Test 1 - History/Bacterial Anatomy Flashcards
First microscope
who/when
Zacharias Janssen; 1590 (before the 1600’s)
-He turned a telescope upside down
Robert Hooke
1665
- British scientist
- First to describe cells (mid 1600’s)
- First to say there are cells living in things
- Published a book of drawings called “Micrography,” this book inspired many people
Anton Van Leeuwenhoek
1673-1723
- Not a scientist (was a merchant/politician); saw first microscopic living things
- No one has been able to successfully replicate his microscope design **
- Read Hooke’s book and made his own simple microscope
Royal Society of London
Hooke helped Leeuwenhoek publish his drawings in the royal society of London which was a scientific publication
What did Leeuwenhoek look at:
-pond water, feces, tooth scrapings, semen *first person to find sperm in semen
Leeuwenhoek was the first to describe:
hint: 5 things
- Bacteria - in all 3 shapes (cocci, bacilli, spiral)
- Protozoa (in pond water)
- Sperm
- Red blood cells
- Capillaries
After Leeuwenhoek died why did further discoveries languish for nearly 100 years?
- Leeuwenhoek was secretive, he didn’t show anyone his techniques, didn’t leave knowledge behind on how he did things etc.
- Microscope technology lagged (existing microscopes were not as good as his)
- “Animalcules” - no one thought they were significant in disease/food spoilage
*Animalcules were what Leeuwenhoek named bacteria and protozoa
In between the 100 years where no discoveries were made what two controversies sparked debate and experimentation?
- Spontaneous Generation
2. Theories of Disease
Spontaneous Generation
- Living creatures arise from nonliving components
ex: eels from mud - Maggots from rotting foods/dead animals
- Fleas from sweaty cloth/animal fur
Theories of Disease
- To explain why some humans got sick and some didn’t
- Cursed by witches
- inheritance
- punishment for sins
- Miasma
- germs (later - early to mid 1800’s)
Miasma
Gases or fumes rising from diseased or dead individuals…if you got into a miasma you might catch the disease
Which two scientists worked on spontaneous generation?
-Redi and Pasteur
Which scientists worked on causes of disease?
- Jenner
- Semmelweiss
- Lister
- Pasteur
- Koch
Reid’s Meat/Maggot Experiment
-mid-late 1600’s
-famous covered jar experiment
-discovered that when decaying meat was kept isolated from flies, maggots never developed, whereas meat exposed to flies was soon infested with maggots.
–basically came up with a “control”
Results: refuted spontaneous generation for macroorganisms (i.e. eels, rats)
What controversy did Redi’s Meat/Maggot experiment settle?
Spontaneous generation for macroorganisms
What method was developed with Redi’s Meat/Maggot experiment?
Use of a control group
Jenner’s Smallpox Experiments
-what two observations did he make?
- Late 1700’s
- cowpox - similar to smallpox, but cowpox is not lethal to humans or cows gives humans immunity to small pox
- Illegal (variolation) induced mild small pox
- cowpox - similar to smallpox, but cowpox is not lethal to humans or cows gives humans immunity to small pox
- people with mild smallpox would give their pus to others to protect them from the sever version
- –however some people with mild symptoms could still have the severe version just a strong immune system
Jenner developed the first _____
Vaccine
-Immune system recognizes proteins on cowpox and smallpox virus as the same. Since cowpox is not lethal, upon injection to a human the body can build up an immunity, which also builds them an immunity to smallpox
Semmelweiss
- Mid 1800’s
- Observed high “childbirth fever” deaths associated with doctors who delivered rich peoples babies
-Midwives delivered babies from poorer people in the hospital while doctors delivered upper class babies.
Semmelweis said that the doctors are transferring something to women from cadavers to patients w/o disinfecting hands/instruments
- introduced use of lime water to disinfection
- -mortality rates then decreased
Lister
- Mid 1800’s (but after Semmelweiss
- read semmelweiss’ work and knew he was right
- Lister’s problem: Anesthesia increased mortality rate
- -believed that things from the air were falling into the open cavity of bodies he was operating on
- -started using Semmelweiss’ technique and mortality rate started going down
Introduced: Asepsis
Lister’s Aseptic Surgery
- Heat sterilization of instruments
- Disinfection of wounds and dressings
- Disinfection of air during surgery
- “father of aseptic surgery”
Louis Pasteur Wine Experiment
-When some grape juice turned into vinegar instead of wine (called sick wine) he was employed to figure out why. He looked at samples of both to determine why this was happening and observed:
- the good wine = “ovals” (yeast)
- bad wine = “sticks” (bacteria) along with ovals
*developed pasteurization (heating of something just enough to kill bacteria)
What procedure did Pasteur develop that is still used today?
Pasteurization
Pasteur’s wine Results
*3 things
- Microorganisms are capable of metabolizing
- *Microbes cause disease in humans (wrote Germ theory of Disease)
- *Microorganisms are not spontaneously generated
*were NOT accepted by the scientific community until later
Pasteur’s S-Flask Experiments
1865
Used an s shaped flask to prove that microorganisms do not spontaneously generate
-S shape allows steam to escape from the open end of the flash while the substance was being boiled, air can move in and out of the flask, meanwhile dust from air settles in the bend keeping infusion sterile indefinitely
-When he broke the necks off some of the flasks, exposing the liquid in them directly to the air, he carefully tilted others so that the liquid touched the deposited dust. The next day all of these flasks were cloudy with microbes
Koch’s Anthrax Experiments
Late 1800’s
- Prussian (german)
- Saw pasteur’s work and also wanted to prove the Germ Theory of Disease
- Studied the cause of anthrax in cattle
- Took bacteria liquid and put it on the surface of potato slices to make it easier to see (Pasteur used beef broth, which just remained cloudy).
