Chapter 1: Scope and History of Microbiology

Transcription

1 Chapter 1: Scope and History of Microbiology

2 Why Study Microbiology? Microbes (bacteria, viruses, fungi, protozoa, and some algae) live in us, on us, and nearly everywhere around us. They have a major impact on our health and environment, they play an important role in many foods we eat, and the medicines we take.... And because you took this course and studying it will help your grade... hehe :)

3 Myth: All microbes cause disease. TRUTH: Less than one percent of all microbes cause disease. Identifying how these few disease-causing microbes (called pathogens) cause and transmit disease, as well as how they can be treated, is critical to our species wellbeing

4 Myth: Microbes throw off the balance of life. TRUTH: Microbes help maintain the balance of nature. Many aquatic microorganisms capture energy from sunlight and store it in molecules that other organisms use as food. Microorganisms decompose dead organisms and waste material and some can even decompose industrial waste!

5 Through decomposition, microbes make nitrogen available to plants. Moo You jerk, I was going to say that! Certain microbes reside in the digestive tracts of grazing animals playing an important role in the digestion of grass.

6 Random Fact: Almost one-half of children under the age of 10 died of infectious disease prior to this century Today- 6 million children around the world will die from infectious (and mostly treatable) diseases before the age of 5- accounting for 68% of the mortality.

7 The food industry uses their ability to carry out biochemical reactions to make pickles, sauerkraut, yogurt, fructose, and aspartame. Fermentation reactions are used to make beer, wine, and bread. Uses for Microorganisms: Microbes provide the ability to synthesize antibiotics (substances derived from one organism that kill or inhibit the growth of other microorganisms.)

8 Altered Microbe Uses: Creation of interferon and growth hormones more economically Microbes to degrade oil spills, remove toxic materials from the soil, and to digest explosives.

9 Why Microbes? 1. Microbial structures are simple. It is easier to study life processes in a unicellular organism than in a complex multicellular one.

10 Why Microbes? 2. Microbes are cheap! Large numbers of microorganisms can be used in an experiment to obtain statistically reliable results for a reasonable cost. A billion bacteria are cheaper than maintaining 10 rats.

11 Why Microbes? 3. Microorganisms reproduce quickly- making them useful for studying the transfer for genetic material. Some bacteria can undergo three cell divisions in an hour, so gene transfer effects can quickly be followed through many generations.

12 What is Microbiology? The study of microbes, organisms so small that a microscope is needed to study them.

13 Kinds of Microbes Bacteria Algae Fungi Viruses *** Refer to your notes from your book for details of each: p. 3-5 *** Protozoa

14 Bacterial Diseases: Anthrax Bacterial Meningitis Botulism Chlamydia Cholera Food poisoning Gonorrhea Lyme Disease Plague Rocky Mountain Spotted Fever Salmonellosis Syphilis Tetanus Toxic Shock Syndrome Tuberulosis Typhoid Fever Viral Diseases: AIDS Hepatitis A,B,C HIV Influenza Measles Mumps Rabies Rubella Yellow Fever Fungal Diseases None Protozoan Diseases Malaria Algal Diseases None

15 Microbiology in History In the bible: Moses instructed soldiers to carry spades and bury solid waste matter. The bible also refers to leprosy and to the isolation of lepers. Greeks- Hippocrates (400 B.C.) noticed particular signs and symptoms were associated with certain illnesses and disease could be spread from one person to another by clothing or other objects.

16 Microbiology in History Romans- Varro (1st century) proposed that tiny invisible animals entered the body through the mouth and nose to cause disease.

17 Bubonic Plague! Also known as the black plague - appeared in the Mediterranean region around 542 A.D.- where it killed millions as it spread through Europe over the next 300 years.

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19 The bubonic plague was was carried by infected fleas and rats and killed rich and poor alike. The Jewish population was the least affected because of their ancient hebrew laws regarding sanitation and the care of the sick kept the rats to a minimum where they lived.

20 1665- Hooke built the first compound microscope (light passes through 2 lenses) and used it to observe thin slices of cork. He coined the term cell to describe the orderly arrangement of small boxes that he saw. Robert Hooke

21 Anton van Leewenhoek First person to make and use lenses to observe living microorganisms Some of his lenses could magnify up to 300x and when he looked at stagnant water, his own mouth, and in sick people he saw what he called animalcules

22 Over the years he observed protozoa, algae, yeast, fungi, and bacteria in spherical, rod and spiral forms. He refused to sell an of his microscopes and continued his research and observations until his death at the age of 91.

23 Germ Theory of Disease Microorganisms (germs) can invade other organisms and cause disease. Even though this is a simple concept today, people thought microorganisms arose from non-living things- spontaneous generation.

24 Louis Pasteur Established that alcohol was only produced in wine if yeast was present- see experiment p. 12: swan-necked flasks Developed the technique of pasteurization- heating wine to 56 degrees Celsius in the absence of oxygen- to kill unwanted organisms He associated specific organisms with particular diseases in silk worms

25 Pasteur s three daughters passed away and he had a cerebral hemorrhage that left him paralyzed, but he still contributed to the development of vaccines. His best known vaccine was the rabies vaccine- made of dried spinal cords from rabbits.

26 Identified the bacteria that causes anthrax Recognized both actively diving cells and dormant cells (spores) and developed techniques for studying them in vitro (outside a living organism) Robert Koch Found a way to grow bacteria in pure cultures (cultures containing only one kind of organism)

27 Koch s Postulates Four postulates to associate a particular organism with a specific disease. Provided scientists with a method of establishing the germ theory of disease. ** See your intro. and p. 13 for postulates **

28 *** Be familiar with the THREE fields of microbiology on your intro ws: immunology, virology, and chemotherapy ***