Helicobacter pylori infection: antibiotic resistance and eradication rate in patients with gastritis showing previous treatment failures.

Forty patients infected by Helicobacter pylori were studied. The treatment was based on the positivity or negativity of cultures (tailored therapy or empiric therapy). The eradication rate was 68% and 82% respectively. Genotypic susceptibility testing proved very useful in case of heteroresistance or mixed infections that represent a real problem possibly leading to a resistance underestimation. Real-time PCR detected the resistant population at a very low concentration not detectable by phenotypic tests. Bismuth quadruple therapy (PPI, bismuth, metronidazole, tetracycline, PBMT) was effective in the Hp eradication rate consistent with a high level of clarithromycin resistance.