TABLE 2.
Virulence assay of Y. pestis Angolaa
| Assay and infection method | Inoculum (CFU) | TTD (days) | L/T |
|---|---|---|---|
| Swiss Webster mice LD50 | |||
| Aerosol challenge | 3.6 × 104 | 7.6 (8,000 CFU) | 25/50 |
| Subcutaneous challenge | 1,153 | 7.6 (8,000 CFU) | 25/50 |
| Pathogenic potential in mice and guinea pigs (intradermal challenge) | |||
| BALBc/inbred mice | 102 | 8 | 6/18 |
| 106 | 8.7 | 18/18 | |
| Hartley guinea pigs | 102 | NA | 0/18 |
| 106 | NA | 0/18 |
a
The virulence of Y. pestis Angola was assayed in two laboratory rodent models following subcutaneous, intradermal, and aerosol challenge. Relative virulence was determined by lethality and mean time to death for each dose. L/T, observed lethality/total number of animals infected; TTD, mean time to death postexposure; NA, not applicable.