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Rodríguez, María Eugenia - One of the best experts on this subject based on the ideXlab platform.
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Bordetella Parapertussis survives inside human macrophages in lipid raft-enriched phagosomes
2019Co-Authors: Gorgojo, Juan Pablo, Harvill, Eric T., Rodríguez, María EugeniaAbstract:Bordetella Parapertussis is a human pathogen that causes whooping cough. The increasing incidence of B. Parapertussis has been attributed to the lack of cross protection induced by pertussis vaccines. It was previously shown that B. Parapertussis is able to avoid bacterial killing by polymorphonuclear leukocytes (PMN) if specific opsonic antibodies are not present at the site of interaction. Here, we evaluated the outcome of B. Parapertussis innate interaction with human macrophages, a less aggressive type of cell and a known reservoir of many persistent pathogens. The results showed that in the absence of opsonins, O antigen allows B. Parapertussis to inhibit phagolysosomal fusion and to remain alive inside macrophages. The O antigen targets B. Parapertussis to lipid rafts that are retained in the membrane of phagosomes that do not undergo lysosomal maturation. Fortyeight hours after infection, wild-type B. Parapertussis bacteria but not the O antigen-deficient mutants were found colocalizing with lipid rafts and alive in nonacidic compartments. Taken together, our data suggest that in the absence of opsonic antibodies, B. Parapertussis survives inside macrophages by preventing phagolysosomal maturation in a lipid raft- and O antigen-dependent manner. Two days after infection, about 15% of macrophages were found loaded with live bacteria inside flotillin-enriched phagosomes that had access to nutrients provided by the host cell recycling pathway, suggesting the development of an intracellular infection. IgG opsonization drastically changed this interaction, inducing efficient bacterial killing. These results highlight the need for B. Parapertussis opsonic antibodies to induce bacterial clearance and prevent the eventual establishment of cellular reservoirs of this pathogen.Centro de Investigación y Desarrollo en Fermentaciones Industriale
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The O antigen is a critical antigen for the development of a protective immune response to Bordetella Parapertussis
2019Co-Authors: Zhang Xuqing, Rodríguez, María Eugenia, Goebel, Elizabeth M., Preston Andrew, Harvill, Eric T.Abstract:Despite excellent vaccine coverage in developed countries, whooping cough is a reemerging disease that can be caused by two closely related pathogens, Bordetella pertussis and B. Parapertussis. The two are antigenically distinct, and current vaccines, containing only B. pertussis-derived antigens, confer efficient protection against B. pertussis but not against B. Parapertussis. B. pertussis does not express the O antigen, while B. Parapertussis retains it as a dominant surface antigen. Since the O antigen is a protective antigen for many pathogenic bacteria, we examined whether this factor is a potential protective antigen for B. Parapertussis. In a mouse model of infection, immunization with wild-type B. Parapertussis elicited a strong antibody response to the O antigen and conferred efficient protection against a subsequent B. Parapertussis challenge. However, immunization with an isogenic mutant lacking the O antigen, B. Parapertussis Δwbm, induced antibodies that recognized other antigens but did not efficiently mediate opsonophagocytosis of B. Parapertussis. The passive transfer of sera raised against B. Parapertussis, but not B. Parapertussis Δwbm, reduced B. Parapertussis loads in the lower respiratory tracts of mice. The addition of 10 μg of purified B. Parapertussis lipopolysaccharide (LPS), which contains the O antigen, but not B. Parapertussis Δwbm LPS drastically improved the efficacy of the acellular vaccine Adacel against B. Parapertussis. These data suggest that the O antigen is a critical protective antigen of B. Parapertussis and its inclusion can substantially improve whooping cough vaccine efficacy against this pathogen.Centro de Investigación y Desarrollo en Fermentaciones Industriale
