Quorum sensing (introduced in Ch. 11, Section 11.4) allows bacteria to detect the number of neighboring cells and to trigger a response only when this number reaches a critical level. Quorum sensing is used by V. fischeri in light production and by many pathogenic bacteria, including Vibrio cholerae, to turn on genes for toxin production only when a critical cell density is reached. Why might quorum sensing be beneficial to pathogenic bacteria?

Verified step by step guidance

1. Step 1: Understand the concept of quorum sensing. Quorum sensing is a system of stimulus and response correlated to population density. Many species of bacteria use quorum sensing to coordinate gene expression according to the density of their local population. In similar fashion, some social insects use quorum sensing to determine where to nest.
2. Step 2: Consider the role of quorum sensing in pathogenic bacteria. In the context of pathogenic bacteria, quorum sensing can regulate the production of virulence factors, which are molecules produced by bacteria that increase their ability to establish and maintain infections.
3. Step 3: Think about the benefits of quorum sensing to pathogenic bacteria. By using quorum sensing to only produce toxins when there is a critical mass of bacteria, the bacteria can save energy and resources when they are in low numbers. This also allows them to avoid detection by the host's immune system until they have reached sufficient numbers to mount an effective attack.
4. Step 4: Understand the implications of quorum sensing. This mechanism allows bacteria to act as a community, coordinating their behavior to increase their overall fitness. It also allows them to adapt to changing environments and to effectively respond to different situations.
5. Step 5: Summarize the benefits of quorum sensing to pathogenic bacteria. Quorum sensing allows pathogenic bacteria to conserve resources, evade the host's immune system, and coordinate their behavior to increase their overall fitness.