Helicobacter /He·li·co·bac·ter/ (hel?i-ko-bak´ter) a genus of gram-negative, microaerophilic bacteria of the family
Spirillaceae; H. cinae´di causes proctitis and colitis in homosexual men and has been implicated in septicemia in
neonates and immunocompromised patients; H. pylo´ri causes gastritis and pyloric ulcers and has been implicated in
gastric carcinogenesis.

Helicobacter genus : Helicobacter pylori is the leading cause of peptic ulcers and chronic gastritis in America.