How 'stealth warrior' bacteria turn a tick's gut microbes against itself

Before infecting humans, tick-borne bacteria or viruses first have to get past a tick's defenses to colonize it. How this occurs is not well understood. To investigate, researchers studied a model of the second-most-common tick-borne infection in the United States, human granulocytic anaplasmosis, which can cause headaches, muscle pain, and even death.