Analysis of the genetic diversity of Candida isolates obtained from diabetic patients and kidney transplant recipients

Abstract

Yeasts of the genus Candida have high genetic variability and are the most common opportunistic pathogenic fungi in humans. In this study, we evaluated the genetic diversity among 120 isolates of Candida spp. obtained from diabetic patients, kidney transplant recipients and patients without any immune deficiencies from Paraná state, Brazil. The analysis was performed using the ITS1-5.8S-ITS2 region and a partial sequence of 28S rDNA. In the phylogenetic analysis, we observed a consistent separation of the species C. albicans, C. dubliniensis, C. glabrata, C. tropicalis, C. parapsilosis, C. metapsilosis and C. orthopsilosis, however with low intraspecific variability. In the analysis of the C. albicans species, two clades were formed. Clade A included the largest number of isolates (91.2%) and the majority of isolates from GenBank (71.4%). The phylogenetic analysis showed low intraspecific genetic diversity, and the genetic polymorphisms between C. albicans isolates were similar to genetic divergence found in other studies performed with isolates from Brazil. This low genetic diversity of isolates can be explained by the geographic proximity of the patients evaluated. It was observed that yeast colonisation was highest in renal transplant recipients and diabetic patients and that C. albicans was the species most frequently isolated.

An Update on Candida tropicalis Based on Basic and Clinical Approaches

“…The main target for yeasts DNA molecular sequencing is the ribosomal (rDNA) region (Pincus et al, 2007 ). This region contains conserved domains separated by variable regions (the small sub unities 18S and 5.8S, besides the large subunit 26S, while these sub unities are separated by the interespacer regions ITS1 and ITS2) which contain species-specific sequences used as the preferential target for universal primers used of identification (Table 2 ; Merseguel et al, 2015 ; Shi et al, 2015 ; Benedetti et al, 2016 ).…”

Colovesicular fistula from Candida dubliniensis in an immunocompetent resulting in poor outcome

“…C. dubliniensis has morphological and biological characteristics that are very similar to C. albicans, urging for the need of speciation of the two species due to C. dubliniensis resistance of fluconazole [6,7]. This yeast should not be dismissed as a colonization due to lack of studies on it.…”

ERG11 gene polymorphisms and susceptibility to fluconazole in Candida isolates from diabetic and kidney transplant patients

“…The patients within the kidney transplant, diabetic and control groups were not paired by gender or age. A total of 94 Candida isolates were obtained, and the species were identified by Benedetti et al 19 . Among the 70 isolates used in this study, 58 were classified as Candida albicans, 6 as Candida glabrata and 8 as Candida tropicalis.…”