SCOPE AND HISTORY OF MICROBIOLOGY CHAPTER 1 Photo courtesy Kenneth Ingham

Why Study Microbiology? Ubiquity Courtesy Jacquelyn G. Black

Microbes in Our Lives Microorganisms are organisms that are too small to be seen with the unaided eye. “Germ” refers to a rapidly growing cell.

Why Study Microbiology? Biological roles- decomposers, recyclers, symbionts Animal digestion - ruminants, methane Food Microbiology - yogurt, sauerkraut, Kim Chee, cheese, beer, bread etc. Food safety - prevent putrefication, disease etc.

Why Study Microbiology? Pharmaceuticals- produce complex drug molecules. (ex. insulin ) Bioremediation - using microbes to clean pollution Pathogenicity - bacteria and viruses that make us sick Fundamental Biology most biochemical pathways worked out with microbes

Microbes in Research Simple structure- many are prokaryotic Large populations - up to billions/ml Rapid growth rates Vibrio harveyii = fastest grower known 1 gen/15 mins

Scale of Microbes

Classification of Microorganisms Three domains Bacteria Archaea Eukarya Protists Fungi Plants Animals

Microbe Types Bacteria prokaryotes Eubacteria Archaebacteria CNRI/ Photo Researchers, Inc.

Bacteria Prokaryotes Peptidoglycan cell walls Binary fission For energy, use organic chemicals, inorganic chemicals, or photosynthesis Figure 1.1a

Archaea: Prokaryotic Lack peptidoglycan Live in extreme environments Include: Methanogens Extreme halophiles Extreme thermophiles Figure 4.5b

Microbe Types Algae Fungi Protista, Planta Eukaryotes R. B. Taylor/Photo Researchers, Inc.

Algae Eukaryotes Cellulose cell walls Use photosynthesis for energy Produce molecular oxygen and organic compounds Volvox Figure 1.1d

Fungi Eukaryotes Chitin cell walls Use organic chemicals for energy Molds and mushrooms are multicellular consisting of masses of mycelia, which are composed of filaments called hyphae Yeasts are unicellular Figure 1.1b

Microbe Types Viruses Living? Thomas Broker/Phototake

Microbe Types Protozoa eukaryotes Michael Abbey/Visuals Unlimited

Protozoa Eukaryotes Absorb or ingest organic chemicals May be motile via pseudopods, cilia, or flagella Amoeba Figure 1.1c

Microbe Types Helminths/Arthropods Eukaryotes (multicellular) Cath Ellis/Photo Researchers, Inc.

Multicellular Animal Parasites Eukaryote Multicellular animals Parasitic flatworms and round worms are called helminths. Microscopic stages in life cycles. tapeworm Figure 12.28

Microorganisms: Figure 1.1

Roles of Microbiologists Biological Pharmaceutical/Vaccines Agricultural- Rumen microbiology

Microbiology Settings Universities Commercial laboratories food prep & cosmetics Courtesy United States Department of Agriculture

Microbiology Settings Legal Clinical Courtesy United States Department of Agriculture

Microbiology Settings Public Health Epidemiology

Microbiology History Plagues in History Pieter Brueghel the Elder (1528–1569), Flemish, Trionfolo della Morte, Painting, Prado, Madrid, Spain/Scala/Art Resource, NY http://www.oddee.com/item_90608.aspx

The Black Plaque-Bubonic plaque 1348 and 1350 (1340 - 1771) Killed 75 million people worldwide Yersinia pestis Flea vector.

Smallpox (430 BC? - 1979): Killed more than 300 million people worldwide in the 20th century alone, and most of the native inhabitants of the Americas. Smallpox (also known by the Latin names Variola or Variola vera) is a contagious disease unique to humans. Smallpox is caused by either of two virus variants named Variola major and Variola minor. The deadlier form, V. major, has a mortality rate of 30–35%, while V. minor causes a milder form of disease called alastrim and kills ~1% of its victims. Long-term side-effects for survivors include the characteristic skin scars. Occasional side effects include blindness due to corneal ulcerations and infertility in male survivors. Smallpox killed an estimated 60 million Europeans, including five reigning European monarchs, in the 18th century alone. Up to 30% of those infected, including 80% of the children under 5 years of age, died from the disease, and one third of the survivors became blind.

Microbiology History Early Studies Hooke Cork Slices- 1st Scope (cell) Van Leeuwenhoek microscope Linnaeus classification Schwann cell theory © Corbis

Fig. 1-9

Fig. 1-10

Germ Theory vs. Spontaneous Generation Redi - maggots http://en.wikipedia.org/wiki/Francesco_Redi Spallanzani - boiling http://en.wikipedia.org/wiki/Lazzaro_Spallanzani

Germ Theory vs. Spontaneous Generation Pasteur © Charles O’Rear/Corbis http://en.wikipedia.org/wiki/Louis_Pasteur

Understanding Disease Robert Koch Koch’s postulates Lister/ Semmelweiss http://en.wikipedia.org/wiki/Robert_Koch Granger Collection disinfection handwashing

Koch’s postulates 1. The suspected causal organism must be constantly associated with the disease. 2. The suspected causal organism must be isolated from an infected plant (or animals) and grown in pure culture. 3. When a healthy susceptible host is inoculated with the pathogen from pure culture, symptoms of the original disease must develop. 4. The same pathogen must be re-isolated from plants (animals) infected under experimental conditions.

