Abstract:

Objective To understand whether there were any differences of sensitivity to antifungals between the species of Saccharomyces（Candidas）isolated from oral cavity in the patients with oral candidosis and healthy volunteers. Observing the effect of nystatin topically used and discussing preliminarily the relationship between MIC and clinical effect in order to offer reference for clinical treatment. Methods The experiment was carried on 61 patients with candidosis in experimental group and 43 healthy volunteers in control group and isolates of Saccharomyces were obtained by the oral rinse technical method. To isolate and identify Saccharomyces in oral cavity by CHROMagar Saccharomyces culture medium and test the MIC of several antifungal agents such as nystatin, ketoconazole and fluconazole against Saccharomyces by NCCLSM27- A microdilution assay. 31 patients in experimental group were administered with nystatin, observing the clinical effect a week later and comparing the results with the MIC. Results ① The incidence of Saccharomyces was 78.69% and 30.23% in experimental group and control group respectively. The proportion of Saccharomyces albicans was 80.70%（experimental group） and 92.31%（control group）. ②There was no significant difference between the susceptibility of Saccharomyces albicans to fluconazole and ketoconazole（P>0.05）, but the MIC data of azole antifungals were lower than nystatin. ③The susceptibility of Saccharomyces albicans to fluconazole, ketoconazole and nystatin was 95.65%, 80.43%, and 89.13%, and a few isolates were resistent to antifungal agents. ④The effectiveness of nystatin was 87.10%, and there were a few cases which MIC differs from the clinical effect. Conclusion At present, the resistance of Saccharomyces in patients with oral fungal infection is not significant, most Saccharomyces albicans are sensitive tofluconazole, ketoconazole and nystatin. The MIC of fluconazole and ketoconazole are lower than nystatin, implying when the clinical effect of nystain is poor, to use an azole antifungal is optional. The MIC is relative to therapeutic effect to some degree, but it is not consistent completely.

Key words: Saccharomyces albicans, antifungal susceptibility test, oral candidosis