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Bordetella Parapertussis survives the innate interaction with human neutrophils by impairing bactericidal trafficking inside the cell through a lipid raft-dependent mechanism mediated by the lipopolysaccharide O antigen
2019Co-Authors: Gorgojo, Juan Pablo, Harvill, Eric T., Lamberti, Yanina Andrea, Valdez, Hugo Alberto, Rodríguez, María EugeniaAbstract:Whooping cough is a reemerging disease caused by two closely related pathogens, Bordetella pertussis and Bordetella Parapertussis. The incidence of B. Parapertussis in whooping cough cases has been increasing since the introduction of acellular pertussis vaccines containing purified antigens that are common to both strains. Recently published results demonstrated that these vaccines do not protect against B. Parapertussis due to the presence of the O antigen on the bacterial surface that impairs antibody access to shared antigens. We have investigated the effect of the lack of opsonization of B. Parapertussis on the outcome of its interaction with human neutrophils (polymorphonuclear leukocytes [PMNs]). In the absence of opsonic antibodies, PMN interaction with B. Parapertussis resulted in nonbactericidal trafficking upon phagocytosis. A high percentage of nonopsonized B. Parapertussis was found in nonacidic lysosome marker (lysosome-associated membrane protein [LAMP])-negative phagosomes with access to the host cell-recycling pathway of external nutrients, allowing bacterial survival as determined by intracellular CFU counts. The lipopolysaccharide (LPS) O antigen was found to be involved in directing B. Parapertussis to PMN lipid rafts, eventually determining the nonbactericidal fate inside the PMN. IgG opsonization of B. Parapertussis drastically changed this interaction by not only inducing efficient PMN phagocytosis but also promoting PMN bacterial killing. These data provide new insights into the immune mechanisms of hosts against B. Parapertussis and document the crucial importance of opsonic antibodies in immunity to this pathogen.Facultad de Ciencias ExactasCentro de Investigación y Desarrollo en Fermentaciones Industriale
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Bordetella Parapertussis Circumvents Neutrophil Extracellular Bactericidal Mechanisms
2019Co-Authors: Gorgojo, Juan Pablo, Harvill, Eric T., Gomez, Ricardo Martin, Scharrig Emilia, Rodríguez, María EugeniaAbstract:B. Parapertussis is a whooping cough etiological agent with the ability to evade the immune response induced by pertussis vaccines. We previously demonstrated that in the absence of opsonic antibodies B. Parapertussis hampers phagocytosis by neutrophils and macrophages and, when phagocytosed, blocks intracellular killing by interfering with phagolysosomal fusion. But neutrophils can kill and/or immobilize extracellular bacteria through nonphagocytic mechanisms such as degranulation and neutrophil extracellular traps (NETs). In this study we demonstrated that B. Parapertussis also has the ability to circumvent these two neutrophil extracellular bactericidal activities. The lack of neutrophil degranulation was found dependent on the O antigen that targets the bacteria to cell lipid rafts, eventually avoiding the fusion of nascent phagosomes with specific and azurophilic granules. IgG opsonization overcame this inhibition of neutrophil degranulation. We further observed that B. Parapertussis did not induce NETs release in resting neutrophils and inhibited NETs formation in response to phorbol myristate acetate (PMA) stimulation by a mechanism dependent on adenylate cyclase toxin (CyaA)-mediated inhibition of reactive oxygen species (ROS) generation. Thus, B. Parapertussis modulates neutrophil bactericidal activity through two different mechanisms, one related to the lack of proper NETs-inducer stimuli and the other one related to an active inhibitory mechanism. Together with previous results these data suggest that B. Parapertussis has the ability to subvert the main neutrophil bactericidal functions, inhibiting efficient clearance in non-immune hosts.Centro de Investigación y Desarrollo en Fermentaciones IndustrialesInstituto de Biotecnologia y Biologia Molecula
