Molecular Techniques and Target Selection for the Identification of Candida spp. in Oral Samples

Abstract

Candida species are the causative agent of oral candidiasis, with medical devices being platforms for yeast anchoring and tissue colonization. Identifying the infectious agent involved in candidiasis avoids an empirical prescription of antifungal drugs. The application of high-throughput technologies to the diagnosis of yeast pathogens has clear advantages in sensitivity, accuracy, and speed. Yet, conventional techniques for the identification of Candida isolates are still routine in clinical and research settings. Molecular approaches are the focus of intensive research, but conversion into clinic settings requires overcoming important challenges. Several molecular approaches can accurately identify Candida spp.: Polymerase Chain Reaction, Microarray, High-Resolution Melting Analysis, Multi-Locus Sequence Typing, Restriction Fragment Length Polymorphism, Loop-mediated Isothermal Amplification, Matrix Assisted Laser Desorption Ionization-mass spectrometry, and Next Generation Sequencing. This review examines the advantages and disadvantages of the current molecular methods used for Candida spp. Identification, with a special focus on oral candidiasis. Discussion regarding their application for the diagnosis of oral infections aims to identify the most rapid, affordable, accurate, and easy-to-perform molecular techniques to be used as a point-of-care testing method. Special emphasis is given to the difficulties that health care professionals need to overcome to provide an accurate diagnosis.

Loop-Mediated Isothermal Amplification (LAMP): Potential Point-of-Care Testing for Vulvovaginal Candidiasis

“…Alternatively, culture-independent analysis based on molecular biological methods might provide an alternative for the accurate and rapid identification of Candida species. Apart from commonly used real-time PCR methods based on species-specific probes or primers targeting specific fungal pathogens, other molecular biology-based methods are available such as peptide nucleic acid fluorescence in situ hybridization (PNA FISH) [35,36], restriction fragment length polymorphism (RFLP) [37], randomly amplified polymorphic DNA (RAPD) analysis [38], Multi locus sequence typing (MLST), and Microsatellite typing [39]. Here, the real-time PCR presented a high NPV for C. albicans, but the PPV was only 82.7%, related to a high false positive rate.…”