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

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?

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.

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

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.

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

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.

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.

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.

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

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

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)

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

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

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

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.

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

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

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

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

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

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

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

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

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

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

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

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

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