ABSTRACT
The ability of prokaryotes to sporulate is one of the evolutionary strategies to cope with stress. Spore-forming microorganisms invest considerable amounts of energy in a refined differentiation process (sporogenesis) that involves the expression of hundreds of genes in order to give a morphologically distinct cell that presents several barriers related to the resistance to physical, chemical, and biological challenges. Studies with cultured eukaryotic cells have contributed to the knowledge of the virulence factors of many pathogens. Different in vivo and ex vivo models of infection have been used to study the pathogenesis of Bacillus spp. Experimental models with cultured eukaryotic cells such as enterocyte-like Caco-2 cells helped unravel extracellular factors involved in the gastrointestinal pathologies as well as to demonstrate the participation of direct bacteria–enterocyte interactions in the virulence. The recent advances in the field of in vivo expression technologies herald further gains in our understanding of the control and treatment of foodborne pathologies associated with Bacillus spp.
