Background: The aim was the investigation of fungal colonization and morphological alterations under the influence of voriconazole in an in-vitro system. Methods: We looked on the colonization and morphology of Candida albicans (SC5314) in RPMI at cover slips in 24 wells micro titer plates. The growth forms were directly represented on the glass surface by fluorescence staining with the optical brightener Blancophor® (Bayer Ltd.) and by vital staining with FUN 1 (Molecular Probes). Results: In the control trial germination and micro-colony formation started after 2 - 4 h. Hyphal forms developed. 6 - 8 h later. We saw a strong colonization in micro-colonies on the cover glass. After the input of voriconazole (2 or 16 mg/l) the growth of C. albicans stopped. On the short mycelia a ramification like an antler was seen. The intensity of voriconazole influence depended on the time of drug input after starting of growth (1 - 4 h). It was stronger under anaerobic growth conditions. In every case the colonization on cover glass was diminished, no formation of micro-colonies. Sometimes only few short fragments of mycelia were to be seen. Blastospores and mycelia were swollen showing a disturbance of the cell membrane and/or cell wall. Staining with FUN 1 resulted in orange-fluorescent structures in the controls of mycelial and yeast cells. This pointed to metabolic activities. After 8 - 24 h lasting influence of voriconazole the cell count and the adherent cells were strongly diminished and the remaining cells showed a green or pale yellow fluorescence. That means a loss of metabolic activities. Conclusions: Voriconazole stops the growth and colonization of C. albicans and produces deformed hyphae or cell detritus. Both blastospores and mycelia are swollen. These effects are stronger under anaerobic conditions. Specific staining with FUN 1 shows a reduction of metabolic activities.
Full conference title:
42nd Interscience Conference on Antimicrobial Agents and Chemotherapy
- ICAAC 42nd