Related Experiment Videos
Phosphatase activity among Candida species and other yeasts isolated from clinical material
Abstract:
A group of 277 yeasts isolated from burned children and 14 reference strains were tested for phosphatase activity by using phenolphthalein phosphate substrates. Phosphatase activity was widely distributed among various species and strains representing seven genera. Candida albicans, which was the most common yeast isolated from clinical material, was notably absent in producing the enzyme, whereas Candida tropicalis was the most consistent, strong, and rapidly active phosphatase-producing organism. The characteristic enzyme activity of a selected isolate of C. tropicalis was demonstrated in the presence of concentrations of inorganic phosphate which inhibited enzyme activity of other species. The greater enzyme activity of C. tropicalis was not related to more rapid or greater cell growth or decrease in the pH of culture media. Extracellular constitutive heat-labile acid phosphatase was found in broth filtrates of C. tropicalis, C. krusei, and a strain of Staphylococcus aureus.
Insights
Candida tropicalis consistently produces strong acid phosphatase, an enzyme absent in Candida albicans. This yeast enzyme activity is heat-labile and unaffected by high phosphate levels.
Area of Science:
- Medical Mycology
- Enzymology
- Clinical Microbiology
Background:
- Phosphatase activity is a key enzymatic characteristic in yeast identification and pathogenicity.
- Understanding enzyme production in yeasts isolated from clinical settings is crucial for diagnostics and treatment.
Purpose of the Study:
- To investigate and compare phosphatase activity among various yeast species, particularly those isolated from burned children.
- To identify yeast strains with significant phosphatase production, focusing on Candida tropicalis and its enzyme characteristics.
Main Methods:
- Assessed phosphatase activity in 277 yeast isolates from burned children and 14 reference strains using phenolphthalein phosphate substrates.
- Characterized the enzyme activity of Candida tropicalis isolates, including their response to inorganic phosphate concentrations and growth conditions.
- Analyzed extracellular acid phosphatase in broth filtrates using heat-labile assays.
Main Results:
- Phosphatase activity was prevalent across seven yeast genera, with notable variation among species and strains.
- Candida albicans, a common clinical isolate, showed no phosphatase activity, while Candida tropicalis exhibited consistent, strong, and rapid production.
- Candida tropicalis enzyme activity persisted at high inorganic phosphate levels that inhibited other species; activity was independent of growth rate or pH.
Conclusions:
- Candida tropicalis is a significant producer of constitutive, heat-labile acid phosphatase, distinguishing it from other yeasts like Candida albicans.
- The unique enzymatic profile of Candida tropicalis, particularly its high phosphate tolerance, warrants further investigation for clinical relevance.
- Extracellular acid phosphatase was identified in broth filtrates of Candida tropicalis, Candida krusei, and Staphylococcus aureus.