In Vitro Antifungal Activity of Echinocandins Against 198 Candida spp Strains

N. Kiraz

Author address: 

Istanbul Univ. Cerrahpasa Faculty of Med., Istanbul, Turkey

Abstract: 

Background: The echinocandins anidulafungin (ANF), caspofungin (CSF), micafungin (MCF) represent a new antifungal group with potent activity against Candida species. A commercially prepared dried colorimetric microdilution panel (Sensititre YeastOne, TREK Diagnostic Systems, Cleveland, OH, USA) is able to determine the susceptibility of echinocandins and demonstrated excellent corelation with the reference method M27-A3 from the Clinical Laboratory Standards Institute (CLSI). Resistance rates were determined by recently revised CLSI antifungal breakpoints. The aim of this study is to evaluate the in vitro activity of ANF, CSF and MCF against clinically significant Candida strains by YeastOne colorimetric microdilution panel.Methods: Isolates were checked of purity and were identified by classical morphological tests including germtube formation in human serum at 37°C for 3 h, blastoconidia, pseudohyphae, truehyphae and chlamydoconidia formation on corn meal agar- Tween 80, integrating with the results of chromogenic agar (CHROMagar, HiMedia, India) and of API 20C AUX kit (Bio Mérieux, France). Identification kit procedure and colorimetric microdilution tests were performed according to the manufacturer’s instructions. Quality control was ensured by testing CLSI-recommended strains C. parapsilosis ATCC 22019 and C. krusei ATCC 6258.Results: Among 198 Candida isolates, 112 were C. albicans, 11 were C. glabrata, 45 were C. parapsilosis, 14 were C. tropicalis, seven C. krusei, three of each C. kefyr and C. lusitaniae, two C. guilliermondii, and one C. pelluculosa. Regarding to the MIC values obtained, resistance to ANF was observed in one C. albicans, two C. tropicalis, five C. parapsilosis strains; resistance to CSF was observed in one C. albicans and one C. parapsilosis strains; and resistance to MCF was observed in two C. albicans, one C. tropicalis and fiveC. Parapsilosis strains. There remaining strains were in vitro susceptible to all echinocandins tested.Conclusions: Based on newly established breakpoints for species-specific interpretive criteria, the results of this study affirmed that echinocandins exhibit excellent activity against the Candida secies most frequently involved in human infections.
2016

abstract No: 

FRIDAY-303

Full conference title: 

ASM Microbe 2016
    • ASM microbe 1st (2016)