Tohoku J. Exp. Med., 2000, 190 (2)

Rapid, Sensitive and Simple Detection of Candida Deep Mycosis by Amplification of 18S Ribosomal RNA Gene; Comparison with Assay of Serum bD-Glucan Level in Clinical Samples

TETSUO SAKAI, KEIICHI IKEGAMI,1 EMI YOSHINAGA, RURIKO UESUGI-HAYAKAWA and AKIRA WAKIZAKA

Department of Biochemistry and Molecular Biology, Kyorin University School of Medicine, Mitaka 181-8611, and 1Trauma and Critical Care Center, Koshigaya Hospital, Dokkyo University School of Medicine, Koshigaya 343-8555

  • We evaluated the clinical usefulness of a polymerase chain reaction (PCR) assay amplifying the 18S ribosomal RNA gene of fungi for the diagnosis of deep candidiasis, compared with that of the b-glucan test or Cand-Tec test. Thirty critically ill patients who had received prolonged care with intravenous hyperalimentation and endotracheal intubation in the intensive care unit and were suspected of having deep fungal infections were examined. Twenty-one were fungi positive in the PCR assay (70%). Among 24 samples in which the PCR assay, b-glucan test and Cand-Tec test were performed simultaneously, 75% of the samples (18/24) were fungi positive in the PCR assay, whereas only 54% (13/24) had positive reactions in the b-glucan test and 21% (5/24) in the Cand-Tec test. The results of the Cand-Tec test showed no relationship with those of the PCR or b-glucan test. The lower limit of detection in the PCR assay was 4-5 CFU/ml of C. albicans in blood. No fungal organism was amplified from the serum of 20 healthy individuals. The results of the PCR assay and b-glucan test showed a significant correlation in this study, but the PCR assay proved to be more sensitive than the b-glucan test (p<0.05), and to be more useful for the clinical diagnosis and monitoring of deep Candidiasis.
    Key words--- polymerase chain reaction; 18S ribosomal RNA; b-glucan; deep mycosis; Candidiasis
    © 2000 Tohoku University Medical Press

    Tohoku J. Exp. Med., 2000, 190, 119-128
    Address for reprints: Tetsuo Sakai, M.D., Department of Biochemistry and Molecular Biology, Kyorin University School of Medicine, 6-20-2 Shinkawa, Mitaka, 181-8611, Japan.
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