title: Candida glabrata and Candida albicans co-infection of an in vitro oral epithelium.
abstract: BACKGROUND
  Candida albicans is regarded as the leading of candidosis. However, Candida glabrata has emerged as an important pathogen of oral mucosa, occurring both singly or in mixed species infections, often with C. albicans. Compared with C. albicans, little is known about the role of C. glabrata in oral infection. The aim of this study was to examine single and mixed species infection of oral epithelium involving C. glabrata and establish its ability to invade and damage tissue.
  
  
  METHODS
  A reconstituted human oral epithelium (RHOE) was infected only with C. glabrata, or simultaneously with C. glabrata and C. albicans. The ability of both species to invade the tissue was examined using species specific peptide nucleic acid (PNA) probe hybridization and confocal laser scanning microscopy. Epithelial damage was assessed by measuring lactate dehydrogenase (LDH) activity.
  
  
  RESULTS
  Candida glabrata strains were able to colonize the RHOE, in a strain dependent manner. Candida glabrata single infection after 12 h, generally revealed no invasion of the RHOE, which contrasted with extensive tissue invasion demonstrated by C. albicans. Mixed infection showed that C. albicans enhanced the invasiveness of C. glabrata, and led to increased LDH release by the RHOE, which paralleled the observed histological damage.
  
  
  CONCLUSIONS
  The results obtained demonstrating enhanced invasion and increased tissue damage caused by mixed C. glabrata and C. albicans infections have important clinical significance and highlight the need to identify Candida species involved in oral candidosis.
authors.affiliation: Institute for Biotechnology and Bioengineering, Universidade do Minho, Campus de Gualtar 4710-057, Braga, Portugal.
authors.forename: Sónia
authors.initials: S
authors.lastname: Silva
authors.forename: Mariana
authors.initials: M
authors.lastname: Henriques
authors.forename: Anthony
authors.initials: A
authors.lastname: Hayes
authors.forename: Rosário
authors.initials: R
authors.lastname: Oliveira
authors.forename: Joana
authors.initials: J
authors.lastname: Azeredo
authors.forename: David W
authors.initials: DW
authors.lastname: Williams
mesh_terms: D000704:Analysis of Variance; D002176:Candida albicans / Q000235:genetics / Q000302:isolation & purification / Q000472:pathogenicity; D041221:Candida glabrata / Q000235:genetics / Q000302:isolation & purification / Q000472:pathogenicity; D002180:Candidiasis, Oral / Q000382:microbiology* / Q000473:pathology; D045744:Cell Line, Tumor; D004848:Epithelium / Q000382:microbiology / Q000473:pathology; D006801:Humans; D015603:Keratinocytes / Q000382:microbiology / Q000473:pathology; D045022:Lactate Dehydrogenases / Q000032:analysis; D018613:Microscopy, Confocal; D009061:Mouth Mucosa / Q000382:microbiology* / Q000473:pathology; D018709:Statistics, Nonparametric; D015163:Superinfection / Q000382:microbiology* / Q000473:pathology; D046509:Tissue Culture Techniques
chemical_list: D045022:Lactate Dehydrogenases