History of Microbiology PDF

Eukaryotic Microbes - Fungi - Yeast - Mold - Mushrooms - Protozoa- Plasmodium - Algae - Viruses - Composed of genetic material (DNA or RNA), protein shell, and sometime wrapped with a lipid envelope - Nonmetabolic - Unable to reproduce in...

Eukaryotic Microbes - Fungi - Yeast - Mold - Mushrooms - Protozoa- Plasmodium - Algae - Viruses - Composed of genetic material (DNA or RNA), protein shell, and sometime wrapped with a lipid envelope - Nonmetabolic - Unable to reproduce independently - Invade cells to produce new viruses - Viruses are non-cellular microbes Representative (Average) Sizes of Microbes A close-up of a microscope Description automatically generated Other Challenges with the Microbe Definitions - Some microbes form: - Biofilms -- made of cells with different functions - Mycelia filamentous growth - Some protozoa and algae can be seen with a naked eye - Some animas, mites and roundworms, can't be seen with a naked eye -- **not microbes** Microbes Shape Human History - Microbes are key in maintaining life - Fix nitrogen, release oxygen, degrade and build organic matter - Ferment many foods products - "Rock-eating" bacteria leach metals from ores - Microbial produced acid can destroy cultural artifact - Smallpox, Bubonic plague, Tuberculosis, HIV/AIDS, Covid-19 are example in history where virus was spread - Robert Hooke builds the first compound microscope - Anton van Leeuwenhoek observed bacteria with a single lens microscope - It took 200 years before a connection was made between microbes and human diseases Medical Microbiology and Immunology Correlating Infectious Disease with Morality - Germ theory: Specific diseases are caused by microscopic "germs" - Disease is common in overcrowded areas like cities and during warefare - Florence Nightingale demonstrated the significance of morality due to infectious disease Proving the "Germ Theory" of Disease - Robert Koch developed the first scientific method for establishing the microbial cause of a disease - He was asked to investigate why the cattle was dying of anthrax Establishing the Cause of an infectious Disease: Four Criteria - Koch's Postulates: used to establish that Bacillus anthracis causes anthrax - Microorganisms must be present in every case of disease -- association - Organisms must be grown in pure culture from diseased host -- isolation - Same disease must be produced when pure culture is introduced into susceptible hosts- causation - Organisms must be recovered from experimentally infected hosts- re-isolating - Limitations - Not everyone has symptoms (Cholera, HIV) - Some organisms cannot be grown in a lab (Syphilis) - Some diseases are polymicrobial (periodontal disease) - Suitable animal host not always available for testing (HIV) Controlling Infectious Diseases - Prevent - Immunization - Identity source - Hygienic practices and Sterilization - We Treat - Antivirals - Antifungals - Antiprotozoal - Antibiotics Vaccinations - Dr. Edward Jenner used fluid from cowpox instead of human smallpox - Cowpox inoculation was called vaccination (Vacca Latin for "cow") Pasteur Developed Attenuated Vaccines - Louis Pasteur showed that exposure to attenuated strains of bacteria conferred immunity to a disease without causing severe symptoms - Developed the first rabies vaccine Antiseptics and Disinfectants Prevent Infection - John Snow stopped an epidemic of cholera by identifying the source of bacterial and disabling access to it - Ignaz Semmelweis suggested the hygienic practices among doctors could protect patients - Joseph Lister used chemical treatment of surgical instruments to prevent transmission Antibiotics Treat Infections - Alexander Fleming noted a mold growing in one of his cultures killed bacteria growing around it - Chemist Florey and Chain purified the chemical the mold produced and successfully treated patients who were dying of bacterial infections - Mass production of penicillin gave birth to the pharmaceutical industry Antibiotics are not invincible - Overreliance = resistance = not able to be treated with it