Bactericidal effect of ecabet sodium on clarithromycin- and metronidazole-resistant clinical isolates of Helicobacter pylori.

Ecabet sodium showed a bactericidal effect on Helicobacter pylori NCTC 11637 which is susceptible to antimicrobial agents (Antimicrob. Agents Chemother, 39: 1295-1299, 1995). In the present study, we investigated the bactericidal effect of ecabet sodium on clarithromycin- and metronidazole-resistant strains of clinical isolates of H. pylori under acidic conditions. In a buffer supplemented with urea at pH 3.0, ecabet sodium decreased the number of viable cells in both isolates. In the morphological study, ecabet sodium changed the isolates from the bacilliform to the horseshoe-shaped form and denatured the cytoplasm. Ecabet sodium also showed the bactericidal effect on both isolates in buffers at pH 4.0 and 5.0, and the bactericidal effect was dependent on pH, i.e., the lower the pH, the greater the effect. These results suggest that the susceptibility of H. pylori to antimicrobial agents does not affect the bactericidal effect of ecabet sodium on H. pylori.