Figure 5.

The survival of enzyme‐treated bacteria by serum killing. Bacterial susceptibility to killing by human serum of two serum‐resistant strains, 2283219(KN3) and 2139670(KN4), with or without enzyme pretreatment was presented. Survival ratio indicates per cent survival of bacteria after 3 h of incubation with serum (viable counts relative to initial inoculum). Three independent experiments were performed, and the survival rates of the two groups, control and enzyme pretreated groups (shown as enz‐), were compared by Student's t‐test analysis. **P < 0.01; ***P < 0.001.