Effect of culture conditions on morphological changes of Helicobacter pylori

• Published in: Journal of gastroenterology 1999, Vol.34 Suppl 11, p.28
• Main Authors: Tominaga, K, Hamasaki, N, Watanabe, T, Uchida, T, Fujiwara, Y, Takaishi, O, Higuchi, K, Arakawa, T, Ishii, E, Kobayashi, K, Yano, I, Kuroki, T
• Format: Article
• Language: English
• Subjects: beta-Cyclodextrins; Culture Media; Cyclodextrins; Helicobacter pylori - growth & development; Humans; Hydrogen-Ion Concentration; Oxygen; Temperature; Time Factors
• ISSN: 0944-1174

The morphological conversion of Helicobacter pylori from the spiral form to the coccoid form may be the expression of a transitory adaptation to an unsuitable environment. The mechanism(s) of this conversion are not clear. In this study, we examined whether the morphological conversion of H. pylori is affected by various culture conditions, such as oxygen concentration, pH, temperature, or the presence of beta-cyclodextrin. H. pylori (NTCC11916) was cultured on Brucella agar, followed by culture in Brucella broth containing 1% agar under several conditions. Morphological conversion of individual H. pylori on the agar plate was investigated with time after incubation under phase contrast microscopy. When H. pylori was inoculated in Brucella broth containing beta-cyclodextrin, the spiral form of the organism was observed even after 6 days of incubation under standard culture conditions: 37 degrees C, pH 7, and microaerobic atmosphere (5% O2/10% CO2/85% N2) (control). The morphological conversion of H. pylori was completed on day 3 in an aerobic atmosphere (20% O2 supply) and on day 2 in an undermicroaerobic atmosphere (