Table 3 The LD50 of strains APEC94 and APEC94Δlsr(Cm)
From: Lsr operon is associated with AI-2 transfer and pathogenicity in avian pathogenic Escherichia coli
APEC strains | Challenge dosage | No. of ducks | Mortality | Living No. | Mortality rate (%) | LD50 (CFU) |
|---|---|---|---|---|---|---|
APEC94 | 109 | 8 | 8 | 0 | 100 | 8.66 × 105 |
108 | 8 | 7 | 1 | 87.5 | ||
107 | 8 | 7 | 1 | 87.5 | ||
106 | 8 | 4 | 4 | 50 | ||
105 | 8 | 2 | 6 | 25 | ||
APEC94Δlsr(Cm) | 109 | 8 | 7 | 1 | 87.5 | 2.55 × 108 |
108 | 8 | 2 | 6 | 25 | ||
107 | 8 | 1 | 7 | 12.5 | ||
106 | 8 | 0 | 8 | 0 | ||
105 | 8 | 0 | 8 | 0 |