Studies on the E strain of Rickettsia prowazeki.
Cultivation of E strain of Rickettsia prowazeki in mouse lung resulted in a marked increase in virulence for guinea pigs following 12 passages (but not 6 passages) in both immunosuppressed and normal mice. Attempts at passaging E strain in normal guinea pigs were unsuccessful. Isolates of E strain in the chicken embryo yolk sac either from testes and peritoneal washings or from the brain of immunosuppressed guinea pigs did not show enhanced virulence for guinea pigs.
D000818:Animals; D001431:Bacteriological Techniques; D006168:Guinea Pigs; D008297:Male; D051379:Mice; D012283:Rickettsia prowazekii / Q000302:isolation & purification / Q000472:pathogenicity*; D013045:Species Specificity; D014774:Virulence