Figure 6.
Analysis of survival of the HPS5 and Δcrp strains in 50 and 90% swine serum. For the 50% serum bactericidal assay, 100 μl of bacterial suspension (~1 × 108 CFU/ml) was mixed with 100 μl of either fresh or inactivated swine serum. For the 90% serum bactericidal assay, 20 μl of bacterial suspension (~1 × 107 CFU/ml) was mixed with 180 μL of either fresh or inactivated swine serum and then incubated at 37°C for 1 h. The proportion of bacteria surviving was calculated by the ratio of colonies in fresh serum to those in heat-treated serum. **p < 0.01.