In Vitro Motility Assays for Acinetobacter Species.

Bacteria belonging to genus Acinetobacter do not encode flagella and are characterized as a non-motile organism. However, several recent studies have demonstrated that Acinetobacter spp. display two types of motility: twitching and swarming. Twitching motility requires the presence of functional type IV pili and occurs on solid surfaces under humid conditions. The extension and the retraction of the pili allows the bacterium to move and spread. In contrast the exact molecular mechanism for swarming motility in Acinetobacter spp. is currently unknown; but it requires semisolid surfaces and humid conditions. Motility has been associated with the bacterial virulence; however, motility appears to be highly dependent on the experimental conditions and the isolate understudy. In this chapter we attempt to provide detailed methods for twitching and swarming motilities that are specific for Acinetobacter spp.