In-vitro evaluation of beta-lactamase inhibition by latamoxef and imipenem.
The in-vitro 50% inhibitory concentrations (IC50s) of latamoxef and imipenem against a set of plasmid-mediated beta-lactamases including TEM-1, TEM-3, TEM-5 and TEM-10 were determined by an enzymatic method using nitrocefin as substrate. The IC50s of both antibiotics against extended-spectrum beta-lactamases were below 0.2 mg/L. The conventional spectrum beta-lactamase TEM-1 was not inhibited by either antibiotic at the highest concentration tested. Except for TEM-10 for which the IC50s of the two antibiotics were the same, imipenem showed significantly greater activity than latamoxef against TEM-3 and TEM-5. Clavulanic acid taken as a control demonstrated greater and wider inhibitory activity, but on the other hand it has no significant antibiotic activity.
Sotto
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Laboratoire Universitaire de Thérapeutique, Service de Médecine B, Hopital Carémeau, Nimes, France.
Brunschwig
C
C
O'Callaghan
D
D
Ramuz
M
M
Jourdan
J
J
D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D004352:Drug Resistance, Microbial; D015378:Imipenem / Q000494:pharmacology*; D066298:In Vitro Techniques; D009070:Moxalactam / Q000494:pharmacology*; D013845:Thienamycins / Q000494:pharmacology*; D065093:beta-Lactamase Inhibitors; D001618:beta-Lactamases / Q000302:isolation & purification
D000900:Anti-Bacterial Agents; D013845:Thienamycins; D065093:beta-Lactamase Inhibitors; D015378:Imipenem; D001618:beta-Lactamases; D009070:Moxalactam