SICKO: Systematic Imaging ofCaenorhabditisKilling Organisms

Abstract

SummaryCaenorhabditis elegansare an important model system for host-microbe research due to the ability to rapidly quantify the influence of microbial exposure on whole-organism survival and rapidly quantify microbial load. To date, the majority of host-microbe interaction studies rely on host group survival and cross-sectional examination of infection severity. Here we present a new system called Systematic Imaging ofCaenorhabditisKilling Organisms (SICKO) capable of characterizing longitudinal interactions between host and microbes in individualC. elegans, enabling researchers to capture dynamic changes in gut colonization between individuals and quantify the impact of bacterial colonization events on host survival. Using this system, we demonstrate that gut colonization by the strain ofEscherichia coliused as a common laboratory food source dramatically impacts the lifespan ofC. elegans. Additionally, we show that immunodeficient animals, lacking thepmk-1gene, do not significantly alter the progression of bacterial infection, but rather suffer an increased rate of gut colony initiation. This new system provides a powerful tool into understanding underlying mechanisms of host-microbe interaction, opening a wide avenue for detailed research into therapies that combat pathogen induced illness, the benefits imparted by probiotic bacteria, and understanding the role of the microbiome in host health.