Phenotypic heterogeneity and host adaptation during stationary phase in sporulating pathogenic Firmicutes – PHHASt

Pathogenic bacteria must constantly adapt to environmental changes during infection. Our results show that the entomopathogenic bacterium Bacillus thuringiensis has developed an alternative to sporulation to survive in the host cadaver. This study, focused on bacteria of the Bacillus cereus group, pathogenic to humans and animals, aims to characterize this state, which has been obscured by sporulation, considered for a long time as the only survival strategy in spore-forming firmicutes. Our objective is to characterize the regulatory networks underlying this physiological state by implementing complementary global and targeted methods at the population and cellular level, using molecular biology, flow cytometry, an animal model and bioinformatics analyses. This project will allow the understanding of a new mechanism leading to phenotypic heterogeneity allowing bacteria to persist in their niche and potentially adapt more rapidly to environmental changes. This research could open new perspectives for the control of spore-forming pathogenic bacteria.