Table 1. Median lethal dose of F. tularensis LVS and derivatives in OS cockroaches and wax worms.
The median lethal dose (LD50) of F. tularensis LVS parental strains, LVS-1 or LVS-2, and deletion mutants of those LVS strains lacking known virulence factors, and E. coli DH5α. LD50 and corresponding 95% confidence intervals were estimated by non-linear regression using the ‘drc’ package in the R programming environment (Version 3.2.1).
| Strain | Host | Temperature | LD50 (95% Cl), CFU |
|---|---|---|---|
| F. tularensis LVS-1 | Juvenile cockroaches | 22°C | 3.2 × 106 (5.6 × 105−1.2 × 107) |
| Juvenile cockroaches | 30°C | 2.9 × 105 (4.6 × 104−1.8 × 106) | |
| Juvenile cockroaches | 37°C | 3.5 × 104 (1.1 × 104−1.0 × 105) | |
| Juvenile cockroaches | 40°C | 1.2 × 104 (4.2 × 103−3.3 × 104) | |
| Adult female cockroaches | 37°C | 5.4 × 104 (9.7 × 103−3.0 × 105) | |
| Adult male cockroaches | 37°C | 1.3 × 103 (4.0 × 102−4.2 × 103) | |
| F. tularensis LVS-1 ΔdsbA | Juvenile cockroaches | 37°C | 2.2 × 106 (1.0 × 106−4.7 × 106) |
| F. tularensis LVS-1 ΔdipA | Juvenile cockroaches | 37°C | 8.1 × 105 (4.0 × 105−1.6 × 106) |
| F. tularensis LVS-2 | Juvenile cockroaches | 37°C | 1.7 × 104 (6.7 × 103−4.4 × 104) |
| F. tularensis LVS-2 ΔiglC | Juvenile cockroaches | 37°C | 1.3 × 106 (2.8 × 105−5.7 × 106) |
| F. tularensis LVS-2 ΔdeoB | Juvenile cockroaches | 37°C | 5.6 × 105 (2.1 × 105−1.8 × 106) |
| E. coli DH5α | Juvenile cockroaches | 37°C | 8.7 × 106 (3.0 × 106−2.5 × 107) |