Caspofungin Susceptibility Testing of Isolates from Cancer Patients with Oral Candidiasis

Background and purpose: Oral candidiasis is a spectrum of opportunistic fungal diseaseswith a rising prevalence in immunocompromised individuals, such as cancer patients,transplant recipients and consumers of immunosuppressive drugs. Candida species have anunstable resistance to common antifungal drugs. The treatment of oral candidiasis requiresthe identification of new anti-Candida agents. Reduction of sensitivity to caspofungin isrelated to the sequence of amino acids in the fks gene region, which is usually a result ofmissenses mutation. The present study aims to investigate the anti-fungal effects ofcaspofungin on oral Candida species isolated from cancer patients.Materials and Methods: Seventy-three Candida species were identified and isolated byculture on CHROM agar Candida medium and API ۲۰CAUX system from cancer patients(n=۱۰۰) suspected of oral candidiasis. The minimum inhibitory concentration (MIC) ofcaspofungin was determined by microdilution assay and was evaluated according to theCLSI-۲۰۱۷. The gene regions of samples were enhanced by ۵۱۴ bp using PCR method.Results: C. glabrata (۳۵, ۴۷.۹%) was predominant species. Most of the Candida strains wereisolated from patients with stomach cancer (۳۵, ۴۷.۹%). Changes to the MIC of caspofunginin the range of ۸-۰.۰۱ μg/ml showed the highest resistance to caspofungin was reported forCandida albicans (۵.۵%, MIC>۲μg /ml). It was found out mutations in fks۱ gene lead to theresistance of Candida species to caspofungin.Conclusions: The results of this study showed that the caspofungin has high antifungal effecton Candida species, especially non-albicans Candida. Therefore, we could hope to treatfungal diseases with an appropriate agent.