Why does Clostridium botulinum kill? – In search for botulinum neurotoxin regulators

Projektinformationen

whyBOTher

ID Finanzhilfevereinbarung: 683099

DOI

10.3030/683099

Projekt abgeschlossen

EK-Unterschriftsdatum 28 November 2016

Startdatum 1 Januar 2017

Enddatum 31 Dezember 2023

Finanziert unter

• EXCELLENT SCIENCE - European Research Council (ERC)

Gesamtkosten

€ 2 000 000,00

EU-Beitrag

€ 2 000 000,00

Koordiniert durch

HELSINGIN YLIOPISTO
Finland

Periodic Reporting for period 5 - whyBOTher (Why does Clostridium botulinum kill? – In search for botulinum neurotoxin regulators)

Berichtszeitraum: 2023-01-01 bis 2023-12-31

Zusammenfassung vom Kontext und den Gesamtzielen des Projekts

Bacterial toxins cause severe illnesses in both humans and animals, with conditions such as necrotic enteritis, gas gangrene, and tetraplegia. While toxin production may offer bacteria an advantage in adverse ecological niches, it likely comes at a cost to their overall fitness. Bacterial populations likely regulate toxin production based on metabolic needs, with non-competitive environments favouring phenotypes that minimize toxin production. Understanding the genetic and cellular mechanisms bacteria employ to modulate toxin production in response to their environment is crucial for developing interventions aimed at disease prevention, antitoxin and vaccine development, and preservation of foods and feeds. Specifically, botulism is caused by botulinum neurotoxins (BOT) from Clostridium botulinum and is a potentially life-threatening disease that results in paralysis and respiratory failure. C. botulinum may thrive and produce BOT in various environments, including foods, dysbiotic gut, deep wounds and abscesses, and decaying matter. Interestingly, BOT is also widely used for medical indications, further justifying the need to characterize C. botulinum and BOT production. In C. botulinum cells, BOT production is linked to metabolic processes and sporulation. Understanding the relationship between these processes could help developing prophylactic and control measures and better understanding the epidemiology of different forms of human botulism. whyBOTher articulated around four main questions: how C. botulinum cultures coordinate BOT production and related traits among single cells and populations in response to their environment, which cellular regulatory and metabolic systems C. botulinum uses to control BOT production, which DNA-related alterations C. botulinum makes to control or give up BOT production, and how BOT works.

Arbeit, die ab Beginn des Projekts bis zum Ende des durch den Bericht erfassten Berichtszeitraums geleistet wurde, und die wichtigsten bis dahin erzielten Ergebnisse

whyBOTher provided significant insights into understanding C. botulinum toxin production and action. The project contributed a fundamental shift in the study of bacterial toxin and sporulation research, moving from traditional population-level observations to incorporating phenotypic heterogeneity in the study of toxinogenic bacteria. The project entailed methodological breakthroughs that allowed pioneering findings in the epidemiology of botulism and the physiology of C. botulinum, with central focus on neurotoxinogenesis. By addressing epidemiological aspects, the project investigated cases of intestinal botulism and infant botulism, providing insights into C. botulinum ecology, evolution, and pathogenesis. This may lead to the development of novel strategies for the prevention and treatment of toxicoinfectious botulism. In specific, whyBOTher focused on understanding the coordination of botulinum neurotoxin production and sporulation within C. botulinum populations. Using multiple approaches, including single-cell fluorescence microscopy analysis and cell sorting, the project analyzed cell populations for the two traits across different growth phases and environmental conditions. Genomic comparisons of strains with distinct genetic backgrounds shed light on variations in botulinum neurotoxin expression and gene cluster mobility among C. botulinum strains and isolates. We looked at the regulatory programs governing botulinum neurotoxin production and sporulation, exploring the role of candidate regulators and associated global regulatory networks in controlling BOT production. We investigated the role of DNA-related changes in governing botulinum neurotoxin production. This involved experiments to understand the role of mutagenesis and DNA modification in regulating toxin production. Finally, we delved into the mechanisms underlying pathogenesis, focusing on the synergic biological role of uncharacterized proteins in BOT toxicity.

Fortschritte, die über den aktuellen Stand der Technik hinausgehen und voraussichtliche potenzielle Auswirkungen (einschließlich der bis dato erzielten sozioökonomischen Auswirkungen und weiter gefassten gesellschaftlichen Auswirkungen des Projekts)

whyBOTher employed an integrative and interdisciplinary approach, utilizing advanced methodologies to unravel the complexities of BOT production and its regulation in C. botulinum. Its comprehensive exploration of epidemiological aspects, cellular networks, DNA-related changes, and pathogenic mechanisms has contributed significantly to our understanding of C. botulinum toxin production, with implications for both basic science and applied contexts. whyBOTher is likely to have significant societal implications. Importantly, we have identified novel proteins that enhance BOT toxicity. Increased mechanistic understanding of BOT holds promise for the development of new therapeutic interventions and applications in clinical settings. It also provides valuable novel insights into the epidemiology and pathogenesis of C. botulinum. The newly characterized proteins have been found in bacteria targeting pest insects, suggesting potential applications in agricultural practices and food production. Taken together, these findings highlight a broad impact of the project, not only advancing scientific knowledge but also potentially offering practical solutions with wide-ranging benefits for public health, agriculture, and food safety.

banner-bot.jpg