This review examines Helicobacter pylori as an organism and as the causative agent of peptic ulcers. The review also examined the classification of ulcers, how the bacterium produces the ulcer, some of the virulence factors possessed by the organism, its metabolism and growth requirements. The incidence and prevalence of peptic ulcers were originally believed to have resulted from some factors such as stress, eating spicy food, long term use of nonsteroidal anti-inflammatory agents (NSAIDs), like aspirin and ibuprofen, smoking, and many alike. presently due to the development in the field of research, researchers from different geographical locations have reported a spiralshaped Gram-negative bacterium called Helicobacter pylori to be responsible for the pathogenesis of peptic ulcer. This confirmation has been supported by the strong and effective diagnostic procedures such as urea breath test, stool test, endoscopy, and blood test. Elimination of Helicobacter pylori by treatment with antibiotics in peptic ulcer patients resulted in the healing of the ulcer. Prevention of Helicobacter pylori infections is difficult because the mode of transmission is not well known.
Key words:Helicobacter pylori, peptic ulcer, causative agent.