Results
3.1. Isolation of a gram-negative and urease-negative bacterium
The histology of the gastric biopsy specimens indicated grandular
atrophy and intestinal metaplasia accompanied by infiltration
of mononuclear cells to the lamina propria, a typical observation in
gastric mucosa infected with H. pylori (Fig. 1A). Though it is not
specific, a few bacteria-like organisms could be seen in the gastric
lumen (Fig. 1B). H. pylori ureA gene was amplified in the paraffinembedded
gastric tissue (not shown).
A bacterium isolated from the culture of biopsy specimen was
named NHP1. The bacterial colonies corroded the agar surface and
had no hemolytic activity on sheep blood agar. Growthwas obtained
at 37 and 42 C under the microaerobic conditions (Table 1). A gramnegative
bacillus, quite similar in size and morphologywith H. pylori
was observed (Fig. 2). However, NHP1 lacked the urease activity.