Rapid, sensitive and simple detection of candida deep mycosis by amplification of 18S ribosomal RNA gene; Comparison with assay of serum beta-D-glucan level in clinical samples

SAKAI, T., IKEGAMI, K., YOSHINAGA, E., UESUGI-HAYAKAWA, R. and WAKIZAKA, A. Rapid, Sensitive and Simple Detection of Candida Deep Mycosis by Amplifica tion of 18S Ribosomal RNA Gene, Comparison with Assay of Serum beta-D-Gluca n Level in Clinical Samples. Tohoku J. Exp. Med., 2000, 190 (2), 119-128-We evaluated the clinical usefulness of a polymerase chain reaction (PCR) ass ay amplifying the 18S ribosomal RNA gene of fungi for the diagnosis of deep candidiasis, compared with that of the beta-glucan test or Cand-Tec test. Thirty critically ill patients who had received prolonged care with intrave nous hyperalimentation and endotracheal intubation in the intensive care un it and were suspected of having deep fungal infections mere examined. Twent y-one mere fungi positive in the PCR assay (70%). Among 24 samples in which the PCR assay, beta-glucan test and Cand-Tec test were performed simultane ously, 75% of the samples (18/24) were fungi positive in the PCR assay, whe reas only 54% (13/24) had positive reactions in the beta-glucan test and 21 % (5/24) in the Cand-Tec test. The results of the Cand-Tec test showed no r elationship with those of the PCR or beta-glucan test. The lower limit of d etection 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 resul ts of the PCR assay and beta-glucan test showed a significant correlation i n this study, but the PCR assay proved to be more sensitive than the beta-g lucan test (p < 0.05), and to be more useful for the clinical diagnosis and monitoring of deep Candidiasis. -polymerase chain reaction; 18S ribosomal RNA; beta-glucan; deep mycosis; Candidiasis (C) 2000 Tohoku University Medi cal Press.