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A recombinant iron transport protein from Bordetella pertussis confers protection against Bordetella Parapertussis
2019Co-Authors: Álvarez Hayes Jimena, Valdez, Hugo Alberto, Oviedo, Juan Marcos, Laborde, Juan Martín, Maschi, Fabricio Alejandro, Ayala, Miguel Ángel, Shah Rohan, Fernandez Lahore Marcelo, Rodríguez, María EugeniaAbstract:Whooping cough, which is caused by Bordetella pertussis and B. Parapertussis, is a reemerging disease. New protective antigens are needed to improve the efficacy of current vaccines against both species. Using proteomic tools, it was here found that B. Parapertussis expresses a homolog of AfuA, a previously reported new vaccine candidate against B. pertussis. It was found that this homolog, named AfuABpp, is expressed during B. Parapertussis infection, exposed on the surface of the bacteria and recognized by specific antibodies induced by the recombinant AfuA cloned from B. pertussis (rAfuA). Importantly, the presence of the O-antigen, a molecule that has been found to shield surface antigens on B. Parapertussis, showed no influence on antibody recognition of AfuABpp on the bacterial surface. The present study further showed that antibodies induced by immunization with the recombinant protein were able to opsonize B. Parapertussis and promote bacterial uptake by neutrophils. Finally, it was shown that this antigen confers protection against B. Parapertussis infection in a mouse model. Altogether, these results indicate that AfuA is a good vaccine candidate for acellular vaccines protective against both causative agents of whooping cough.Facultad de Ciencias ExactasFacultad de Ciencias Veterinarias (FCV)Centro de Investigación y Desarrollo en Fermentaciones Industriales (CINDEFI
Eric T. Harvill - One of the best experts on this subject based on the ideXlab platform.
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Image_3_Blood or Serum Exposure Induce Global Transcriptional Changes, Altered Antigenic Profile, and Increased Cytotoxicity by Classical Bordetellae.JPEG
2018Co-Authors: Monica C. Gestal, Israel Rivera, Laura K. Howard, Kalyan K. Dewan, Illiassou Hamidou Soumana, Margaret Dedloff, Tracy L. Nicholson, Bodo Linz, Eric T. HarvillAbstract:The classical Bordetellae sense and respond to a variety of environments outside and within their mammalian hosts. By causing inflammation and tissue damage, we reasoned that Bordetellae are likely to encounter components of blood and/or serum during the course of a respiratory infection, and that detecting and responding to these would be advantageous. Therefore, we hypothesized that classical Bordetellae have the ability to sense and respond to blood or serum. Blood or serum exposure resulted in substantial transcriptional changes in Bordetella bronchiseptica, including enhanced expression of many virulence-associated genes. Exposure to blood or serum additionally elicited production of multiple antigens not otherwise detectable, and led to increased bacterial cytotoxicity against macrophages. Transcriptional responses to blood/serum were observed in a Bvg− phase-locked mutant, indicating that the response is not solely dependent on a functional BvgAS system. Similar transcriptional responses to blood/serum were observed for the other classical Bordetellae, Bordetella pertussis and Bordetella Parapertussis. These data suggest the classical Bordetellae respond to signals present in blood and serum by changing their behavior in ways that likely contribute to their remarkable success, via effects on pathogenesis, persistence and/or transmission between hosts.
