation of large bacterial aggregates in the nasopharynx and lungs of infected mice as well as in continuous flow-through models of mature biofilms. Using numerous methods, including complementation of mutants with BR domain deficient constructs, fluorescent microscopy with Cy3-labeled recombinant (r)BR, Far Western blotting of bacterial lysates, co-immunoprecipitation with rBR, and growth of biofilms in the presence of antibodies and competitive peptides, we determined that the BR domain, in particular amino acids 122–166 of PsrP, promoted bacterial aggregation and that antibodies against the BR domain were neutralizing. Using similar methodologies, we also determined that SraP and GspB, the Serine-rich repeat proteins (SRRPs) of Staphylococcus aureus and Streptococcus gordonii, respectively, also promoted bacterial aggregation and that their Non-repeat domains bound to their respective SRRPs. This is the first report to show the presence of biofilm-like structures in the lungs of animals infected with S. pneumoniae and show that SRRPs have dual roles as host and bacterial adhesins. These studies suggest that recombinant Non-repeat domains of SRRPs (i.e. BR for S. pneumoniae) may be useful as vaccine antigens to protect against Gram-positive bacteria that cause infection. Serine-rich repeat proteins (SRRPs) are a family of surface-expressed proteins found in numerous Gram-positive pathogens, including Staphylococcus aureus, Streptococcus pneumoniae, Group B streptococci, and the oral streptococci that cause infective endocarditis. For all of these bacteria, SRRPs have been demonstrated to play pivotal roles in adhesion to tissues and the development of invasive disease. It is now known that biofilm formation is an important step for bacterial pathogenesis. Bacteria in biofilms have been shown to have differences in metabolism, gene expression, and protein production that contribute to enhanced surface adhesion and the persistence of an infection. Herein we describe a novel role for PsrP, the S. pneumoniae SRRP, as an intra-species bacterial adhesin that promotes bacterial aggregation in the lungs of infected mice during pneumonia. In vitro we show that the Basic Region domain of PsrP promotes self-interactions that result in denser biofilms, greater biofilm biomass, and altered architectures of surface grown cultures; these interactions could be neutralized by antibodies to PsrP that are protective against pneumococcal infection. We also demonstrate that the SRRPs of S. aureus and Streptococcus gordonii also function as intra-species bacterial adhesins. Therefore we conclude that SRRPs have dual roles as host-cell and intra-species bacterial adhesins.
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MESH Headings
- Adhesins, Bacterial/chemistry
- Adhesins, Bacterial/genetics
- Adhesins, Bacterial/metabolism
- Amino Acid Motifs
- Animals
- Bacterial Adhesion/physiology
- Biofilms/growth & development
- Blotting, Western
- Female
- Immunoprecipitation
- Mice
- Mice, Inbred BALB C
- Microscopy, Confocal
- Microscopy, Electron, Scanning
- Microscopy, Fluorescence
- Protein Structure, Tertiary/genetics
- Reverse Transcriptase Polymerase Chain Reaction
- Streptococcus pneumoniae/metabolism
- Streptococcus pneumoniae/pathogenicity
- Streptococcus pneumoniae/physiology
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Affiliation(s)
- Carlos J. Sanchez
- Department of Microbiology and Immunology, The University of Texas Health Science Center San Antonio, San Antonio, Texas, United States of America
| | - Pooja Shivshankar
- Department of Microbiology and Immunology, The University of Texas Health Science Center San Antonio, San Antonio, Texas, United States of America
| | - Kim Stol
- Laboratory of Pediatric Infectious Diseases, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
| | - Samuel Trakhtenbroit
- Department of Microbiology and Immunology, The University of Texas Health Science Center San Antonio, San Antonio, Texas, United States of America
| | - Paul M. Sullam
- Division of Infectious Diseases, San Francisco VA Medical Center and the University of California, San Francisco, California, United States of America
| | - Karin Sauer
- Department of Biological Sciences, Binghamton University, Binghamton, New York, United States of America
| | - Peter W. M. Hermans