Koch’s Postulates
1: In every case of disease you need to find pathogen present and isolate it from all cases of disease (in infected individuals, but absent from healthy individuals)
- Pasteur was never able to do this
2. Isolated pathogen must be grown in culture medium
3. Cultured pathogen must cause disease in a healthy animal
- inject and must get sick
4. Re-isolated pathogen from (newly sick host) same as the original pathogen
Koch’s anthrax results
- Proved, “Germ Theory of Disease”
- -anthrax caused bacillus anthraces
Why are Koch’s anthrax results still important today?
- Useful because:
1. Postulates used for causative agent ID - –modified for viruses because they don’t grow in a culture medium
2. Pure culture methods and staining methods
Pasteur’s Attenuation
Late 1800’s
-Method of making vaccines by weakening a pathogen to inject into a subject
Attenuation was discovered accidentally when:
Using Koch’s Postulates with chicken cholera, when he got to step 3 and none of the chickens got sick. Repeated experiment using fresh bacteria (not old like before) and only half got sick.
The half that got sick were new chickens that hadn’t been exposed to the old culture, letting him know that older cultures were not strong enough to cause disease, but can still help the body build up immunity
Attenuation Methods included:
- Aging culture
- Drying culture or tissue containing organism (worked with the rabies virus)
- -dried a spinal cord from an infected rabbit and powdered it up
- Exposure to weak acids
- -expose bacteria to weakened HCl to weaken them
- Exposure to other harsh chemicals
- Passage through animals
- -Birds almost never got sick from human diseases. Put human pathogens in animals to make it evolve up until it makes the animal sick. Once it makes the animal sick the disease has changed so much that it no longer makes humans sick (vaccine)
The Golden Age
1850-1900 (Koch v. Pasteur)
Alexander Flemming
- After Golden Age
- First microbiologist pHD and MD
- Worked with staph
- Dirty dishes accident = left petri dishes in a sink over a weekend and came back to a plate of fungus and staph, saw that the fungus was producing a chemical that kept bacteria from growing
- isolated first antibiotic, penicillin, from Penicillium notatum mold
- Smuggled mold spores in his coat to the U.S to work with scientists that helped him purify the antibiotic
Who studied fermentation
- Spallanzani
- Gram
- Pasteur
- Koch
Pasteur
Koch’s work involving anthrax was significant because it was the first time ______.
- Bacteria had been seen in a microscope
- Bacteria had been grown in a lab
- A bacterium had been proven to cause a disease
- Anthrax had been discovered in humans
A bacterium had been proven to cause a disease
Robert Koch sought a “magic bullet” for the treatment of disease caused by bacteria
T/F
False
Which of the following individuals pioneered the use of chemicals to reduce the incidence of infections during surgery?
- Semmelweis
- Nightingale
- Snow
- Lister
Lister
Semmelweis advocated hand washing as a method of preventing which of the following diseases?
- Anthrax
- Puerperal fever
- Cholera
- Smallpox
- Syphilis
Puerperal fever
The first true vaccine protected against diseased cause by a(n) ____ pathogen
- Archaeal
- Bacterial
- Protozoal
- Viral
- Fungal
Viral
Which of the following types of microbe was NOT observed by Leeuwenhoek?
- Prokaryote
- Protozoan
- Fungus
- Virus
- Alga
Virus
Which of the following was NOT an aspect of Pasteur’s experiments to disprove spontaneous generation?
- The necks of the flasks he used were bent into an S-shape
- The flasks were free of microbes until they were opened
- He boiled the infusions to kill any microbes present
- The flasks he used were sealed with corks
- The flasks were incubated for very long periods of time
The flasks he used were sealed with corks
Robert Koch was involved in research on all of the following topics EXCEPT:
- The cause of anthrax
- The cause of fermentation
- Techniques for isolating microbes in the lab
- Development of a method to determine the cause of an infections disease
- The cause of tuberculosis
The cause of fermentation
What was the first disease shown to be bacterial in origin?
- yellow fever
- malaria
- cholera
- tuberculosis
- anthrax
Anthrax
Who discovered penicillin?
- Fleming
- Ehrlich
- Kitasato
- Pasteur
- Domagk
Fleming
Koch’s postulates can be used only to determine the cause of infections diseases
T/F
True
Morphology of bacteria
hint - 3 types
- Cocci - round (coccus=singular)
- Bacilli - rods (bacillus = singular)
- Spirilli - spirals/curved cells (spirillus - singular)
Arrangements of bacteria
~6
- Strepto - chains
- Staphylo - grapelike clusters (no nice pattern)
- Diplo - twos
- Tetrad/Sarcina - square packets of 4 and 8 (4 leaf clover)
- Pallisade - side to side
- V-shape - ex diptheria
All bacterial cells have…
- Cell membrane
- Cytoplasm
- Genome
- Ribosomes
- Cell wall
Bacterial cell membrane
Selectively permeable membrane, phospholipid bilayer
- lacks sterols found in eukaryotic cells
- acts as a barrier between inside and outside world
- not unique enough to function as a drug target
Bacterial cytoplasm
Mainly water, which contains dissolved enzymes etc. “watery solvent” that chemical reactions occur in
- can store lipids, starch w/o a membrane pouch
- not unique enough to be a drug target
Bacterial genome
Set of genes required to grow the whole cell
- bacteria have one circular “chromosome”
- still a DNA double helix - but just a circle (attached to 1 part of the cell wall)
Bacterial Ribosomes
Not membrane bound
- made up of rNA and small proteins
- make proteins
- size 70s (individual subunits are also smaller) compared to eukaryotic which is 80s