Description:
<jats:sec><jats:title>Background</jats:title><jats:p>Antibiotic susceptibility of <jats:italic>Helicobacter pylori</jats:italic> to antibiotics may vary among different niches of the stomach. The progression of chronic <jats:italic>H. pylori</jats:italic> gastritis to atrophy changes intragastric physiology that may influence selection of resistant strains.</jats:p></jats:sec><jats:sec><jats:title>Aim</jats:title><jats:p>To study the antibiotic resistance of <jats:italic>H. pylori</jats:italic> taking the severity of atrophic gastritis in antrum and corpus into account.</jats:p></jats:sec><jats:sec><jats:title>Methods</jats:title><jats:p><jats:italic>Helicobacter pylori</jats:italic>-positive patients (<jats:italic>n</jats:italic> = 110, <jats:italic>m</jats:italic> = 32, mean age 52.6 ± 13.9 years) without prior <jats:italic>H. pylori</jats:italic> eradication undergoing upper gastrointestinal (GI) endoscopy for dyspeptic symptoms were included in a prospective study. Patients were stratified into three groups depending on the grade of atrophy: no atrophy (OLGA Stage 0), mild atrophy (OLGA Stage I–II) and moderate/severe atrophy (OLGA Stage III–IV). Two biopsies each from the antrum and the corpus and one from the angulus were taken and assessed according to the updated Sydney system. <jats:italic>H. pylori</jats:italic> strains were isolated from antrum and corpus biopsies and tested for antibiotic susceptibility (AST) for amoxicillin, clarithromycin, metronidazole, levofloxacin, tetracycline, and rifampicin by the agar dilution methods. A Chi-square test of independence with a 95% confidence interval was used to detect differences in the proportion of patients with susceptible and resistant <jats:italic>H. pylori</jats:italic> strains.</jats:p></jats:sec><jats:sec><jats:title>Results</jats:title><jats:p>Among 110 patients, primary clarithromycin resistance (R) was 30.0%, both in the antrum and corpus; metronidazole resistance accounted for 36.4 and 34.5% in the antrum and corpus; and levofloxacin was 19.1 and 22.7% in the antrum and corpus, respectively. Resistance rates to amoxicillin, tetracycline, and rifampicin were below 5%. Dual antibiotic resistance rate was 21.8%, and triple resistance rate was 9.1%. There was a significant difference in the resistance rate distribution in antrum (<jats:italic>p</jats:italic> &lt; 0.0001) and corpus (<jats:italic>p</jats:italic> &lt; 0.0001). With increasing severity of atrophy according to OLGA stages, there was a significant increase in clarithromycin-R and metronidazole-R.</jats:p></jats:sec><jats:sec><jats:title>Conclusion</jats:title><jats:p>In treatment-naïve patients, antibiotic resistance and heteroresistance were related to the severity of atrophy. The high clarithromycin resistance in atrophic gastritis suggests that <jats:italic>H. pylori</jats:italic> antibiotic susceptibility testing should always be performed in this condition before selecting the eradication regimen.</jats:p></jats:sec>