TABLE 1.
Effects of transmission route on virulence of caf-negative Y. pestis
| Y. pestis strain | LD50 by transmission routea:
|
||
|---|---|---|---|
| i.v. | i.d. | Flea bite | |
| Wild type | <10 (<10) | 46 (66 ± 21) | 8/10 |
| Δcaf1M1A1 | <12 (<12) | 55 (86 ± 48) | 4/10 |
a
LD50 values measured using the Reed-Muench equation and (in parentheses) the Probit method (95% confidence interval) are given for intravenous (i.v.) and i.d. injection, and disease incidence is given for fleabite transmission (number of mice that developed terminal disease/number of mice challenged).