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Blood or Serum Exposure Induce Global Transcriptional Changes, Altered Antigenic Profile, and Increased Cytotoxicity by Classical Bordetellae
Frontiers Media S.A., 2018Co-Authors: Monica C. Gestal, Israel Rivera, Laura K. Howard, Kalyan K. Dewan, Illiassou Hamidou Soumana, Margaret Dedloff, Tracy L. Nicholson, Bodo Linz, Eric T. HarvillAbstract:The classical Bordetellae sense and respond to a variety of environments outside and within their mammalian hosts. By causing inflammation and tissue damage, we reasoned that Bordetellae are likely to encounter components of blood and/or serum during the course of a respiratory infection, and that detecting and responding to these would be advantageous. Therefore, we hypothesized that classical Bordetellae have the ability to sense and respond to blood or serum. Blood or serum exposure resulted in substantial transcriptional changes in Bordetella bronchiseptica, including enhanced expression of many virulence-associated genes. Exposure to blood or serum additionally elicited production of multiple antigens not otherwise detectable, and led to increased bacterial cytotoxicity against macrophages. Transcriptional responses to blood/serum were observed in a Bvg− phase-locked mutant, indicating that the response is not solely dependent on a functional BvgAS system. Similar transcriptional responses to blood/serum were observed for the other classical Bordetellae, Bordetella pertussis and Bordetella Parapertussis. These data suggest the classical Bordetellae respond to signals present in blood and serum by changing their behavior in ways that likely contribute to their remarkable success, via effects on pathogenesis, persistence and/or transmission between hosts
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Table_1_Blood or Serum Exposure Induce Global Transcriptional Changes, Altered Antigenic Profile, and Increased Cytotoxicity by Classical Bordetellae.DOCX
2018Co-Authors: Monica C. Gestal, Israel Rivera, Laura K. Howard, Kalyan K. Dewan, Illiassou Hamidou Soumana, Margaret Dedloff, Tracy L. Nicholson, Bodo Linz, Eric T. HarvillAbstract:The classical Bordetellae sense and respond to a variety of environments outside and within their mammalian hosts. By causing inflammation and tissue damage, we reasoned that Bordetellae are likely to encounter components of blood and/or serum during the course of a respiratory infection, and that detecting and responding to these would be advantageous. Therefore, we hypothesized that classical Bordetellae have the ability to sense and respond to blood or serum. Blood or serum exposure resulted in substantial transcriptional changes in Bordetella bronchiseptica, including enhanced expression of many virulence-associated genes. Exposure to blood or serum additionally elicited production of multiple antigens not otherwise detectable, and led to increased bacterial cytotoxicity against macrophages. Transcriptional responses to blood/serum were observed in a Bvg− phase-locked mutant, indicating that the response is not solely dependent on a functional BvgAS system. Similar transcriptional responses to blood/serum were observed for the other classical Bordetellae, Bordetella pertussis and Bordetella Parapertussis. These data suggest the classical Bordetellae respond to signals present in blood and serum by changing their behavior in ways that likely contribute to their remarkable success, via effects on pathogenesis, persistence and/or transmission between hosts.
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Bordetella Parapertussis Circumvents Neutrophil Extracellular Bactericidal Mechanisms
2017Co-Authors: Juan Gorgojo, Eric T. Harvill, Emilia Scharrig, Ricardo M. Gómez, Maria Eugenia RodríguezAbstract:B. Parapertussis is a whooping cough etiological agent with the ability to evade the immune response induced by pertussis vaccines. We previously demonstrated that in the absence of opsonic antibodies B. Parapertussis hampers phagocytosis by neutrophils and macrophages and, when phagocytosed, blocks intracellular killing by interfering with phagolysosomal fusion. But neutrophils can kill and/or immobilize extracellular bacteria through non-phagocytic mechanisms such as degranulation and neutrophil extracellular traps (NETs). In this study we demonstrated that B. Parapertussis also has the ability to circumvent these two neutrophil extracellular bactericidal activities. The lack of neutrophil degranulation was found dependent on the O antigen that targets the bacteria to cell lipid rafts, eventually avoiding the fusion of nascent phagosomes with specific and azurophilic granules. IgG opsonization overcame this inhibition of neutrophil degranulation. We further observed that B. Parapertussis did not induce NETs release in resting neutrophils and inhibited NETs formation in response to phorbol myristate acetate (PMA) stimulation by a mechanism dependent on adenylate cyclase toxin (CyaA)-mediated inhibition of reactive oxygen species (ROS) generation. Thus, B. Parapertussis modulates neutrophil bactericidal activity through two different mechanisms, one related to the lack of proper NETs-inducer stimuli and the other one related to an active inhibitory mechanism. Together with previous results these data suggest that B. Parapertussis has the ability to subvert the main neutrophil bactericidal functions, inhibiting efficient clearance in non-immune hosts.
