Medical microbiology is a branch of medical science concerned with the prevention, diagnosis and treatment of infectious diseases. In addition, this field of science studies various clinical applications of microbes for the improvement of health.

There are four kinds of microorganisms that cause infectious disease: bacteria, fungi, parasites and viruses and one type of infectious protein called a prion.

The subject uses illustrations from the bacterial and immunological diseases of the humans that play an important role in understanding medicine and health care.