The Study of Organisms That Are Microscopic in Size MICROBIOLOGY: The Study of Organisms That Are Microscopic in Size 1

WHAT ORGANISMS WILL WE STUDY IN THIS UNIT? A. VIRUSES - Virology B. BACTERIA - Bacteriology C. PROTOZOA - Protozoology 2

WHY SHOULD WE STUDY MICROBIOLOGY? A. Microbes cause disease B. Microbes are essential in decay (good/bad) C. Microbes are important organisms at the bottom of the food chain D. Many medicines are made from microbes 3

WHO IS THE ‘FATHER OF MICROBIOLOGY’? LOUIS PASTEUR 4

WHY WAS HE GIVEN THIS NAME? 1. Developed Pasteurization 2. Developed vaccine for Rabies 3. Proposed ‘Germ Theory’ (which states that micro- organisms cause disease) 5

OTHER FAMOUS MICROBIOLOGISTS: JENNER - Smallpox vaccine SALK/SABIN - Polio vaccine LISTER - 1st Antiseptic (Listerine) FLEMING - 1st Antibiotic (Penicillin) REED - Malaria treatment; vaccine for Yellow Fever 6

WHAT, HOW AND WHY DO WE GET SICK ??? 7

WHAT ARE THE CAUSES OF SICKNESS AND DISEASE? Viruses Bacteria Protozoa Fungi 8

HOW DO WE GET THESE DISEASES? Contact - contagious Vectors - Insects, snails, bats, etc. TERMS: Contagious - spread by contact Non-contagious - not spread by contact; spread by vectors 9

WHY DO WE GET SICK? (What does the microbe do to us?) Produces poisons (i.e. Botulism) Destroys tissue (i.e. Tuberculosis in lungs) Prevents normal cell functions (i.e. Strep Throat) 10

WHAT BODY DEFENSES DO WE HAVE AGAINST DISEASE AND INFECTION? 11

EXAMPLES OF BODY DEFENSES: Skin Sweat Tears White Blood Cells Stomach Acid Fever Cilia 12

THE ANTIGEN-ANTIBODY REACTION CONTAINS 2 PARTS: 1. ANTIGEN - The invader (microbe) 2. ANTIBODY - Protein produced in blood to fight specific invaders 13

The vaccine contains dead or weakened antigens (invaders) HOW DOES A VACCINE WORK? The vaccine contains dead or weakened antigens (invaders) The presence of these antigens causes the body to produce antibodies to fight that invader 14

THINK ABOUT IT! In order to protect you from suffering from a disease, doctors will sometimes infect you with that disease! 15

Your body’s resistance to disease and infection WHAT IS IMMUNITY? Your body’s resistance to disease and infection 16

VIRUSES ‘Virus’ is Latin for Poison. Viruses are measured in nanometers (one billionth of a meter -- TINY!!) Viruses can only be seen with an electron microscope. 17

TWO BASIC PARTS TO A VIRUS: Protein coat DNA or RNA 18

Round virus particles along with rod-shaped bacteria 1. Bacteriophage injecting DNA into E. coli bacteria THE SHAPE OF A VIRUS: 3. 2. 19

HIV Transmission electron micrograph of HIV on infected human lymphocyte. Daughter HIV cells leave infected cell for a new host.

EFFECTS ON LIVING THINGS: Viruses can cause damage to all living things - not just humans! 20

EXAMPLES: Plants - Tobacco Mosaic, Tomato Mosaic, Dutch Elm 21

EXAMPLES: Dogs - Distemper, Rabies, Parvo Add Parvo 22

Examples Humans AIDS Strep Hepatitis

VIRUSES REPRODUCE IN AN UNUSUAL WAY: A. Virus attaches to a host cell 23

VIRUSES REPRODUCE IN AN UNUSUAL WAY: B. DNA/RNA injected into host cell. 24

VIRUSES REPRODUCE IN AN UNUSUAL WAY: C. Host cell DNA/RNA is replaced with the viral DNA/RNA. D. The host cell nucleus causes the cell to make more viruses. 25

VIRUSES REPRODUCE IN AN UNUSUAL WAY: E VIRUSES REPRODUCE IN AN UNUSUAL WAY: E. Host cell eventually bursts, spilling thousands of new viruses into the body. 26

Let’s see the movie version! http://pc65.frontier.osrhe.edu/hs/science/bvirus.htm LINK IS NOT GOOD, FIND A NEW ONE…

SO ARE VIRUSES LIVING OR NON-LIVING? Viruses are non-living because they need a living host cell to carry out life’s functions Most treatments that “kill” a virus also destroy the host cells Prevent viral invasions by: Receiving vaccines Maintaining good hygiene Avoiding risky behaviors