METRONIDAZOLE UPTAKE IN HELICOBACTER-PYLORI

Currently, the mechanism of metronidazole resistance is not understood in Helicobacter pylori. We have looked at uptake of metronidazole int o a sensitive and a resistant strain of H. pylori. Both strains displa yed rapid uptake of [C-14]metronidazole, although the resistant strain accumulated the drug at a slower rate and to a lesser amount than the sensitive strain. Uptake was inhibited by KCN and carbonyl cyanide m- chlorophenyl-hydrazone (CCCP) but not by sodium arsenate. Thin-layer c hromatography analysis of lysed cell supernatants showed that metronid azole was metabolized in both strains. A variety of related imidazole compounds inhibited metronidazole uptake, consistent with a common tra nsport system for this group of antibiotics. Our data do not support a n absence of uptake or metabolism as a cause of resistance in the stra in examined.