These exist on a spectrum, sometimes the relationship between organisms can vary depending on conditions. Vibro bacteria are common in salt water and make up a large part of the digestive tract fauna of many marine organisms, however in high concentrations Quorum sensing genes turn on and the bacteria become aggressive and invade the host tissue. | These exist on a spectrum, sometimes the relationship between organisms can vary depending on conditions. Vibro bacteria are common in salt water and make up a large part of the digestive tract fauna of many marine organisms, however in high concentrations Quorum sensing genes turn on and the bacteria become aggressive and invade the host tissue. |