Chromatin modifications, at the level of histones, are fundamental regulators of gene expression in eukaryotes as they control the access of the transcriptional machinery to the targeted promoter regions. Recent studies have found that chromatin modifications induced by bacterial pathogens interfere with the host transcriptional program. However, the mechanisms at play are poorly characterized and the role of these modifications for the host or for the bacterium remain unknown. Research in our team is centered on this new facet of host-pathogen interactions using 2 bacterial models, Listeria monocytogenes and Streptococcus pneumoniae, a pathogen and a natural colonizer respectively. The main goal of our research is to characterize the role of chromatin modifications induced upon bacteria-host interactions and their long term consequences. Our work is at the interface between microbiology, chromatin biology/epigenetics and innate immunity. This multidisciplinary approach will allow the discovery of strategies used by bacteria to reprogram host transcription either during colonization or acute infection, and also provide new insight into fundamental cellular processes such as tolerance to prolonged stimulation and epigenetic memory. In addition, understanding bacteria-induced epigenomic regulation of immune responses could transform our view of immunological memory in vertebrates thereby leading to the development of new antimicrobial agents.