Flow cytometric assay for estimating fungicidal activity of Amphotericin B in human serum

✍ Scribed by Edith Martin; Ute Schlasius; Sucharit Bhakdi

• Publisher: Springer-Verlag
• Year: 1992
• Tongue: English
• Weight: 615 KB
• Volume: 181
• Category: Article
• ISSN: 0300-8584
• DOI: 10.1007/bf00202051

✦ Synopsis

We describe a simple and rapid bioassay for estimating fungicidal activity of Amphotericin B in human serum using flow cytometry. The method exploits the fact that Candida albicans damaged by Amphotericin B show a decrease in size and take up propidium iodide to exhibit a red fluorescence after deoxycholate treatment. These phenomena display characteristic dose dependencies, and their assessment permits serum fungicidal activity to be broadly grouped into three categories: (1) subfungicidal; (2) fungicidal; and (3) strongly fungicidal. In normal human serum, these three categories correspond to Amphotericin B concentrations of 0 less than or equal to 0.5 micrograms/ml, 0.75-1.5 micrograms/ml, and greater than 2 micrograms/ml, respectively. Pilot analysis of serum samples obtained from four patients undergoing Amphotericin B therapy confirmed the feasibility of using the flow cytometric assay for estimating drug fungicidal activity ex vivo. The method is very simple, generates results within 5 h, and could prove useful for monitoring therapy with this effective but toxic drug.