Helicobacter Colonization of Biopsy Specimens Cultured in Vitro Is Dependent on Both Mucosal Type and Bacterial Strain

Abstract

Background: Colonization by Helicobacter pylori is strictly tissue-specific. We have previously reported on an in vitro adhesion model for pig and human gastric mucosa, in which biopsy specimens were successfully infected and cultured for 72 h. The aim of this study was to compare H. pylori colonization of different mucosae and by different Helicobacter strains. Methods: Specimens from pig, rabbit, and rat antrum, pig urinary bladder, and pig duodenum were inoculated with two H. pylori strains and one H. mustelae strain. Four additional strains, including one mutant lacking flagella, were compared on pig antral specimens. Results: The viability of all mucosae was comparable at 48 h of culture. The percentage ahdering bacteria increased with time in all mucosae, reaching 17%, 11%, and 2% in pig, rabbit, and rat antral mucosa, 11% in pig bladder, and 3% in duodenum at 48 h. The type of H. pylori strain was a strong determinant for adhesion in pig antrum. Strain SVA40 had the highest adhesion; the mutant lacking flagella colonized very poorly. H. mustelae adhered to all types of mucosae in a more unspecific manner. Conclusions: On the basis of tissue viability, bacterial colonization, and adhesion, pig antral mucosa is clearly superior. H. pylori strains differ in their ability to adhere to and colonize cultured mucosa.

Key Words:

• Gastric antrum
• Helicobacter mustelae
• Helicobacter pylori
• in vitro
• organ culture
• pig
• rabbit
• rat
• urinary bladder