In a recent review article, Niels Høiby defined microbial biofilms as “an aggregate of microbial cells surrounded by a self-produced polymer matrix” (Høiby 2017). Discussing their history, he said, “The observation of biofilms is old,” “since both Leeuwenhoek and Pasteur have described the phenomenon.” In the late 1600s, Anthony van Leeuwenhoek (1632–1723) wrote to the Royal Society of London about his observations of the plaque between his…