Reproduction of vaccine and virulent Rickectsia prow azeki strains in continuous cell lines at different temperatures.

The features of intracellular development of the virulent Breinl strain and 3 vaccine E strains of Rickettsia prowazeki have been followed in continuous FL, McCoy, and B cell cultures at temperatures of 30, 35, 37, 38.5 and 40 degrees C. The virulent Breinl strain multiplied well at these temperatures in McCoy and B cells but in had been gradually lost when cultured at 40 degrees C in FL cells.

Quantitative study on the reproduction of virulent and vaccine Rickettsia prow azeki strains in cells of different origin.

Vaccine and virulent strains of Rickettsia prowazeki differ by the degree of reproduction in McCoy, B, and chick embryo cells but replicate to similar levels in FL cells. As distinct from the virulent Breinl strain, the vaccine E strain rickettsiae permanently lost their capacity for long-term reproduction in McCoy cell cultures but retained their capacity to adsorb on to and penetrate into these cells. Consequently, the reproduction of rickettsiae is limited at later stages of intracellular infection.

[Intracellular development of Rickettsia].

Microcinematography, cytological and cytochemical studies revealed new features of D. sibericus, D. murinus, and R.