Spirillum (plural Spirilla) is any bacterium that is shaped like a spiral. It is one of the three shapes of bacteria. The other two are Coccus and Bacillus.It can be said as Spiral Bacteria.
Spirillum is also the name of a genus of Gram-negative bacteria in the family Spirillaceae. The two species in the Spirillum genus are Spirillum minus and Spirillum pulli.