Antifungal susceptibility of Candida isolates at the American University of Beirut Medical Center.

For the first time from Lebanon, the antifungal susceptibility patterns of 70 consecutive clinical candida isolates (each from one patient) representing 48 C. albicans, 12 C. tropicalis, 6 C. parapsilosis, 2 C. kruseii, and 2 C. (Torulopsis) glabrata were studied against amphotericin B (AP), 5-fluorocytosine (FC), ketoconazole (KE), fluconazole (FL), and itraconazole (IT) using the Epsilometer test (E-test; AB Biodisk, Solna, Sweden). The MIC90 (and MIC range, mg/l) determined, at 24 h incubation, for each antifungal agent against C. albicans were: AP 0.032 (< or = 0.002-0.064), FC 0.75 (0.023-2), KE 0.064 (0.002- > 32), FL 2 (0.064- > 256), and IT 0.19 (0.012-2), against C. tropicalis were: AP 0.016 (< 0.002-0.047), FC 0.125 (0.023-0.19), KE 0.094 (0.012-0.19), FL 2 (0.5-2), and IT 0.5 (0.047-1) and against C. parapsilosis were: AP < 0.002 (< 0.002-0.002), FC 0.047 (0.003-0.5), KE 0.004 (0.002-0.004), FL 0.125 (0.032-0.19), and IT 0.004 (< 0.002-0.004). Based on the NCCLS established MICs breakpoints, resistance was found among C. albicans to FL (MIC > or = 6 mg/l) and IT (MIC > or = 1 mg/l) in 6 and 4%, respectively, and among C. tropicalis to IT in 17% of the isolates. The susceptibility dependent upon dose (S-DD) was noted only to IT (MIC 0.25-0.5 mg/l) among C. albicans (8%) and C. tropicalis (58%). MICs determination at 48 h incubation were higher, showed more resistance rates and more endpoint trailing particularly with the azoles drugs. The small numbers of C. kruseii and C. glabrata preclude providing meaningful results. Thus, this study indicates that the antifungal susceptibility by E-test can be conveniently incorporated and performed in a hospital-based clinical laboratory. Despite the uniform susceptibility to AP and FC, resistance to azoles drugs is encountered in a range of 4-17% among candida isolates in this country.