70 results on '"Deora R"'
Search Results
2. Mechanism for regulation of DNA binding of Bordetella bronchiseptica BpsR by 6-hydroxynicotinic acid
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Booth, W.T., primary, Davis, R.R., additional, Deora, R., additional, and Hollis, T., additional
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- 2019
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3. Polysaccharides Cellulose, Poly- -1,6-N-Acetyl-D-Glucosamine, and Colanic Acid Are Required for Optimal Binding of Escherichia coli O157:H7 Strains to Alfalfa Sprouts and K-12 Strains to Plastic but Not for Binding to Epithelial Cells
- Author
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Deora, R., Torres, A. G., Matthysse, A. G., and Mishra, M.
- Abstract
When Escherichia coli O157:H7 bacteria are added to alfalfa sprouts growing in water, the bacteria bind tightly to the sprouts. In contrast, laboratory K-12 strains of E. coli do not bind to sprouts under similar conditions. The roles of E. coli O157:H7 lipopolysaccharide (LPS), capsular polysaccharide, and exopolysaccharides in binding to sprouts were examined. An LPS mutant had no effect on the binding of the pathogenic strain. Cellulose synthase mutants showed a significant reduction in binding; colanic acid mutants were more severely reduced, and binding by poly-β-1,6-N-acetylglucosamine (PGA) mutants was barely detectable. The addition of a plasmid carrying a cellulose synthase gene to K-12 strains allowed them to bind to sprouts. A plasmid carrying the Bps biosynthesis genes had only a marginal effect on the binding of K-12 bacteria. However, the introduction of the same plasmid allowed Sinorhizobium meliloti and a nonbinding mutant of Agrobacterium tumefaciens to bind to tomato root segments. These results suggest that although multiple redundant protein adhesins are involved in the binding of E. coli O157:H7 to sprouts, the polysaccharides required for binding are not redundant and each polysaccharide may play a distinct role. PGA, colanic acid, and cellulose were also required for biofilm formation by a K-12 strain on plastic, but not for the binding of E. coli O157:H7 to mammalian cells.
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- 2008
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4. The influence of litter quality and micro-habitat on litter decomposition and soil properties in a silvopasture system
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Tripathi, G., primary, Deora, R., additional, and Singh, G., additional
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- 2013
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5. Bordetella bronchiseptica in a Paediatric Cystic Fibrosis Patient: Possible Transmission from a Household Cat
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Register, K. B., primary, Sukumar, N., additional, Palavecino, E. L., additional, Rubin, B. K., additional, and Deora, R., additional
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- 2012
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6. A phosphorylation site in Bruton's tyrosine kinase selectively regulates B cell calcium signaling efficiency by altering phospholipase C- activation
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Guo, S., primary, Ferl, G. Z., additional, Deora, R., additional, Riedinger, M., additional, Yin, S., additional, Kerwin, J. L., additional, Loo, J. A., additional, and Witte, O. N., additional
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- 2004
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7. Alternative transcription factor sigmaSB of Staphylococcus aureus: characterization and role in transcription of the global regulatory locus sar
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Deora, R, primary, Tseng, T, additional, and Misra, T K, additional
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- 1997
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8. Purification and Characterization of DNA-Dependent RNA Polymerase from Staphylococcus aureus
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Deora, R., primary and Misra, T.K., additional
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- 1995
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9. The adjuvant BcfA activates antigen presenting cells through TLR4 and supports T FH and T H 1 while attenuating T H 2 gene programming.
- Author
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Shamseldin MM, Read KA, Hall JM, Tuazon JA, Brown JM, Guo M, Gupta YA, Deora R, Oestreich KJ, and Dubey P
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- Animals, Mice, Humans, Antigen-Presenting Cells immunology, Antigen-Presenting Cells metabolism, Mice, Knockout, Dendritic Cells immunology, Mice, Inbred C57BL, T Follicular Helper Cells immunology, Cytokines metabolism, Lymphocyte Activation immunology, Toll-Like Receptor 4 immunology, Toll-Like Receptor 4 metabolism, Th1 Cells immunology, Th2 Cells immunology, Adjuvants, Immunologic pharmacology
- Abstract
Introduction: Adjuvants added to subunit vaccines augment antigen-specific immune responses. One mechanism of adjuvant action is activation of pattern recognition receptors (PRRs) on innate immune cells. Bordetella colonization factor A (BcfA); an outer membrane protein with adjuvant function, activates T
H 1/TH 17-polarized immune responses to protein antigens from Bordetella pertussis and SARS CoV-2. Unlike other adjuvants, BcfA does not elicit a TH 2 response., Methods: To understand the mechanism of BcfA-driven TH 1/TH 17 vs. TH 2 activation, we screened PRRs to identify pathways activated by BcfA. We then tested the role of this receptor in the BcfA-mediated activation of bone marrow-derived dendritic cells (BMDCs) using mice with germline deletion of TLR4 to quantify upregulation of costimulatory molecule expression and cytokine production in vitro and in vivo. Activity was also tested on human PBMCs., Results: PRR screening showed that BcfA activates antigen presenting cells through murine TLR4. BcfA-treated WT BMDCs upregulated expression of the costimulatory molecules CD40, CD80, and CD86 and produced IL-6, IL-12/23 p40, and TNF-α while TLR4 KO BMDCs were not activated. Furthermore, human PBMCs stimulated with BcfA produced IL-6. BcfA-stimulated murine BMDCs also exhibited increased uptake of the antigen DQ-OVA, supporting a role for BcfA in improving antigen presentation to T cells. BcfA further activated APCs in murine lungs. Using an in vitro TH cell polarization system, we found that BcfA-stimulated BMDC supernatant supported TFH and TH 1 while suppressing TH 2 gene programming., Conclusions: Overall, these data provide mechanistic understanding of how this novel adjuvant activates immune responses., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. The author(s) declared that they were an editorial board member of Frontiers, at the time of submission. This had no impact on the peer review process and the final decision., (Copyright © 2024 Shamseldin, Read, Hall, Tuazon, Brown, Guo, Gupta, Deora, Oestreich and Dubey.)- Published
- 2024
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10. Opposing effects of acellular and whole cell pertussis vaccines on Bordetella pertussis biofilm formation, Siglec-F+ neutrophil recruitment and bacterial clearance in mouse nasal tissues.
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Hall JM, Gutiérrez-Ferman JL, Shamseldin MM, Guo M, Gupta YA, Deora R, and Dubey P
- Abstract
Despite global vaccination, pertussis caused by Bordetella pertussis ( Bp ) is resurging. Pertussis resurgence is correlated with the switch from whole cell vaccines (wPV) that elicit T
H 1/TH 17 polarized immune responses to acellular pertussis vaccines (aPV) that elicit primarily TH 2 polarized immune responses. One explanation for the increased incidence in aPV-immunized individuals is the lack of bacterial clearance from the nose. To understand the host and bacterial mechanisms that contribute to Bp persistence, we evaluated bacterial localization and the immune response in the nasal associated tissues (NT) of naïve and immunized mice following Bp challenge. Bp resided in the NT of unimmunized and aPV-immunized mice as biofilms. In contrast, Bp biofilms were not observed in wPV-immunized mice. Following infection, Siglec-F+ neutrophils, critical for eliminating Bp from the nose, were recruited to the nose at higher levels in wPV immunized mice compared to aPV immunized mice. Consistent with this observation, the neutrophil chemokine CXCL1 was only detected in the NT of wPV immunized mice. Importantly, the bacteria and immune cells were primarily localized within the NT and were not recovered by nasal lavage (NL). Together, our data suggest that the TH 2 polarized immune response generated by aPV vaccination facilitates persistence in the NT by impeding the infiltration of immune effectors and the eradication of biofilms In contrast, the TH 1/TH 17 immune phenotype generated by wPV, recruits Siglec-F+ neutrophils that rapidly eliminate the bacterial burden and prevent biofilm establishment. Thus, our work shows that aPV and wPV have opposing effects on Bp biofilm formation in the respiratory tract and provides a mechanistic explanation for the inability of aPV vaccination to control bacterial numbers in the nose and prevent transmission., Competing Interests: Conflict of interest No conflicts.- Published
- 2024
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11. Systemic priming and intranasal booster with a BcfA-adjuvanted acellular pertussis vaccine generates CD4+ IL-17+ nasal tissue resident T cells and reduces B. pertussis nasal colonization.
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Yount KS, Hall JM, Caution K, Shamseldin MM, Guo M, Marion K, Fullen AR, Huang Y, Maynard JA, Quataert SA, Deora R, and Dubey P
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- Animals, Female, Male, Mice, Adjuvants, Immunologic, Adjuvants, Pharmaceutic, CD4-Positive T-Lymphocytes, Interleukin-17, Pertussis Vaccine, Bordetella pertussis, Whooping Cough prevention & control
- Abstract
Introduction: Resurgence of pertussis, caused by Bordetella pertussis, necessitates novel vaccines and vaccination strategies to combat this disease. Alum-adjuvanted acellular pertussis vaccines (aPV) delivered intramuscularly reduce bacterial numbers in the lungs of immunized animals and humans, but do not reduce nasal colonization. Thus, aPV-immunized individuals are sources of community transmission. We showed previously that modification of a commercial aPV (Boostrix) by addition of the Th1/17 polarizing adjuvant Bordetella Colonization Factor A (BcfA) attenuated Th2 responses elicited by alum and accelerated clearance of B. pertussis from mouse lungs. Here we tested whether a heterologous immunization strategy with systemic priming and mucosal booster (prime-pull) would reduce nasal colonization., Methods: Adult male and female mice were immunized intramuscularly (i.m.) with aPV or aPV/BcfA and boosted either i.m. or intranasally (i.n.) with the same formulation. Tissue-resident memory (TRM) responses in the respiratory tract were quantified by flow cytometry, and mucosal and systemic antibodies were quantified by ELISA. Immunized and naïve mice were challenged i.n. with Bordetella pertussis and bacterial load in the nose and lungs enumerated at days 1-14 post-challenge., Results: We show that prime-pull immunization with Boostrix plus BcfA (aPV/BcfA) generated IFNγ+ and IL-17+ CD4+ lung resident memory T cells (TRM), and CD4+IL-17+ TRM in the nose. In contrast, aPV alone delivered by the same route generated IL-5+ CD4+ resident memory T cells in the lungs and nose. Importantly, nasal colonization was only reduced in mice immunized with aPV/BcfA by the prime-pull regimen., Conclusions: These results suggest that TH17 polarized TRM generated by aPV/BcfA may reduce nasal colonization thereby preventing pertussis transmission and subsequent resurgence., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Yount, Hall, Caution, Shamseldin, Guo, Marion, Fullen, Huang, Maynard, Quataert, Deora and Dubey.)
