Longitudinal monitoring of individual infection progression in Drosophila melanogaster

• Published in: iScience 2022-11, Vol.25 (11), p.105378-105378, Article 105378
• Main Authors: Ramirez-Corona, Bryan A., Love, Anna C., Chandrasekaran, Srikiran, Prescher, Jennifer A., Wunderlich, Zeba
• Format: Article
• Language: English
• Subjects: Microbiology; Optical imaging
• ISSN: 2589-0042; 2589-0042
• DOI: 10.1016/j.isci.2022.105378

The innate immune system is critical for infection survival. Drosophila melanogaster is a key model for understanding the evolution and dynamics of innate immunity. Current toolsets for fly infection studies are limited in throughput and, because of their destructive nature, cannot generate longitudinal measurements in individual animals. We report a bioluminescent imaging strategy enabling non-invasive characterization of pathogen load. By using Escherichia coli expressing the ilux operon, we demonstrate that photon flux from autobioluminescent bacteria can be used to monitor pathogen loads in individual, living flies. Because animal sacrifice is not necessary to estimate pathogen load, stochastic responses to infection can be characterized in individuals over time. The high temporal resolution of bioluminescence imaging enables visualization of the dynamics of microbial clearance on the hours time-scale. This non-invasive imaging strategy provides a simple and scalable platform to observe changes in pathogen load in vivo over time. [Display omitted] •Light output reports on bacterial load in flies injected with bioluminescent E. coli•This enables the quantification of infection dynamics in individual flies over time•Flies can be housed in 96-well plates to increase throughput•The resulting data reveals resurgent infections and markers of time to death Optical imaging; Microbiology