Isolation and characterization of Campylobacter pyloridis from gastric biopsies.

Gastric biopsy specimens were examined microbiologically and histologically for the presence of Campylobacter pyloridis. Of 51 randomly selected patients, 22 (43%) were found to harbor C. pyloridis in the gastric mucosa. The histologic demonstration of spiral organisms observed by staining with hematoxylin and eosin correlated well with microbiologic isolation of the organisms. There was a strong association (95.5%) between C. pyloridis in the gastric mucosa and histologically defined gastritis. However, there was no obvious association between C. pyloridis and ulcers. All C. pyloridis strains isolated exhibited uniform biochemical characteristics and had almost identical protein profiles, which indicated that they belong to a relatively homogeneous group distinct from other Campylobacter species. All C. pyloridis isolates were uniformly susceptible to ampicillin, amoxicillin, cephalothin, gentamicin, kanamycin, tetracycline, coumermycin, ciprofloxacin, novobiocin, clorobiocin, and nitrofurantoin. They were moderately resistant to nalidixic acid.