- Published
- 2023
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12. Prime-Pull Immunization of Mice with a BcfA-Adjuvanted Vaccine Elicits Sustained Mucosal Immunity That Prevents SARS-CoV-2 Infection and Pathology.
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Shamseldin MM, Kenney A, Zani A, Evans JP, Zeng C, Read KA, Hall JM, Chaiwatpongsakorn S, Mahesh KC, Lu M, Eltobgy M, Denz P, Deora R, Li J, Peeples ME, Oestreich KJ, Liu SL, Corps KN, Yount JS, and Dubey P
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- Humans, Animals, Mice, Immunity, Mucosal, COVID-19 Vaccines, SARS-CoV-2, Immunization, Adjuvants, Immunologic, Antibodies, Viral, Antibodies, Neutralizing, Aluminum Hydroxide, COVID-19 prevention & control
- Abstract
Vaccines against SARS-CoV-2 that induce mucosal immunity capable of preventing infection and disease remain urgently needed. In this study, we demonstrate the efficacy of Bordetella colonization factor A (BcfA), a novel bacteria-derived protein adjuvant, in SARS-CoV-2 spike-based prime-pull immunizations. We show that i.m. priming of mice with an aluminum hydroxide- and BcfA-adjuvanted spike subunit vaccine, followed by a BcfA-adjuvanted mucosal booster, generated Th17-polarized CD4+ tissue-resident memory T cells and neutralizing Abs. Immunization with this heterologous vaccine prevented weight loss following challenge with mouse-adapted SARS-CoV-2 (MA10) and reduced viral replication in the respiratory tract. Histopathology showed a strong leukocyte and polymorphonuclear cell infiltrate without epithelial damage in mice immunized with BcfA-containing vaccines. Importantly, neutralizing Abs and tissue-resident memory T cells were maintained until 3 mo postbooster. Viral load in the nose of mice challenged with the MA10 virus at this time point was significantly reduced compared with naive challenged mice and mice immunized with an aluminum hydroxide-adjuvanted vaccine. We show that vaccines adjuvanted with alum and BcfA, delivered through a heterologous prime-pull regimen, provide sustained protection against SARS-CoV-2 infection., (Copyright © 2023 by The American Association of Immunologists, Inc.)
- Published
- 2023
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13. Architecture and matrix assembly determinants of Bordetella pertussis biofilms on primary human airway epithelium.
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Fullen AR, Gutierrez-Ferman JL, Rayner RE, Kim SH, Chen P, Dubey P, Wozniak DJ, Peeples ME, Cormet-Boyaka E, and Deora R
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- Humans, Biofilms, Epithelium, Respiratory System, Bordetella pertussis genetics, Whooping Cough microbiology
- Abstract
Traditionally, whooping cough or pertussis caused by the obligate human pathogen Bordetella pertussis (Bp) is described as an acute disease with severe symptoms. However, many individuals who contract pertussis are either asymptomatic or show very mild symptoms and yet can serve as carriers and sources of bacterial transmission. Biofilms are an important survival mechanism for bacteria in human infections and disease. However, bacterial determinants that drive biofilm formation in humans are ill-defined. In the current study, we show that Bp infection of well-differentiated primary human bronchial epithelial cells leads to formation of bacterial aggregates, clusters, and highly structured biofilms which are colocalized with cilia. These findings mimic observations from pathological analyses of tissues from pertussis patients. Distinct arrangements (mono-, bi-, and tri-partite) of the polysaccharide Bps, extracellular DNA, and bacterial cells were visualized, suggesting complex heterogeneity in bacteria-matrix interactions. Analyses of mutant biofilms revealed positive roles in matrix production, cell cluster formation, and biofilm maturity for three critical Bp virulence factors: Bps, filamentous hemagglutinin, and adenylate cyclase toxin. Adherence assays identified Bps as a new Bp adhesin for primary human airway cells. Taken together, our results demonstrate the multi-factorial nature of the biofilm extracellular matrix and biofilm development process under conditions mimicking the human respiratory tract and highlight the importance of model systems resembling the natural host environment to investigate pathogenesis and potential therapeutic strategies., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2023 Fullen et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)
- Published
- 2023
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14. Development of carbohydrate based next-generation anti-pertussis vaccines.
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Wang P, Ramadan S, Dubey P, Deora R, and Huang X
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- Humans, Pertussis Vaccine, Bordetella pertussis, Oligosaccharides chemistry, Antibodies, Bacterial, Whooping Cough prevention & control
- Abstract
Pertussis is a highly contagious respiratory disease caused by the Gram-negative bacterial pathogen, Bordetella pertussis. Despite high global vaccination rates, pertussis is resurging worldwide. Here we discuss the development of current pertussis vaccines and their limitations, which highlight the need for new vaccines that can protect against the disease and prevent development of the carrier state, thereby reducing transmission. The lipo-oligosaccharide of Bp is an attractive antigen for vaccine development as the anti-glycan antibodies could have bactericidal activities. The structure of the lipo-oligosaccharide has been determined and its immunological properties analyzed. Strategies enabling the expression, isolation, and bioconjugation have been presented. However, obtaining the saccharide on a large scale with high purity remains one of the main obstacles. Chemical synthesis provides a complementary approach to accessing the carbohydrate epitopes in a pure and structurally well-defined form. The first total synthesis of the non-reducing end pertussis pentasaccharide is discussed. The conjugate of the synthetic glycan with a powerful immunogenic carrier, bacteriophage Qβ, results in high levels and long-lasting anti-glycan IgG antibodies, paving the way for the development of a new generation of anti-pertussis vaccines with high bactericidal activities and biocompatibilities., Competing Interests: Declaration of Competing Interest XH is a founder of Iaso Therapeutics, which is dedicated to develop next generation conjugate vaccines including those against pertussis. The authors declare no other conflicts of interests., (Copyright © 2022 Elsevier Ltd. All rights reserved.)
- Published
- 2022
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15. Bps polysaccharide of Bordetella pertussis resists antimicrobial peptides by functioning as a dual surface shield and decoy and converts Escherichia coli into a respiratory pathogen.
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Fullen AR, Gutierrez-Ferman JL, Yount KS, Love CF, Choi HG, Vargas MA, Raju D, Corps KN, Howell PL, Dubey P, and Deora R
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- Animals, Humans, Mice, Antimicrobial Peptides, Biofilms, Bordetella pertussis genetics, Escherichia coli, Mice, Inbred C57BL, Pertussis Vaccine, Polysaccharides, Escherichia coli Infections, Whooping Cough
- Abstract
Infections and disease caused by the obligate human pathogen Bordetella pertussis (Bp) are increasing, despite widespread vaccinations. The current acellular pertussis vaccines remain ineffective against nasopharyngeal colonization, carriage, and transmission. In this work, we tested the hypothesis that Bordetella polysaccharide (Bps), a member of the poly-β-1,6-N-acetyl-D-glucosamine (PNAG/PGA) family of polysaccharides promotes respiratory tract colonization of Bp by resisting killing by antimicrobial peptides (AMPs). Genetic deletion of the bpsA-D locus, as well as treatment with the specific glycoside hydrolase Dispersin B, increased susceptibility to AMP-mediated killing. Bps was found to be both cell surface-associated and released during laboratory growth and mouse infections. Addition of bacterial supernatants containing Bps and purified Bps increased B. pertussis resistance to AMPs. By utilizing ELISA, immunoblot and flow cytometry assays, we show that Bps functions as a dual surface shield and decoy. Co-inoculation of C57BL/6J mice with a Bps-proficient strain enhanced respiratory tract survival of the Bps-deficient strain. In combination, the presented results highlight the critical role of Bps as a central driver of B. pertussis pathogenesis. Heterologous production of Bps in a non-pathogenic E. coli K12 strain increased AMP resistance in vitro, and augmented bacterial survival and pathology in the mouse respiratory tract. These studies can serve as a foundation for other PNAG/PGA polysaccharides and for the development of an effective Bp vaccine that includes Bps., Competing Interests: The authors have declared that no competing interests exist.
- Published
- 2022
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16. Genomic, morphological, and biochemical analyses of a multi-metal resistant but multi-drug susceptible strain of Bordetella petrii from hospital soil.
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Halder U, Biswas R, Kabiraj A, Deora R, Let M, Roy RK, Chitikineni A, Majhi K, Sarkar S, Dutta B, Laha A, Datta A, Khan D, Varshney RK, Saha D, Chattopadhyay S, and Bandopadhyay R
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- Anti-Bacterial Agents, Bordetella, Genomics, Hospitals, Phylogeny, Metals, Heavy toxicity, Soil
- Abstract
Contamination of soil by antibiotics and heavy metals originating from hospital facilities has emerged as a major cause for the development of resistant microbes. We collected soil samples surrounding a hospital effluent and measured the resistance of bacterial isolates against multiple antibiotics and heavy metals. One strain BMCSI 3 was found to be sensitive to all tested antibiotics. However, it was resistant to many heavy metals and metalloids like cadmium, chromium, copper, mercury, arsenic, and others. This strain was motile and potentially spore-forming. Whole-genome shotgun assembly of BMCSI 3 produced 4.95 Mb genome with 4,638 protein-coding genes. The taxonomic and phylogenetic analysis revealed it, to be a Bordetella petrii strain. Multiple genomic islands carrying mobile genetic elements; coding for heavy metal resistant genes, response regulators or transcription factors, transporters, and multi-drug efflux pumps were identified from the genome. A comparative genomic analysis of BMCSI 3 with annotated genomes of other free-living B. petrii revealed the presence of multiple transposable elements and several genes involved in stress response and metabolism. This study provides insights into how genomic reorganization and plasticity results in evolution of heavy metals resistance by acquiring genes from its natural environment., (© 2022. The Author(s).)
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- 2022
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17. Whoop! There it is: The surprising resurgence of pertussis.
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Fullen AR, Yount KS, Dubey P, and Deora R
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- Biological Evolution, Humans, Bordetella pertussis genetics, Bordetella pertussis immunology, Pertussis Vaccine therapeutic use, Whooping Cough prevention & control
- Abstract
Competing Interests: The authors have declared that no competing interests exist.
