title: Metronidazole-resistant clinical isolates of Trichomonas vaginalis have lowered oxygen affinities.
abstract: Oxygen affinities of metronidazole susceptible and resistant isolates of the parasitic flagellate protozoon Trichomonas vaginalis were determined by mass spectrometric methods. Apparent O2Km values for the respiration of non-proliferating cell suspensions were about 10-fold higher for metronidazole resistant strains than for the susceptible strains C1-NIH or NYH-286. Simultaneous monitoring of hydrogen evolution in the presence of increasing O2 tensions enabled apparent Ki values for H2 to be determined; and this function was independent of metronidazole susceptibility. Apparent O2 affinities of the hydrogenosomal and non-sedimentable fractions were determined for the strains CDC 85 (metronidazole resistant) and C1-NIH, which showed the deficiency in the O2 scavenging capacity by the resistant strain to be associated with the hydrogenosome-containing fraction.
mesh_terms: D000818:Animals; D004351:Drug Resistance; D007700:Kinetics; D008795:Metronidazole / Q000494:pharmacology*; D010101:Oxygen Consumption; D014246:Trichomonas vaginalis / Q000187:drug effects / Q000378:metabolism*
chemical_list: D008795:Metronidazole