Title:Effect of Treatment with Caspofungin on the Diagnosis of Fungal Infections by Gamma Scintigraphy
Volume: 10
Issue: 2
Author(s): Leticia Gabriela Fernández González, Ana Laura Reyes Veiga, Patricia Oliver and Mariella Terán Gretter*
Affiliation:
- Cátedra de Radioquímica, Departamento Estrella Campos, Facultad de Química, Universidad de la República-Uruguay, Montevideo,Uruguay
Keywords:
Radiopharmaceuticals, infection diagnosis, scintigraphy, 99mTc, Caspofungin, nude mice, Candida albicans,
Staphylococcus aureus.
Abstract: The aim of this work was to assess the influence of treatment with U-Caspofungin, on the
quality of diagnostic scintigraphic images of induced lesions in nude mice undergoing both bacterial
and fungal infections and to determine the level of specificity of 99mTc-tricarbonyl-Caspofungin to
discriminate between fungal or bacterial infections.
In vitro studies on the behaviour of the 99mTc-tricarbonyl-Caspofungin complex binding percentage at
different yeast concentrations of Candida albicans or Staphyolococcus aureus were determined. The
incubation was performed with and without U-Caspofungin.
In vivo evaluation was performed of 6
groups of athymic mice: sham, inflammation (LPS), fungal infection with Candida albicans (CA) and
bacterial infection with Staphylocuccus aureus (SA).
In vitro studies showed that the uptake of the complex by both yeasts and bacteria, depends on the concentration
of colony forming units (cfu), and that this uptake is favoured by the presence of UCaspofungin
that increases the membrane permeability to the 99mTc-tricarbonyl-Caspofungin complex.
In vivo evaluation showed low uptake in sterile inflammation model and moderate to high uptake
in infections models both treated or not with U-Caspofungin. The results of biodistributions were compatible
with scintigraphic images.
Conclusion: The uptake of the complex depends on the load of microorganisms, but it presents high
sensibility, even at low concentrations of the infecting agent. The treatment with U-Caspofungin has no
influence on the quality of the scintigraphic images used for diagnosis and localization of infection
foci.
