The prevalence of primary and secondary Helicobacter pylori resistance to clarithromycin and probable contributing cofactors: data from southeastern Anatolia.

BACKGROUND/AIMS: Antibiotic resistance of Helicobacter pylori is the most important reason for failure in its eradication. We aimed to determine the prevalence of primary and secondary H. pylori resistance to clarithromycin in isolated H. pylori from dyspeptic patients in southeastern Anatolia and to evaluate the cofactors affecting this clinical problem. METHODOLOGY: The study involved adult patients who had already been diagnosed with symptomatic H. pylori infection based on rapid urease test, gastric histopathological examination and culture. H. pylori strains were isolated from antral biopsies taken during upper endoscopy in 142 dyspeptic patients with no previous therapy against the microorganism. MICs of clarithromycin were determined by E-test. Patients were treated for 14 days with standard triple-agent protocol. H. pylori eradication rate was assessed after 8 weeks. Each patient was re-interviewed to determine secondary resistance. Primary clarithromycin resistance was defined as pre-treatment resistance, while secondary as after treatment resistance. Strains were considered resistant to clarithromycin if the MIC > 1 microg/mL. RESULTS: In total 213-105 women and 108 men-patients was enrolled to the study. The mean age was 35.5+/-14.1 years. In 142 (66.7%) patients out of the total patients enrolled in the study, H. pylori was detected. H. pylori could be cultured from only 61 (43%) of them. In 16.4% of the cases, primary clarithromycin resistance was noted. After 8 weeks, seventy-seven (54.2%) of the 142 patients were reevaluated. Helicobacter pylori eradication could be achieved in 68.8% of them. The proportion of H. pylori eradication in clarithromycin-sensitive patients was 75.8% and the respective proportion was 10% for resistant cases. In the group where H. pylori was still positive the secondary resistance percentage was found to be 27.2%. CONCLUSIONS: The prevalence of primary clarithromycin resistance is relatively high in our geographical area. Secondary resistance rate was 27.2%. None of the criteria of age, gender, presence of endoscopic lesions, detected H. pylori concentration and gastritis activity showed any effect on the primary resistance.