title: Reproduction of vaccine and virulent Rickectsia prow azeki strains in continuous cell lines at different temperatures.
abstract: 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. In contrast to the virulent Breinl strain the vaccine E strains have lost their capacity of long term reproduction at 38.5 degrees C. At 40 degrees C the E strains did not multiply in and had been eliminated from the McCoy and B cells; thus the vaccine E strains revealed a ts-phenotype and, accordingly, it was found to represent a ts-mutant.
mesh_terms: D000818:Animals; D002460:Cell Line; D002642:Chick Embryo; D012283:Rickettsia prowazekii / Q000254:growth & development* / Q000276:immunology / Q000472:pathogenicity; D012290:Rickettsial Vaccines / Q000032:analysis*; D013696:Temperature; D013997:Time Factors; D014612:Vaccines / Q000032:analysis*
chemical_list: D012290:Rickettsial Vaccines; D014612:Vaccines