[Determination of the cytotoxic action of cell fractions of Streptococcus group A on continuous human heart cells].

The work deals with the study of the cytotoxic action of the fractions of group A streptococcal cells, type 1, on human heart cells in continuous cell cultures, carried out by the method of J. L. Middlebrook and R. B. Dorland based on the determination of the protein content in the surviving monolayer cells. The addition of crude cytoplasm and the supernatant of sonicated streptococcal cell walls to human heart cell culture has made it possible to obtain a statistically significant decrease in the protein content of the remaining monolayer cells. The action of purified cytoplasm has resulted in faint statistically insignificant suppression of cell growth, thus decreasing the content of cell protein. This method of studying the cytotoxicity of streptococcal cell fractions is simple, convenient and can be used in research work.