Helicobacter pylori susceptibility to fosfomycin, rifampin, and 5 usual antibiotics for H. pylori eradication

The aim of the study was to assess Helicobacter pylori resistance to fosfomycin, rifampin, and 5 other antibiotics. Susceptibility of 50 consecutive H. pylori strains was tested by E test and breakpoint susceptibility testing method. Overall and primary resistance rates were amoxicillin 2.0 and 0%, metronidazole 34.0 and 31.2%, tetracycline 2.0 and 2.1%, levofloxacin 18.0 and 16.7%, rifampin 12.0 and 10.4%, and fosfomycin 8.3 and 6.5%, respectively. Clarithromycin resistance was >20.0% in all patients (22.0%) and in untreated subjects (20.8%). Rifampin resistance was higher than those usually reported. Quinolone resistance rose from 2005–2007 (8.7%) to 2012–2013 (18.0%). High double/multidrug resistance rates (overall 22.0% and 20.0% in untreated adults), including a 5-fold resistance, were found. In conclusion, fosfomycin and rifampin resistance rates were much lower than that of metronidazole and slightly lower than those of clarithromycin and levofloxacin. MICs90 of both fosfomycin and rifampin were lower than those of clarithromycin and metronidazole. Thus, in countries of high/increasing H. pylori resistance and multidrug resistance, both rifamycins and fosfomycin could be helpful in rescue regimens.