Prevalence of Helicobacter pylori resistance to clarithromycin and metronidazole determined by 23S ribosomal RNA and rdxA gene analyses in Hiroshima, Japan

Background and Aims: Resistance to antibiotics in Helicobacter pylori is increasing and becoming a serious problem in eradication treatment of H. pylori. The prevalence of H. pylori infections that are resistant to clarithromycin, metronidazole, or both were determined in H. pylori isolates in Hiroshima, Japan. Methods: Sixty Japanese patients with H. pylori infection were collected between 1999 and 2000. To detect the resistance to clarithromycin and metronidazole, mutations of the 23S ribosomal RNA (rRNA) and rdxA genes that are responsible for resistance in H. pylori, were examined by direct sequencing analysis. Results: Resistance to clarithromycin and metronidazole was detected in 12 (20.0%) and nine (15.0%) of the patients, respectively. Dual resistance to clarithromycin and metronidazole was detected in five (8.3%) patients. Conclusion: These results indicate that the relatively high prevalence of the dual resistance in H. pylori isolates may need special attention and new therapeutic approaches in Japan.