Abstract 1965 Two sides of the same coin: the pathogenic side of the symbiont Vibrio fischeri

What makes a bacterium pathogenic? People have categorized bacteria as pathogens or non-pathogens, those that cause harm and those that do not, since the early days of germ theory. However, this binary view is not always accurate. Vibrio fischeri is an exclusive mutualistic symbiont found within the light organs of Hawaiian bobtail squid. This symbiotic interaction requires V. fischeri to utilize a range of behaviors and produce molecules that are often associated with pathogenicity. During symbiosis establishment, V.