- Published
- 2020
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18. Chemical Synthesis and Immunological Evaluation of a Pentasaccharide Bearing Multiple Rare Sugars as a Potential Anti-pertussis Vaccine.
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Wang P, Huo CX, Lang S, Caution K, Nick ST, Dubey P, Deora R, and Huang X
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- Animals, Cattle, Enzyme-Linked Immunosorbent Assay, Fucose chemistry, Hemocyanins chemistry, Immunoglobulin G blood, Lipopolysaccharides chemical synthesis, Lipopolysaccharides chemistry, Lipopolysaccharides immunology, Mice, Oligosaccharides chemical synthesis, Oligosaccharides chemistry, Pertussis Vaccine chemistry, Pertussis Vaccine immunology, Serum Albumin, Bovine chemistry, Oligosaccharides immunology, Pertussis Vaccine chemical synthesis
- Abstract
With the infection rate of Bordetella pertussis at a 60-year high, there is an urgent need for new anti-pertussis vaccines. The lipopolysaccharide (LPS) of B. pertussis is an attractive antigen for vaccine development. With the presence of multiple rare sugars and unusual glycosyl linkages, the B. pertussis LPS is a highly challenging synthetic target. In this work, aided by molecular dynamics simulation and modeling, a pertussis-LPS-like pentasaccharide was chemically synthesized for the first time. The pentasaccharide was conjugated with a powerful carrier, bacteriophage Qβ, as a vaccine candidate. Immunization of mice with the conjugate induced robust anti-glycan IgG responses with IgG titers reaching several million enzyme-linked immunosorbent assay (ELISA) units. The antibodies generated were long lasting and boostable and could recognize multiple clinical strains of B. pertussis, highlighting the potential of Qβ-glycan as a new anti-pertussis vaccine., (© 2020 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)
- Published
- 2020
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19. Structural mechanism for regulation of DNA binding of BpsR, a Bordetella regulator of biofilm formation, by 6-hydroxynicotinic acid.
- Author
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Booth WT, Davis RR, Deora R, and Hollis T
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- Amino Acids metabolism, Bacterial Proteins, Bordetella pertussis metabolism, Niacin metabolism, Transcription Factors metabolism, Virulence physiology, Biofilms growth & development, DNA metabolism, Nicotinic Acids metabolism, Transcription Factors genetics
- Abstract
Bordetella bacteria are respiratory pathogens of humans, birds, and livestock. Bordetella pertussis the causative agent of whopping cough remains a significant health issue. The transcriptional regulator, BpsR, represses a number of Bordetella genes relating to virulence, cell adhesion, cell motility, and nicotinic acid metabolism. DNA binding of BpsR is allosterically regulated by interaction with 6-hydroxynicotinic acid (6HNA), the first product in the nicotinic acid degradation pathway. To understand the mechanism of this regulation, we have determined the crystal structures of BpsR and BpsR in complex with 6HNA. The structures reveal that BpsR binding of 6HNA induces a conformational change in the protein to prevent DNA binding. We have also identified homologs of BpsR in other Gram negative bacteria in which the amino acids involved in recognition of 6HNA are conserved, suggesting a similar mechanism for regulating nicotinic acid degradation., Competing Interests: The authors have declared that no competing interests exist.
- Published
- 2019
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20. Bordetella Colonization Factor A (BcfA) Elicits Protective Immunity against Bordetella bronchiseptica in the Absence of an Additional Adjuvant.
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Yount KS, Jennings-Gee J, Caution K, Fullen AR, Corps KN, Quataert S, Deora R, and Dubey P
- Subjects
- Animals, Bordetella Infections immunology, Bordetella Infections microbiology, Bordetella bronchiseptica immunology, Bordetella bronchiseptica pathogenicity, Dogs, Female, Humans, Immunization, Immunogenicity, Vaccine, Male, Mice, Mice, Inbred BALB C, Th1 Cells drug effects, Th1 Cells immunology, Th1 Cells microbiology, Th1-Th2 Balance drug effects, Th17 Cells drug effects, Th17 Cells immunology, Th17 Cells microbiology, Th2 Cells drug effects, Th2 Cells immunology, Th2 Cells microbiology, Adhesins, Bacterial administration & dosage, Adjuvants, Immunologic administration & dosage, Antigens, Bacterial administration & dosage, Bacterial Outer Membrane Proteins administration & dosage, Bacterial Vaccines administration & dosage, Bordetella Infections prevention & control, Bordetella bronchiseptica drug effects, Virulence Factors, Bordetella administration & dosage
- Abstract
Bordetella bronchiseptica is an etiologic agent of respiratory diseases in animals and humans. Despite the widespread use of veterinary B. bronchiseptica vaccines, there is limited information on their composition and relative efficacy and on the immune responses that they elicit. Furthermore, human B. bronchiseptica vaccines are not available. We leveraged the dual antigenic and adjuvant functions of Bordetella colonization factor A (BcfA) to develop acellular B. bronchiseptica vaccines in the absence of an additional adjuvant. BALB/c mice immunized with BcfA alone or a trivalent vaccine containing BcfA and the Bordetella antigens FHA and Prn were equally protected against challenge with a prototype B. bronchiseptica strain. The trivalent vaccine protected mice significantly better than the canine vaccine Bronchicine and provided protection against a B. bronchiseptica strain isolated from a dog with kennel cough. Th1/17-polarized immune responses correlate with long-lasting protection against bordetellae and other respiratory pathogens. Notably, BcfA strongly attenuated the Th2 responses elicited by FHA and Prn, resulting in Th1/17-skewed responses in inherently Th2-skewed BALB/c mice. Thus, BcfA functions as both an antigen and an adjuvant, providing protection as a single-component vaccine. BcfA-adjuvanted vaccines may improve the efficacy and durability of vaccines against bordetellae and other pathogens., (Copyright © 2019 American Society for Microbiology.)
- Published
- 2019
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21. A porcine xenograft-derived bone scaffold is a biocompatible bone graft substitute: An assessment of cytocompatibility and the alpha-Gal epitope.
- Author
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Bracey DN, Seyler TM, Jinnah AH, Smith TL, Ornelles DA, Deora R, Parks GD, Van Dyke ME, and Whitlock PW
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- Animals, Biomarkers metabolism, Enzyme-Linked Immunosorbent Assay, Heterografts metabolism, Heterografts microbiology, Humans, Immunohistochemistry, Swine, alpha-Galactosidase immunology, Bone Substitutes metabolism, Heterografts immunology, Tissue Scaffolds microbiology, Transplantation, Heterologous, alpha-Galactosidase metabolism
- Abstract
Background: Xenografts are an attractive alternative to traditional bone grafts because of the large supply from donors with predictable morphology and biology as well as minimal risk of human disease transmission. Clinical series involving xenograft bone transplantation, most commonly from bovine sources, have reported poor results with frequent graft rejection and failure to integrate with host tissue. Failures have been attributed to residual alpha-Gal epitope in the xenograft which humans produce natural antibody against. To the authors' knowledge, there is currently no xenograft-derived bone graft substitute that has been adopted by orthopedic surgeons for routine clinical use., Methods: In the current study, a bone scaffold intended to serve as a bone graft substitute was derived from porcine cancellous bone using a tissue decellularization and chemical oxidation protocol. In vitro cytocompatibility, pathogen clearance, and alpha-Gal quantification tests were used to assess the safety of the bone scaffold intended for human use., Results: In vitro studies showed the scaffold was free of processing chemicals and biocompatible with mouse and human cell lines. When bacterial and viral pathogens were purposefully added to porcine donor tissue, processing successfully removed these pathogens to comply with sterility assurance levels established by allograft tissue providers. Critically, 98.5% of the alpha-Gal epitope was removed from donor tissue after decellularization as shown by ELISA inhibition assay and immunohistochemical staining., Conclusions: The current investigation supports the biologic safety of bone scaffolds derived from porcine donors using a decellularization protocol that meets current sterility assurance standards. The majority of the highly immunogenic xenograft carbohydrate was removed from donor tissue, and these findings support further in vivo investigation of xenograft-derived bone tissue for orthopedic clinical application., (© 2019 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)
- Published
- 2019
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22. Evaluation of Host-Pathogen Responses and Vaccine Efficacy in Mice.
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Caution K, Yount K, Deora R, and Dubey P
- Subjects
- Animals, Antibodies, Bacterial immunology, Bordetella pertussis immunology, Bordetella pertussis physiology, Female, Male, Mice, Th17 Cells immunology, Vaccination, Whooping Cough prevention & control, Host-Pathogen Interactions, Pertussis Vaccine immunology
- Abstract
Vaccines are a 20
th century medical marvel. They have dramatically reduced the morbidity and mortality caused by infectious diseases and contributed to a striking increase in life expectancy around the globe. Nonetheless, determining vaccine efficacy remains a challenge. Emerging evidence suggests that the current acellular vaccine (aPV) for Bordetella pertussis (B. pertussis) induces suboptimal immunity. Therefore, a major challenge is designing a next-generation vaccine that induces protective immunity without the adverse side effects of a whole-cell vaccine (wPV). Here we describe a protocol that we used to test the efficacy of a promising, novel adjuvant that skews immune responses to a protective Th1/Th17 phenotype and promotes a better clearance of a B. pertussis challenge from the murine respiratory tract. This article describes the protocol for mouse immunization, bacterial inoculation, tissue harvesting, and analysis of immune responses. Using this method, within our model, we have successfully elucidated crucial mechanisms elicited by a promising, next-generation acellular pertussis vaccine. This method can be applied to any infectious disease model in order to determine vaccine efficacy.- Published
- 2019
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23. Structural Analysis of Bordetella pertussis Biofilms by Confocal Laser Scanning Microscopy
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Cattelan N, Yantorno OM, and Deora R
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- 2018
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24. The Transcriptional Regulator BpsR Controls the Growth of Bordetella bronchiseptica by Repressing Genes Involved in Nicotinic Acid Degradation.
