Antifungal susceptibility testing of fluconazole by flow cytometry correlates with clinical outcome.
Susceptibility testing of fungi by flow cytometry (also called fluorescence-activated cell sorting [FACS]) using vital staining with FUN-1 showed a good correlation with the standard M27-A procedure for assessing MICs. In this study we determined MICs for blood culture isolates from patients with candidemia by NCCLS M27-A and FACS methods and correlated the clinical outcome of these patients with in vitro antifungal resistance test results. A total of 24 patients with candidemia for whom one or more blood cultures were positive for a Candida sp. were included. Susceptibility testing was performed by NCCLS M27-A and FACS methods. The correlation of MICs (NCCLS M27-A and FACS) and clinical outcome was calculated. In 83% of the cases, the MICs of fluconazole determined by FACS were within 1 dilution of the MICs determined by the NCCLS M27-A method. For proposed susceptibility breakpoints, there was 100% agreement between the M27-A and FACS methods. In the FACS assay, a fluconazole MIC of <1 microg/ml was associated with cure (P < 0.001) whereas an MIC of > or =1 microg/ml was associated with death (P < 0.001). The M27-A-derived fluconazole MICs did not correlate with outcome (P = 1 and P = 0.133).
Wenisch
C
C
Division of Infectious Diseases, Department of Medicine, Karl-Franzens University, Auenbruggerplatz 15, A-8036 Graz, Austria. christoph.wenisch@kfunigraz.ac.at
Moore
C B
CB
Krause
R
R
Presterl
E
E
Pichna
P
P
Denning
D W
DW
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000935:Antifungal Agents / Q000494:pharmacology* / Q000627:therapeutic use; D001769:Blood / Q000382:microbiology; D002175:Candida / Q000187:drug effects*; D002177:Candidiasis / Q000188:drug therapy / Q000382:microbiology* / Q000401:mortality; D003470:Culture Media; D004352:Drug Resistance, Microbial; D005260:Female; D005434:Flow Cytometry / Q000379:methods; D015725:Fluconazole / Q000494:pharmacology* / Q000627:therapeutic use; D016469:Fungemia / Q000188:drug therapy / Q000382:microbiology* / Q000401:mortality; D006801:Humans; D007223:Infant; D008297:Male; D008826:Microbial Sensitivity Tests / Q000379:methods; D008875:Middle Aged; D016896:Treatment Outcome
D000935:Antifungal Agents; D003470:Culture Media; D015725:Fluconazole