Most microbes are beneficial; and like humans (most are good people) I am sorry to say the "bad ones" often get the most attention and notoriety. Early in your study of microbiology, it is important to understand some of the important activities of microbes.

Students in health-related science majors are aware that microbes are used in the medical fields. Microbes are used to make vaccines (attenuated or weak/dead microbes) which can be injected or inoculated into a host organism to stimulate the production of blood substances (called antibodies) to insure future protection against the possible contact with an unwanted microbe. Vaccines are most often produced by using attenuated viruses or bacteria. Later in the course we will discuss vaccination series such as MMR and DPT. A second important medical use of microbes involves the production of antibiotics like penicillin and bacitracin. Antibiotics are molecules produced by bacteria and molds (or talented chemists) that can be injected, taken orally, or occasionally used topically to inhibit new growth of bacteria. Transferring genes (usually by a loose strand of DNA called a plasmid) cells can be directed to produced needed substances like insulin and erythropoeitin (hormone needed for development of red blood cells). This bio-engineering is an exceptionally important use of microbes in modern science.