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Antigenic Variation among Bordetella Bordetella BRONCHISEPTICA STRAIN MO149 EXPRESSES A NOVEL O CHAIN THAT IS POORLY IMMUNOGENIC
The Journal of biological chemistry, 2010Co-Authors: Evguenii Vinogradov, Eric T. Harvill, Jerry D. King, Ashutosh K. Pathak, Andrew PrestonAbstract:The O chain polysaccharide (O PS) of Bordetella bronchiseptica and Bordetella Parapertussis lipopolysaccharide is a homopolymer of 2,3-diacetamido-2,3-dideoxygalacturonic acid (GalNAc3NAcA) in which some of the sugars are present as uronamides. The terminal residue contains several unusual modifications. To date, two types of modification have been characterized, and a survey of numerous strains demonstrated that each contained one of these two modification types. Host antibody responses against the O PS are directed against the terminal residue modifications, and there is little cross-reactivity between the two types. This suggests that Bordetella O PS modifications represent a means of antigenic variation. Here we report the characterization of the O PS of B. bronchiseptica strain MO149. It consists of a novel two-sugar repeating unit and a novel terminal residue modification, with the structure Me-4-alpha-L-GalNAc3NAcA-(4-beta-D-GlcNAc3NAcA-4-alpha-L-GalNAc3NAcA-)(5-6)-, which we propose be defined as the B. bronchiseptica O3 PS. We show that the O3 PS is very poorly immunogenic and that the MO149 strain contains a novel wbm (O PS biosynthesis) locus. Thus, there is greater diversity among Bordetella O PSs than previously recognized, which is likely to be a result of selection pressure from host immunity. We also determine experimentally, for the first time, the absolute configuration of the diacetimido-uronic acid sugars in Bordetella O PS.
Elisabeth Njamkepo - One of the best experts on this subject based on the ideXlab platform.
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evolution of french Bordetella pertussis and Bordetella Parapertussis isolates increase of Bordetellae not expressing pertactin
Clinical Microbiology and Infection, 2012Co-Authors: Nicolas Hegerle, A S Paris, Delphine Brun, Gregory J Dore, Elisabeth NjamkepoAbstract:Bordetella pertussis and Bordetella Parapertussis are closely related bacterial agents of whooping cough. Whole-cell pertussis (wP) vaccine was introduced in France in 1959. Acellular pertussis (aP) vaccine was introduced in 1998 as an adolescent booster and was rapidly generalized to the whole population, changing herd immunity by specifically targeting the virulence of the bacteria. We performed a temporal analysis of all French B. pertussis and B. Parapertussis isolates collected since 2000 under aP vaccine pressure, using pulsed-field gel electrophoresis (PFGE), genotyping and detection of expression of virulence factors. Particular isolates were selected according to their different phenotype and PFGE type and their characteristics were analysed using the murine model of respiratory infection and in vitro cell cytotoxic assay. Since the introduction of the aP vaccines there has been a steady increase in the number of B. pertussis and B. Parapertussis isolates collected that are lacking expression of pertactin. These isolates seem to be as virulent as those expressing all virulence factors according to animal and cellular models of infection. Whereas wP vaccine-induced immunity led to a monomorphic population of B. pertussis, aP vaccine-induced immunity enabled the number of circulating B. pertussis and B. Parapertussis isolates not expressing virulence factors to increase, sustaining our previous hypothesis.
