Helicobacter pylori: clarithromycin resistance and eradication rates in Szeged, Hungary – a pilot study

Helicobacter pylori (H. p.) infection can be successfully cured with regimens of multiple antimicrobial agents. Resistance to these antimicrobials, and particularly to metronidazole and clarithromycin (CLA), is a leading cause of treatment failure.

Aim. To assess the efficacy of different eradication therapies in H. p.-infected patients in relation to the CLA resistance (CLA-R) of H. p. strains.

Patients. 107 H. p.-infected adults with peptic ulcer, erosive gastroduodenitis or nonulcer dyspepsia. 47 of them carried H. p. with CLA-R. Samples from a group of 60 pts exhibited CLA-sensitivity (CLA-S).

Methods. Genotypic CLA-R was investigated by a fluorescent in situ hybridization method on gastric biopsy specimens.

Results. To date, the treatment of 75 pts has been completed. The pts with CLA-S H. p. infection (n=43) were treated with CLA-containing regimens (proton pump inhibitor [PPI]+CLA+amoxycillin [AMO] or PPI+CLA+metronidazole [MET]), while those with CLA-R H. p. (n=32) received usually CLA-free therapy (26/32; ranitidine bismuth citrate/PPI+tetracycline+MET or PPI+AMO+MET). The overall eradication rates (78.2% for pts with CLA-S and 76.1% for those with CLA-R H. p.) were not significantly different. Surprisingly, 6 infections with CLA-R H. p. were successfully eradicated with CLA-containing therapy, in which AMO or MET was used as second antimicrobial agent. There were 6 therapeutic failures in pts with CLA-R infections, even though they had received CLA-free combined therapy. Of the 12 eradication failures in pts with CLA-S infections, 7 involved with CLA-containing regimens and 5 tetracycline-based therapy.

Conclusions. Through the choice of appropriate therapeutic regimens, pts with genotypic CLA-R H. p. infections can be cured as effectively as those with CLA-S H. p. Nevertheless, the therapeutic failures observed in both groups demand further analyses.