1. Unit 1 The Science Of Microbiology Donna Howell Medical Microbiology Blacksburg High School

2. What is Microbiology? Microbiology is defined as the study of the structure, function, uses, etc. of microscopic organisms. It is a specialized branch of Biology.

3. Why Microbes Matter Here’s how they affect our lives: –Cause disease –Decompose dead organisms –Help maintain balance of nature –Capture energy from Sun for re-use –Can be used to control other pests –Used in genetic engineering –Used to make food products –Used to produce medicines –Can be used to clean up oil spills Microbes RULE!

4. The First Observations In 1665, Robert Hooke was the first to notice that life’s smallest living units were made up of cells, which was the beginning of the cell theory. In the late 1600’s, Antoni van Leeuwenhoek invented the first true microscope. He was the first to describe living microbes.

5. Spontaneous Generation Up until the 1800’s, scientists believed that life could arise spontaneously from nonliving matter.

6. Spontaneous Generation In 1668, Francisco Redi demonstrated that maggots did NOT arise spontaneously from meat. This was the beginning of the proof that spontaneous generation did not exist.

7. Spontaneous Generation In 1858, Rudolf Virchow challenged spontaneous generation with the concept of biogenesis, which says that living cells can ONLY arise from other living cells.

8. Spontaneous Generation In 1861, Louis Pasteur settled the issue. He proved that microbes can be destroyed by heat. This was the beginning of aseptic technique, which is the use of techniques that prevent contamination by unwanted microbes in laboratories and medical facilities. He is also credited with the development of the “germ theory of disease”, which says that microbes cause disease.

9. Golden Age of Microbiology Beginning in 1857 with Pasteur’s discovery of germ theory of disease, and for the next 60 years, many branches of microbiology were established and many new microorganisms were discovered. This was called “The Golden Age of Microbiology” due to the many discoveries! Microbiology

10. The Golden Age of Microbiology During the “Golden Age”, many other discoveries were made: –Electron microscope invented – could see viruses for the first time! –Antibiotics were discovered –More research money available after war was over –Genes beginning to be studied

11. The Golden Age of Microbiology There were other accomplishments too: –In 1796, Edward Jenner was the first to “vaccinate” people against smallpox. –In late 1800’s, Pasteur discovered fermentation and pasteurization –In the 1860’s, Joseph Lister began using aseptic technique to medical procedures –In 1876, Robert Koch proved that bacteria caused disease (Koch’s Postulates)

12. Birth of Modern Chemotherapy Now that scientists knew microbes caused disease, they tried to find ways to cure disease. Treatment of disease by using chemical substances is called “chemotherapy”. In 1910, Paul Ehrlich came up with the first synthetic drug (not an antibiotic) used to treat syphilis. In 1928, Alexander Fleming discovered the first antibiotic, Penicillin

13. Modern Microbiology There are now many branches of microbiology due to specialization: –Bacteriology – study of bacteria –Mycology – study of fungi –Parasitology – study of protozoa and parasitic worms –Virology – study of viruses –Immunology – study of the immune system and how it responds to microorganisms –Genomics – study of genes –Biotechnology – use of microbes in practical ways

14. Introducing….Archaea! The first group of microbes we will study is the Archaea. These are the “ancient” bacteria – they have cell walls different than normal bacteria, and live in extreme environments: –Thermophiles – found in HOT temperatures –Psychrophiles – found in COLD temperatures –Halophiles – found in SALTY habitats –Acidophiles – found in ACIDIC habitats Hot Springs Deep Sea Hydrothermal Vent

15. Introducing….Bacteria! Found everywhere – literally! Can be autotrophic or heterotrophic. Can live with or without oxygen. Can be beneficial or harmful. Most numerous organisms on Earth.

16. Introducing….Viruses! Made of a core of nucleic acid and a protein coat. Cannot survive on own – need a host cell. Can infect ANY type of cell, not just human. Smallest of all microbes. Two subgroups: –Viroids – only contain nucleic acid –Prions – only contain protein coat

17. Introducing….Protozoa! A type of Protist that is medically significant – very diverse group. Includes 4 subgroups: –Ciliates – move with cilia, or hairs –Flagellates – have flagella for movement –Sarcodines – move with pseudopods, or false feet –Apicomplexans – do not move; need a host animal Giardia Trypanosoma Plasmodium

18. Introducing….Algae! Plant-like microorganisms, can undergo photosynthesis. Produce 75% or more of planet’s oxygen Important to the food chain Types: –Green algae – most like plants; found in water –Diatoms – hard shell; found in ocean –Dinoflagellates – found in ocean; can glow. Cause of red tide. Cyanobacteria Diatoms Dinoflagellates

19. Introducing….Fungi! Can be single-celled to multi-cellular Decomposers of organic matter Have cell walls of chitin Heterotrophic; absorb food Cannot undergo photosynthesis Examples: mushrooms, slime molds, water molds Yeast Cells

20. Introducing….Helminths! Also known as parasitic worms. Multicellular, eukaryotic animals Must have host(s) to reproduce. Examples: hookworm, pinworms, etc. Hookworm Ascaris

21. Introducing….Parasitic Insects! Insects that are human parasites are also included in the field of microbiology. Examples are scabies, crabs, head lice, and some others.

22. The End!