Medical microbiology is a branch of medical science and deals with studies on microbiology applied to medicine. It is 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 diseases such as bacteria, fungi, parasites and viruses, and one type of infectious protein called prion. A medical microbiologist studies the characteristics of pathogens, their modes of transmission, mechanisms of infection and growth. Based on this information, a treatment can be devised. Medical microbiologists often serve as consultants for physicians, providing identification of pathogens and suggesting treatment options. Other tasks may include the identification of potential health risks to the community or monitoring the evolution of potentially virulent or resistant strains of microbes, educating the community and assisting in the design of health practices.