- Author
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Guragain M, Jennings-Gee J, Cattelan N, Finger M, Conover MS, Hollis T, and Deora R
- Subjects
- Bacterial Proteins genetics, Base Sequence, Bordetella bronchiseptica genetics, Gene Deletion, Genes, Regulator, Transcription, Genetic, Bacterial Proteins metabolism, Bordetella bronchiseptica growth & development, Bordetella bronchiseptica metabolism, Gene Expression Regulation, Bacterial, Niacin metabolism
- Abstract
Many of the pathogenic species of the genus Bordetella have an absolute requirement for nicotinic acid (NA) for laboratory growth. These Gram-negative bacteria also harbor a gene cluster homologous to the nic cluster of Pseudomonas putida which is involved in the aerobic degradation of NA and its transcriptional control. We report here that BpsR, a negative regulator of biofilm formation and Bps polysaccharide production, controls the growth of Bordetella bronchiseptica by repressing the expression of nic genes. The severe growth defect of the Δ bpsR strain in Stainer-Scholte medium was restored by supplementation with NA, which also functioned as an inducer of nic genes at low micromolar concentrations that are usually present in animals and humans. Purified BpsR protein bound to the nic promoter region, and its DNA binding activity was inhibited by 6-hydroxynicotinic acid (6-HNA), the first metabolite of the NA degradative pathway. Reporter assays with the isogenic mutant derivative of the wild-type (WT) strain harboring deletion in nicA , which encodes a putative nicotinic acid hydroxylase responsible for conversion of NA to 6-HNA, showed that 6-HNA is the actual inducer of the nic genes in the bacterial cell. Gene expression profiling further showed that BpsR dually activated and repressed the expression of genes associated with pathogenesis, transcriptional regulation, metabolism, and other cellular processes. We discuss the implications of these findings with respect to the selection of pyridines such as NA and quinolinic acid for optimum bacterial growth depending on the ecological niche. IMPORTANCE BpsR, the previously described regulator of biofilm formation and Bps polysaccharide production, controls Bordetella bronchiseptica growth by regulating the expression of genes involved in the degradation of nicotinic acid (NA). 6-Hydroxynicotinic acid (6-HNA), the first metabolite of the NA degradation pathway prevented BpsR from binding to DNA and was the actual in vivo inducer. We hypothesize that BpsR enables Bordetella bacteria to efficiently and selectively utilize NA for their survival depending on the environment in which they reside. The results reported herein lay the foundation for future investigations of how BpsR and the alteration of its activity by NA orchestrate the control of Bordetella growth, metabolism, biofilm formation, and pathogenesis., (Copyright © 2018 American Society for Microbiology.)
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- 2018
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25. The Adjuvant Bordetella Colonization Factor A Attenuates Alum-Induced Th2 Responses and Enhances Bordetella pertussis Clearance from Mouse Lungs.
- Author
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Jennings-Gee J, Quataert S, Ganguly T, D'Agostino R Jr, Deora R, and Dubey P
- Subjects
- Adaptive Immunity, Adjuvants, Immunologic, Alum Compounds, Animals, Bordetella pertussis immunology, Down-Regulation, Immunity, Innate, Mice, Vitamin B 12 immunology, Whooping Cough prevention & control, Bordetella pertussis physiology, Lung microbiology, Pertussis Vaccine immunology, Vitamin B 12 analogs & derivatives, Whooping Cough microbiology
- Abstract
The reemergence of pertussis or whooping cough in several countries highlights the need for better vaccines. Acellular pertussis vaccines (aPV) contain alum as the adjuvant and elicit Th2-biased immune responses that are less effective in protecting against infection than the reactogenic whole-cell pertussis vaccines (wPV), which elicit primarily a Th1/Th17 response. An important goal for the field is to devise aPV that will induce immune responses similar to those of wPV. We show that Bordetella colonization factor A (BcfA), an outer membrane protein from Bordetella bronchiseptica , has strong adjuvant function and elicits cellular and humoral immune responses to heterologous and Bordetella pertussis antigens. Addition of BcfA to a commercial aPV resulted in greater reduction of B. pertussis numbers from the lungs than that elicited by aPV alone. The more-efficient pathogen clearance was accompanied by increased interleukin-17 (IL-17) and reduced IL-5 and an increased ratio of IgG2/IgG1 antibodies. Thus, our results suggest that BcfA improves aPV-induced responses by modifying the alum-induced Th2-biased aPV response toward Th1/Th17. A redesigned aPV containing BcfA may allow better control of pertussis reemergence by reshaping immune responses to resemble those elicited by wPV immunization., (Copyright © 2018 American Society for Microbiology.)
- Published
- 2018
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26. PgaB orthologues contain a glycoside hydrolase domain that cleaves deacetylated poly-β(1,6)-N-acetylglucosamine and can disrupt bacterial biofilms.
- Author
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Little DJ, Pfoh R, Le Mauff F, Bamford NC, Notte C, Baker P, Guragain M, Robinson H, Pier GB, Nitz M, Deora R, Sheppard DC, and Howell PL
- Subjects
- Acetylation, Amidohydrolases chemistry, Bordetella growth & development, Crystallography, X-Ray, Escherichia coli growth & development, Escherichia coli Proteins chemistry, Glycoside Hydrolases chemistry, Operon, Protein Conformation, beta-Glucans metabolism, Amidohydrolases metabolism, Biofilms growth & development, Bordetella enzymology, Escherichia coli enzymology, Escherichia coli Proteins metabolism, Glycoside Hydrolases metabolism, beta-Glucans chemistry
- Abstract
Poly-β(1,6)-N-acetyl-D-glucosamine (PNAG) is a major biofilm component of many pathogenic bacteria. The production, modification, and export of PNAG in Escherichia coli and Bordetella species require the protein products encoded by the pgaABCD operon. PgaB is a two-domain periplasmic protein that contains an N-terminal deacetylase domain and a C-terminal PNAG binding domain that is critical for export. However, the exact function of the PgaB C-terminal domain remains unclear. Herein, we show that the C-terminal domains of Bordetella bronchiseptica PgaB (PgaBBb) and E. coli PgaB (PgaBEc) function as glycoside hydrolases. These enzymes hydrolyze purified deacetylated PNAG (dPNAG) from Staphylococcus aureus, disrupt PNAG-dependent biofilms formed by Bordetella pertussis, Staphylococcus carnosus, Staphylococcus epidermidis, and E. coli, and potentiate bacterial killing by gentamicin. Furthermore, we found that PgaBBb was only able to hydrolyze PNAG produced in situ by the E. coli PgaCD synthase complex when an active deacetylase domain was present. Mass spectrometry analysis of the PgaB-hydrolyzed dPNAG substrate showed a GlcN-GlcNAc-GlcNAc motif at the new reducing end of detected fragments. Our 1.76 Å structure of the C-terminal domain of PgaBBb reveals a central cavity within an elongated surface groove that appears ideally suited to recognize the GlcN-GlcNAc-GlcNAc motif. The structure, in conjunction with molecular modeling and site directed mutagenesis led to the identification of the dPNAG binding subsites and D474 as the probable catalytic acid. This work expands the role of PgaB within the PNAG biosynthesis machinery, defines a new glycoside hydrolase family GH153, and identifies PgaB as a possible therapeutic agent for treating PNAG-dependent biofilm infections.
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- 2018
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27. Bordetella Pertussis virulence factors in the continuing evolution of whooping cough vaccines for improved performance.
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Dorji D, Mooi F, Yantorno O, Deora R, Graham RM, and Mukkur TK
- Subjects
- Bordetella pertussis pathogenicity, Drug Discovery trends, Humans, Pertussis Vaccine isolation & purification, Whooping Cough epidemiology, Antigens, Bacterial immunology, Bordetella pertussis immunology, Disease Transmission, Infectious prevention & control, Pertussis Vaccine immunology, Virulence Factors immunology, Whooping Cough prevention & control
- Abstract
Despite high vaccine coverage, whooping cough caused by Bordetella pertussis remains one of the most common vaccine-preventable diseases worldwide. Introduction of whole-cell pertussis (wP) vaccines in the 1940s and acellular pertussis (aP) vaccines in 1990s reduced the mortality due to pertussis. Despite induction of both antibody and cell-mediated immune (CMI) responses by aP and wP vaccines, there has been resurgence of pertussis in many countries in recent years. Possible reasons hypothesised for resurgence have ranged from incompliance with the recommended vaccination programmes with the currently used aP vaccine to infection with a resurged clinical isolates characterised by mutations in the virulence factors, resulting in antigenic divergence with vaccine strain, and increased production of pertussis toxin, resulting in dampening of immune responses. While use of these vaccines provide varying degrees of protection against whooping cough, protection against infection and transmission appears to be less effective, warranting continuation of efforts in the development of an improved pertussis vaccine formulations capable of achieving this objective. Major approaches currently under evaluation for the development of an improved pertussis vaccine include identification of novel biofilm-associated antigens for incorporation in current aP vaccine formulations, development of live attenuated vaccines and discovery of novel non-toxic adjuvants capable of inducing both antibody and CMI. In this review, the potential roles of different accredited virulence factors, including novel biofilm-associated antigens, of B. pertussis in the evolution, formulation and delivery of improved pertussis vaccines, with potential to block the transmission of whooping cough in the community, are discussed.
- Published
- 2018
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28. Hyperbiofilm Formation by Bordetella pertussis Strains Correlates with Enhanced Virulence Traits.
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Cattelan N, Jennings-Gee J, Dubey P, Yantorno OM, and Deora R
- Subjects
- Animals, Bacterial Adhesion, Bordetella pertussis isolation & purification, Bordetella pertussis pathogenicity, Disease Models, Animal, Epithelial Cells microbiology, Humans, Mice, Nose microbiology, Trachea microbiology, Virulence, Biofilms growth & development, Bordetella pertussis physiology, Whooping Cough microbiology
- Abstract
Pertussis, or whooping cough, caused by the obligate human pathogen Bordetella pertussis is undergoing a worldwide resurgence. The majority of studies of this pathogen are conducted with laboratory-adapted strains which may not be representative of the species as a whole. Biofilm formation by B. pertussis plays an important role in pathogenesis. We conducted a side-by-side comparison of the biofilm-forming abilities of the prototype laboratory strains and the currently circulating isolates from two countries with different vaccination programs. Compared to the reference strain, all strains examined herein formed biofilms at high levels. Biofilm structural analyses revealed country-specific differences, with strains from the United States forming more structured biofilms. Bacterial hyperaggregation and reciprocal expression of biofilm-promoting and -inhibitory factors were observed in clinical isolates. An association of increased biofilm formation with augmented epithelial cell adhesion and higher levels of bacterial colonization in the mouse nose and trachea was detected. To our knowledge, this work links for the first time increased biofilm formation in bacteria with a colonization advantage in an animal model. We propose that the enhanced biofilm-forming capacity of currently circulating strains contributes to their persistence, transmission, and continued circulation., (Copyright © 2017 American Society for Microbiology.)
- Published
- 2017
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29. The Bordetella Bps Polysaccharide Is Required for Biofilm Formation and Enhances Survival in the Lower Respiratory Tract of Swine.
