<prompt> Swarming growth on culture is characteristic of which Gram-negative organismClostridium welchiiClostridium tetaniBacillus cereusProteus mirabilis  <response>: 1. Swarming - Proteus has an ability to swarm or spread on solid media. They spread on the surface of the plate in successive waves to form a thin filmy layer in concentric circles. This is known as swarming. 2. Organism which swarm: Proteus, Clostridium tetani, V. parahemolyticus, and Serratia. Clostridium welchii - non motile Clostridium tetani - Gram positive Bacillus cereus- motile, gram positive rod Proteus mirabilis - peritrichous flagella 