Hi, I made 40% urea broth medium(Biolife Italiana) to find out the presece of helicobacter pylori in gastric biopsy but this medium responds very slowly for positive biopsy (about 2 hours) while this medium has been tested with pure proteus mirabilis bacteria and give a very fast reaction for a few seconds. My question is why this medium don't work quickly on the biopsy sample and what is needed for a rapid reaction?