title: Rapid Detection of Candida albicans by Polymerase Spiral Reaction Assay in Clinical Blood Samples.
abstract: Candida albicans is the most common human yeast pathogen which causes mucosal infections and invasive fungal diseases. Early detection of this pathogen is needed to guide preventative and therapeutic treatment. The aim of this study was to establish a polymerase spiral reaction (PSR) assay that rapidly and accurately detects C. albicans and to assess the clinical applicability of PSR-based diagnostic testing. Internal transcribed spacer 2 (ITS2), a region between 5.8S and 28S fungal ribosomal DNA, was used as the target sequence. Four primers were designed for amplification of ITS2 with the PSR method, which was evaluated using real time turbidity monitoring and visual detection using a pH indicator. Fourteen non-C. albicans yeast strains were negative for detection, which indicated the specificity of PSR assay was 100%. A 10-fold serial dilution of C. albicans genomic DNA was subjected to PSR and conventional polimerase chain reaction (PCR) to compare their sensitivities. The detection limit of PSR was 6.9 pg/μl within 1 h, 10-fold higher than that of PCR (69.0 pg/μl). Blood samples (n = 122) were collected from intensive care unit and hematological patients with proven or suspected C. albicans infection at two hospitals in Beijing, China. Both PSR assay and the culture method were used to analyze the samples. Of the 122 clinical samples, 34 were identified as positive by PSR. The result was consistent with those obtained by the culture method. In conclusion, a novel and effective C. albicans detection assay was developed that has a great potential for clinical screening and point-of-care testing.
authors.affiliation: School of Environment and Natural Resources, Renmin University of China Beijing, China.
authors.forename: Xiaoqun
authors.initials: X
authors.lastname: Jiang
authors.affiliation: Institute of Disease Control and Prevention, Academy of Military Medical Sciences Beijing, China.
authors.forename: Derong
authors.initials: D
authors.lastname: Dong
authors.affiliation: Department of Gynecology, 307th Hospital of Chinese People's Liberation Army Beijing, China.
authors.forename: Lihong
authors.initials: L
authors.lastname: Bian
authors.affiliation: Institute of Disease Control and Prevention, Academy of Military Medical Sciences Beijing, China.
authors.forename: Dayang
authors.initials: D
authors.lastname: Zou
authors.affiliation: Institute of Disease Control and Prevention, Academy of Military Medical Sciences Beijing, China.
authors.forename: Xiaoming
authors.initials: X
authors.lastname: He
authors.affiliation: Institute of Disease Control and Prevention, Academy of Military Medical Sciences Beijing, China.
authors.forename: Da
authors.initials: D
authors.lastname: Ao
authors.affiliation: Institute of Disease Control and Prevention, Academy of Military Medical Sciences Beijing, China.
authors.forename: Zhan
authors.initials: Z
authors.lastname: Yang
authors.affiliation: Institute of Disease Control and Prevention, Academy of Military Medical Sciences Beijing, China.
authors.forename: Simo
authors.initials: S
authors.lastname: Huang
authors.affiliation: Institute of Disease Control and Prevention, Academy of Military Medical Sciences Beijing, China.
authors.forename: Ningwei
authors.initials: N
authors.lastname: Liu
authors.affiliation: Institute of Disease Control and Prevention, Academy of Military Medical Sciences Beijing, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Liu
authors.affiliation: Institute of Disease Control and Prevention, Academy of Military Medical Sciences Beijing, China.
authors.forename: Liuyu
authors.initials: L
authors.lastname: Huang
keywords: C. albicans; ITS2; PSR; isothermal; rapid diagnosis