Necessity of multiple gastric biopsies from different sites for detection of clarithromycin-resistant Helicobacter pylori strains.

BACKGROUND

It has been reported that approximately 10% of patients infected with Helicobacter pylori have both clarithromycin-susceptible and clathromycin-resistant strains. However, there have been no reports indicating whether only one gastric biopsy is sufficient to detect clarithromycin-resistant strains.

METHODS

Sixty-five H. pylori-infected patients were selected for this study, and 40 of them were given clarithromycin-based eradication therapy. Four gastric biopsies, 2 from the antrum and 2 from the corpus, were obtained from each of the 65 patients. Susceptibility of H. pylori strains to clarithromycin was examined by detecting mutations of the 23S ribosomal RNA (rRNA) gene of H. pylori.

RESULTS

The clarithromycin-resistant strains were detected in 16 of the 65 (25%) patients. Only 5 of the 16 (31%) patients had the resistant strains in both the antrum and corpus. When only 1 or the other biopsy from the antrum was used, the resistant strains were detected in 8 (50%) or 9 (56%) of the 16 patients.

CONCLUSIONS

These data indicate that multiple gastric biopsies from both the antrum and the corpus should be used to detect clarithromycin-resistant H. pylori strains.