口腔內 Candida의 分布 및 抗眞菌劑에 對한 感受性

DISTRIBUTION OF CANDIDA IN ORAL CAVITY AND SUSCEPTIBILITY TO ANTIFUNGAL DRUGS

The distribution of Candida in oral cavity was studied in 473 patients with various oral disorders. A total of 261 strains of Candida were isolated and tested for the susceptibility to 4 antifungal drugs. Of 473 patients, 163 (34.5%) carried Candida in oral cavity. Isolation frequency of Candida was higher in females (42.3%) than in males (22.3%) and increased with ages from 14.6% to 50%, but children under ten years of age carried with high frequency (43.8%). The distribution of Candida in oral cavity was higher in specimens from tongue than from gingiva. The incidence by site was 32.5% from tongue, 10.4% from gingiva, and 57.1% from both sites. Of 261 Candida isolated, 94.6% were identified as C. albicans and 5.4% as C. tropicalis. The specimens from females produced greater number of colonies than those from males, but there was no correlation with ages. The incidence of Candida was 43.3% in patients with oral disease and dental caries, 41.2% with dental caries, 32.1% with oral disease and these incidence were higher than in normal group (23.7%). There was no correlation with various oral disorders in number of yeast colonies formed. In denture wearers, Candida were isolated with high frequency (53.6%) and with the tendency of producing greater numbers of colonies. Concentrations required to inhibit 90% of strains (MIC₉₀) of amphotericin B, nystatin, miconazole nitrate (MCN), and ketoconazole (KCZ) were 0.1 ㎍/㎖, 1.6, 12.5, and 25 to C. albicans and 0.2 ㎍/㎖, 3.1, 25, and 25 to C. tropicalis, respectively. MIC₉₀ of drugs to C. tropicalis were twofold higher than to C. albicans, while MIC₉₀ of KCZ were the same to both Candida species. MIC₉₀ of KCZ to Candida was twofold lower in buffered casein-yeast extract-glucose agar (CYGA), pH 7.0, than in CYGA, pH 6.0, whereas there was no difference between both media with MCN. MIC₉₀ of MCN to C. albicans was twofold lower in Sabouraudglucose agar (SGA) than in CYGA, yeast morphology agar (YMA), and yeast nitrogen base medium added agar (YNA), and MIC₉₀ to C. tropicalis was in SGA, YMA, and YNA than in CYGA. MIC₉₀ of KCZ to C. tropicalis was twofold lower in YMA, YNA than in CYGA and SGA, whereas there was no difference among 4 media in those of C. albicans.