IN VIVO PASSAGE OF CANDIDA ALBICANS RESULTS IN PHENOTYPIC VARIANTS WITH DIFFERING VIRULENCE POTENTIAL

Cheng SJ, Clancy CJ, Nguyen MH

Author address: 

University of Florida College of Medicine, Gainesville, USA

Abstract: 

We previously reported on 5 patients who relapsed with candidemia at least 1 month after receiving apparently successful treatment. In each case, molecular typing and antifungal susceptibility testing confirmed that the original and recurrent strains were identical. Nevertheless, 4/5 patients died, leading us to hypothesize that the strains might have become more virulent with persistent exposure to the host environment. Indeed, serial passage of bacteria and viruses in animal hosts leads to adaptive responses that increase replicative capacity and virulence. To investigate this possibility in C. albicans, we infected ICR mice intravenously with 1x105 CFU of SC5314. Organisms (designated KidneyPassage1) were recovered from the kidneys of moribund mice by growing onto SDA plates with antibiotics, and inoculated into a new set of mice. The organisms were again recovered from the kidney (KidneyPassage2), and four additional passages were performed (KidneyPassages3-6). Similarly, organisms from the liver and spleen were recovered from the original infection with SC5314 and serially passed (LiverPassages1-6 and SpleenPassages1-6, respectively). Passage of C. albicans through the kidney and liver resulted in heightened virulence: mice infected with KidneyPassages4-6 and LiverPassages4-6 survived a median of 7 days, compared to 18 days for mice infected with SC5314, KidneyPassages1-3 and LiverPassages1-3 (p
2004

abstract No: 

none

Full conference title: 

14th Annual Focus on Fungal Infections
    • FFI 14th (2004)