Antibiotic resistance, heteroresistance, and eradication success of Helicobacter pylori infection in children.

BACKGROUND: Antibiotic resistance is a well-known factor of Helicobacter pylori eradication failure. Heteroresistance indicates the coexistence of resistant and susceptible strains and might lead to underestimating antimicrobial resistance. This study aims to evaluate the susceptibility profile, the frequency of heteroresistance of H. pylori strains, and their effect on eradication success in a pediatric population. MATERIALS AND METHODS: Children aged 2-17 years who underwent an upper gastrointestinal endoscopy from 2011 to 2019 with positive H. pylori status were included. Susceptibility was measured by disk diffusion and E-test. The difference in susceptibility profiles between isolates from the antrum and the corpus was used to detect heteroresistance. For those who received eradication treatment, we evaluated eradication rate and factors affecting treatment success. RESULTS: Inclusion criteria were met by 565 children. Strains susceptible to all antibiotics were detected in 64.2%. Primary resistance rates for clarithromycin (CLA), metronidazole (MET), levofloxacin (LEV), tetracyclin (TET), and amoxicillin (AMO) were 11%, 22.9%, 6.9%, 0.4%, and 0% and secondary resistance rates were 20.4%, 29.4%, 9.3%, 0%, and 0%. Heteroresistance was present in untreated children in 2%, 7.1%, 0.7%, 0.7%, and 0% for CLA, MET, LEV, TET, and AMO. First-line eradication rates were 78.5% in intention-to-treat (ITT), 88.3% in full-analysis-set (FAS), and 94.1% in per-protocol (PP). Factors affecting eradication success were the duration of treatment when the triple-tailored treatment was used, the number of daily doses of amoxicillin administered, and the patient's adherence to treatment. CONCLUSIONS: This study shows the presence of relatively low primary resistance rates for H. pylori isolates but demonstrates the presence of heteroresistance in our population. Routine biopsies from the antrum and corpus must be considered for susceptibility testing to allow tailored treatments and increase eradication rates. Treatment success is affected by treatment choice, correct dosing of medications, and adherence. All these factors should be considered when evaluating the efficacy of an eradication regimen.

Sequential therapy versus tailored triple therapies for Helicobacter pylori infection in children.

AIMS: The aim of the study was to compare sequential versus tailored triple therapy regimens on Helicobacter pylori (H pylori) eradication rates in children and to assess the effect of antimicrobial susceptibility. PATIENTS AND METHODS: Prospective, open-label, multicenter study. Children received randomly either a 10-day sequential treatment comprising omeprazole (OME) with amoxicillin for 5 days and OME, clarithromycin (CLA), and metronidazole (MET) for the remaining 5 days, or a 7-day triple therapy comprising OME with amoxicillin and CLA in cases of a CLA-susceptible strain or MET in cases of CLA-resistant strain. H pylori eradication was assessed by C-urea breath test. RESULTS: One hundred sixty-five children, 95 girls and 70 boys, of median age 10.4 years, were included. The intention-to-treat (ITT) eradication rate was 76.9% (sequential 68/83 = 81.9%, triple therapy 59/82 = 71.9%, ns), and the per-protocol (PP) eradication rate was 84.6% (sequential 68/77 = 88.3%, triple therapy 59/73 = 81.8%, ns). Eradication rates tended to be higher using the sequential treatment, but the difference was only statistically significant for ITT analysis in children harboring both CLA- and MET-susceptible strains (87.8% vs 68.5%, odds ratio [OR] 3.3, P = 0.03). Both ITT and PP eradication rates were significantly lower with sequential treatment in CLA-resistant compared with CLA-susceptible strains (ITT: 56.2% vs 72.7%, OR 5.5, P = 0.008; PP 64.3% vs 80.0%, OR 7.9, P = 0.009). Both treatments were well tolerated. CONCLUSIONS: Sequential treatment is greatly effective for eradicating H pylori in children except in CLA-resistant strains. Sequential treatment can be used as a first-line therapy, but only in areas with a low CLA resistance rate.