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prevalence of Bordetella pertussis and Bordetella Parapertussis infections in tunisian hospitalized infants results of a 4 year prospective study
Diagnostic Microbiology and Infectious Disease, 2012Co-Authors: Asma Zouari, Delphine Brun, Elisabeth Njamkepo, Hanen Smaoui, Soufien Sghaier, Emna Zouari, Renaud Felix, K MenifAbstract:The prevalence of pertussis in Tunisia remains undetermined essentially because of the unavailability of a basic laboratory diagnostic service. Specific diagnostic tools were applied for the first time in a Tunisian prospective study in order to get a first estimation of the prevalence of Bordetella pertussis/Parapertussis infections and to evaluate their use to determine the epidemiologic characteristics of these infections in Tunisian infants. Between 2007 and 2011, a total of 626 samples from 599 infants aged <1 year with and without pertussoid cough were investigated for the presence of B. pertussis/Parapertussis using culture and real-time polymerase chain reaction (PCR). The real-time PCR (RT-PCR) targets include IS481 commonly found in B. pertussis, B. bronchiseptica, and B. holmesii; IS1001 specific of B. Parapertussis, in combination with the pertussis toxin promoter region gene (ptx) of B. pertussis; and the recA gene specific of B. holmesii. When possible, patients' household contacts provided nasopharyngeal aspirates (NPAs) for RT-PCR detection of B. pertussis/Parapertussis or single-serum samples for anti-PT IgG quantification. All except 1 NPAs were negative by conventional culture, whereas PCR gave positive signals for 126 specimens (21%): B. pertussis, B. Parapertussis, and Bordetella spp. were detected in 82%, 6%, and 4% of the samples, respectively. The simultaneous presence of B. pertussis and B. Parapertussis was noted in 8% of the cases. Pertussis was reported throughout the year with a peak during the summer of the year 2009. The prevalence of Bordetella infection was 20% between 2007 and 2011. Most of these cases corresponded to patients younger than 6 months who received <3 doses of pertussis vaccine. Among the household contacts enrolled in the study, mothers seemed to be the likely source of infection. This study showed that pertussis is still prevalent in Tunisia and that the disease remains a public health problem affecting not only infants but also adults. Given this situation, sensitive and specific laboratory tests are needed to improve the accuracy of pertussis diagnosis.
Andrew Preston - One of the best experts on this subject based on the ideXlab platform.
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Antigenic Variation among Bordetella Bordetella BRONCHISEPTICA STRAIN MO149 EXPRESSES A NOVEL O CHAIN THAT IS POORLY IMMUNOGENIC
The Journal of biological chemistry, 2010Co-Authors: Evguenii Vinogradov, Eric T. Harvill, Jerry D. King, Ashutosh K. Pathak, Andrew PrestonAbstract:The O chain polysaccharide (O PS) of Bordetella bronchiseptica and Bordetella Parapertussis lipopolysaccharide is a homopolymer of 2,3-diacetamido-2,3-dideoxygalacturonic acid (GalNAc3NAcA) in which some of the sugars are present as uronamides. The terminal residue contains several unusual modifications. To date, two types of modification have been characterized, and a survey of numerous strains demonstrated that each contained one of these two modification types. Host antibody responses against the O PS are directed against the terminal residue modifications, and there is little cross-reactivity between the two types. This suggests that Bordetella O PS modifications represent a means of antigenic variation. Here we report the characterization of the O PS of B. bronchiseptica strain MO149. It consists of a novel two-sugar repeating unit and a novel terminal residue modification, with the structure Me-4-alpha-L-GalNAc3NAcA-(4-beta-D-GlcNAc3NAcA-4-alpha-L-GalNAc3NAcA-)(5-6)-, which we propose be defined as the B. bronchiseptica O3 PS. We show that the O3 PS is very poorly immunogenic and that the MO149 strain contains a novel wbm (O PS biosynthesis) locus. Thus, there is greater diversity among Bordetella O PSs than previously recognized, which is likely to be a result of selection pressure from host immunity. We also determine experimentally, for the first time, the absolute configuration of the diacetimido-uronic acid sugars in Bordetella O PS.
