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Updated: Sep 1, 2026
Generation of Fluorescent Protein Fusions in Candida Species
Published on: March 4, 2017
[Biological features and experimental pathogenicity of Candida strains isolated by hemoculture at the Hospital
M L Ramírez Aguilar1, A Pérez Miravete, J I Santos Preciado
1Departamento de Bacteriología e Infectología, Hospital Infantil de México Federico Gómez.
Abstract:
In a period of 15 months (1990-1991) it was carried out 5781 blood cultures in which 180 strains of yeast-like were isolated. 116 of these strains were selected for biochemical classification, cellular and colonial morphology and experimental determination of virulence in mice. Most of the strains were classified as Candida albicans (60%) and the others were C. tropicalis (15.5%); C. guillermondii (10.3%); T. glabrata (6.8%); Rhodotorula rubra (3.4%); Cryptococcus neoformans (2.58%) y C. parapsilosis (0.86%). C. albicans ATCC14053, y C. tropicalis ATCC14056 and T. glabrata ATCC15545 were employed as controls. The virulence test was performed using mice of 20-30 gr (4-6 weeks age) by intravenous injection in caudal vein with 0.5 ml of different suspension from 10(5) to 10(9) CFU/ml. Observation time was 10 days. Target organ was kidney by macro and microscopic observation of micro-abscess death. LD50 was estimated by the Reed-muench method. Intraspecific and interspecific differences were observed. It is more valid if we take into account that the experiment was done in homogenous population of host without risk factor which influences the human population in hospitals. Experimental virulence was compared with the evolution of diseases in the human host of which the strain was isolated.
Insights
This study isolated 180 yeast strains from blood cultures, with Candida albicans being the most common. Experimental virulence in mice revealed intraspecific and interspecific differences among these fungi.
Area of Science:
- Medical Mycology
- Infectious Diseases
- Experimental Pathology
Background:
- Bloodstream infections caused by yeast-like fungi pose a significant clinical challenge.
- Accurate identification and virulence assessment are crucial for understanding and managing these infections.
Purpose of the Study:
- To classify yeast strains isolated from blood cultures.
- To determine the experimental virulence of these yeast strains in a murine model.
- To compare experimental virulence with clinical observations.
Main Methods:
- Isolation and identification of 116 yeast strains from 5781 blood cultures.
- Biochemical and morphological characterization of isolates.
- Virulence testing in mice via intravenous injection, determining LD50 using the Reed-Muench method.
Main Results:
- Candida albicans (60%) was the predominant species, followed by Candida tropicalis (15.5%).
- Significant intraspecific and interspecific variations in virulence were observed among the tested yeast strains.
- Kidney micro-abscesses and mortality were used to assess virulence and target organ damage.
Conclusions:
- The study highlights the diversity of yeast species causing fungemia and their varying pathogenic potentials.
- Experimental virulence in a controlled host model provides insights into fungal pathogenicity.
- Findings contribute to understanding yeast-like fungal infections and inform clinical management strategies.
