Helicobacter pylori antimicrobial resistance during a 5-year period (2013-2017) in northern Spain and its relationship with the eradication therapies

Background Antibiotic resistance is the main cause for Helicobacter pylori therapy failure. Frequently, empirical regimens have been recommended in patients with various H. pylori eradication failures. In patients with H. pylori-resistant to various families of antibiotics, the treatment guided by antimicrobial susceptibility testing allows the achievement of good eradication rates. Aim To evaluate the effectiveness of susceptibility-guided antimicrobial treatment for H. pylori infection in patients with resistance to one or various families of antibiotics. Methods A total of 3170 consecutive patients infected by H. pylori during 2013-2017 were tested for antimicrobial susceptibility. 66.6% patients showed resistance to one antimicrobial, 18.9% to two, and 2.4% to three families of antibiotics. A cohort of 162 H. pylori-positive patients were enrolled in this study. Forty-three with single H. pylori resistance to clarithromycin (CLR) were treated with omeprazole (PPI), amoxicillin (AMX), and levofloxacin (LVX)-OAL (31 subjects) or omeprazole, AMX, and metronidazole (MTZ)-OAM (12 patients) and 77 patients with dual H. pylori resistance (51 to CLR and MTZ, 12 to CLR plus LVX, and 14 to MTZ plus LVX) received OAL or OBTM (PPI, bismuth subcitrate, tetracycline, and MTZ), OAM, and OAC, respectively. Other 42 patients with triple H. pylori resistance (CLR, LVX, and MTZ) were treated with PPI, AMX, and rifabutin-OAR (18 subjects), PPI, AMX, and doxycycline-OAD (8), OADB (7), OBTM (6), and ODBR (3). All subjects received standard doses for 10 days. Eradication rate was confirmed by C-13-UBT. Adverse events were assessed by a questionnaire. Results Intention-to-treat analysis demonstrates that eradication rates using triple therapies in patients with H. pylori resistance to one and to two families of antibiotics were 93% and 94.8%, respectively. In subjects with H. pylori-resistant to three families of antibiotics, cure rate was higher in naive patients treated with OAR-10 days compared to those treated with bismuth-containing quadruple therapies (90% vs 75%). Adverse events were limited (18 of 162, 11.1%), all of them mild-moderate. Conclusions The implementation of susceptibility-guided triple therapy for 10 days leads to eradication rate >= 95% in naive patients with H. pylori resistance to one or two families of antimicrobials. In naive patients with H. pylori resistance to three families, OAR treatment achieved a 90% of eradication.