- Laboratory of Pediatric Infectious Diseases, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands
| | - Carlos J. Orihuela
- Department of Microbiology and Immunology, The University of Texas Health Science Center San Antonio, San Antonio, Texas, United States of America
- * E-mail:
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29
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Lizcano A, Chin T, Sauer K, Tuomanen EI, Orihuela CJ. Early biofilm formation on microtiter plates is not correlated with the invasive disease potential of Streptococcus pneumoniae. Microb Pathog 2010; 48:124-30. [PMID: 20096771 DOI: 10.1016/j.micpath.2010.01.002] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2009] [Revised: 01/04/2010] [Accepted: 01/14/2010] [Indexed: 12/18/2022]
Abstract
Biofilm formation has been suggested to play an important role during Streptococcus pneumoniae nasopharyngeal colonization and may facilitate progression to pneumonia. To test whether the ability of S. pneumoniae to form biofilms was important for virulence we screened the ability of 30 invasive and 22 non-invasive clinical isolates of serotype 6A and 6B to form early biofilms on polystyrene microtiter plates and infect mice following intranasal and intratracheal challenge. We first determined that no correlation existed between the ability to form early biofilms and whether isolates were collected from healthy carriers or individuals with invasive disease. A disconnect between biofilm forming ability and the capacity to colonize the nasopharynx, cause pneumonia, and enter the bloodstream was also observed in mice. Importantly, S. pneumoniae mutants deficient in the established virulence determinants pneumolysin, CbpA, and hydrogen peroxide formed biofilms normally. Incidentally, we determined that robust biofilm production was dependent on the formation and coalescing of bacterial aggregates on a thin layer of bacteria attached to the plate surface. In summary, these studies suggest that the ability to form early biofilms in vitro does not reflect virulence potential. More complex studies are required to determine if biofilm formation is important for virulence.
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Affiliation(s)
- Anel Lizcano
- Department of Microbiology and Immunology, The University of Texas Health Science Center at San Antonio, San Antonio, TX 78229, USA
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30
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Higgins MA, Whitworth GE, El Warry N, Randriantsoa M, Samain E, Burke RD, Vocadlo DJ, Boraston AB. Differential recognition and hydrolysis of host carbohydrate antigens by Streptococcus pneumoniae family 98 glycoside hydrolases. J Biol Chem 2009; 284:26161-73. [PMID: 19608744 DOI: 10.1074/jbc.m109.024067] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The presence of a fucose utilization operon in the Streptococcus pneumoniae genome and its established importance in virulence indicates a reliance of this bacterium on the harvesting of host fucose-containing glycans. The identities of these glycans, however, and how they are harvested is presently unknown. The biochemical and high resolution x-ray crystallographic analysis of two family 98 glycoside hydrolases (GH98s) from distinctive forms of the fucose utilization operon that originate from different S. pneumoniae strains reveal that one enzyme, the predominant type among pneumococcal isolates, has a unique endo-beta-galactosidase activity on the LewisY antigen. Altered active site topography in the other species of GH98 enzyme tune its endo-beta-galactosidase activity to the blood group A and B antigens. Despite their different specificities, these enzymes, and by extension all family 98 glycoside hydrolases, use an inverting catalytic mechanism. Many bacterial and viral pathogens exploit host carbohydrate antigens for adherence as a precursor to colonization or infection. However, this is the first evidence of bacterial endoglycosidase enzymes that are known to play a role in virulence and are specific for distinct host carbohydrate antigens. The strain-specific distribution of two distinct types of GH98 enzymes further suggests that S. pneumoniae strains may specialize to exploit host-specific antigens that vary from host to host, a factor that may feature in whether a strain is capable of colonizing a host or establishing an invasive infection.
