Verification of false-positive blood culture results generated by the BACTEC 9000 series by eubacterial 16S rDNA and panfungal 18S rDNA directed polymerase chain reaction (PCR).
A small but significant proportion of blood cultures processed by the BACTEC 9000 series systems is signaled positive, while subsequent Gram's stain and culture on solid media yield no pathogens. In this study, 15 "false-positive" vials (7 aerobes, 8 anaerobes) from 15 patients were investigated for the presence of bacteria and fungi by eubacterial 16S rDNA and panfungal 18S rDNA amplification, respectively. All samples turned out negative by both methods. Most patients (7) had neutropenia, which does not support the theory that high leukocyte counts enhance the generation of false-positive results. In conclusion, the results of this study indicate that false-negative results generated by the BACTEC 9000 series are inherent to the automated detection and not due to the growth of fastidious organisms.
Daxboeck
Florian
F
Department of Pediatrics, University of Graz, Graz, Austria. florian.daxboeck@akh-wien.ac.at
Dornbusch
Hans Jürgen
HJ
Krause
Robert
R
Assadian
Ojan
O
Wenisch
Christoph
C
D000328:Adult; D000368:Aged; D001420:Bacteria, Aerobic / Q000145:classification*; D001421:Bacteria, Anaerobic / Q000145:classification*; D015373:Bacterial Typing Techniques; D001483:Base Sequence; D001769:Blood / Q000382:microbiology; D005189:False Positive Reactions; D005260:Female; D005658:Fungi / Q000145:classification*; D006801:Humans; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction / Q000379:methods*; D012336:RNA, Ribosomal, 16S / Q000032:analysis; D012337:RNA, Ribosomal, 18S / Q000032:analysis; D012494:Sampling Studies; D012680:Sensitivity and Specificity
D012336:RNA, Ribosomal, 16S; D012337:RNA, Ribosomal, 18S