In vitro activities of six antifungal drugs against Candida glabrata isolates: An emerging pathogen
Joint Conference on GLOBAL APPLIED MICROBIOLOGY CONFERENCE & International Congress on MICROBIAL & BIOCHEMICAL RESEARCH AND TECHNOLOGIES
October 18-19, 2017 Toronto, Canada
Nasrin Amirrajab, Tahereh Shokohi, Hamid Badali, Mojtaba Didehdar, Mohammad Hosein Afsarian, Rasoul Mohammadi and Nazanin Lotfi
Ahvaz Jundishapur University of Medical Sciences, Iran Mazandaran University of Medical Sciences, Iran Arak University of Medical Sciences, Iran Fasa University of Medical Sciences Iran 5Isfahan University of Medical Sciences, Iran
Posters & Accepted Abstracts : Microbiology: Current Research
Background: Candida glabrata is pathogenic yeast with several unique biological features and associated with an increased incidence rate of candidiasis. It exhibits a great degree of variation in its pathogenicity and antifungal susceptibility. Objectives: The aim of the present study was to evaluate the in vitro antifungal susceptibilities of the following six antifungal drugs against clinical C. glabrata strains: amphotericin B (AmB), ketoconazole (KTZ), fluconazole (FCZ), itraconazole (ITZ), voriconazole (VCZ), and caspofungin (CASP). Materials & Methods: Forty clinical C. glabrata strains were investigated using DNA sequencing. The in vitro antifungal susceptibility was determined as described in clinical laboratory standard institute (CLSI) documents (M27-A3 and M27-S4). Results: The sequence analysis of the isolate confirmed as C. glabrata and deposited on NCBI GenBank under the accession number no. KT763084-KT763123. The geometric mean MICs against all the tested strains were as follows, in increasing order: CASP (0.17 g/mL), VCZ (0.67 g/mL), AmB (1.1 g/mL), ITZ (1.82 g/ mL), KTZ (1.85 g/mL), and FCZ (6.7 g/mL). The resistance rates of the isolates to CASP, FCZ, ITZ, VZ, KTZ, and AmB were 5%, 10%, 72.5%, 37.5%, 47.5%, and 27.5%, respectively. Discussion: The intrinsically low susceptibility of C. glabrata, an emerging opportunistic fungal pathogen, to azole antifungals has made its treatment challenging, and infection is accompanied by frequent relapse and failure. The findings indicate that the decreased susceptibility of Candida to azole agents may contribute to the increased proportion of infections caused by these species. Caution is thus recommended with CASP therapy for C. glabrata infections when azole resistance is predicted. The resistance of C. glabrata clinical isolates to both azoles and echinocandins has emerged over time. This is problematic, owing to its treatment limitations. Conclusion: These findings confirm that CASP, compared to the other antifungals, is the potent agent for treating candidiasis caused by C. glabrata. However, the clinical efficacy of these novel antifungals remains to be determined.
Nasrin Amirrajab is working in Ahvaz Jundishapur University of Medical Sciences, Iran. She is from Iran.