TY - JOUR
T1 - Triazole cross-resistance among Candida spp.
T2 - Case report, occurrence among bloodstream isolates, and implications for antifungal therapy
AU - Magill, Shelley S.
AU - Shields, Christine
AU - Sears, Cynthia L.
AU - Choti, Michael A.
AU - Merz, William G
PY - 2006/2
Y1 - 2006/2
N2 - Candida spp. are common causes of bloodstream infections among hospitalized patients. Fluconazole (FLC) remains a first-line therapy for candidemia; and voriconazole (VRC), an expanded-spectrum triazole, was recently approved for the treatment of candidemia in nonneutropenic patients. In vitro studies have suggested that VRC has potent activity against Candida spp. with reduced susceptibilities to FLC. We present a case report of invasive candidiasis and candidemia due to a Candida glabrata isolate that developed resistance to all currently available triazole antifungals after a course of FLC treatment. This case prompted us to determine the frequency of cross-resistance among bloodstream Candida isolates collected during a recent 12-month period at a large, academic medical center. FLC MICs were determined for 125 of 153 isolates (81.7%). Thirty of 125 isolates (24%) were resistant or showed reduced susceptibilites to FLC (MICs ≥ 16 μg/ml). When 28 of these 30 isolates were tested for their VRC susceptibilities, 9 (32%) had MICs that were ≥2 μg/ml. Five of these nine isolates were C. glabrata, two isolates were Candida tropicalis, one isolate was Candida albicans, and one isolate was Candida parapsilosis. All five Candida krusei isolates tested had VRC MICs ≤0.5 μg/ml. These data have prompted the introduction of reflexive FLC susceptibility testing of first bloodstream Candida isolates at our institution. The case report and our data also suggest that VRC should be avoided as initial therapy in unstable patients with invasive candidiasis, particularly in the setting of prior azole exposure. Studies are needed to define the clinical significance of in vitro resistance to the newer antifungal agents.
AB - Candida spp. are common causes of bloodstream infections among hospitalized patients. Fluconazole (FLC) remains a first-line therapy for candidemia; and voriconazole (VRC), an expanded-spectrum triazole, was recently approved for the treatment of candidemia in nonneutropenic patients. In vitro studies have suggested that VRC has potent activity against Candida spp. with reduced susceptibilities to FLC. We present a case report of invasive candidiasis and candidemia due to a Candida glabrata isolate that developed resistance to all currently available triazole antifungals after a course of FLC treatment. This case prompted us to determine the frequency of cross-resistance among bloodstream Candida isolates collected during a recent 12-month period at a large, academic medical center. FLC MICs were determined for 125 of 153 isolates (81.7%). Thirty of 125 isolates (24%) were resistant or showed reduced susceptibilites to FLC (MICs ≥ 16 μg/ml). When 28 of these 30 isolates were tested for their VRC susceptibilities, 9 (32%) had MICs that were ≥2 μg/ml. Five of these nine isolates were C. glabrata, two isolates were Candida tropicalis, one isolate was Candida albicans, and one isolate was Candida parapsilosis. All five Candida krusei isolates tested had VRC MICs ≤0.5 μg/ml. These data have prompted the introduction of reflexive FLC susceptibility testing of first bloodstream Candida isolates at our institution. The case report and our data also suggest that VRC should be avoided as initial therapy in unstable patients with invasive candidiasis, particularly in the setting of prior azole exposure. Studies are needed to define the clinical significance of in vitro resistance to the newer antifungal agents.
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U2 - 10.1128/JCM.44.2.529-535.2006
DO - 10.1128/JCM.44.2.529-535.2006
M3 - Article
C2 - 16455909
AN - SCOPUS:32344436774
SN - 0095-1137
VL - 44
SP - 529
EP - 535
JO - Journal of Clinical Microbiology
JF - Journal of Clinical Microbiology
IS - 2
ER -