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comparison of the genome sequence of the poultry pathogen Bordetella avium with those of b bronchiseptica b pertussis and b Parapertussis reveals extensive diversity in surface structures associated with host interaction
Journal of Bacteriology, 2006Co-Authors: Mohammed Sebaihia, Andrew Preston, Duncan J. Maskell, Holly Kuzmiak, Terry D Connell, Natalie D King, Paul E Orndorff, David M Miyamoto, Nicholas R Thomson, David HarrisAbstract:Bordetella avium is a pathogen of poultry and is phylogenetically distinct from Bordetella bronchiseptica, Bordetella pertussis, and Bordetella Parapertussis, which are other species in the Bordetella genus that infect mammals. In order to understand the evolutionary relatedness of Bordetella species and further the understanding of pathogenesis, we obtained the complete genome sequence of B. avium strain 197N, a pathogenic strain that has been extensively studied. With 3,732,255 base pairs of DNA and 3,417 predicted coding sequences, it has the smallest genome and gene complement of the sequenced Bordetellae. In this study, the presence or absence of previously reported virulence factors from B. avium was confirmed, and the genetic bases for growth characteristics were elucidated. Over 1,100 genes present in B. avium but not in B. bronchiseptica were identified, and most were predicted to encode surface or secreted proteins that are likely to define an organism adapted to the avian rather than the mammalian respiratory tracts. These include genes coding for the synthesis of a polysaccharide capsule, hemagglutinins, a type I secretion system adjacent to two very large genes for secreted proteins, and unique genes for both lipopolysaccharide and fimbrial biogenesis. Three apparently complete prophages are also present. The BvgAS virulence regulatory system appears to have polymorphisms at a poly(C) tract that is involved in phase variation in other Bordetellae. A number of putative iron-regulated outer membrane proteins were predicted from the sequence, and this regulation was confirmed experimentally for five of these.
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complete structures of Bordetella bronchiseptica and Bordetella Parapertussis lipopolysaccharides
Journal of Biological Chemistry, 2006Co-Authors: Andrew Preston, Bent O Petersen, Jens O Duus, Joanna Kublerkielb, Gil Benmenachem, Evgeny VinogradovAbstract:The structures of the lipopolysaccharide (LPS) core and O antigen of Bordetella bronchiseptica and Bordetella Parapertussis are known, but how these two regions are linked to each other had not been determined. We have studied LPS from several strains of these microorganisms to determine the complete carbohydrate structure of the LPS. LPS was analyzed using different chemical degradations, NMR spectroscopy, and mass spectrometry. This identified a novel pentasaccharide fragment that links the O chain to the core in all the LPS studied. In addition, although the O chain of these bacteria was reported as a homopolymer of 1,4-linked 2,3-diacetamido-2,3-dideoxy-alpha-galacturonic acid, we discovered that the polymer contains several amidated uronic acids, the number of which varies between strains. These new data describe the complete structure of the LPS carbohydrate backbone for both Bordetella species and help to explain the complex genetics of LPS biosynthesis in these bacteria.
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Comparative analysis of the genome sequences of Bordetella pertussis, Bordetella Parapertussis and Bordetella bronchiseptica.
Nature genetics, 2003Co-Authors: Julian Parkhill, Andrew Preston, Mohammed Sebaihia, Nicholas R Thomson, David Harris, Lee Murphy, Matthew T. G. Holden, Carol Churcher, Stephen D. Bentley, Karen MungallAbstract:Bordetella pertussis, Bordetella Parapertussis and Bordetella bronchiseptica are closely related Gram-negative beta-proteobacteria that colonize the respiratory tracts of mammals. B. pertussis is a strict human pathogen of recent evolutionary origin and is the primary etiologic agent of whooping cough. B. Parapertussis can also cause whooping cough, and B. bronchiseptica causes chronic respiratory infections in a wide range of animals. We sequenced the genomes of B. bronchiseptica RB50 (5,338,400 bp; 5,007 predicted genes), B. Parapertussis 12822 (4,773,551 bp; 4,404 genes) and B. pertussis Tohama I (4,086,186 bp; 3,816 genes). Our analysis indicates that B. Parapertussis and B. pertussis are independent derivatives of B. bronchiseptica-like ancestors. During the evolution of these two host-restricted species there was large-scale gene loss and inactivation; host adaptation seems to be a consequence of loss, not gain, of function, and differences in virulence may be related to loss of regulatory or control functions.
