In vitro susceptibility of Candida albicans isolates from apical and marginal periodontitis to common antifungal agents

The susceptibility of a total of 70 Candida albicans strains to five common antifungal agents was determined. Thirty-five of the strains were isolated from persistent cases of apical periodontitis and 35 from cases of margina l periodontitis. The susceptibility of the strains to amphotericin B, 5-flu orocytosine and three azoles: fluconazole, miconazole and clotrimazole, was tested. The antifungal agents and yeast inoculums were prepared according to the NCCLS (National Committee for Clinical Laboratory Standards) recomme ndations. The yeasts were incubated with ten different concentrations of an tifungal agents at 35 degrees C for 48 h. Yeast growth was measured spectro photometrically. All strains from both isolation sources were susceptible t o low concentrations of amphotericin B and 5-fluorocytosine, whereas the su sceptibility to the three azoles varied, and three of the strains showed az ole cross-resistance. These findings are in agreement with recent reports o f increased azole resistance in Candida species in general and suggest the possibility that the oral cavity may act as a reservoir of resistant yeast isolates in systemic infections.