Special Fields of Study Immunology Virology Immune system and it’s interaction with microbes Study of very small ?living? Viral particles

Special Fields of Study Chemotherapy Antibiotics Synthetics Natural products penicillin © UPI/Bettmann/Corbis Man-made Erhlich Alexander Fleming Penicillin doxycycline

Special fields of Study Genetics/Molecular Biology genes and how they are expressed Recombinant DNA technology Genomics decyphering genomes and expression Proteomics decyphering protein structure/function

Microbes I know and Love? Bacillus megaterium Klebsiella aerogenes Escherichia coli Klebsiella pneumoniae Mycobacterium smegmatis Mycobacterium marinum

A Brief History of Microbiology Ancestors of bacteria were the first life on Earth. The first microbes were observed in 1673. http://en.wikipedia.org/wiki/Antonie_van_Leeuwenhoek

The First Observations In 1665, Robert Hooke reported that living things were composed of little boxes or cells. In 1858, Rudolf Virchow said cells arise from preexisting cells. Cell Theory. All living things are composed of cells and come from preexisting cells

The Golden Age of Microbiology 1857-1914 Beginning with Pasteur’s work, discoveries included the relationship between microbes and disease, immunity, and antimicrobial drugs

Fermentation and Pasteurization Pasteur showed that microbes are responsible for fermentation. Fermentation is the conversation of sugar to alcohol to make beer and wine. Microbial growth is also responsible for spoilage of food. Bacteria that use alcohol and produce acetic acid spoil wine by turning it to vinegar (acetic acid).

Fermentation and Pasteurization Pasteur demonstrated that these spoilage bacteria could be killed by heat that was not hot enough to evaporate the alcohol in wine. This application of a high heat for a short time is called pasteurization. Figure 1.4

The Germ Theory of Disease 1835: Agostino Bassi showed a silkworm disease was caused by a fungus. 1865: Pasteur believed that another silkworm disease was caused by a protozoan. 1840s: Ignaz Semmelweiss advocated handwashing to prevent transmission of puerperal fever from one OB patient to another.

The Germ Theory of Disease 1860s: Joseph Lister used a chemical disinfectant to prevent surgical wound infections after looking at Pasteur’s work showing microbes are in the air, can spoil food, and cause animal diseases. 1876: Robert Koch provided proof that a bacterium causes anthrax and provided the experimental steps, Koch’s postulates, used to prove that a specific microbe causes a specific disease.

Vaccination 1796: Edward Jenner inoculated a person with cowpox virus. The person was then protected from smallpox. Called vaccination from vacca for cow The protection is called immunity

The Birth of Modern Chemotherapy Treatment with chemicals is chemotherapy. Chemotherapeutic agents used to treat infectious disease can be synthetic drugs or antibiotics. Antibiotics are chemicals produced by bacteria and fungi that inhibit or kill other microbes. Quinine from tree bark was long used to treat malaria. 1910: Paul Ehrlich developed a synthetic arsenic drug, salvarsan, to treat syphilis. 1930s: Sulfonamides were synthesized.

The Birth of Modern Chemotherapy 1928: Alexander Fleming discovered the first antibiotic. He observed that Penicillium fungus made an antibiotic, penicillin, that killed S. aureus. 1940s: Penicillin was tested clinically and mass produced. Figure 1.5

Modern Developments in Microbiology Bacteriology is the study of bacteria. Mycology is the study of fungi. Parasitology is the study of protozoa and parasitic worms. Recent advances in genomics, the study of an organism’s genes, have provided new tools for classifying microorganisms.

Modern Developments in Microbiology Immunology is the study of immunity. Vaccines and interferons are being investigated to prevent and cure viral diseases. The use of immunology to identify some bacteria according to serotypes (variants within a species) was proposed by Rebecca Lancefield in 1933.

Modern Developments in Microbiology Virology is the study of viruses. Recombinant DNA is DNA made from two different sources. In the 1960s, Paul Berg inserted animal DNA into bacterial DNA and the bacteria produced an animal protein. Recombinant DNA technology or genetic engineering involves microbial genetics and molecular biology.

Modern Developments in Microbiology Using microbes George Beadle and Edward Tatum showed that genes encode a cell’s enzymes (1942) Oswald Avery, Colin MacLeod, and Maclyn McCarty showed that DNA was the hereditary material (1944). Francois Jacob and Jacques Monod discovered the role of mRNA in protein synthesis (1961).

Selected Novel Prizes in Physiology or Medicine 1901* von Behring Diphtheria antitoxin 1902 Ross Malaria transmission 1905 Koch TB bacterium 1908 Metchnikoff Phagocytes 1945 Fleming, Chain, Florey Penicillin 1952 Waksman Streptomycin 1969 Delbrück, Hershey, Luria Viral replication 1987 Tonegawa Antibody genetics 1997 Prusiner Prions * The first Nobel Prize in Physiology or Medicine.