Swarming motility is shown by
**Core Concept**
Swarming motility is a type of bacterial movement characterized by the coordinated movement of a large number of bacteria over a solid surface, often resulting in a characteristic "swarm" or "ramp" pattern. This phenomenon is typically observed in Proteus species, which exhibit a unique form of motility that allows them to move rapidly across agar surfaces.
**Why the Correct Answer is Right**
Swarming motility in Proteus species is mediated by the production of a diffusible substance that triggers the coordinated movement of bacteria. This substance is thought to be a quorum sensing molecule, which allows the bacteria to communicate with each other and synchronize their movement. The swarming motility of Proteus species is also influenced by the presence of specific enzymes, such as proteases and lipases, which help to break down the agar surface and facilitate movement.
**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect because swarming motility is not typically associated with this species.
* **Option B:** This option is incorrect because while some bacteria may exhibit a form of "swarming" motility, it is not characterized by the same level of coordination and speed as seen in Proteus species.
* **Option C:** This option is incorrect because while some bacteria may exhibit a form of "swarming" motility, it is not typically associated with this species.
**Clinical Pearl / High-Yield Fact**
It's worth noting that swarming motility is often used as a diagnostic feature in the identification of Proteus species, and can be an important clue in the laboratory diagnosis of urinary tract infections.
**Correct Answer:** D