Antibacterial peptide from H-pylori

Colonization of the human stomach by the bacterium Helicobacter pylori is a predisposing factor for gastrointestinal illnesses such as gastritis and peptic ulcers1. But most infections are asymptomatic, and it has recently been suggested that H. pylori may actually have beneficial effects on infected carriers who are heavily exposed to other gastrointestinal pathogens2. We find that H. pylori possesses antibacterial activity to which it is itself resistant. We have traced this activity to cecropin-like amino-terminal peptides derived from the ribosomal protein L1 (RpL1).