VetBact
VetBact logo

VetBact

Swedish University of Agricultural Sciences

Veterinary bacteriology: information about important bacteria
Veterinary bacteriology
Quick search:
 
Advanced search


Show all terms

Swarming

A swarming bacterium does not form discrete colonies on an agar plate, but flows out over the entire agar surface at a rate of 2–10 μm/s. If a bacterium swarms, one cannot determine its macromorphology, nor could colonies be counted. Swarming can be prevented for some bacteria by growing them on a medium with low electrolyte content (= low salt concentration), such as e.g. CLED agar. Bacteria that can swarm are commonly found in the genera: Aeromonas, Bacillus, Brachyspira, Campylobacter, Clostridium, Escherichia, Paeniclostridium, Proteus, Pseudomonas, Salmonella, Serratia, Vibrio and Yersinia. It is not known why some bacteria swarm. However, it has been observed that active swarming bacteria of Salmonella Typhimurium exhibit an increased resistance to certain antibiotics compared to non-swarming cells.

Updated: 2019-09-26.


Recently Updated

Recent blog posts


Swedish University of Agricultural Sciences