Quantitative Comparisons of Responses of Cotton Rats and Albino Mice to Measured Doses of Epidemic Typhus Rickettsiae

[摘要] On the basis of titrations, dosage-response curves were obtained for three types of response to viable epidemic typhus rickettsiae: acute lethal toxic effect in mice, lethal infection in cotton rats, and immunity in cotton rats. The following approximate relationships were revealed: one mouse LD50 equals 101 cotton rat LD50 or 106.5 cotton rat ID50; one cotton rat LD50 equals 105.5 cotton rat ID50. A dose which kills one hundred per cent of mice by an acute toxic effect contains at least one lethal infective dose for cotton rats when administered by the intracardial route. These observations are discussed in relation to the problem of detecting and measuring immunity by a challenge of test cotton rats.

[学科分类] 生物科学（综合）