Peritrichous

Flagellar arrangements

• Monotrichous bacteria such as Vibrio cholerae have a single polar flagellum.
• Amphitrichous bacteria have a single flagellum on each of two opposite ends (e.g., Campylobacter jejuni or Alcaligenes faecalis)—both flagella rotate but coordinate to produce coherent thrust.
• Lophotrichous bacteria (lopho Greek combining term meaning crest or tuft) have multiple flagella located at the same spot on the bacterial surface such as Helicobacter pylori, which act in concert to drive the bacteria in a single direction. In many cases, the bases of multiple flagella are surrounded by a specialized region of the cell membrane, called the polar organelle.
• Peritrichous bacteria have flagella projecting in all directions (e.g., E. coli).