Transport and storage of Helicobacter pylori from gastric mucosal biopsies and clinical isolates

Various transport and storage conditions for the recovery of Helicobacter pylori from gastric biopsies were evaluated. Gastric mucosal biopsies from 16 Helicobacter pylori-infected patients were stored in cysteine-Albimi medium containing 20% glycerol in a refrigerator (4 degrees C) for 1 and 2 weeks and in a -20 degrees C laboratory freezer for 4 and 12 weeks. Two clinical isolates were stored in saline, Stuart's transport media, cysteine-Albimi broth with 20% glycerol, brucella broth with 20% glycerol and skim milk with 17% glycerol at room temperature, 4 degrees C, -20 degrees C and -70 degrees C. Storage at 4 degrees C for 1 and 2 weeks resulted in Helicobacter pylori recovery from 81% and 19% of biopsies, respectively. Storage at -20 degrees C yielded Helicobacter pylori recovery in 100% and 57% after 4 and 12 weeks, respectively. At room temperature after 6 h, the Helicobacter pylori titer was reduced. The best storage media for frozen isolates were skim milk/glycerol, brucella broth/glycerol and cysteine-Albimi/glycerol (in descending order). Recovery was better at -70 degrees C than -20 degrees C.