Effect of Harvest Time of Rickettsia rickettsii from Duck Embryo Cell Cultures on Rocky Mountain Spotted Fever Infection in the Rhesus Monkey.

Abstract : This study was undertaken to determine the optimum harvest time for infected duck embryo cell (DEC) cultures to yield the highest rickettsial titers and greatest infectivity for rhesus monkeys. A consistently reproducible Rocky Mountain spotted fever-infected monkey model for pathogenesis studies and testing vaccine is produced when the inoculum given intravenously contains =1000000 chick embryo median lethal dose organisms. This is optimally attained with day-4 DEC culture harvest material. (Author)