Growth of Helicobacter pylori in a long spiral form does not alter expression of immunodominant proteins

The six strains used in this study were American Type Culture Collection 43504, 43579, 49503, 51652, and 51653, and Sydney Strain I. Each strain was grown on solid media and in broth culture using conditions previously shown to induce the long spiral morphology in strain 43504. DNA from each was subjected to urease gene fingerprint analysis. Results of the molecular analysis showed identical fingerprint patterns for each strain independent of culture source, indicating that only a single strain was present in each culture. Expression of immunodominant proteins was assessed by SDS polyacrylamide gel electrophoresis and Western blotting with hyperimmune rabbit anti H. pylori sera or serum from an H. pylori infected patient. Analysis of protein profiles revealed some variation between strains but no significant differences associated with morphologic alterations.These results indicate that growth of H. pylori in a long spiral form does not affect expression of immunodominant proteins, thus in vivo growth in the long spiral form (not documented to date) would not be distinguishable by serology.Curved and spiral-shaped bacteria have been described in the gastric mucosa of humans for over a century, but it was not until the early 1980s that Helicobacter pylori was successfully cultured and determined to cause chronic gastritis and peptic ulcer disease [1-3]. It is now well established that this organism is a human pathogen, and evidence gathered to date suggests that chronic H. pylori infection can also predispose an individual to gastric cancer [4].H. pylori is a gram negative bacterium typically appearing as a curved rod or short spiral. It is believed to be one of the more common pathogenic infections of man, with prevalence rates reaching 30–60% in developed countries, depending on age and socioeconomic status [4-7]. A related organism, Helicobacter heilmannii, has also been linked to gastritis in humans [8,9]. Infection with H. heilmannii is thought to occur at a sig