Rapid Microdilution-Colorimetric Assay for Yeast Susceptibility to Fluorocytosine

Rapid microdilution-colorimetric assay for yeast susceptibility to fluorocytosine.

Acid production by certain yeast species through the fermentation of glucose was used as the basis of an in vitro test for measuring susceptibility of these organisms to 5-fluorocytosine. Serial dilutions of 5-fluorocytosine in yeast nitrogen base broth, with bromothymol blue indicator dye, were made on microtiter plates. A fixed-concentration suspension of yeast cells was added to successive w...

Rapid colorimetric assay for antimicrobial susceptibility testing of Pseudomonas aeruginosa.

A colorimetric assay based on the reduction of a tetrazolium salt [2,3-bis[2-methyloxy-4-nitro-5-sulfophenyl]-2H-tetrazolium-5-carboxanilide (XTT)] for rapidly determining the susceptibility of Pseudomonas aeruginosa isolates to bactericidal antibiotics is described. There was excellent agreement between the tobramycin and ofloxacin MICs determined after 5 h using the XTT assay and after 18 h u...

Multisite reproducibility of colorimetric broth microdilution method for antifungal susceptibility testing of yeast isolates.

MICs of fluconazole and amphotericin B were determined independently for 100 coded yeast isolates by each of six laboratories to determine reproducibility of results by using a colorimetric oxidation-reduction-based broth microdilution test. In addition, each site tested five quality control isolates on at least four different occasions during the study. Results agreed within a three-dilution r...

Colorimetric Assay for Antifungal Susceptibility

Use of a colorimetric system for yeast susceptibility testing.

We examined the reliability and accuracy of a colorimetric assay using Alamar Blue reagent in the performance of susceptibility tests for Candida albicans. We compared the broth macrodilution method recommended by the National Committee for Clinical Laboratory Standards (NCCLS) with a macrodilution method modified with the Alamar reagent and a microdilution method modified with the Alamar reage...