Delayed host mortality and immune response upon infection with persister cells.

Chronic infections are a heavy burden on healthcare systems worldwide. Persister cells are thought to be largely responsible for chronic infection due to their tolerance to antimicrobials and recalcitrance to innate immunity factors. is a common and clinically relevant pathogen that contains stereotypical persister cells. Despite their importance in chronic infection, there have been limited efforts to study persister cell infections has a well-described innate immune response similar to that of vertebrates and is a good candidate for the development of an model of infection for persister cells. Similar to what is observed in other bacterial strains, in this work we found that infection with persister cells resulted in a delayed mortality phenotype in , , and compared to infection with regular cells. An in-depth characterization of infected found that bacterial loads differed between persister and regular cells' infections during the early stages. Furthermore, hemocyte activation and antimicrobial peptide expression were delayed/reduced in persister infections over the same time course, indicating an initial suppression of, or inability to elicit, the fly immune response. Overall, our findings support the use of as a model in which to study persister cells where this bacterial subpopulation exhibits delayed virulence and an attenuated immune response.