Chapters 1 Flashcards
What are microorganisms?
- too small to be seen with naked eye
- true cellular forms
- ubiquitous
- helpful and problematic
Scope and relevance of microorganism-
- 1st living things on planet
- live everywhere life is possible
- largest component of earth’s biomass
- ecosystems depend on their activities
- contribute 40% of earth’s oxygen
Why study microorganisms?
- recycle vital element
- bioremediation - remove pollutants
- agriculture - nat. pesticide from spores
- biotechnology/ genetic engineering
- food micro - yeast in beer
- industrial micro - solvant, adhesives
- normal microbiota - humans- inhibit pathogen growth
- disease causings- pathogens >1%
Common ancestor
give rise to 3 domains of life Two Prokaryotic - bacteria and archaea One Eukaryotic - Eukarya
Prokaryoyes
Asexual; unicellular, no membrane bound organelles
Type of Prokaryotes
Archaea- not known to be human pathogens
- usually found in extreme environments
Bacteria - some pathenogenic
- multiple morphological and physiological
differences from archeae
Eukaryotes
unicellular or multicellular; sexual and asexual reproduction; multiple membranous organelles
Types of eukaryotes
Plants, animals- Helminths- paracitic worms, have micro lifestage, fungi- yeast, mildew
protists- single celled- algae, protozoa
Algae
unicellular or multi; photsynthetic; high morphological diversity; not pathogenic
Fungi
uni and multicellular; absorb nutrients from their environments; primarily opportunistic pathogens
Protozoa
- unicellular
- most are mobile- pseudopods, flagella, cillia
- absorb nutrients from environment or live as parasites
- many are pathenogenic
Helminths
- Multi-cellular animals
- Flatworms and round worms
- many are pathogenic
- only some life stages are microscopic
Viruses
- obligatory intracellular parasite
- no true cellular organization
- living or non-living??
1 angstrom
10^-10 meter
1 micron
10^-6 meter
Robert Hooke
1665 saw cells through a microscope- cells
Anton van Leeuwenhoek
1673 animalcules- made better microscopes and saw living cells
Schleiden and Schwann
1838/39 Cell theory recognized some are unicellular and others are multi-cellular
Franscesco Redi
1668 Spontaneous Generation performed an experiment that disproved spontaneous generation- jars with meat and fly larvae
Cell Theory
All living things are made up of cells
Spontaneous Generation
life can arise from non-living matter
John Needham
1745- experimented with broth to show that spon. gen. can happen with microorganisms
Lazzaro Spallanzani
1765- reproduced Needham’s experiment to show spon. gen. was not possible
Rudolf Virchow
1855- biogenesis
Biogenesis
living cells can only arise from preexisting living cells
Louis Pasteur
1861- “Father of Immunology”
- aseptic techniques
- swan neck flask
- fermentation
- pasteurization
Aseptic techniques
prevent contamination of unwanted microorganism
Pateurization
heating beer or wine just enough to kill most of the bacteria that cause spoilage
Fermentation
yeasts convert sugars to alcohol in the abscence of air
sepsis
asepsis
contamination
not contaminated
Golden Age of Microbiology
1874 - 1914
Supporters of theories that invisible agents cause disease
Ignaz Semmelweis 1840
Joseph Lister 1867
John Tyndall
Ignaz Swemmelweis
Childbed fever- death after childbirth
Joseph Lister
Aseptic surgery- blood bacteria- clean surgery, chemical used to sterilize instruments
John Tyndall
Had same idea as Pasteur- filter air cannot contaminate
Disease meant what at this time?
Punishment or possession from God
Germ Theory of Disease
Idea that microorganisms might cause
Robert Koch
1876 -developed Koch’s Postulates- sequence of steps to relate a specific microb to a specific diease
- direct contact with microb to get disease
- anthrax
Walther Hesse
1882 - discovered agar to solidify- worked in Koch’s lab
Edward Jenner
1798- discovered a milkmaid who had cowpox cannot get small pox- tested on a boy and was correct- called vaccine
immunity
protection from disease provided by vaccination/ or by recovery from the disease itself
Disease
any change in the normal stage of health
Luis Pasteur 1880
came out with rabies vaccine; tested chickens
Vaccine
cultures of avirulent microorganisms used for preventative inoculation
virulence
ability to cause disease
Chemotherapy
chemical treatment of disease
Selective toxicity
chemicals that kill pathogens with little to no harm to the host
Paul Ehrlich
- speculated a “magic bullet” could hunt down and destroy pathogens with out harming the infected host
- found salvarsan- treatment for syphilis-arsenic derivative
Antibiotics
chemicals produced naturally by bacteria or fungi to act against other microorganisms
synthetic drugs
chemotherapeutic agents prepared from chemicals in the laboratory
Alexander Fleming
1928- discovered properties of penicillin- active inhibitor of Penicillium chrysogenum
- discovered by accident
Penicillin
an antibiotic produced by fungus
Gerhard Domagk & Ernest Fourneau
1935-36 - developed sulfa drugs- treats infectious diseases
Selman Waksman
1940- Nobel Prize for antibiotic for strep-isolated from Steptomyces
Howard Florey & Ernest Chain
1940- preformed clinical tests and mass produced penicillin
Problems with modern chemotherapeutics
- toxicity
- resistance
- lack of adequate anti-viral drugs
- microbes resistant
Infectious disease remains a threat…
750 million cases each yr in US
Emerging diseases
spreading again in different locations
Factors associated with emerging diseases
- microbial evolution-changing
- Changing human behavior/lifestyles-high
- Complacency of human population- no precautions
- population expansion/global travel-risk
1918-1919
2009
50 million people died from Spanish Flu(Swine flu)
18,000 people died
Jump Species
human can be the host