Delphine Brun - One of the best experts on this subject based on the ideXlab platform.
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evolution of french Bordetella pertussis and Bordetella Parapertussis isolates increase of Bordetellae not expressing pertactin
Clinical Microbiology and Infection, 2012Co-Authors: Nicolas Hegerle, A S Paris, Delphine Brun, Gregory J Dore, Elisabeth NjamkepoAbstract:Bordetella pertussis and Bordetella Parapertussis are closely related bacterial agents of whooping cough. Whole-cell pertussis (wP) vaccine was introduced in France in 1959. Acellular pertussis (aP) vaccine was introduced in 1998 as an adolescent booster and was rapidly generalized to the whole population, changing herd immunity by specifically targeting the virulence of the bacteria. We performed a temporal analysis of all French B. pertussis and B. Parapertussis isolates collected since 2000 under aP vaccine pressure, using pulsed-field gel electrophoresis (PFGE), genotyping and detection of expression of virulence factors. Particular isolates were selected according to their different phenotype and PFGE type and their characteristics were analysed using the murine model of respiratory infection and in vitro cell cytotoxic assay. Since the introduction of the aP vaccines there has been a steady increase in the number of B. pertussis and B. Parapertussis isolates collected that are lacking expression of pertactin. These isolates seem to be as virulent as those expressing all virulence factors according to animal and cellular models of infection. Whereas wP vaccine-induced immunity led to a monomorphic population of B. pertussis, aP vaccine-induced immunity enabled the number of circulating B. pertussis and B. Parapertussis isolates not expressing virulence factors to increase, sustaining our previous hypothesis.
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prevalence of Bordetella pertussis and Bordetella Parapertussis infections in tunisian hospitalized infants results of a 4 year prospective study
Diagnostic Microbiology and Infectious Disease, 2012Co-Authors: Asma Zouari, Delphine Brun, Elisabeth Njamkepo, Hanen Smaoui, Soufien Sghaier, Emna Zouari, Renaud Felix, K MenifAbstract:The prevalence of pertussis in Tunisia remains undetermined essentially because of the unavailability of a basic laboratory diagnostic service. Specific diagnostic tools were applied for the first time in a Tunisian prospective study in order to get a first estimation of the prevalence of Bordetella pertussis/Parapertussis infections and to evaluate their use to determine the epidemiologic characteristics of these infections in Tunisian infants. Between 2007 and 2011, a total of 626 samples from 599 infants aged <1 year with and without pertussoid cough were investigated for the presence of B. pertussis/Parapertussis using culture and real-time polymerase chain reaction (PCR). The real-time PCR (RT-PCR) targets include IS481 commonly found in B. pertussis, B. bronchiseptica, and B. holmesii; IS1001 specific of B. Parapertussis, in combination with the pertussis toxin promoter region gene (ptx) of B. pertussis; and the recA gene specific of B. holmesii. When possible, patients' household contacts provided nasopharyngeal aspirates (NPAs) for RT-PCR detection of B. pertussis/Parapertussis or single-serum samples for anti-PT IgG quantification. All except 1 NPAs were negative by conventional culture, whereas PCR gave positive signals for 126 specimens (21%): B. pertussis, B. Parapertussis, and Bordetella spp. were detected in 82%, 6%, and 4% of the samples, respectively. The simultaneous presence of B. pertussis and B. Parapertussis was noted in 8% of the cases. Pertussis was reported throughout the year with a peak during the summer of the year 2009. The prevalence of Bordetella infection was 20% between 2007 and 2011. Most of these cases corresponded to patients younger than 6 months who received <3 doses of pertussis vaccine. Among the household contacts enrolled in the study, mothers seemed to be the likely source of infection. This study showed that pertussis is still prevalent in Tunisia and that the disease remains a public health problem affecting not only infants but also adults. Given this situation, sensitive and specific laboratory tests are needed to improve the accuracy of pertussis diagnosis.