Effect of an acidic environment on the susceptibility ofHelicobacter pylori to trospectomycin and other antimicrobial agents

The susceptibility of 30 clinical isolates ofHelicobacter pylori to trospectomycin, ampicillin, metronidazole, clarithromycin, azitromycin and clindamycin under varying pH conditions was evaluated. An acidic environment was shown to affect unfavourably the activity of all the antimicrobial agents tested. This pH effect was most marked for the two macrolides and for clindamycin.