Colony variation of Helicobacter pylori: pathogenic potential is correlated to cell wall lipid composition.

Background: Differences in expression of disease after infection with Helicobacter pylori have so far been connected with host factors and bacterial interstrain variation. In this study, spontaneous and ecology-mediated intrastrain variation was examined.

Methods: Four clinical isolates of H.

Nutritional requirements for growth of Helicobacter pylori.

A chemically defined medium consisting of a buffered mineral base supplemented with amino acids, a purine, and thiamine supported growth of 23 clinical isolates and the type strain of Helicobacter pylori. The growth of four strains was inhibited by the presence of certain amino acids. All but one strain required alanine for growth.