GROWTH AND MORPHOLOGICAL TRANSFORMATIONS OF HELICOBACTER-PYLORI IN BROTH MEDIA

Helicobacter pylori, a cause of peptic ulcer disease and certain types of gastric cancers, has usually been cultured on diverse agar-based m edia, resulting in a requirement for 2 to 4 days of growth at 37 degre es C, We have developed a novel broth medium consisting of a base medi um supplemented with 2% newborn calf serum, Mg2+, Cu2+, Fe2+, Zn2+, Mn 2+, and 1 mg of lysed human erythrocytes per ml, This medium supports rapid growth of H. pylori, with a doubling time of about 50 min. Optim al growth was obtained in a pH range higher than that supporting mast other gram-negative bacteria (at pH 8.5), H. pylori cultured in this s upplemented broth retains the spiral morphology seen in both histologi cal sections and cultures from agar-based media and also retains a hig h urease activity, After 18 h in this broth, H. pylori transforms to a coccal form with a complete loss of urease activity, Previously these cocci have been reported to be senescent, since they could not be sub cultured on agar medium, Our experiments suggest that some of the cocc i can revert back to the spiral morphology with full recovery of ureas e activity when subcultured in fresh microaerobic broth medium.