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Nicholson TL, Brockmeier SL, Sukumar N, Paharik AE, Lister JL, Horswill AR, Kehrli ME Jr, Loving CL, Shore SM, and Deora R
- Subjects
- Animals, Bacterial Proteins genetics, Bordetella Infections immunology, Bordetella bronchiseptica chemistry, Bordetella bronchiseptica genetics, Bordetella bronchiseptica immunology, Bronchi microbiology, Gene Expression Regulation, Bacterial, Mutation, Nose microbiology, Swine, Biofilms growth & development, Bordetella Infections microbiology, Bordetella bronchiseptica pathogenicity, Polysaccharides, Bacterial metabolism, Trachea microbiology
- Abstract
Bordetella bronchiseptica is pervasive in swine populations and plays multiple roles in respiratory disease. Additionally, B. bronchiseptica is capable of establishing long-term or chronic infections in swine. Bacterial biofilms are increasingly recognized as important contributors to chronic bacterial infections. Recently the polysaccharide locus bpsABCD has been demonstrated to serve a critical role in the development of mature biofilms formed by the sequenced laboratory strain of B. bronchiseptica We hypothesized that swine isolates would also have the ability to form mature biofilms and the bpsABCD locus would serve a key role in this process. A mutant containing an in-frame deletion of the bpsABCD structural genes was constructed in a wild-type swine isolate and found to be negative for poly-N-acetylglucosamine (PNAG)-like material by immunoblot assay. Further, the bpsABCD locus was found to be required for the development and maintenance of the three-dimensional structures under continuous-flow conditions. To investigate the contribution of the bpsABCD locus to the pathogenesis of B. bronchiseptica in swine, the KM22Δ bps mutant was compared to the wild-type swine isolate for the ability to colonize and cause disease in pigs. The bpsABCD locus was found to not be required for persistence in the upper respiratory tract of swine. Additionally, the bpsABCD locus did not affect the development of anti- Bordetella humoral immunity, did not contribute to disease severity, and did not mediate protection from complement-mediated killing. However, the bpsABCD locus was found to enhance survival in the lower respiratory tract of swine., (Copyright © 2017 American Society for Microbiology.)
- Published
- 2017
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30. Erratum for Carbonetti et al., "Highlights of the 11th International Bordetella Symposium: from Basic Biology to Vaccine Development".
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Carbonetti NH, Wirsing von König CH, Lan R, Jacob-Dubuisson F, Cotter PA, Deora R, Merkel TJ, van Els CA, Locht C, Hozbor D, and Rodriguez ME
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- 2017
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31. Highlights of the 11th International Bordetella Symposium: from Basic Biology to Vaccine Development.
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Carbonetti NH, Wirsing von König CH, Lan R, Jacob-Dubuisson F, Cotter PA, Deora R, Merkel TJ, van Els CA, Locht C, Hozbor D, and Rodriguez ME
- Subjects
- Animals, Argentina epidemiology, Bacterial Outer Membrane Proteins immunology, Humans, Infant, Vaccination, Virulence Factors, Bordetella immunology, Whooping Cough epidemiology, Whooping Cough microbiology, Bordetella pertussis immunology, Bordetella pertussis physiology, Pertussis Vaccine immunology, Whooping Cough immunology
- Abstract
Pertussis is a severe respiratory disease caused by infection with the bacterial pathogen Bordetella pertussis The disease affects individuals of all ages but is particularly severe and sometimes fatal in unvaccinated young infants. Other Bordetella species cause diseases in humans, animals, and birds. Scientific, clinical, public health, vaccine company, and regulatory agency experts on these pathogens and diseases gathered in Buenos Aires, Argentina from 5 to 8 April 2016 for the 11th International Bordetella Symposium to discuss recent advances in our understanding of the biology of these organisms, the diseases they cause, and the development of new vaccines and other strategies to prevent these diseases. Highlights of the meeting included pertussis epidemiology in developing nations, genomic analysis of Bordetella biology and evolution, regulation of virulence factor expression, new model systems to study Bordetella biology and disease, effects of different vaccines on immune responses, maternal immunization as a strategy to prevent newborn disease, and novel vaccine development for pertussis. In addition, the group approved the formation of an International Bordetella Society to promote research and information exchange on bordetellae and to organize future meetings. A new Bordetella.org website will also be developed to facilitate these goals., (Copyright © 2016, American Society for Microbiology. All Rights Reserved.)
- Published
- 2016
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32. Bordetella biofilms: a lifestyle leading to persistent infections.
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Cattelan N, Dubey P, Arnal L, Yantorno OM, and Deora R
- Subjects
- Animals, Carrier State microbiology, Disease Outbreaks, Humans, Biofilms growth & development, Bordetella Infections microbiology, Bordetella bronchiseptica physiology, Bordetella pertussis physiology
- Abstract
Bordetella bronchiseptica and B. pertussis are Gram-negative bacteria that cause respiratory diseases in animals and humans. The current incidence of whooping cough or pertussis caused by B. pertussis has reached levels not observed since the 1950s. Although pertussis is traditionally known as an acute childhood disease, it has recently resurged in vaccinated adolescents and adults. These individuals often become silent carriers, facilitating bacterial circulation and transmission. Similarly, vaccinated and non-vaccinated animals continue to be carriers of B. bronchiseptica and shed bacteria resulting in disease outbreaks. The persistence mechanisms of these bacteria remain poorly characterized. It has been proposed that adoption of a biofilm lifestyle allows persistent colonization of the mammalian respiratory tract. The history of Bordetella biofilm research is only a decade long and there is no single review article that has exclusively focused on this area. We systematically discuss the role of Bordetella factors in biofilm development in vitro and in the mouse respiratory tract. We further outline the implications of biofilms to bacterial persistence and transmission in humans and for the design of new acellular pertussis vaccines., (© FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)
- Published
- 2016
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33. The protein BpsB is a poly-β-1,6-N-acetyl-D-glucosamine deacetylase required for biofilm formation in Bordetella bronchiseptica.
- Author
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Little DJ, Milek S, Bamford NC, Ganguly T, DiFrancesco BR, Nitz M, Deora R, and Howell PL
- Subjects
- Amidohydrolases genetics, Amidohydrolases metabolism, Amino Acid Motifs, Bacterial Proteins genetics, Bacterial Proteins metabolism, Cobalt chemistry, Cobalt metabolism, Nickel chemistry, Nickel metabolism, Protein Structure, Tertiary, beta-Glucans metabolism, Amidohydrolases chemistry, Bacterial Proteins chemistry, Biofilms growth & development, Bordetella bronchiseptica physiology, beta-Glucans chemistry
- Abstract
Bordetella pertussis and Bordetella bronchiseptica are the causative agents of whooping cough in humans and a variety of respiratory diseases in animals, respectively. Bordetella species produce an exopolysaccharide, known as the Bordetella polysaccharide (Bps), which is encoded by the bpsABCD operon. Bps is required for Bordetella biofilm formation, colonization of the respiratory tract, and confers protection from complement-mediated killing. In this report, we have investigated the role of BpsB in the biosynthesis of Bps and biofilm formation by B. bronchiseptica. BpsB is a two-domain protein that localizes to the periplasm and outer membrane. BpsB displays metal- and length-dependent deacetylation on poly-β-1,6-N-acetyl-d-glucosamine (PNAG) oligomers, supporting previous immunogenic data that suggests Bps is a PNAG polymer. BpsB can use a variety of divalent metal cations for deacetylase activity and showed highest activity in the presence of Ni(2+) and Co(2+). The structure of the BpsB deacetylase domain is similar to the PNAG deacetylases PgaB and IcaB and contains the same circularly permuted family four carbohydrate esterase motifs. Unlike PgaB from Escherichia coli, BpsB is not required for polymer export and has unique structural differences that allow the N-terminal deacetylase domain to be active when purified in isolation from the C-terminal domain. Our enzymatic characterizations highlight the importance of conserved active site residues in PNAG deacetylation and demonstrate that the C-terminal domain is required for maximal deacetylation of longer PNAG oligomers. Furthermore, we show that BpsB is critical for the formation and complex architecture of B. bronchiseptica biofilms., (© 2015 by The American Society for Biochemistry and Molecular Biology, Inc.)
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- 2015
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34. The Bordetella pertussis Bps polysaccharide enhances lung colonization by conferring protection from complement-mediated killing.
- Author
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Ganguly T, Johnson JB, Kock ND, Parks GD, and Deora R
- Subjects
- Animals, Bordetella pertussis immunology, Complement Membrane Attack Complex metabolism, Host-Pathogen Interactions, Humans, Immunity, Innate, Lung immunology, Mice, Inbred C57BL, Mice, Knockout, Microbial Viability, Whooping Cough immunology, Whooping Cough microbiology, Bordetella pertussis physiology, Complement System Proteins metabolism, Lung microbiology, Polysaccharides, Bacterial genetics, Virulence Factors, Bordetella genetics
- Abstract
Bordetella pertussis is a human-restricted Gram-negative bacterial pathogen that causes whooping cough or pertussis. Pertussis is the leading vaccine preventable disease that is resurging in the USA and other parts of the developed world. There is an incomplete understanding of the mechanisms by which B. pertussis evades killing and clearance by the complement system, a first line of host innate immune defence. The present study examined the role of the Bps polysaccharide to resist complement activity in vitro and in the mouse respiratory tract. The isogenic bps mutant strain containing a large non-polar in-frame deletion of the bpsA-D locus was more sensitive to serum and complement mediated killing than the WT strain. As determined by Western blotting, flow cytometry and electron microscopic studies, the heightened sensitivity of the mutant strain was due to enhanced deposition of complement proteins and the formation of membrane attack complex, the end-product of complement activation. Bps was sufficient to confer complement resistance as evidenced by a Bps-expressing Escherichia coli being protected by serum killing. Additionally, Western blotting and flow cytometry assays revealed that Bps inhibited the deposition of complement proteins independent of other B. pertussis factors. The bps mutant strain colonized the lungs of complement-deficient mice at higher levels than that observed in C57Bl/6 mice. These results reveal a previously unknown interaction between Bps and the complement system in controlling B. pertussis colonization of the respiratory tract. These findings also make Bps a potential target for the prevention and therapy of whooping cough., (© 2014 John Wiley & Sons Ltd.)
- Published
- 2014
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35. Comparative analyses of a cystic fibrosis isolate of Bordetella bronchiseptica reveal differences in important pathogenic phenotypes.
