In vitro susceptibilities of Candida dubliniensis isolates tested against the new triazole and echinocandin antifungal agents

Candida dubliniensis is a newly recognized fungal pathogen causing mucosal disease in AIDS patients. Although preliminary studies indicate that most s trains of C. dubliniensis are susceptible to established antifungal agents, fluconazole-resistant strains have been detected. Furthermore, fluconazole -resistant strains are easily derived in vitro, and these strains exhibit i ncreased expression of multidrug resistance transporters, especially MDR1. Because of the potential for the development of resistant strains of C. dub liniensis, it is prudent to explore the in vitro activities of several of t he newer triazole and echinocandin antifungals against isolates of C. dubli niensis, In this study we tested 71 isolates of C. dubliniensis against the triazoles BMS-207147, Sch 56592, and voriconazole and a representative of the echinocandin class of antifungal agents, MK-0991. We com pared the acti vities of these agents with those of the established antifungal agents fluc onazole, itraconazole, amphotericin B, and 5-fluorocytosine (5FC) by using National Committee for Clinical Laboratory Standards microdilution referenc e methods. Our findings indicate that the vast majority of clinical isolate s of C, dubliniensis are highly susceptible to both new and established ant ifungal agents. Strains with decreased susceptibilities to fluconazole rema ined susceptible to the investigational agents as well as to amphotericin B and 5FC, The increased potencies of the new triazole and echinocandin anti fungal agents may provide effective therapeutic options for the treatment o f infections due to C. dubliniensis.