A comparison between CHROMagar, PCR-RFLP and PCR-FSP for identification of Candida species

Abstract

Background and Purpose:The epidemiological alteration in the distribution of Candida species, as well as the significantly increasing trend of either intrinsic or acquired resistance of some of these fungi highlights the need for a reliable method for the identification of the species. Polymerase chain reaction (PCR) is one of the methods facilitating the quick and precise identification of Candida species. The aim of this study was to compare the efficiency of CHROMagar, PCR-restriction fragment length polymorphism (PCR-RFLP), and PCR-fragment size polymorphism (PCR-FSP) assays in the identification of Candida species to determine the benefits and limitations of these methods.Materials and Methods:This study was conducted on 107 Candida strains, including 20 standard strains and 87 clinical isolates. The identification of the isolates was accomplished by using CHROMagar as a conventional method. The PCR-RFLP assay was performed on the entire internal transcribed spacer (ITS) region of ribosomal DNA (rDNA), and the consequent enzymatic digestion was compared with PCR-FSP results in which ITS1 and ITS2 regions were separately PCR amplified. In both molecular assays, yeast identification was carried out through the specific electrophoretic profiles of the PCR products.Results:According to the results, the utilization of CHROMagar resulted in the identification of 29 (33.3%) Candida isolates, while the PCR-RFLP and PCR-FSP facilitated the identification of 83 (95.4%) and 80 (91.9%) clinical isolates, respectively. The obtained concordances between CHROMagar and PCR-RFLP, between CHROMagar and PCR-FSP, as well as between PCR-RFLP and PCR-FSP were 0.23, 0.20, and 0.77, respectively.Conclusion:The recognition of the benefits and limitations of PCR methods allows for the selection of the most efficient technique for a fast and correct differentiation. The PCR-RFLP and PCR-FSP assays had satisfactory concordance. The PCR-FSP provides a rapid, technically simple, and cost-effective method for the identification of Candida species. Nevertheless, to accurately differentiate among the taxonomically related species, PCR-RFLP should be implemented.

Identification of Candida Species from Clinical Samples in a Honduran Tertiary Hospital

“…Jafari et al compared CHROMagar Candida ® and two molecular assays. According to their results, the concordances (k coefficient) between the phenotypic assay and the molecular methods were 0.87 and 0.89 [26].…”

“…Several studies reported similar findings when analyzing clinical samples of diverse origins. A study conducted with clinical samples obtained from Iranian hospitals showed a higher frequency of C. albicans, followed by C. parapsilosis, C. glabrata, and C. rugosa identified by PCR-RFLP [26]. A second study analyzed five different types of clinical samples in Iran, and showed that C. albicans was the predominant species, followed by C. glabrata and C. tropicalis [27].…”

“…The causes of inconsistencies between methods could be attributed to a limited ability of phenotypic approaches, such as HardyCHROM ® , to identify rare species [26], nor can PCR-RFLP identify all potential restriction patterns. Another reason could be the presence of more than one species of yeast in a seemingly pure culture.…”

Identification of <em>Candida</em> Species from Clinical Samples in a Honduran Tertiary Hospital

“…albicans, followed by C. parapsilosis, C. glabrata, and C. rugosa identified by PCR-RFLP [26]. A second study analyzed 5 different types of clinical samples in Iran, and showed that C. albicans was the predominant species, followed by C. glabrata and C. tropicalis [27].…”

Factors associated with the isolation of Candida Spp. from the oral microbiota of people living with HIV

“…With the inclusion of chromogenic substrates, the colonies presented with certain characteristics, that is, Candida albicans, Candida tropicalis, and Candida krusei colonies presented a different coloration. [18] The dishes presenting no Candida spp. growth were discarded after 15 days, following the recommendations for biological waste disposal.…”