Microbiology is that the study of microscopic organisms, like bacteria, viruses, archaea, fungi and protozoa. This discipline includes fundamental research on the biochemistry, physiology, cell biology, ecology, evolution and clinical aspects of microorganisms, including the host response to those agents. Medical microbiology, the massive subset of microbiology that's applied to medicine, may be a branch of life science concerned with the prevention, diagnosis and treatment of infectious diseases. additionally , this field of science studies various clinical applications of microbes for the development of health. There are four sorts of microorganisms that cause infectious disease: bacteria, fungi, parasites and viruses, and one sort of infectious protein called prion.