| Test | Method | Measurement | Interpretation |
| Virulence for mice | Intraperitoneal injection of bacterial suspension to observe the death rate of mice | 50 percent lethal dose: LD50 (CFU) | Highly virulent: ≤103 CFU |
| Moderate virulence: 104-105 CFU | |||
| Low virulence: 106-107CFU | |||
| No virulence: ≥108 CFU | |||
| Phagocytosis: macrophage adherence assay | Human or mouse macrophage are mixed with bacteria to quantify ingesting cells | Percent of 100 macrophages containing attached or ingested bacteria | Low-level binding: 2 to 3 percent |
| High-level binding: 8 to 13 percent | |||
| Serum resistance assay | Nonimmune human serum are incubated with bacteria to determine colony count at serial hours | Survival curve (the average survival ratio against time) | Bacteria that actively proliferate in serum are resistant to serum killing |
| Whole blood resistance | Incubate fresh mouse blood with bacterial suspension | Survival of bacteria in blood |
