Specific identification ofCandida albicans andCandida dubliniensis by PCR using species-specific primers

Abstract

The aim of our study was to evaluate the effectiveness of phenotyping and genotyping methods for the identification of Candida albicans and Candida dubliniensis. Phenotyping methods used are colony colour on CHROMagar Candida medium, growth at 45 ºC, TTC (2,3,5-triphenyl-tetrazolium chloride) reduction, germ tube and chlamydospores formation, and API 20C AUX. We also used C. albicans and C. dubliniensis specific primers for identification performed with genotyping methods. DNAs of C. albicans reference strains, different Candida species, Cryptococcus neoformans, mycelial fungi, bacterial strains and human DNA were used as a template in order to evaluate the specificity of the primers. These primers yielded a 175-base-pair product only when C. albicans DNA exists; however when other DNAs (except two isolates that are phenotypically identified as C. dubliniensis and C. tropicalis) exist no product appeared. In another PCR assay conducted by using C. albicans DNA and C. dubliniensis specific primers, no product was observed. Candida albicans and C. dubliniensis specific primers were designed by Mannarelli and Kurtzman. Detection limit of C. albicans primers was found to be 19 pg chromosomal DNA. In order to verify phenotypical definition with PCR amplification, C. albicans and C.dubliniensis specific primers were exposed to PCR by using DNAs that belong to 25 phenotypically defined oral Candida isolates.

Comparative Genome-Wide Characterization of Microsatellites in <b><i>Candida albicans</i></b> and <b><i>Candida dubliniensis</i></b> Leading to the Development of Species-Specific Marker

“…We also studied our primers’ specificity by performing the PCR on the template DNA of different Candida species along with Cd . It is important as differences in Ca and Cd is either not noticed or often they are misidentified while performing the germ tube test in serum and other routine conventional methods used in the laboratories [53]. In our PCR experiment, we have used the DNA of two reference strains of Cd , which gave the desired product with our Cd -specific primer.…”

Candida albicans ssp. dubliniensis stat.et comb. nov., a new combination for Candida dubliniensis based on genetic criteria

“…based on phenotypic criteria alone have been revealed to be unreliable markers, although they enabled us to elucidate some taxonomic complications between C. albicans and C. dubliniensis, such as similarities in the phenotypic characters, especially in their color on chromogenic agar, as well as following other conventional criteria, although not the perfect solution for the differences between them (Ahmed et al, 2002;Marot-Leblond et al, 2006;Imran and Al Asadi, 2014). In fact, misidentifications between some Candida spp., particularly between C. dubliniensis and C. albicans have frequently been observed (Tamura et al, 2001;Abaci et al, 2008). Coronado-Castellote and Jiménez-Soriano (2013) referred to C. dubliniensis as exhibiting similarity with C. albicans in their germ tubes and chlamydoconidia, as well as the high probability for mating between them and the similarity in some of their sequences at different loci (Pujol et al, 2004).…”

Candida clinical species identification: molecular and biochemical methods

“…Misidentifications between some Candida species are frequently observed, particularly between C. dubliniensis and C. albicans (Abaci et al 2008). To distinguish between them, methods such as the latex agglutination test can be used (Kurzai et al 1999;Marot-Leblond et al 2006).…”