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Affiliation(s)
- Melanie A Higgins
- Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia V8W 3P6, Canada
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31
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Shivshankar P, Sanchez C, Rose LF, Orihuela CJ. The Streptococcus pneumoniae adhesin PsrP binds to Keratin 10 on lung cells. Mol Microbiol 2009; 73:663-79. [PMID: 19627498 DOI: 10.1111/j.1365-2958.2009.06796.x] [Citation(s) in RCA: 120] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Pneumococcal serine-rich repeat protein (PsrP) is a pathogenicity island-encoded adhesin that mediates attachment to lung cells. It is a member of the serine-rich repeat protein family and the largest bacterial protein known. PsrP production by S. pneumoniae was confirmed by immunoblotting and a truncated version of the protein was determined to be glycosylated. Using isogenic psrP mutants complemented with various PsrP constructs and competitive inhibition assays with recombinant proteins, we determined that PsrP requires an extended SRR2 domain for function and that adhesion is mediated through amino acids 273-341 of its basic region (BR) domain. Affinity chromatography, immunoprecipitation, enzyme-linked immunosorbent assay (ELISA), fluorescent-activated cell sorting (FACS) and immunofluorescent colocalization studies determined that PsrP binds to Keratin 10 (K10) on the surface of lung but not nasopharyngeal epithelial cells. Unglycosylated K10 bound to wild type but not psrP deficient pneumococci; suggesting that unlike other serine-rich repeat proteins, PsrP-mediated adhesion is independent of lectin activity. Finally, mice immunized with recombinant (r)PsrP(BR) had significantly less bacteria in their blood and improved survival versus controls following intranasal challenge. We conclude that the BR domain of PsrP binds to K10 in a lectin-independent manner, that K10 is expressed on lung cells and that vaccination with rPsrP(BR) is protective against pneumococcal disease.
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Affiliation(s)
- Pooja Shivshankar
- Department of Microbiology and Immunology, University of Texas Health Science Center at San Antonio, San Antonio, TX 78229-3900, USA
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32
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Blood group antigen recognition by a solute-binding protein from a serotype 3 strain of Streptococcus pneumoniae. J Mol Biol 2009; 388:299-309. [PMID: 19285508 DOI: 10.1016/j.jmb.2009.03.012] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2009] [Revised: 02/27/2009] [Accepted: 03/05/2009] [Indexed: 11/22/2022]
Abstract
Streptococcus pneumoniae is a common bacterial pathogen that is well known for its ability to cause acute respiratory disease (pneumonia), ear infections, and other serious illnesses. This Gram-positive bacterium relies on its carbohydrate-metabolizing capabilities for full virulence in its host; however, the range of glycan targets that it can attack is presently not fully appreciated. S. pneumoniae is known to have a fucose utilization operon that in the TIGR4 strain plays a role in its virulence. Here we identify a second type of fucose utilization operon that is present in a subset of S. pneumoniae strains, including the serotype 3 strain SP3-BS71. This operon contains a transporter with a solute-binding protein, FcsSBP (fucose solute-binding protein), that interacts tightly (Ka approximately 1 x 10(6) M(-1)) and specifically with soluble A- and B-antigen trisaccharides but displays no selectivity between these two sugars. The structure of the FcsSBP in complex with the A-trisaccharide antigen, determined to 2.35 A, reveals its mode of binding to the reducing end of this sugar, thus highlighting this protein's requirement for soluble blood group antigen ligands. Overall, this report exposes a heretofore unknown capability of certain S. pneumoniae strains to transport and potentially metabolize the histo-blood group antigen carbohydrates of its host.
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Shelburne SA, Davenport MT, Keith DB, Musser JM. The role of complex carbohydrate catabolism in the pathogenesis of invasive streptococci. Trends Microbiol 2008; 16:318-25. [PMID: 18508271 DOI: 10.1016/j.tim.2008.04.002] [Citation(s) in RCA: 91] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2008] [Revised: 04/03/2008] [Accepted: 04/11/2008] [Indexed: 01/09/2023]
Abstract
Historically, the study of bacterial catabolism of complex carbohydrates has contributed to understanding basic bacterial physiology. Recently, however, genome-wide screens of streptococcal pathogenesis have identified genes encoding proteins involved in complex carbohydrate catabolism as participating in pathogen infectivity. Subsequent studies have focused on specific mechanisms by which carbohydrate utilization proteins might contribute to the ability of streptococci to colonize and infect the host. Moreover, transcriptome and biochemical analyses have uncovered novel regulatory pathways by which streptococci link environmental carbohydrate availability to virulence factor production. Herein we review new insights into the role of complex carbohydrates in streptococcal host-pathogen interaction.
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Affiliation(s)
- Samuel A Shelburne
- Section of Infectious Diseases, Department of Medicine, Baylor College of Medicine, 1 Baylor Plaza, Houston, TX 77030, USA
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