Effect of culture conditions on morphological changes of Helicobacter pylori.

Accession number;00A0234923
Title;Effect of culture conditions on morphological changes of Helicobacter pylori.
Author; TOMINAGA K (Osaka City Univ. Medical School, Osaka, Jpn) HAMASAKI N (Osaka City Univ. Medical School, Osaka, Jpn) WATANABE T (Osaka City Univ. Medical School, Osaka, Jpn) UCHIDA T (Osaka City Univ. Medical School, Osaka, Jpn) TAKAISHI O (Osaka City Univ. Medical School, Osaka, Jpn) ISHII E (Osaka City Inst. Public Health And Environmental Sci., Osaka, Jpn) KOBAYASHI K (Osaka City Univ. Medical School, Osaka, Jpn) YANO I (Osaka City Univ. Medical School, Osaka, Jpn) KUROKI T (Osaka City Univ. Medical School, Osaka, Jpn)
Journal Title;J Gastroenterol
Journal Code:Z0748A
ISSN:0944-1174
VOL.34;NO.Supplement 11;PAGE.28-31(1999)
Figure&Table&Reference;FIG.4, REF.15
Pub. Country;Japan
Language;English
Abstract;The morphological conversion of Helicoba-cterpylori 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%, 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 atomosphere (20% O2 Supply) and on day 2 in an undermicroaerobic atmosphere (<0.1% O2). Its complete morphological conversion was observed at pH 8 on day 5 and at pH 4 on day 6. All of the H. pylori (100%) incubated at 20.DEG. or 42.DEG.C. had converted from the bacillary to the coccoid form on day 4. Conditioned medium without .BETA.-cyclodextrin caused complete conversion on day 5. These results suggest that oxgen concentration, pH, temperature, and .BETA.-cyclodextrin may be related to the H. pylori morphological conversion from the bacillary to the coccoid form. (author abst.)
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