Project description:Bordetella pertussis is the etiological agent of whooping cough, a bacterial infection of especially children, which may be fatal without treatment. In frame of studies to investigate putative effects of vaccination on host-pathogen interaction and clonal distribution of strains, in addition to Corynebacterium diphtheriae and Clostridium tetani toxoid vaccines, also whole-cell and acellular pertussis vaccines were analyzed by mass spectrometry.
Project description:To our knowledge, we provide the first proteomics study of Bordetella parapertussis, one of the causative agents of whooping cough. We compared the identified proteins different to Bordetella pertussis, the other pathogen causing whooping cough. In addition, we extended the study to investigate the proteome response to iron limitation, a stress condition the pathogens face while infection.
Project description:Copper is both essential and toxic to living beings, which therefore tightly control its intracellular concentration. At the host-pathogen interface, copper is used by phagocytic cells to kill invading microorganisms. We investigated copper homeostasis in the whooping cough agent Bordetella pertussis, which lives in the human respiratory mucosa and has no environmental reservoir. B. pertussis has considerably streamlined copper homeostasis mechanisms relative to other Gram-negative bacteria. Its single remaining defense line against copper intoxication consists in a metallochaperone diverted for copper passivation and two enzymes involved in peroxide detoxification, which together fight two stresses encountered in phagolysosomes. The three proteins are encoded by an original, composite operon assembled in an environmental ancestor and which is under sensitive control by copper. Interestingly, this system appears to play a role in persistent infection in the nasal cavity of B. pertussis-infected mice. Combining responses to co-occurring stresses in a tailored operon reveals a new strategy adopted by a host-restricted pathogen to optimize survival at minimal energy expenditure.
Project description:Genomic content of Bordetella pertussis clinical isolates circulating in areas of intensive children vaccination. 13 isolates and one reference strain of Bordetella pertussis used.
Project description:Background Bordetella pertussis is a Gram-negative bacterium that infects the human respiratory tract and causes pertussis or whooping cough. The disease has resurged in many countries including Finland where the whole-cell pertussis vaccine has been used for more than 50 years. Antigenic divergence has been observed between vaccine strains and clinical isolates in Finland. To better understand genome evolution in B. pertussis circulating in the immunized population, we developed an oligonucleotide-based microarray for comparative genomic analysis of Finnish strains isolated during the period of 50 years. Methodology/Principal Findings The microarray consisted of 3,582 oligonucleotides (70-mer) and covered 94% of the genome of Tohama I, the strain of which the genome has been sequenced [21]. Twenty isolates from 1953 to 2004 were studied together with two Finnish vaccine strains and two international reference strains. The isolates were selected according to their characteristics, e.g. the year and place of isolation and pulsed-field gel electrophoresis profiles. Genomic DNA of the tested strains, along with reference DNA of Tohama I strain, was labelled and hybridized. The absence of genes as established with microarrays, was confirmed by PCR. Compared to the Tohama I strain, Finnish isolates lost 7 (8.6 kb) to 49 (55.3 kb) genes, clustered in one to four distinct loci. The number of lost genes increased with time, and one third of lost genes had functions related to ion transport, metabolism, or energy production and conversion. All four loci of lost genes were flanked by the insertion sequence element IS481. Conclusion/Significance Our results showed that the progressive gene loss occurred in Finnish B. pertussis strains isolated during a period of 50 years and confirmed that B. pertussis is dynamic and is continuously evolving, suggesting that the bacterium may use gene loss as one strategy to adapt to highly immunized populations. Keywords: comparetive genomic hybridisation
Project description:Acetylation on ε-amino groups of lysine residues (N-ε-lysine acetylation) represents an important mechanism of post-translational regulation of protein function. However, its role and extent in the whooping cough agent Bordetella pertussis remain unknown. In this study, we analyzed the acetylomes of two bacterial mutants lacking putative lysine deacetylases encoded by genes BP0960 and BP3063 and compared them with the acetylome of wild-type B. pertussis. The results suggest that acetylation on lysine residues may modulate the activities of proteins involved in bacterial virulence and of multiple histone-like proteins.
Project description:Bordetella pertussis is a Gram-negative, strictly human respiratory pathogen and the causative agent of whooping cough (pertussis). Similar to other Gram-negative pathogens, B. pertussis produces a functional type III secretion system, but its role in pathogenesis of B. pertussis is enigmatic and has not yet been elucidated. Here, we applied omics RNA-seq as well as LC-MS/MS techniques and co-immunoprecipitation method to identify and characterize the novel CesT family T3SS chaperone BP2265. Our results show that the chaperone BP2265 specifically interacts with the secreted T3SS anti-sigma factor BtrA. Moreover, in the absence of the chaperone, secretion but not production of BtrA and several early, intermediate, and late T3SS substrates is severely impaired. It appears that the role of BtrA in regulating T3SS is more complex and extends beyond its activity as an antagonist of the sigma factor BtrS. We propose to rename BP2265 as BtcB for the Bordetella type III chaperone of BtrA.
Project description:Bordetella pertussis is the bacterial causative agent of whooping cough, a serious respiratory illness. An extensive knowledge on its virulence regulation and metabolism is a key factor to ensure pertussis vaccine manufacturing process robustness. The aim of this study was to refine our comprehension of B. pertussis physiology along the fermentation process. A longitudinal multi-omics analysis was carried out over a 26-hour small-scale fermentation of B. pertussis. Fermentations were performed in batch mode and under culture conditions intending to mimic industrial processes. Putative cysteine and proline starvations were respectively observed at the beginning of the exponential phase (from 4h to 8h) and during the exponential phase (18h45). As revealed by multi-omics analyses, the proline starvation induced major molecular changes, including a transient metabolism with internal stock consumption. In the meantime, growth and specific total PT, PRN and Fim2 antigen productions were negatively affected. Interestingly, the master virulence-regulating two-component system of B. pertussis (BvgASR) was not evidenced as the sole virulence regulator in this in vitro growth condition. Indeed, novel intermediate regulators were identified as putatively involved in the expression of some virulence-activated genes (vags). Such longitudinal multi-omics analysis applied to B. pertussis fermentation process emerges as a powerful tool for characterization and incremental optimization of vaccine antigen production.
Project description:Bordetella pertussis, the causative agent of whooping cough, produces a microcapsule at its surface but its role in pertussis pathogenesis remained to be investigated.Absence of KpsT, a membrane-associated protein involved in the polysaccharide transport resulted in the down-modulation of a large number of virulence genes which correlated with strong attenuation in vivo.