A Candida parapsilosis Overexpression Collection Reveals Genes Required for Pathogenesis

Abstract

Relative to the vast data regarding the virulence mechanisms of Candida albicans, there is limited knowledge on the emerging opportunistic human pathogen Candida parapsilosis. The aim of this study was to generate and characterize an overexpression mutant collection to identify and explore virulence factors in C. parapsilosis. With the obtained mutants, we investigated stress tolerance, morphology switch, biofilm formation, phagocytosis, and in vivo virulence in Galleria mellonella larvae and mouse models. In order to evaluate the results, we compared the data from the C. parapsilosis overexpression collection analysis to the results derived from previous deletion mutant library characterizations. Of the 37 overexpression C. parapsilosis mutants, we identified eight with altered phenotypes compared to the controls. This work is the first report to identify CPAR2_107240, CPAR2_108840, CPAR2_302400, CPAR2_406400, and CPAR2_602820 as contributors to C. parapsilosis virulence by regulating functions associated with host-pathogen interactions and biofilm formation. Our findings also confirmed the role of CPAR2_109520, CPAR2_200040, and CPAR2_500180 in pathogenesis. This study was the first attempt to use an overexpression strategy to systematically assess gene function in C. parapsilosis, and our results demonstrate that this approach is effective for such investigations.

Transcriptome and proteome profiling reveals complex adaptations of Candida parapsilosis cells assimilating hydroxyaromatic carbon sources

“…The gene expression analysis was performed in the strain CLIB214 (CBS604), which is, together with derived mutants, commonly used in experimental studies [e.g. 15 – 18 ]. This strain was originally isolated from a patient with tropical diarrhea in Puerto Rico [ 19 ] and it represents the type strain of C .…”

Transcriptome and proteome profiling reveals complex adaptations of Candida parapsilosis cells assimilating hydroxyaromatic carbon sources

“…The gene expression analysis was performed in the strain CLIB214 (CBS604), which is together with derived mutants commonly used in experimental studies (e.g. [15][16][17][18]. This strain was originally isolated from a patient with tropical diarrhea in Puerto Rico (19) and it represents the type strain of C. parapsilosis.…”

Lack of Functional Trehalase Activity in Candida Parapsilosis Increases Susceptibility to Itraconazole

“…The correct disruption of both individual genes was also confirmed by the higher basal content of endogenous trehalose recorded in the mutant (Table 2). These azoles were chosen because the relevant C. parapsilosis strains display lower in vitro susceptibility to echinocandins with high MIC values [9] and azoles are recommended as preferred therapeutic antifungals [5][6][7].…”

“…Although Candida albicans remains the most prevalent species of Candida responsible for both superficial and invasive candidiasis, which mainly affects the immunodebilitated population [1-3], another group of opportunistic yeasts belonging to the genus Candida and referred to as "non-albicans" has emerged in recent years as responsible of numerous nosocomial outbreaks [3,4]. The taxonomical complex C. parapsilosis has an increasing clinical incidence, being the second or third most frequently isolated, depending on the geographic region studied [5][6][7]. As a matter of fact, although infections caused by C. parapsilosis generally have lower morbidity and mortality rates than C. albicans, they pose a serious threat in patients undergoing intensive surgery and in those harboring catheters and other implants, due to the formation of tenacious biofilms [5][6][7][8].…”