Hyperexpression of CDRs and HWP1 genes negatively impacts on Candida albicans virulence

PLoS One. 2021 Jun 1;16(6):e0252555. doi: 10.1371/journal.pone.0252555. eCollection 2021.

Abstract

C. albicans is a commensal organism present in the human microbiome of more than 60% of the healthy population. Transition from commensalism to invasive candidiasis may occur after a local or a general failure of host's immune system. This transition to a more virulent phenotype may reside either on the capacity to form hyphae or on an acquired resistance to antifungal drugs. Indeed, overexpression of genes coding drug efflux pumps or adhesins, cell wall proteins facilitating the contact between the fungus and the host, usually marks the virulence profile of invasive Candida spp. In this paper, we compare virulence of two clinical isolates of C. albicans with that of laboratory-induced resistant strains by challenging G. mellonella larvae with these pathogens along with monitoring transcriptional profiles of drug efflux pumps genes CDR1, CDR2, MDR1 and the adhesin genes ALS1 and HWP1. Although both clinical isolates were found resistant to both fluconazole and micafungin they were found less virulent than laboratory-induced resistant strains. An unexpected behavior emerged for the former clinical isolate in which three genes, CDR1, CDR2 and HWP1, usually correlated with virulence, although hyperexpressed, conferred a less aggressive phenotype. On the contrary, in the other isolate, we observed a decreased expression of CDR1, CDR2 and HWP1as well as of MDR1 and ALS1 that may be consistent with the less aggressive performance observed in this strain. These altered gene expressions might directly influence Candida virulence or they might be an epiphenomenon of a vaster rearrangement occurred in these strains during the challenge with the host's environment. An in-deepth comprehension of this scenario could be crucial for developing interventions able to counteract C. albicans invasiveness and lethality.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Antifungal Agents / pharmacology
  • Candida albicans / drug effects
  • Candida albicans / genetics*
  • Candida albicans / isolation & purification
  • Candida albicans / pathogenicity*
  • Candidiasis / microbiology
  • Drug Resistance, Fungal / drug effects
  • Drug Resistance, Fungal / genetics
  • Female
  • Fluconazole / pharmacology
  • Fungal Proteins / genetics*
  • Gene Expression Regulation, Fungal*
  • Gene Expression*
  • Humans
  • Hyphae / genetics
  • Larva / microbiology
  • Lepidoptera / microbiology
  • Membrane Glycoproteins / genetics*
  • Membrane Transport Proteins / genetics*
  • Micafungin / pharmacology
  • Microbial Sensitivity Tests
  • Phenotype
  • Virulence / genetics

Substances

  • Antifungal Agents
  • CDR1 protein, Candida albicans
  • Fungal Proteins
  • HWP1 protein, Candida albicans
  • Membrane Glycoproteins
  • Membrane Transport Proteins
  • Fluconazole
  • Micafungin

Grants and funding

LA, GM, BM. Grant number: RM 1181641E9150B3 Sapienza University of Rome https://wwwuniroma1.it The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.