In vitro evaluation of putative virulence attributes of oral isolates of Candida spp. obtained from elderly healthy individuals

Mycopathologia. 2008 Oct;166(4):209-17. doi: 10.1007/s11046-008-9139-7. Epub 2008 Jul 3.

Abstract

Identification of Candida isolates obtained from oral cavity of elderly healthy individuals revealed the predominance of non-albicans Candida species (88.9%) compared to Candida albicans (11%). CHROMagar Candida differential medium and PCR revealed the presence of Candida tropicalis (33.3%), Candida glabrata (27.8%), and Candida krusei (16.7%). We investigated the presence of virulence attributes in a total of 18 isolates, including acid protease and phospholipase production, hemolytic activity, and biofilm production. Extracellular protease was found in five isolates (27.8%) whereas extracellular phospholipase was found in three isolates (17%). All isolates showed hemolytic activity. About 56% of the isolates were weakly positive for biofilm formation (score +) whereas a minority (5.6%) of them showed strong biofilm formation (score 4+). Susceptibility in vitro of the isolates to fluconazole was carried out by microdilution method. Fluconazole showed a strong inhibition against most buccal isolates. The resistant isolates were 2 C. tropicalis, 2 C. glabrata, and 1 C. krusei.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Animals
  • Antifungal Agents / pharmacology
  • Biofilms / growth & development
  • Candida / genetics*
  • Candida / pathogenicity
  • Candida / physiology
  • Fluconazole / pharmacology
  • Fungal Proteins / genetics
  • Fungal Proteins / metabolism
  • Fungal Proteins / physiology
  • Genotype
  • Hemolysin Proteins / metabolism
  • Hemolysis
  • Humans
  • Microbial Sensitivity Tests
  • Mouth / microbiology
  • Phenotype
  • Phospholipases / genetics
  • Phospholipases / metabolism
  • Polymerase Chain Reaction
  • Sheep
  • Virulence / genetics
  • Virulence Factors / genetics
  • Virulence Factors / metabolism

Substances

  • Antifungal Agents
  • Fungal Proteins
  • Hemolysin Proteins
  • Virulence Factors
  • Fluconazole
  • Phospholipases