General Microbiology 130 Fall 2007 Roberta Brashear Kaulfers

Class cards Syllabus distribution Website information: http://hawaii.hawaii.edu/brashear

Chapter 1 Scope & History of Microbiology

 Q 1 How would you describe a microbiologist?

Let the adventure begin!

 Definitions:  Microbes- germs that cause disease  Biology- study of life  Microorganisms- bacteria, fungi, protozoa and some algae, closely related to humans in us, on us, and everywhere around us

Why Study Microbiology?

 1) Microorganisms are part of human environment, and important to human health  a) essential to life in every environment  b) Maintain balance of nature and essential links in food chains  2) Produce new foods  3) Ability to synthesize antibiotics

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Why Study Microbiology?

4) Major tools of genetic engineering  5) Certain microbes cause disease  6) Study provides insight into life in all life forms  Ecologists  Biochemists  Geneticists processes

Microorganisms are useful in Research for 3 reasons

 1) Simple structures  2) Large numbers available, less cost, more numbers provide more reliable results  3) Reproduce quickly (some 20 minutes), can be used for gene transfer Scientists have achieved great success in understanding life processes, and disease control by studying microbes

Importance of bacteria to our planet is now being revealed

 Bacteria have been found in:  1) Deep/hot depths (1.6 km in France – 5.2 km Sweden)  2) Surface biosphere  3) Caves  4) Deep sea smokers- ocean floor vents  5) Cold seeps- off Continental shelf of US  6 ) Boiling mud pots- Japan, Yellowstone

Scope of Microbiology 2 dimensions of Scope

 Microbiology – study of microbes  1) Variety of kinds of microbes  2) Kinds of work microbiologists do

Major Groups of Microbes

 1) Bacteria- prokaryotic, single cell, most studied  2) Algae-eukaryotic, single cell to large size, photosynthesize own food  3) Fungi- eukaryotic, single celled-yeast and molds  4) Virus- acellular, nucleic acid and protein need a host for replication

Major Groups of Microbes

 5) Protozoa-eukaryotic, many mobile  6) Helminth worms- disease causing parasites  7) Arthropod – insect vectors

Classification systems

   Binomial nomenclature everything has 2 names: Genus – species Virus are less precise- named for group they belong to or disease type Microbiologists study many things and work in many fields: life cycles, metabolism, make antibiotics and vaccines, control crop and insect pests, work in labs and Universities, create GMO’s, virology, industry and research

Historical Roots of Microbiology

 1) Bible- Moses  2) Greeks- 400BC Hippocrates  3) Romans- 100BC Varro  4) Mediterranean-542 AD Black Death bubonic plague  5) Europe-1347- 1700 AD – plague spreads from central Asis through caravans *Jewish population less impacted

Historical Roots of Microbiology

 6) Robert Hooke- 1665 compound microscope, saw cork cells  7) Anton van Leeuwenhoek-1650’s lens maker, studied “animalcules”  8) Carolus Linnaeus- classification system of binomial nomenclature  9) Schleiden/Schwann- Cell theory

Germ Theory of Disease

 Microorganisms (germs) can invade other organisms and cause disease  Spontaneous generation experiments

Germ Theory of Disease Early Studies

 Redi- experiments against Spontaneous generation  Spallanzani- used broth infusions  Pasteur- pasteurization process-heat wine to 56C/without O2 and kills microbes   Robert Koch- physicain who studied anthrax bacteria, gre pure cultures on agar Koch’s Postulates: Germ theory of disease

Koch’s Postulates: Germ Theory of Disease

     1) specific causative agent must be found in every case of the disease 2) disease organism must be isolated in pure culture 3) inoculation of sample into a healthy organism must produce the same disease 4) disease organism must be recovered from inoculated animal Koch identified organisms for TB, Cholera, and won Nobel prize in 1905

Work toward controlling Infections

 1800’s physicians:  Semmelweiss  Lister- father of antiseptic surgery

Emergence of Special Fields of Microbiology

  Immunology- host response reactions 1100’s Chinese –people who had smallpox and survived will not get it again   1717- Lady Ashley Montagu- variolation= took thread with smallpox blister exposure and place into incision in arm 1800’s Jenner- milkmaids who got cowpox, did not get smallpox

Immunology

 Jenner created vaccinia-vaccine for small pox  Pasteur created vaccine for rabies and cholera  Metchnikoff – 1880 studied phagocytosis “cell eating” sea star cells.

He received the Nobel prize 1908

Virology

 Virus particles are very small  Chamberland-1884 used a bacterial filter and particles that went through were still infectious  Beijerinck-infectious particles were called virus or poisons  Stanley- 1935- TMV tobacco mosiac virus   Hershey/ Chase-1952 genetic material is DNA Many viruses were discovered in the 1950’s

Chemotherapy

 Greek physicians- extracts from medicinal plants-digitalis, curare, morphine-herbals  16 th cent-metallic chemicals  17 th cent- cinchona bark= malaria  19 th cent- extracted morphine from opium poppy  Ehrlich- certain chemicals kill microbes but not animal cells=he tested 100’s of chemicals

Chemotherapy

 Fleming- 1922 lysozymes  1917- antibiotics from bacteria  1928 to WWII- penicillin became safe  1935- sulfa drugs used for streptococci, TB  1941- Actinomycin antibiotic,  1943- Streptomycin for TB  Some antibiotics from soil, others from the sea, many others may be in the rainforest

Genetics and Molecular Biology

       1900’s rediscovered Mendel’s work 1928- Griffith discovered live bacteria acquire traits from dead ones 1940’s- Avery, Mac Leod, McCarty-DNA 1953- Watson and Crick-structure of DNA 1950’s Beadle and Tatum- genetic controls in

Neurospora

– yeast Mc Clintock- jumping genes in corn Genes shuffle and splice together to create antibodies

Tomorrow’s History

 Microbiology is ongoing  1874-1917- Golden Age of Microbiology  1900 until now, many Nobel Prizes in physiology and medicine  Microbiology is in the forefront now with AIDS research and  Genetic engineering-designer microbes  1990 -1 st gene therapy patient

Bioethics and the Future

  1920-1930’s Bacteriophage-virus that attack and kill certain bacteria (still used in Russia today) Phages that attack

Listeria

–foodborne pathogen created a solution to agricultural food problems  Bioterrorism-phage to protect against Anthrax

Genomics

 Human Genome Project Goal to Identify human genes started in 1990 and completed in 2000 3 billion base pairs sequenced = 30,000 genes 75% of the code is “junk” DNA Similarities between bacteria and human = 43 Similariteies between mouse and human= 300