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

2. Imagine…………. Close your eyes and picture this:
It is the year 1450, and your father develops huge purple bumps on his neck and groin area. You know he is VERY sick. No one else in the family has this disease. But you don’t know that microorganisms exist yet.
What are some things people might have said caused the disease?

3. 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.

4. Why Microbes Matter Here’s how they affect our lives: Microbes RULE!
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

5. 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.

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

7. 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.

8. 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.

9. 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.

10. 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

11. 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

12. 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)

13. 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

14. 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

15. 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

16. 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.

17. 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

18. 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

19. 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

20. 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

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

22. Careers in Microbiology
Hospitals and Clinics
Isolate and identify disease microbes
Research
Diagnostic testing
Public Health
Control and prevent disease
Track down sources of disease outbreaks
Education
Teach life sciences
With PhD, do research
Executive position in gov’t. and industry

23. Careers in Microbiology
Business
Work in pharmaceutical companies – development of new drugs
Develop and evaluate anti-microbial products
Food industry – work in fermentation industry (beer, wine, etc); look for safe ways to preserve food

24. Careers in Microbiology
Environmental and Agriculture
Investigate the effects of biological and chemical activity on environment
Identify disease and harmful microorganisms of animals
Check for quality and safety of items used in environment
Enhance and improve soil fertilizer
Look for biological ways to control pests

25. Careers in Microbiology
Areas of Specialization:
Virologists – study viruses
Immunologists – investigate body’s defense against disease
Bacteriologist – study bacteria
Biochemist – study how organisms obtain energy, eat, and reproduce
Biotechnologist – manipulate genes in order to modify microorganisms
Cell Biologists – explore actions of molecules in and on the cell

26. Careers in Microbiology
Areas of Specialization:
Parasitologists – study organisms that depend on others for survival
Geneticists – study how organisms inherit and transmit genetic information
Mycologists – study fungi

27. Sample Employers Hospitals US Dept. Agriculture
US Environ. Protection Agency
Centers for Disease Control
US FDA
Food Processing Firms
Public Health Agencies
Research Laboratories
Health and Human Services

28. Sample Employers National Institute of Health
Colleges and Universities
Pharmaceutical Companies
Manufacturing Firms
National Cancer Institute

29. The End!