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.

Vincent, Elio and Michael recorded this episode before an audience at the 2013 General Meeting of the American Society for Microbiology in Denver, Colorado, where they spoke with Andrew, Ferric, Suzanne, and Michelle about their research on a phage system for evading innate immunity, retractions of research papers, bacterial infections of the eye, and cytoplasmic defenses against intracellular bacteria.