The status of antimicrobial resistance of Helicobacter pylori in eastern Europe

Objective To evaluate the primary, secondary and combined resistance to five antimicrobial agents of 2340 Helicobacter pylori isolates from 19 centers in 10 countries in eastern Europe. Methods Data were available for centers in Bulgaria, Croatia, the Czech Republic, Estonia, Greece, Lithuania, Poland, Russia, Slovenia and Turkey. Susceptibility was tested by agar dilution (seven countries), E test (five countries) and disk diffusion (three countries) methods. Resistance breakpoints (mg/L) were: metronidazole 8, clarithromycin 1, amoxicillin 0.5, tetracycline 4, and ciprofloxacin 1 or 4 in most centers. Primary and post-treatment resistance was assessed in 2003 and 337 isolates respectively. Results for 282 children and 201 adults were compared. Results Primary resistance rates since 1998 were: metronidazole 37.9%, clarithromycin 9.5%, amoxicillin 0.9%, tetracycline 1.9%, ciprofloxacin 3.9%, and both metronidazole and clarithromycin 6.1%. Isolates from centers in Slovenia and Lithuania exhibited low resistance rates. Since 1998, amoxicillin resistance has been detected in the southeastern region. From 1996, metronidazole resistance increased significantly from 30.5% to 36.4%, while clarithromycin resistance increased slightly from 8.9% to 10.6%. In centers in Greece, Poland, and Bulgaria, the mean metronidazole resistance was slightly higher in adults than in children (39% versus 31.2%, P > 0.05); this trend was not found for clarithromycin or amoxicillin (P > 0.20). Post-treatment resistance rates exhibited wide variations. Conclusions In eastern Europe, primary H. pylori resistance to metronidazole is considerable, and that to clarithromycin is similar to or slightly higher than that in western Europe. Resistance to amoxicillin, ciprofloxacin and tetracycline was detected in several centers. Primary and post-treatment resistance rates vary greatly between centers.