title: Lactate dehydrogenase activity as a cause of metronidazole resistance in Bacteroides fragilis NCTC 11295.
abstract: Enzymes acting on pyruvate as a parameter of the ATP regeneration system were studied as a cause of metronidazole resistance in Bacteroides fragilis NCTC 11295. The resistant strain had higher lactate dehydrogenase activity and produced more lactate than susceptible strains, suggesting that the enzyme is more active in lactic acid fermentation. Furthermore, the reaction catalysed by lactate dehydrogenase occurred up to 48 mg/L metronidazole, whereas the reaction catalysed by pyruvate: ferredoxin oxidoreductase reaction stopped at 2 mg/L. The mechanism of metronidazole resistance in B. fragilis NCTC 11295 may be due to the high activity of lactate dehydrogenase which compensates for the decreased activity of pyruvate: ferredoxin oxidoreductase in the presence of metronidazole.
authors.affiliation: Department of Laboratory Medicine, St Marianna University School of Medicine, Kanagawa, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Narikawa
authors.forename: T
authors.initials: T
authors.lastname: Suzuki
authors.forename: M
authors.initials: M
authors.lastname: Yamamoto
authors.forename: M
authors.initials: M
authors.lastname: Nakamura
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism; D001441:Bacteroides fragilis / Q000187:drug effects / Q000201:enzymology*; D004352:Drug Resistance, Microbial; D005285:Fermentation; D005947:Glucose / Q000378:metabolism; D007658:Ketone Oxidoreductases / Q000378:metabolism; D007770:L-Lactate Dehydrogenase / Q000378:metabolism*; D008795:Metronidazole / Q000494:pharmacology*; D008826:Microbial Sensitivity Tests; D050743:Pyruvate Synthase
chemical_list: D008795:Metronidazole; D000255:Adenosine Triphosphate; D007770:L-Lactate Dehydrogenase; D007658:Ketone Oxidoreductases; D050743:Pyruvate Synthase; D005947:Glucose