Oral Candidal Isolates In Patients With Oral Fungal Infection And Their Sensitivity To Antifungal Drug

Recently, the incidence of fungal infection has been increasing because of a variety of reasons. Candida albicans are the predominant pathogens. Along with the incease of candidiasis , all kinds of antifungal drugs have been widely used and the treatment of candidiasis has acquired a great progress, at the same time, more and more resistant fungal isolates have been found because of the abuse of antifungal agents. And because of the wide use of fluconazole, there has a tendency for Candida isolates of transfering from Candida anbicans to non-candida albicans.Today, scientists engaging in the research of fungus pay more attention to the incidence of fungus, the distribution and change of fungal isolates, and the real relationship of their sensitivity to antifungal drug and clinical effect. During resent 10-15 years, there are . a number of reports about antifungal susceptibility testing , and researchs abroad mostly aim for systemic candidiasis or oropharyngeal candidiasis of HIV populations, while the researchs of oral candidiasis about Chinese populations are relatively deficient, and none adopt the microdilution method of NCCLS(National Comiittee Clinical Laboratory Standards)M27-A.Based on the backgrounds above-mentioned, our research intends to understand the incidence and the distribution of Candidas in the fungal infection cases and among healthy volunteers, mensurate the MIC of several antifungal agents against Candida ioslates in oral cavity, and to understand the difference of sensitivity in order to helpclinicians select proper antigungal agents, and discuss the relationship between antifungal susceptibility and clinical effect.In our experiment, we isolate and identify Candidas in oral cavity by CHROMagar Candida culture medium and mensurate the MIC of several antifungal agents against Candidas by NCCLSM27-A microdilution assay.The results as follows: (1) The incidence of Candidas is 78.69% and 30.23% in case group and control group respectively. The proportion of Candida albicans are 80.70%(case group) and 92.31%(control group). (2) There is no significant difference between the susceptibility of Candida albicans to fluconazole and ketoconazole (p>0.05), but Candida albicans are more sensitive to azoles than to nystatin. The susceptibility of oral isolates to antifungal drugs in case group is similar to control group, and there is no significant difference between the susceptibility of Candida albicans and non-candida albicans. (P>0.05). (3) The susceptibility of Candida albicans to fluconazole, ketoconazole and nystatin is 95.65%, 80.43%,and 89.13%,and a few isolates are resistent to antifungal agents. (4) The effectiveness of nystatin is 87.1%, and the MIC is relative to clinical effect.In conclusion, Candidas are commensals in oral cavity of healthy population. The incidence of Candidas in healthy group is 30.23%, whereas the incidence of Candidas in candidiasis patients is 78.69% in which Candida albicans are commonly isolated. Candida albicans are more sensitive to azoles than to nystatin. If the clinical effect of nystain is poor, then it's better to choose azoles. At present, the resistance of Candidas is not common. The MIC is relative to clinical effect to some degree, but it is not consistent completely.