Vincent, Elio, and Michele review how horizontal gene transfer from bacteria to an insect genome enables a tripartite nested mealybug symbiosis, and how probiotic bacteria work by competing for iron in the intestine.

On episode #17 of the podcast This Week in Microbiology, Vincent, Michael and Elio focus on endosymbiosis: the spread of Rickettsia in whitefiles, and a metabolic patchwork in nested symbionts of mealybugs.