Pathogenesis of human-derived Bacillus cereus strains: lessons from the insect Galleria mellonella immune responses

Introduction: ), suggesting that certain virulence mechanisms may be conserved between mammals and insects. Methods: strains (i.e., T1 and B10502), which were previously isolated from food poisoning outbreaks and that differ in their virulence toward human enterocyte cell cultures. We combined genomic analysis with larval infection assays to examine survival, bacterial persistence, immune activation, and spore formation. Results: species. Both strains induced dose-dependent mortality following oral gavage, with strain T1 showing a better persistence than strain B10502 in both living and dead larvae, with heat-resistant spores detectable up to 144 h post-infection, unlike strain B10502. Infection with strain B10502 elicited higher phenoloxidase activity and greater melanization than with strain T1. Both strains similarly reduced hemocyte viability. Discussion/conclusion: strains.