Bliss JM et al. – Individual isolates of Candida species vary in their virulence properties. Strains with higher virulence are associated with certain clinical outcomes.Methods
- Clinical isolates were studied from 2 populations of premature infants, those colonized with Candida spp (commensal; n = 27) and those with invasive candidiasis (n = 81).
- Individual isolates of C albicans and C parapsilosis were tested for virulence in 3 assays: phenotypic switching, adhesion, and cytotoxicity.
- Invasive isolates were considered to have enhanced virulence if detected at a level >1 SD above the mean for the commensal isolates in at least one assay.
- Outcomes of patients with invasive isolates with enhanced virulence were compared with those with invasive isolates lacking enhanced virulence characteristics.
- Enhanced virulence was detected in 61% of invasive isolates of C albicans and 42% of invasive isolates of C parapsilosis.
- All C albicans cerebrospinal fluid isolates (n = 6) and 90% of urine isolates (n = 10) had enhanced virulence, compared with 48% of blood isolates (n = 40).
- Infants with more virulent isolates were younger at the time of positive culture and had higher serum creatinine levels.