Analysis of the cytotoxic properties of collection strains of coccidioidomycosis causative agents

Tereshko D.L., Novitskaya I.V.

Federal Government Health Institution «Volgograd Plague Control Research Institute» of the Federal Service for Surveillance in the Sphere of Consumers Rights Protection and Human Welfare, Volgograd, Russia

Introduction. C. immitis and C. posadasii are primary pathogens and are of reasonable interest in terms of their biological properties and, in particular, cytotoxic characteristics.
Aim. To study the cytotoxicity of strains of coccidioidomycosis causative agents using the MTT test on in vitro models of cell lines.
Materials and methods. Strains Coccidioides spp. were cultivated in a nutrient medium intended for cell lines. Cultures Wehi 3 and HEp-2 were exposed to sterile filtrates of the growth medium of causative agents of coccidioidomycosis in various dilutions, followed by measuring the mitochondrial activity of cells in the MTT-assay on day 4. The cytotoxic properties of fungi of the genus Coccidioides were assessed by calculating the cytotoxic concentration (СС50) of the metabolic products of micromycetes.
Results. The most adequate cell model was selected, as well as the conditions for setting the MTT test for the in vitro study of the cytopathogenic effects of micromycetes of the genus Coccidioides were worked out. It was found that the strains Coccidioides spp. have different intensities of metabolite production, which, in turn, does not directly correlate with their cytotoxicity. By calculating the cytotoxic concentration (CC50), data were obtained on the cytotoxic properties of 7 collection strains of coccidioidomycosis pathogens in the mycelial growth phase.
Conclusion. Based on the results of assessing the mitochondrial activity of cells of the lines Wehi 3 and HEp-2, the pronounced cytotoxic properties of the collection strains of coccidioidomycosis causative agents, which were subcultured in vitro for a long time, were confirmed.