Activity of β-lactamase produced by Prevotella intermedia isolated from human oral cavity

Abstract

     We evaluated β-lactamase activity in β-lactam antibiotic-resistant strains of Prevotella intermedia by microiodometric assay of β-lactamase. The β-lactamase activity of ten oral strains was 24.0–70.2 mU/mg against ampicillin, and 23.5–54.7 mU/mg against cefazolin. Although these enzymes resolved cephaloridine and cefuroxime, their resolution of imipenem, latamoxef and aztreonam was different for each strain. Penicillin G and cephalexin induced production of β-lactamase in one strain tested, but not in two others.
     We concluded that constitutive β-lactamase produced by β-lactam antibiotic-resistant strains of P. intermedia plays an important role in this resistance mechanism, and that these enzymes are oxyiminocephalosporinase.