This applies the principles of Koch's postulates.
Step-by-step explanation:
Koch's postulates explain the causative relationship between the microbe and disease. According to Koch's postulates, the disease causative agent should be separated from others. The disease causing agent must be cultured away from the host. The sample from the disease causing agent should be injected into the host. After injecting the sample, the host must get affected by the disease. The same etiologic agent must be cultured from the healthy host when it becomes sick.