- Author
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Sukumar N, Nicholson TL, Conover MS, Ganguly T, and Deora R
- Subjects
- Animals, Bacterial Adhesion, Biofilms growth & development, Bordetella Infections microbiology, Bordetella bronchiseptica metabolism, Bordetella bronchiseptica pathogenicity, Disease Models, Animal, Female, Genome, Bacterial, Mice, Mice, Inbred C57BL, Microarray Analysis, Nose microbiology, Phenotype, Sequence Analysis, DNA, Virulence genetics, Bacterial Proteins genetics, Bordetella Infections genetics, Bordetella bronchiseptica genetics, Comparative Genomic Hybridization, Cystic Fibrosis microbiology
- Abstract
Bordetella bronchiseptica is a Gram-negative bacterium that infects and causes disease in a wide variety of animals. B. bronchiseptica also infects humans, thereby demonstrating zoonotic transmission. An extensive characterization of human B. bronchiseptica isolates is needed to better understand the distinct genetic and phenotypic traits associated with these zoonotic transmission events. Using whole-genome transcriptome and CGH analysis, we report that a B. bronchiseptica cystic fibrosis isolate, T44625, contains a distinct genomic content of virulence-associated genes and differentially expresses these genes compared to the sequenced model laboratory strain RB50, a rabbit isolate. The differential gene expression pattern correlated with unique phenotypes exhibited by T44625, which included lower motility, increased aggregation, hyperbiofilm formation, and an increased in vitro capacity to adhere to respiratory epithelial cells. Using a mouse intranasal infection model, we found that although defective in establishing high bacterial burdens early during the infection process, T44625 persisted efficiently in the mouse nose. By documenting the unique genomic and phenotypic attributes of T44625, this report provides a blueprint for understanding the successful zoonotic potential of B. bronchiseptica and other zoonotic bacteria.
- Published
- 2014
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36. D-alanine modification of a protease-susceptible outer membrane component by the Bordetella pertussis dra locus promotes resistance to antimicrobial peptides and polymorphonuclear leukocyte-mediated killing.
- Author
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Taneja NK, Ganguly T, Bakaletz LO, Nelson KJ, Dubey P, Poole LB, and Deora R
- Subjects
- Bacterial Outer Membrane Proteins genetics, Bordetella pertussis genetics, Cells, Cultured, Endopeptidase K metabolism, Humans, Proteolysis, Antimicrobial Cationic Peptides metabolism, Bacterial Outer Membrane Proteins metabolism, Bordetella pertussis immunology, Bordetella pertussis metabolism, Drug Resistance, Bacterial, Genetic Loci, Neutrophils immunology
- Abstract
Bordetella pertussis is the causative agent of pertussis, a highly contagious disease of the human respiratory tract. Despite very high vaccine coverage, pertussis has reemerged as a serious threat in the United States and many developing countries. Thus, it is important to pursue research to discover unknown pathogenic mechanisms of B. pertussis. We have investigated a previously uncharacterized locus in B. pertussis, the dra locus, which is homologous to the dlt operons of Gram-positive bacteria. The absence of the dra locus resulted in increased sensitivity to the killing action of antimicrobial peptides (AMPs) and human phagocytes. Compared to the wild-type cells, the mutant cells bound higher levels of cationic proteins and peptides, suggesting that dra contributes to AMP resistance by decreasing the electronegativity of the cell surface. The presence of dra led to the incorporation of d-alanine into an outer membrane component that is susceptible to proteinase K cleavage. We conclude that dra encodes a virulence-associated determinant and contributes to the immune resistance of B. pertussis. With these findings, we have identified a new mechanism of surface modification in B. pertussis which may also be relevant in other Gram-negative pathogens.
- Published
- 2013
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37. The genetic composition of Oxalobacter formigenes and its relationship to colonization and calcium oxalate stone disease.
- Author
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Knight J, Deora R, Assimos DG, and Holmes RP
- Subjects
- Animals, Anti-Bacterial Agents adverse effects, Diet, Genome, Bacterial, Humans, Intestinal Mucosa metabolism, Intestines drug effects, Intestines microbiology, Microbiota, Nephrolithiasis etiology, Nephrolithiasis prevention & control, Oxalates administration & dosage, Oxalates metabolism, Oxalobacter formigenes drug effects, Probiotics, Risk Factors, Symbiosis, Calcium Oxalate metabolism, Nephrolithiasis microbiology, Oxalobacter formigenes genetics, Oxalobacter formigenes metabolism
- Abstract
Oxalobacter formigenes is a unique intestinal organism that relies on oxalate degradation to meet most of its energy and carbon needs. A lack of colonization is a risk factor for calcium oxalate stone disease. Protection against calcium oxalate stone disease appears to be due to the oxalate degradation that occurs in the gut on low calcium diets with a possible further contribution from intestinal oxalate secretion. Much remains to be learned about how the organism establishes and maintains gut colonization and the precise mechanisms by which it modifies stone risk. The sequencing and annotation of the genomes of a Group 1 and a Group 2 strain of O. formigenes should provide the informatic tools required for the identification of the genes and pathways associated with colonization and survival. In this review we have identified genes that may be involved and where appropriate suggested how they may be important in calcium oxalate stone disease. Elaborating the functional roles of these genes should accelerate our understanding of the organism and clarify its role in preventing stone formation.
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- 2013
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38. BpsR modulates Bordetella biofilm formation by negatively regulating the expression of the Bps polysaccharide.
- Author
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Conover MS, Redfern CJ, Ganguly T, Sukumar N, Sloan G, Mishra M, and Deora R
- Subjects
- Animals, Bacterial Proteins genetics, Base Sequence, Bordetella genetics, Bordetella metabolism, Down-Regulation, Gene Deletion, Humans, Operon, Polysaccharides genetics, Promoter Regions, Genetic, Transcription, Genetic, Bacterial Proteins metabolism, Biofilms growth & development, Bordetella physiology, Gene Expression Regulation, Bacterial physiology, Polysaccharides metabolism
- Abstract
Bordetella bacteria are Gram-negative respiratory pathogens of animals, birds, and humans. A hallmark feature of some Bordetella species is their ability to efficiently survive in the respiratory tract even after vaccination. Bordetella bronchiseptica and Bordetella pertussis form biofilms on abiotic surfaces and in the mouse respiratory tract. The Bps exopolysaccharide is one of the critical determinants for biofilm formation and the survival of Bordetella in the murine respiratory tract. In order to gain a better understanding of regulation of biofilm formation, we sought to study the mechanism by which Bps expression is controlled in Bordetella. Expression of bpsABCD (bpsA-D) is elevated in biofilms compared with levels in planktonically grown cells. We found that bpsA-D is expressed independently of BvgAS. Subsequently, we identified an open reading frame (ORF), BB1771 (designated here bpsR), that is located upstream of and in the opposite orientation to the bpsA-D locus. BpsR is homologous to the MarR family of transcriptional regulators. Measurement of bpsA and bpsD transcripts and the Bps polysaccharide levels from the wild-type and the ΔbpsR strains suggested that BpsR functions as a repressor. Consistent with enhanced production of Bps, the bpsR mutant displayed considerably more structured biofilms. We mapped the bpsA-D promoter region and showed that purified BpsR protein specifically bound to the bpsA-D promoter. Our results provide mechanistic insights into the regulatory strategy employed by Bordetella for control of the production of the Bps polysaccharide and biofilm formation.
- Published
- 2012
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39. Positive and negative regulation of prostate stem cell antigen expression by Yin Yang 1 in prostate epithelial cell lines.
- Author
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Tang S, Mishra M, Frazier DP, Moore ML, Inoue K, Deora R, Sui G, and Dubey P
- Subjects
- Animals, Antigens, Neoplasm metabolism, Base Sequence, Binding Sites, Cell Line, Chromatin Immunoprecipitation, Consensus Sequence, Electrophoretic Mobility Shift Assay, GPI-Linked Proteins genetics, GPI-Linked Proteins metabolism, Gene Knockdown Techniques, Humans, Male, Mice, Molecular Sequence Data, Mutagenesis, Site-Directed, Neoplasm Proteins metabolism, Polynucleotides chemistry, Promoter Regions, Genetic, Protein Binding, Receptors, Androgen metabolism, Response Elements, YY1 Transcription Factor chemistry, YY1 Transcription Factor genetics, Antigens, Neoplasm genetics, Epithelial Cells metabolism, Gene Expression Regulation, Neoplasm Proteins genetics, Prostate cytology, YY1 Transcription Factor metabolism
- Abstract
Prostate cancer is influenced by epigenetic modification of genes involved in cancer development and progression. Increased expression of Prostate Stem Cell Antigen (PSCA) is correlated with development of malignant human prostate cancer, while studies in mouse models suggest that decreased PSCA levels promote prostate cancer metastasis. These studies suggest that PSCA has context-dependent functions, and could be differentially regulated during tumor progression. In the present study, we identified the multi-functional transcription factor Yin Yang 1 (YY1) as a modulator of PSCA expression in prostate epithelial cell lines. Increased YY1 levels are observed in prostatic intraepithelial neoplasia (PIN) and advanced disease. We show that androgen-mediated up-regulation of PSCA in prostate epithelial cell lines is dependent on YY1. We identified two direct YY1 binding sites within the PSCA promoter, and showed that the upstream site inhibited, while the downstream site, proximal to the androgen-responsive element, stimulated PSCA promoter activity. Thus, changes in PSCA expression levels in prostate cancer may at least partly be affected by cellular levels of YY1. Our results also suggest multiple roles for YY1 in prostate cancer which may contribute to disease progression by modulation of genes such as PSCA.
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- 2012
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40. Transcriptome profiling reveals stage-specific production and requirement of flagella during biofilm development in Bordetella bronchiseptica.
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Nicholson TL, Conover MS, and Deora R
- Subjects
- Bordetella bronchiseptica cytology, Bordetella bronchiseptica ultrastructure, Cluster Analysis, DNA, Complementary genetics, Gene Expression Regulation, Bacterial, Genes, Bacterial genetics, Microscopy, Confocal, Mutation genetics, Phenotype, Transcription, Genetic, Biofilms growth & development, Bordetella bronchiseptica genetics, Bordetella bronchiseptica physiology, Flagella genetics, Gene Expression Profiling methods
- Abstract
We have used microarray analysis to study the transcriptome of the bacterial pathogen Bordetella bronchiseptica over the course of five time points representing distinct stages of biofilm development. The results suggest that B. bronchiseptica undergoes a coordinately regulated gene expression program similar to a bacterial developmental process. Expression and subsequent production of the genes encoding flagella, a classical Bvg(-) phase phenotype, occurs and is under tight regulatory control during B. bronchiseptica biofilm development. Using mutational analysis, we demonstrate that flagella production at the appropriate stage of biofilm development, i.e. production early subsequently followed by repression, is required for robust biofilm formation and maturation. We also demonstrate that flagella are necessary and enhance the initial cell-surface interactions, thereby providing mechanistic information on the initial stages of biofilm development for B. bronchiseptica. Biofilm formation by B. bronchiseptica involves the production of both Bvg-activated and Bvg-repressed factors followed by the repression of factors that inhibit formation of mature biofilms.
