Probing the Genome-Scale Metabolic Landscape of Bordetella pertussis, the Causative Agent of Whooping Cough

• Published in: Applied and environmental microbiology Vol. 83; no. 21
• Main Authors: Branco Dos Santos, Filipe, Olivier, Brett G, Boele, Joost, Smessaert, Vincent, De Rop, Philippe, Krumpochova, Petra, Klau, Gunnar W, Giera, Martin, Dehottay, Philippe, Teusink, Bas, Goffin, Philippe
• Format: Journal Article
• Language: English
• Published: United States American Society for Microbiology 01.11.2017
• Subjects: Algorithms; Arginine; Bordetella pertussis; Carbon sources; Citric acid; Cough; Genes; Genomes; Gram-negative bacteria; Growth media; Lactic acid; Metabolism; Nutrient requirements; Nutrient sources; Optimization; Organic acids; Pertussis; Pertussis toxin; Physiology; Reconstruction; Regulatory mechanisms (biology); Respiratory diseases; Spotlight; Substrates; Sulfur; Sulfur sources; Thiosulfate; Tricarboxylic acid cycle; Vaccination; Whooping cough; vaccine production; constraint-based modeling; whooping cough; rational medium design; Bordetella pertussis; genome-scale metabolic model
• ISSN: 0099-2240; 1098-5336
• DOI: 10.1128/AEM.01528-17

Whooping cough is a highly contagious respiratory disease caused by Despite widespread vaccination, its incidence has been rising alarmingly, and yet, the physiology of remains poorly understood. We combined genome-scale metabolic reconstruction, a novel optimization algorithm, and experimental data to probe the full metabolic potential of this pathogen, using strain Tohama I as a reference. Experimental validation showed that secretes a significant proportion of nitrogen as arginine and purine nucleosides, which may contribute to modulation of the host response. We also found that can be unexpectedly versatile, being able to metabolize many compounds while displaying minimal nutrient requirements. It can grow without cysteine, using inorganic sulfur sources, such as thiosulfate, and it can grow on organic acids, such as citrate or lactate, as sole carbon sources, providing demonstration that its tricarboxylic acid (TCA) cycle is functional. Although the metabolic reconstruction of eight additional strains indicates that the structural genes underlying this metabolic flexibility are widespread, experimental validation suggests a role of strain-specific regulatory mechanisms in shaping metabolic capabilities. Among five alternative strains tested, three strains were shown to grow on substrate combinations requiring a functional TCA cycle, but only one strain could use thiosulfate. Finally, the metabolic model was used to rationally design growth media with >2-fold improvements in pertussis toxin production. This study thus provides novel insights into physiology and highlights the potential, but also the limitations, of models based solely on metabolic gene content. The metabolic capabilities of , the causative agent of whooping cough, were investigated from a systems-level perspective. We constructed a comprehensive genome-scale metabolic model for and challenged its predictions experimentally. This systems approach shed light on new potential host-microbe interactions and allowed us to rationally design novel growth media with >2-fold improvements in pertussis toxin production. Most importantly, we also uncovered the potential for metabolic flexibility of (significantly larger range of substrates than previously alleged; novel active pathways allowing growth in minimal, nearly mineral nutrient combinations where only the carbon source must be organic), although our results also highlight the importance of strain-specific regulatory determinants in shaping metabolic capabilities. Deciphering the underlying regulatory mechanisms appears to be crucial for a comprehensive understanding of 's lifestyle and the epidemiology of whooping cough. The contribution of metabolic models in this context will require the extension of the genome-scale metabolic model to integrate this regulatory dimension.