Faculty Collaboration Database

Comparison of fungal viability assays using Candida albicans yeast cells undergoing prolonged incubation in the absence of nutrients. Mycoses 1998 Dec;41(11-12):487-92

Date

01/27/1999

Pubmed ID

9919892

DOI

10.1111/j.1439-0507.1998.tb00711.x

Scopus ID

2-s2.0-0032435944 (requires institutional sign-in at Scopus site)   13 Citations

Abstract

Staining methods for determining fungal viability are usually assessed by comparisons with enumeration of colony-forming units (CFU) on solid media. The purpose of the present study was to compare viability as assessed by the acridine orange (AO) and MTT methods with the numbers of CFUs obtained for Candida albicans yeast cells undergoing prolonged incubation in distilled water. In initial assessments of the assays using various proportions of control and heat-killed C. albicans, the AO and MTT methods consistently indicated significantly higher values for viability than did CFU determinations. Experiments using organisms cultured overnight revealed that approximately 95% of the cells were capable of dividing at least once in a microscopic proliferation assay, whereas only 69% were capable of forming colonies. Parallel assays comparing AO uptake and MTT reduction gave excellent agreement with the microscopic proliferation assay, but not with CFU determinations. Using organisms undergoing prolonged incubations in distilled water, much lower viabilities were obtained with the CFU method at 7 and 10 days than with the microscopic proliferation assay or the two staining methods. These results indicate that the AO and MTT assays correlate well with the ability of C. albicans to divide at least once, but may not accurately indicate the percentage of organisms actually able to form colonies.

Author List

Hjertstedt J, Hahn BL, Kos WL, Sohnle PG

Author

Peter G. Sohnle MS, MD Emeritus Professor in the Medicine department at Medical College of Wisconsin

MESH terms used to index this publication - Major topics in bold

Acridine Orange
Candida albicans
Colony Count, Microbial
Mycology
Tetrazolium Salts
Thiazoles
Water