Phenotypic and genotypic characteristics of Candida albicans isolates from bloodstream and mucosal infections

Abstract

The interaction of Candida albicans with the host is of a complex nature involving fungal factors and host's response. In this study, we concentrated on the phenotypic expression of virulence attributes and genotypic characteristics of C. albicans isolates from two distinct clinical entities of candidiasis-blood stream and vaginal infections, and the possible role of these factors. Hence, we conducted a comparative in vitro assessment of virulence characteristics, including adhesion to epithelial cells and HaCat cell line, biofilm formation, aspartic proteinases and phospholipase activity of 20 C. albicans isolates from patients with C. albicans bloodstream infection and 22 isolates from patients with C. albicans vaginitis. Further, we studied the epigenetic phenotypic switching of the strains and their ploidy, by flow cytometry and CHEF techniques. These studies indicated that although no overall differentiation between the isolates of the two groups (bloodstream infection and vaginitis) could be demonstrated, several characteristics were more specific to one of the groups than the other. While the strains from vaginal infection had higher capacity to adhere, the strains from patients with bloodstream infection had higher activity of phospholipase. Differences were also noted in phenotypic switching, with the strains from bloodstream infection revealing primarily the "white" type colonies, known to be more virulent, and had higher DNA content. This study is unique considering the concurrent comparison of isolates from different clinical entities, at the phenotypic and genotypic level.

Identification ofCandida albicansregulatory genes governing mucosal infection

“…Different isolates and strains of C. albicans vary significantly in the interactions that they establish with the host mucosa (Mandelblat et al, 2017;Schönherr et al, 2017). Experiments in mice have shown, for example, that independently of the source (e.g., bloodstream, OPC, or VVC), some C. albicans isolates can persist for a long time in the tongues of these animals with no associated pathology, whereas other isolates induce an acute immune response and are cleared rapidly (Schönherr et al, 2017).…”

ABC genotyping and putative virulence factors of Candida albicans clinical isolates

“…However, the relationship between virulence and hemolysin production still needs to be further investigated and evaluated (Watanabe, 1999). On the other hand, all of the isolates in our study have revealed primarily the white-type colonies, which are reported to be more virulent than the opaque phenotype (Huang 2012;Mandelblat et al, 2017). White and opaque cells are different in terms of mating abilities and in the expression of many metabolic genes, indicating that these two types are adapted to various environments within a host (Tuch et al, 2010).…”

Modulation of the Fungal-Host Interaction by the Intra-Species Diversity of C. albicans

“…Interestingly, the source of the isolates did not seem to correlate with pathogenicity [ 10 ]. This was also true when strains were assessed in different experimental models [ 26 , 27 ]. In the OPC model, a high degree of damage induction by C. albicans strains correlated with strong inflammatory response and rapid fungal clearance, while strains inducing low epithelial cell damage triggered only a low degree of inflammation and in consequence colonized the host persistently [ 10 ].…”