- Published
- 2012
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- View/download PDF
41. Extracellular DNA is essential for maintaining Bordetella biofilm integrity on abiotic surfaces and in the upper respiratory tract of mice.
- Author
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Conover MS, Mishra M, and Deora R
- Subjects
- Animals, Biofilms drug effects, Bordetella bronchiseptica cytology, Bordetella bronchiseptica drug effects, Bordetella bronchiseptica metabolism, Bordetella pertussis cytology, Bordetella pertussis drug effects, Bordetella pertussis metabolism, Deoxyribonuclease I pharmacology, Extracellular Space drug effects, Female, Hydrodynamics, Mice, Mice, Inbred C57BL, Nasal Septum drug effects, Nasal Septum microbiology, Nasopharynx drug effects, Nasopharynx microbiology, Respiratory System drug effects, Surface Properties, Biofilms growth & development, Bordetella bronchiseptica physiology, Bordetella pertussis physiology, DNA, Bacterial metabolism, Extracellular Space metabolism, Respiratory System microbiology
- Abstract
Bacteria form complex and highly elaborate surface adherent communities known as biofilms which are held together by a self-produced extracellular matrix. We have previously shown that by adopting a biofilm mode of existence in vivo, the gram negative bacterial pathogens Bordetella bronchiseptica and Bordetella pertussis are able to efficiently colonize and persist in the mammalian respiratory tract. In general, the bacterial biofilm matrix includes polysaccharides, proteins and extracellular DNA (eDNA). In this report, we investigated the function of DNA in Bordetella biofilm development. We show that DNA is a significant component of Bordetella biofilm matrix. Addition of DNase I at the initiation of biofilm growth inhibited biofilm formation. Treatment of pre-established mature biofilms formed under both static and flow conditions with DNase I led to a disruption of the biofilm biomass. We next investigated whether eDNA played a role in biofilms formed in the mouse respiratory tract. DNase I treatment of nasal biofilms caused considerable dissolution of the biofilm biomass. In conclusion, these results suggest that eDNA is a crucial structural matrix component of both in vitro and in vivo formed Bordetella biofilms. This is the first evidence for the ability of DNase I to disrupt bacterial biofilms formed on host organs.
- Published
- 2011
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- View/download PDF
42. FHA-mediated cell-substrate and cell-cell adhesions are critical for Bordetella pertussis biofilm formation on abiotic surfaces and in the mouse nose and the trachea.
- Author
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Serra DO, Conover MS, Arnal L, Sloan GP, Rodriguez ME, Yantorno OM, and Deora R
- Subjects
- Animals, Mice, Virulence Factors, Bordetella, Adhesins, Bacterial physiology, Biofilms, Bordetella pertussis pathogenicity, Cell Adhesion physiology, Nose microbiology, Trachea microbiology
- Abstract
Bordetella spp. form biofilms in the mouse nasopharynx, thereby providing a potential mechanism for establishing chronic infections in humans and animals. Filamentous hemagglutinin (FHA) is a major virulence factor of B. pertussis, the causative agent of the highly transmissible and infectious disease, pertussis. In this study, we dissected the role of FHA in the distinct biofilm developmental stages of B. pertussis on abiotic substrates and in the respiratory tract by employing a murine model of respiratory biofilms. Our results show that the lack of FHA reduced attachment and decreased accumulation of biofilm biomass on artificial surfaces. FHA contributes to biofilm development by promoting the formation of microcolonies. Absence of FHA from B. pertussis or antibody-mediated blockade of surface-associated FHA impaired the attachment of bacteria to the biofilm community. Exogenous addition of FHA resulted in a dose-dependent inhibitory effect on bacterial association with the biofilms. Furthermore, we show that FHA is important for the structural integrity of biofilms formed on the mouse nose and trachea. Together, these results strongly support the hypothesis that FHA promotes the formation and maintenance of biofilms by mediating cell-substrate and inter-bacterial adhesions. These discoveries highlight FHA as a key factor in establishing structured biofilm communities in the respiratory tract., (© 2011 Serra et al.)
- Published
- 2011
- Full Text
- View/download PDF
43. AmrZ beta-sheet residues are essential for DNA binding and transcriptional control of Pseudomonas aeruginosa virulence genes.
- Author
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Waligora EA, Ramsey DM, Pryor EE Jr, Lu H, Hollis T, Sloan GP, Deora R, and Wozniak DJ
- Subjects
- Alginates, Amino Acid Sequence, Animals, DNA, Bacterial genetics, Glucuronic Acid biosynthesis, Hexuronic Acids, Mice, Models, Molecular, Mutation, Protein Binding, Protein Structure, Secondary, Pseudomonas aeruginosa physiology, Transcription, Genetic, Virulence, DNA, Bacterial metabolism, Gene Expression Regulation, Bacterial physiology, Pseudomonas aeruginosa genetics, Pseudomonas aeruginosa pathogenicity
- Abstract
AmrZ is a putative ribbon-helix-helix (RHH) transcriptional regulator. RHH proteins utilize residues within the β-sheet for DNA binding, while the α-helices promote oligomerization. AmrZ is of interest due to its dual roles as a transcriptional activator and as a repressor, regulating genes encoding virulence factors associated with both chronic and acute Pseudomonas aeruginosa infection. In this study, cross-linking revealed that AmrZ forms oligomers in solution but that the amino terminus, containing an unordered region and a β-sheet, were not required for oligomerization. The first 12 unordered residues (extended amino terminus) contributed minimally to DNA binding. Mutagenesis of the AmrZ β-sheet demonstrated that residues 18, 20, and 22 were essential for DNA binding at both activation and repressor sites, suggesting that AmrZ utilizes a similar mechanism for binding to these sites. Mice infected with amrZ mutants exhibited reduced bacterial burden, morbidity, and mortality. Direct in vivo competition assays showed a 5-fold competitive advantage for the wild type over an isogenic amrZ mutant. Finally, the reduced infection phenotype of the amrZ-null strain was similar to that of a strain expressing a DNA-binding-deficient AmrZ variant, indicating that DNA binding and transcriptional regulation by AmrZ is responsible for the in vivo virulence defect. These recent infection data, along with previously identified AmrZ-regulated virulence factors, suggest the necessity of AmrZ transcriptional regulation for optimal virulence during acute infection.
- Published
- 2010
- Full Text
- View/download PDF
44. The Bps polysaccharide of Bordetella pertussis promotes colonization and biofilm formation in the nose by functioning as an adhesin.
- Author
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Conover MS, Sloan GP, Love CF, Sukumar N, and Deora R
- Subjects
- Adhesins, Bacterial genetics, Animals, Bacterial Adhesion, Bordetella pertussis genetics, Carrier State, Cell Line, Escherichia coli genetics, Gene Deletion, Genetic Complementation Test, Humans, Lung microbiology, Mice, Mice, Inbred C57BL, Polysaccharides, Bacterial genetics, Whooping Cough microbiology, Adhesins, Bacterial physiology, Biofilms growth & development, Bordetella pertussis pathogenicity, Nose microbiology, Polysaccharides, Bacterial physiology
- Abstract
Many respiratory pathogens establish persistent infection or a carrier state in the human nasopharynx without overt disease symptoms but the presence of these in the lungs usually results in disease. Although the anatomy and microenvironments between nasopharynx and lungs are different, a virulence factor with an organ-specific function in the colonization of the nasopharynx is unknown. In contrast to the severity of pertussis and mortality in non-vaccinated young children, Bordetella pertussis results in milder and prolonged cough in vaccinated adolescents and adults. Individuals harbouring bacteria in the nasopharynx serve as reservoirs for intrafamilial and nosocomial transmission. We show that the Bps polysaccharide of B. pertussis is critical for initial colonization of the mouse nose and the trachea but not of the lungs. Our data reveal a biofilm lifestyle for B. pertussis in the nose and the requirement of Bps in this developmental process. Bps functions as an adhesin by promoting adherence of B. pertussis and Escherichia coli to human nasal but not to human lung epithelia. Patient serum specifically recognized Bps suggesting its expression during natural human infections. We describe the first bacterial factor that exhibits a differential role in colonization and adherence between the nasopharynx and the lungs., (© 2010 Blackwell Publishing Ltd.)
- Published
- 2010
- Full Text
- View/download PDF
45. Cross-species protection mediated by a Bordetella bronchiseptica strain lacking antigenic homologs present in acellular pertussis vaccines.
- Author
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Sukumar N, Sloan GP, Conover MS, Love CF, Mattoo S, Kock ND, and Deora R
- Subjects
- Animals, Antibodies, Bacterial blood, Bordetella pertussis immunology, Colony Count, Microbial, Enzyme-Linked Immunosorbent Assay, Female, Histocytochemistry, Mice, Mice, Inbred C57BL, Microscopy, Opsonin Proteins blood, Phagocytosis, Respiratory System microbiology, Respiratory System pathology, Vaccines, Attenuated immunology, Whooping Cough immunology, Bordetella bronchiseptica immunology, Cross Protection, Pertussis Vaccine immunology, Whooping Cough prevention & control
- Abstract
The Bordetella species are Gram-negative bacterial pathogens that are characterized by long-term colonization of the mammalian respiratory tract and are causative agents of respiratory diseases in humans and animals. Despite widespread and efficient vaccination, there has been a world-wide resurgence of pertussis, which remains the leading cause of vaccine-preventable death in developed countries. It has been proposed that current acellular vaccines (Pa) composed of only a few bacterial proteins may be less efficacious because of vaccine-induced antigenic shifts and adaptations. To gain insight into the development of a newer generation of vaccines, we constructed a Bordetella bronchiseptica strain (LPaV) that does not express the antigenic homologs included in any of the Pa vaccines currently in use. This strain also lacks adenylate cyclase toxin, an essential virulence factor, and BipA, a surface protein. While LPaV colonized the mouse nose as efficiently as the wild-type strain, it was highly deficient in colonization of the lower respiratory tract and was attenuated in induction of inflammation and injury to the lungs. Strikingly, to our surprise, we found that in an intranasal murine challenge model, LPaV elicited cross-species protection against both B. bronchiseptica and Bordetella pertussis. Our data suggest the presence of immunogenic protective components other than those included in the pertussis vaccine. Combined with the whole-genome sequences of many Bordetella spp. that are available, the results of this study should serve as a platform for strategic development of the next generation of acellular pertussis vaccines.
