AUTHOR=Jiang Xiaoqun , Dong Derong , Bian Lihong , Zou Dayang , He Xiaoming , Ao Da , Yang Zhan , Huang Simo , Liu Ningwei , Liu Wei , Huang Liuyu 

TITLE=Rapid Detection of Candida albicans by Polymerase Spiral Reaction Assay in Clinical Blood Samples

JOURNAL=Frontiers in Microbiology

VOLUME=7

YEAR=2016

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2016.00916

DOI=10.3389/fmicb.2016.00916

ISSN=1664-302X

ABSTRACT=<p><italic>Candida albicans</italic> 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 <italic>C. albicans</italic> 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-<italic>C. albicans</italic> yeast strains were negative for detection, which indicated the specificity of PSR assay was 100%. A 10-fold serial dilution of <italic>C. albicans</italic> 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 (<italic>n</italic> = 122) were collected from intensive care unit and hematological patients with proven or suspected <italic>C. albicans</italic> 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 <italic>C. albicans</italic> detection assay was developed that has a great potential for clinical screening and point-of-care testing.</p>