BETA-LACTAMASE PRODUCTION BY ORAL PIGMENTED PREVOTELLA SPECIES ISOLATED FROM YOUNG-CHILDREN

The frequency of beta-lactamase production by oral pigmented Prevotell a species isolated from 23 healthy young children and the minimal inhi bitory concentrations (MICs) for 186 available beta-lactamase-positive isolates were examined by using the chromogenic cephalosporin disk te st (AB BIODISK, Solna, Sweden) and the Etest (AB BIODISK) and/or the a gar dilution method of the National Committee for Clinical Laboratory Standards (Villanova, PA, USA), respectively. beta-Lactamase-positive Prevotella melaningoenica strains were isolated from all children, and more than two-thirds of the Prevotella denticola and Prevotella loesc heii strains isolated from the children were beta-lactamase-positive. The beta-lactamase-producing Prevotella intermedia group consisted of Prevotella nigrescens and the P. intermedia/P. nigrescens-like organis m (PINLO); P. intermedia was not found. Only two P. nigrescens isolate s but most of the PINLO isolates produced beta-lactamase. The MICs for beta-lactamase-producing strains varied between 0.38 and 64 mu g/mL. beta-Lactamase production by oral pigmented Prevotella species coloniz ing young children is already frequent. The phenomenon should be taken into account in the treatment of pediatric anaerobic infections of or al origin.