Primary antimicrobial resistance rates and prevalence of Helicobacter pylori infection in the north of Spain. A 13-year retrospective study

Abstract

Objective: Helicobacter pylori resistance to antimicrobial agents is on the rise and it is thus imperative to be aware of local resistance rates. The main objective of the present study was to describe the evolution of primary antimicrobial resistance in H. pylori, analysing its antibiotic susceptibility over a 13-year period in a region of northern Spain, as well as host-related factors.

Patients and methods: Between 2004 and 2016 a total of 3426 patients who met the H. pylori eradication criteria underwent gastroscopy. The gastric biopsies were processed and those testing positive for H. pylori were identified and tested for clarithromycin, metronidazole and levofloxacin susceptibility using E-test.

Results: H. pylori was isolated in 1604 (47%) patients, ranging from 63% (133/212) in 2004 to 39% (137/347) in 2016. Primary resistances to clarithromycin, metronidazole and levofloxacin were on average 19% (278/1116), 40% (572/865) and 17% (137/669), respectively. Clarithromycin resistance was 24% (167/686) in females and 15% (11/753) in males (p=0.0002); metronidazole resistance was 29% (72/246) in patients over 70 years compared to 42% (499/1190) in younger patients (p=0.0396); levofloxacin resistance increased with age, being 13% (57/439) in patients ≤55 years, 19% (46/236) for those between 56 and 70, and 26% (34/130) in patients >70 years (p=0.0087).

Discussion: A decline in the prevalence of H. pylori infection was observed over the years, along with relatively high rates of primary resistance to clarithromycin, metronidazole and levofloxacin. Variations in resistance rates were found with sex and age.

Keywords: Antibiotics; Antibióticos; Helicobacter pylori; Resistance; Resistencia; Tratamiento dirigido según antibiograma; Treatment directed according to antibiogram.