Helicobacter colonization of biopsy specimens cultured in vitro is dependent on both mucosal type and bacterial strain.

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 72h. 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 48h of culture. The percentage adhering 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 48h. 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.