title: Persistence of Rickettsia prowazekii with different initial biological properties in infected cotton rats.
abstract: Evidence has been obtained indicating the association of certain biological properties of Rickettsia prowazekii with their capacity for persistence. Highly virulent rickettsial cultures inducing increased levels of complement-fixing antibodies were shown to cause a high percentage of rickettsial carriers in infected cotton rats. Within an interval of 133-189 days after inoculation with the virulent Breinl strain, rickettsial carrier-state was still demonstrable in 20% of the animals. The vaccine strain E of R. prowazekii had a low capacity for persistence in cotton rats, because 64 days after inoculation all animals were found free of rickettsiae.
mesh_terms: D000818:Animals; D000907:Antibodies, Bacterial / Q000032:analysis; D003411:Arvicolinae; D002353:Carrier State / Q000382:microbiology; D008297:Male; D012283:Rickettsia prowazekii / Q000276:immunology / Q000302:isolation & purification*; D014438:Typhus, Epidemic Louse-Borne / Q000382:microbiology*
chemical_list: D000907:Antibodies, Bacterial