Susceptibility of Helicobacter pylori to mupirocin, oxazolidinones, quinupristin/dalfopristin and new quinolones

The in vitro activities of mupirocin, quinupristin/dalfopristin, linezolid, eperezolid, sitafloxacin, clinafloxacin, moxifloxacin, amoxycillin, metron idazole and clarithromycin were tested at pH 7.4 against 57 strains of Heli cobacter pylori. The most active agents (mupirocin, sitafloxacin and clinaf loxacin) were also tested for activity at pH 5.4 against the same strains, Mupirocin was very active at pH 7.4 and 5.4 (MIC90 0.25 and 0.12 mg/L, resp ectively). Quinupristin/dalfopristin, linezolid and eperezolid had low acti vity (MIC90 4, 8 and 4 mg/L, respectively), Sitafloxacin (MIC90 less than o r equal to 0.008 mg/L) was the most active fluoroquinolone, while clinaflox acin (MIC90 0.12 mg/L) and moxifloxacin (MIC90 2 mg/L) were least active.