Fluorescence in situ hybridization with peptide nucleic acid probes for rapid identification of Candida albicans directly from blood culture bottles.
A new fluorescence in situ hybridization (FISH) method that uses peptide nucleic acid (PNA) probes for identification of Candida albicans directly from positive-blood-culture bottles in which yeast was observed by Gram staining (herein referred to as yeast-positive blood culture bottles) is described. The test (the C. albicans PNA FISH method) is based on a fluorescein-labeled PNA probe that targets C. albicans 26S rRNA. The PNA probe is added to smears made directly from the contents of the blood culture bottle and hybridized for 90 min at 55 degrees C. Unhybridized PNA probe is removed by washing of the mixture (30 min), and the smears are examined by fluorescence microscopy. The specificity of the method was confirmed with 23 reference strains representing phylogenetically related yeast species and 148 clinical isolates covering the clinically most significant yeast species, including C. albicans (n = 72), C. dubliniensis (n = 58), C. glabrata (n = 5), C. krusei (n = 2), C. parapsilosis (n = 4), and C. tropicalis (n = 3). The performance of the C. albicans PNA FISH method as a diagnostic test was evaluated with 33 routine and 25 simulated yeast-positive blood culture bottles and showed 100% sensitivity and 100% specificity. It is concluded that this 2.5-h method for the definitive identification of C. albicans directly from yeast-positive blood culture bottles provides important information for optimal antifungal therapy and patient management.
Rigby
Susan
S
Applied Biosystems, Bedford, Massachusetts 01730, USA.
Procop
Gary W
GW
Haase
Gerhard
G
Wilson
Deborah
D
Hall
Geraldine
G
Kurtzman
Cletus
C
Oliveira
Kenneth
K
Von Oy
Sabina
S
Hyldig-Nielsen
Jens J
JJ
Coull
James
J
Stender
Henrik
H
D001769:Blood / Q000382:microbiology*; D002176:Candida albicans / Q000145:classification* / Q000235:genetics; D002177:Candidiasis / Q000175:diagnosis / Q000382:microbiology; D003470:Culture Media; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D015341:Nucleic Acid Probes / Q000235:genetics*; D020135:Peptide Nucleic Acids / Q000235:genetics*; D012338:RNA, Ribosomal, 23S / Q000235:genetics; D012680:Sensitivity and Specificity; D013997:Time Factors
D003470:Culture Media; D015341:Nucleic Acid Probes; D020135:Peptide Nucleic Acids; D012338:RNA, Ribosomal, 23S