Surveillance of the Antimicrobial Resistance Rates of Helicobacter pylori Ten Years Later in the Western Central Region, Colombia

Background: Helicobacter pylori is a bacterium associated with gastroduodenal disease and gastric cancer. Empirical therapy in the treatment of H. pylori infection increases the risk of apparition of antimicrobial drug resistance. In a previous report, in H. pylori clinical isolates, resistance rates to commonly used antimicrobial drugs were as follows: metronidazole 82%, clarithromycin 3.8%, and amoxicillin 1.9%. The aim was to establish the variation of resistance rates and the detection of H. pylori genetic mutations isolated from dyspeptic patients. Methods: Antimicrobial susceptibility profiles were performed by the E-test method for metronidazole, clarithromycin, amoxicillin, and tetracycline in 61 clinical isolates. Sequencing was performed to detect mutations associated with resistance to clarithromycin. Results: According to our results, resistance rates found in the 61 isolates were 78.60% for metronidazole and 8.20% for clarithromycin. None of the studied isolates had resistance to tetracycline and amoxicillin. Secondary resistance rates displayed an increase when compared to primary rates for metronidazole (87.50 vs. 77.35%) and for clarithromycin (25.66 vs. 5.66%). Of 5 isolates resistant to clarithromycin, 3 had the A2143G mutation. By comparing the results in this work with previous reports, antimicrobial drug resistance rates did not show major modifications for metronidazole, amoxicillin, and tetracycline during the last 10 years. For clarithromycin, the resistance rate showed a moderate increase; nevertheless, it remains low (<15%) and this change was not statistically significant. Conclusion: Together, all findings in this work indicate that these antimicrobial drugs can still be used as first line of defense on infected patients living in this region of the country.