What characteristic shape describes the Helicobacter pylori bacterium?

Helicobacter pylori is best characterized by its spiral shape, which plays a significant role in its biology and pathogenicity. This unique morphology allows it to be motile through gastric mucus, facilitating colonization of the gastric epithelium and helping it to survive in the harsh acidic environment of the stomach. The spiral shape also aids in burrowing into the tissue, evading the host's immune responses and contributing to the development of conditions such as gastritis and peptic ulcers. This structural adaptation is crucial for its survival and the diseases it can cause, making the spiral shape a defining characteristic of Helicobacter pylori.