Rapid identification of Candida albicans in blood by combined capillary electrophoresis and fluorescence in situ hybridization.
A CE method based on whole-cell molecular labeling via fluorescence in situ hybridization was developed for the detection of Candida albicans in whole blood. Removal of potentially interfering red blood cells (RBC) with a simple hypotonic/detergent lysis step enabled us to detect and quantitate contaminating C. albicans cells at concentrations that were orders of magnitude lower than background RBC counts ( approximately 7.0 x 10(9) RBC/mL). In the presence of the lysed blood matrix, yeast cells aggregated without the use of a blocking plug to stack the cells. Short (15 min) hybridizations yielded bright Candida-specific fluorescence in situ hybridization signals, enabling us to detect as few as a single injected cell. The peak area response of the stacked Candida cells showed a strong linear correlation with cell concentrations determined by plate counts, up to approximately 10(7) CFU/mL (or approximately 1 x 10(4) injected cells). This rapid and quantitative method for detecting Candida in blood may have advantageous applications in both human and veterinary diagnostics.
Lantz
Andrew W
AW
Department of Chemistry, Grand Valley State University, Allendale, MI, USA. lantza@gvsu.edu
Bisha
Bledar
B
Tong
Man-Yung
MY
Nelson
Ryan E
RE
Brehm-Stecher
Byron F
BF
Armstrong
Daniel W
DW
D002176:Candida albicans / Q000235:genetics* / Q000302:isolation & purification*; D041022:Candida tropicalis / Q000235:genetics / Q000302:isolation & purification*; D002177:Candidiasis / Q000097:blood* / Q000175:diagnosis / Q000382:microbiology; D015342:DNA Probes; D003902:Detergents; D019075:Electrophoresis, Capillary / Q000379:methods; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D009693:Nucleic Acid Hybridization
D015342:DNA Probes; D003902:Detergents