What is the primary purpose of Koch's postulates?

The primary purpose of Koch's postulates is to determine the cause of infections. Developed by Robert Koch in the late 19th century, these postulates provide a systematic method for linking specific pathogens to specific diseases. The four criteria outlined in Koch's postulates help establish a causal relationship between a microbe and a disease, allowing scientists and health professionals to identify the microbial agents responsible for infectious diseases.

Koch's postulates pioneered the field of microbiology by encouraging researchers to prove that a pathogen is the cause of a particular disease rather than just being present in the host. While the other options, such as describing bacterial structures, promoting vaccination, or identifying viruses, are significantly important in the field of microbiology and public health, they don't capture the specific intent of Koch's postulates, which is centered on establishing causation between infectious agents and disease.