- Published
- 2010
- Full Text
- View/download PDF
46. Active and passive immunizations with Bordetella colonization factor A protect mice against respiratory challenge with Bordetella bronchiseptica.
- Author
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Sukumar N, Love CF, Conover MS, Kock ND, Dubey P, and Deora R
- Subjects
- Animals, Antibodies, Bacterial blood, Antibodies, Bacterial immunology, Bacterial Outer Membrane Proteins genetics, Bacterial Outer Membrane Proteins metabolism, Bacterial Vaccines immunology, Bordetella bronchiseptica metabolism, Dose-Response Relationship, Immunologic, Female, Gene Expression Regulation, Bacterial physiology, Lung pathology, Mice, Mice, Inbred C57BL, Bacterial Outer Membrane Proteins immunology, Bacterial Vaccines administration & dosage, Bordetella Infections prevention & control, Bordetella bronchiseptica immunology, Immunization, Passive, Respiratory Tract Infections prevention & control
- Abstract
Bordetella colonization factor A (BcfA) is an outer membrane immunogenic protein, which is critical for efficient colonization of the murine respiratory tract. These properties of BcfA prompted us to examine its utility in inducing a protective immune response against Bordetella bronchiseptica in a mouse model of intranasal infection. Mice vaccinated with BcfA demonstrated reduced pathology in the lungs and harbored lower bacterial burdens in the respiratory tract. Immunization with BcfA led to the generation of BcfA-specific antibodies in both the sera and lungs, and passive immunization led to the reduction of B. bronchiseptica in the tracheas and lungs. These results suggest that protection after immunization with BcfA is mediated in part by antibodies against BcfA. To further investigate the mechanism of BcfA-induced immune clearance, we examined the role of neutrophils and macrophages. Our results demonstrate that neutrophils are critical for anti-BcfA antibody-mediated clearance and that opsonization with anti-BcfA serum enhances phagocytosis of B. bronchiseptica by murine macrophages. We show that immunization with BcfA results in the production of gamma interferon and subclasses of immunoglobulin G antibodies that are consistent with the induction of a Th1-type immune response. In combination, our findings suggest that the mechanism of BcfA-mediated immunity involves humoral and cellular responses. Expression of BcfA is conserved among multiple clinical isolates of B. bronchiseptica. Our results demonstrate the striking protective efficacy of BcfA-mediated immunization, thereby highlighting its utility as a potential vaccine candidate. These results also provide a model for the development of cell-free vaccines against B. bronchiseptica.
- Published
- 2009
- Full Text
- View/download PDF
47. Polysaccharides cellulose, poly-beta-1,6-n-acetyl-D-glucosamine, and colanic acid are required for optimal binding of Escherichia coli O157:H7 strains to alfalfa sprouts and K-12 strains to plastic but not for binding to epithelial cells.
- Author
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Matthysse AG, Deora R, Mishra M, and Torres AG
- Subjects
- Agrobacterium tumefaciens genetics, Agrobacterium tumefaciens physiology, Biofilms growth & development, Cellulose genetics, Escherichia coli K12 genetics, Escherichia coli O157 genetics, Escherichia coli Proteins genetics, Genetic Complementation Test, Glucosyltransferases genetics, Mutation, Plant Roots microbiology, Plasmids, Plastics, Polysaccharides genetics, Sinorhizobium meliloti genetics, Sinorhizobium meliloti physiology, Bacterial Adhesion, Cellulose metabolism, Epithelial Cells microbiology, Escherichia coli K12 physiology, Escherichia coli O157 physiology, Medicago sativa microbiology, Polysaccharides metabolism, beta-Glucans metabolism
- Abstract
When Escherichia coli O157:H7 bacteria are added to alfalfa sprouts growing in water, the bacteria bind tightly to the sprouts. In contrast, laboratory K-12 strains of E. coli do not bind to sprouts under similar conditions. The roles of E. coli O157:H7 lipopolysaccharide (LPS), capsular polysaccharide, and exopolysaccharides in binding to sprouts were examined. An LPS mutant had no effect on the binding of the pathogenic strain. Cellulose synthase mutants showed a significant reduction in binding; colanic acid mutants were more severely reduced, and binding by poly-beta-1,6-N-acetylglucosamine (PGA) mutants was barely detectable. The addition of a plasmid carrying a cellulose synthase gene to K-12 strains allowed them to bind to sprouts. A plasmid carrying the Bps biosynthesis genes had only a marginal effect on the binding of K-12 bacteria. However, the introduction of the same plasmid allowed Sinorhizobium meliloti and a nonbinding mutant of Agrobacterium tumefaciens to bind to tomato root segments. These results suggest that although multiple redundant protein adhesins are involved in the binding of E. coli O157:H7 to sprouts, the polysaccharides required for binding are not redundant and each polysaccharide may play a distinct role. PGA, colanic acid, and cellulose were also required for biofilm formation by a K-12 strain on plastic, but not for the binding of E. coli O157:H7 to mammalian cells.
- Published
- 2008
- Full Text
- View/download PDF
48. The Bordetella Bps polysaccharide is critical for biofilm development in the mouse respiratory tract.
- Author
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Sloan GP, Love CF, Sukumar N, Mishra M, and Deora R
- Subjects
- Animals, Bordetella bronchiseptica genetics, Bordetella bronchiseptica ultrastructure, Female, Mice, Mice, Inbred C57BL, Nasal Cavity microbiology, Nasal Cavity ultrastructure, Biofilms growth & development, Bordetella Infections microbiology, Bordetella bronchiseptica growth & development, Bordetella bronchiseptica metabolism, Polysaccharides, Bacterial metabolism, Respiratory Tract Infections microbiology
- Abstract
Bordetellae are respiratory pathogens that infect both humans and animals. Bordetella bronchiseptica establishes asymptomatic and long-term to life-long infections of animal nasopharynges. While the human pathogen Bordetella pertussis is the etiological agent of the acute disease whooping cough in infants and young children, it is now being increasingly isolated from the nasopharynges of vaccinated adolescents and adults who sometimes show milder symptoms, such as prolonged cough illness. Although it has been shown that Bordetella can form biofilms in vitro, nothing is known about its biofilm mode of existence in mammalian hosts. Using indirect immunofluorescence and scanning electron microscopy, we examined nasal tissues from mice infected with B. bronchiseptica. Our results demonstrate that a wild-type strain formed robust biofilms that were adherent to the nasal epithelium and displayed architectural attributes characteristic of a number of bacterial biofilms formed on inert surfaces. We have previously shown that the Bordetella Bps polysaccharide encoded by the bpsABCD locus is critical for the stability and maintenance of three-dimensional structures of biofilms. We show here that Bps is essential for the formation of efficient nasal biofilms and is required for the colonization of the nose. Our results document a biofilm lifestyle for Bordetella in mammalian respiratory tracts and highlight the essential role of the Bps polysaccharide in this process and in persistence of the nares.
- Published
- 2007
- Full Text
- View/download PDF
49. Inhibition of Pseudomonas aeruginosa biofilm formation with Bromoageliferin analogues.
- Author
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Huigens RW 3rd, Richards JJ, Parise G, Ballard TE, Zeng W, Deora R, and Melander C
- Subjects
- Agelas, Animals, Hydrocarbons, Brominated chemistry, Hydrocarbons, Brominated pharmacology, Pseudomonas aeruginosa drug effects, Biofilms drug effects, Imidazoles chemistry, Imidazoles pharmacology, Pseudomonas aeruginosa physiology, Pyrroles chemistry, Pyrroles pharmacology
- Published
- 2007
- Full Text
- View/download PDF
50. Differential Bvg phase-dependent regulation and combinatorial role in pathogenesis of two Bordetella paralogs, BipA and BcfA.
- Author
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Sukumar N, Mishra M, Sloan GP, Ogi T, and Deora R
- Subjects
- Animals, Base Sequence, Bordetella bronchiseptica metabolism, Female, Gene Deletion, Gene Expression Regulation, Bacterial, Lac Operon, Molecular Sequence Data, Open Reading Frames genetics, Phosphorylation, Promoter Regions, Genetic physiology, Rats, Rats, Wistar, Trachea microbiology, Transcriptional Activation, Virulence, Virulence Factors, Bordetella genetics, Virulence Factors, Bordetella metabolism, Bacterial Outer Membrane Proteins genetics, Bacterial Outer Membrane Proteins metabolism, Bacterial Proteins metabolism, Bordetella Infections microbiology, Bordetella bronchiseptica genetics, Bordetella bronchiseptica pathogenicity, Trans-Activators metabolism
- Abstract
To successfully colonize their mammalian hosts, many bacteria produce multiple virulence factors that play essential roles in disease processes and pathogenesis. Some of these molecules are adhesins that allow efficient attachment to host cells, a prerequisite for successful host colonization. Bordetella spp. express a number of proteins which either play a direct role in attachment to the respiratory epithelia or exhibit similarity to known bacterial adhesins. One such recently identified protein is BipA. Despite the similarity of BipA to intimins and invasins, deletion of this protein from B. bronchiseptica did not result in any significant defect in respiratory tract colonization. In this study, we identified an open reading frame in B. bronchiseptica, designated bcfA (encoding BcfA [bordetella colonization factor A]), that is similar to bipA. In contrast to the maximal expression of bipA in the Bvg intermediate (Bvg(i)) phase, bcfA is expressed at high levels in both the Bvg(+) and Bvg(i) phases. We show here that BvgA and phosphorylated BvgA bind differentially to the bcfA promoter region. Utilizing immunoblot assays, we found that BcfA is localized to the outer membrane and that it is expressed during animal infection. While deletion of either bipA or bcfA did not significantly affect respiratory tract colonization, concomitant deletion of both genes resulted in a defect in colonization of the rat trachea. Our results indicate that the two paralogous proteins have a combinatorial role in mediating efficient respiratory tract colonization.
- Published
- 2007
- Full Text
- View/download PDF
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