The History & Scope of Microbiology Flashcards
What is Microbiology
Study of microorganism that cannot seen by naked eye
Characteristics of Microorganism (3)
- Ubiquitous in nature (can be found everywhere)
- Microorganisms associated to humans (majority are innocuous, some are useful, some are harmful or deadly–human pathogens
- Most are unicelluar, but can be multicellular (ex. fungi)
Study perspective (9)
gross morphology
fine structure
nutrition
reproduction
physiology
genetics
classification
evolution
distribution
MO are found in:
3 kingdoms of life
Bacteria
Archaea
Eukaryotes
(1 billion different species)
Groups of MO (3)
*Prokaryotes
Bacteria (singular,bacterium)
Archaea (singular,archaeon)
*Eukaryotes
Algae (singular,alga)
Fungi (singular,fungus)
Protozoa (singular,protozoon)
*Non-living microorganisms (acellular entities)
Prokaryotic and eukaryotic viruses
Common features of MO (5)
- Physically grow in size
- Metabolism (acquire and consume nutrients)
-consume, transform, store energy
-consume nutrients and excrete wastes - Motion
-moving themselves
-having internal motion - Reproduction
create identical entities that are separate - Response to stimuli
act upon certain environment conditions
What is the basic structural unit of life?
Cell
“Invisible organisms cause disease”
Lucretius and Fracastoro
“Invents and develops the first microscope”
what is the magnification?
Zacharias Janssen
3-9x
“First description and depiction of a microorganism”
What he use?
What he see?
Robert Hooke
microscope
sporangia
Structure and strategy of sporangia
Sporangium (the cell)
consume nutrients on surface
nutrients complete, grow sporangiophores
Sporangiophores (the spore)
Sporangium burst open and spores pick up by wind
Find other surface
“Discovery of bacteria and protozoa”
What did he use?
What did he see?
What did he find about the thing he see?
The influence of his finding?
Anthony van Leeuwenhoek
Small hand-held microscopes (50X to 300X)
Invisible creatures, “animalcule”
everywhere
alive
increase in numbers and move
appeared in certain materials
Revived the “Spontaneous generation” theory
What is Spontaneous Generation theory?
living organisms spontaneously appear or develop from inanimate matters
Dust generates mites
Decaying meat generates fly larvae and flies
Decaying garbage generates mice and rat
Dark field illumination
bright specimen on a dark background
don’t need to stain
Experiments that disproved Spontaneous Generation (4)
- Francesco Redi
-3 flasks: unsealed, sealed, covered with gauze
-fly larvae can only develop in meat that fly can reach——unsealed flask - Lazzaro Spallanzani
put broth in a flask, sealed it and than boiled it. No microorganisms appeared - Louis Pasteur
-boiled meat broth in a flask and curved the neck of the flask, air could freely enter the flask but not dust, no microorganisms developed
-when he tilted the broth into the neck of the flask or broke the neck, microorganisms appeared in the broth
Disproved spontaneous generation for microorganisms and Microbiology became an experimental science as opposed to an observational science
- John Tyndall
Dust-free box
Support Pasteur’s finding
Demonstrating dust carry MO
Experiment that support Spontaneous Generation
John Needham
Boiled mutton broth and put it in a flask and sealed it——>Microorganisms appeared
When Microbiology became an experimental science as opposed to an observational science
1861 Louis Pasteur-Curved flask experiment
Old believes of the cause of disease (3)
· Supernatural forces
· Poisonous vapors called miasmas
· Imbalances between the four humors of the body
-Blood
-Phlegm (mucus)
-Yellow bile (choler)
-Black bile (melancholy)
microorganism (fungus) can cause disease in silkworms, beginning of the “germ theory of disease”
Agostino Bassi
The great potato blight of Ireland (1800s) was also caused by a fungus
M.J. Berkeley
Silkworms were parasitized by a protozoan in the French silk industry, they started to raise caterpillars from eggs produced by healthy moths
What does his finding suggest?
Louis Pasteur
MO can cause disease but not directly on human
Heat sterilized instruments and used phenol on surgical dressings and directly on patient wounds to prevent infection
What does his finding suggest?
Joseph Lister
Influenced by Pasteur’s work showing that heat and phenol can kill microorganism
Indirectly suggested the role of microorganisms in causing disease
Demonstrated that a bacterium (Bacillus anthracis) was causing anthrax
What does he do in his experiment?
Robert Koch
Experiment:
-Injected healthy mice with biological material from diseased animals (mice became ill)
-Transferred anthrax through a series of 20 mice (all got sick)
-Incubated a piece of spleen from mice #20 in beef broth (bacteria grew, produced endospores)
-Isolated endospores from the bacterial culture were injected into healthy mice (developed anthrax)
What is Koch’s postulates (4)? What does it show?
- The microorganism must be present in every case of the disease but absent from healthy organisms
- The suspected microorganism must be isolated and grown in a pure culture
- The same disease must result when the isolated microorganism is inoculated into a healthy host
- The same microorganism must be isolated again from the diseased host
Relationship between a microorganism and a specific disease
Koch want to isolate human pathogens
Difficult to work with liquid cultures
Tried on slices of boiled potatoes (bad growth)
Tried on solidified culture media (liquid media + gelatin):
-Gelatin is degraded by microorganisms
-Gelatin melts at 37°C, optimal growth temperature for human pathogens
Agar, Petri dish, brain-heart infusion
Fanny Eilshemius Hesse-agar
Richard Petri
Koch-media similar to body fluid
Koch isolated Mycobacterium tuberculosis, numerous other human pathogens were rapidly isolated in different laboratories
Immunized people against smallpox using the cowpox virus
Edward Jenner
The father of Immunology
Created the first attenuated live vaccine
What did he do for this?
Louis Pasteur
Grew pure cultures of human pathogens–Attenuate them (42-43°C or potassium bichromate)–did not cause disease but confer immunity
Avian cholera (Vibrio cholerae) and rabies (rabies virus)
Killed microbial cells were also effective as vaccines
Daniel Elmer Salmon and Theobald Smith
Discovered humoral immunity: antibodies are produced in blood against the diphteria toxin and be protective against infection
Emil von Behring
Discovered cellular immunity. He demonstrated that phagocytes (blood leukocytes) can engulf disease-causing bacteria and provide immunological protection against infection
Elie Metchnikoff
Microorganisms are responsible for fermentation (chemical instability of sugar)
Louis Pasteur
Yeast was being replaced by lactic acid bacteria–less alcohol and sour taste
Soil bacteria can obtain energy by the oxidation of iron, sulfur and ammonia and transform carbon dioxyde into organic matter
Sergei N. Winogradsky
Isolated nitrogen-fixing bacteria and sulfate-reducing bacteria
Beijerinck
Introduced the enrichment-culture technique and use of selective med
Beijerinck and Winogradsky
