In vitro antifungal susceptibility of Candida species isolated from oropharyngeal lesions of patients with cancer to some antifungal agents

Introduction and objective: Oropharyngeal candidiasis is a relatively common mycotic infection in cancer patients. In vitro susceptibility of oropharyngeal Candida isolates can be useful in selecting the appropriate treatment for the best therapeutic outcome. The aim of this study was to evaluate the in vitro antifungal activity of Candida species against antifungal agents.

Material and methods: In vitro activities of four antifungals were detected in 69 Candida isolates recovered from cancer patients in four university hospitals using the microdilution method described in the CLSI M27-A3 guideline.

Result: Only 12(17.4%) of Candida isolate were resistant to antifungal agents. Three isolates (4.4% included C. albicans, C. glabrata, C. tropicalis, and C. pelliculosa) were resistant to amphotericin B, 5(7.2% included two C. albicans, two C. glabrata, and one C. kefyr) were itraconazole resistant. Two (2.9% include one C. albicans and one C. glabrata) were fluconazole resistant. Caspofungin resistance was detected in two C. infanticola strains which were reported as a clinical isolate for the first time. All Candida isolates (n=69) taken together gave minimum inhibitory concentration (MIC₉₀) value for amphotericin B, fluconazole, itraconazole and caspofungin of 1, 0.25, 32 and 0.25μg/ml, respectively. In total, 18.7% of C. glabrata and 7.8% of C. albicans isolates were fully resistant to both itraconazole and fluconazole.

Conclusion: Caspofungin had activity against oropharyngeal non- albicans Candida species isolates, particularly against those with reduced susceptibility to amphotericin B, fluconazole and itraconazole.