Geographic distribution of antibiotic resistance of Helicobacter pylori: A study in Bulgaria.

Prevalence of antibiotic resistant Helicobacter pylori was compared between 50 patients living outside the capital city and 50 matched pairs of capital city residents (CCRs). H. pylori isolates from 2018 to 2022 were included. Resistance rates in CCRs and those living elsewhere were 4.0 and 6.0% to amoxicillin, 48.0 and 42.0% to metronidazole, 30 and 30% to clarithromycin, and 4.0 and 4.0% to tetracycline, respectively. Levofloxacin resistance was higher (38.0%) in the capital city vs 20.0% (P = 0.047) in the country. Odd ratio for levofloxacin resistance between pair-matched groups was 2.45 (95% CI, OR 1.0-6.02, P value = 0.05) and relative risk for fluoroquinolone resistance was 1.90 (95% CI for RR 0.98-3.67) for CCRs vs residents in other regions. Resistance rates to levofloxacin and clarithromycin were worryingly high in our study, most probably due to the high quinolone consumption (2.86 DDD/day in 2017) in Bulgaria and the increase in macrolide, lincosamide and streptogramin consumption, especially of azithromycin, by >42% with the start of COVID-19 pandemic. Briefly, antibiotic resistance of H. pylori has a dynamic change, and it can display different patterns in certain geographic regions. The results imply that antibiotic consumption should be carefully controlled and unjustified use of levofloxacin should be restricted, especially in some large cities. Antibiotic policy should be further strengthened and regular monitoring of resistance in various geographic regions is needed for treatment optimization.