Test 1 - History/Bacterial Anatomy Flashcards
1
Q
First microscope
who/when
A
Zacharias Janssen; 1590 (before the 1600’s)
-He turned a telescope upside down
2
Q
Robert Hooke
A
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
3
Q
Anton Van Leeuwenhoek
A
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
4
Q
Royal Society of London
A
Hooke helped Leeuwenhoek publish his drawings in the royal society of London which was a scientific publication
5
Q
What did Leeuwenhoek look at:
A
-pond water, feces, tooth scrapings, semen *first person to find sperm in semen
6
Q
Leeuwenhoek was the first to describe:
hint: 5 things
A
- Bacteria - in all 3 shapes (cocci, bacilli, spiral)
- Protozoa (in pond water)
- Sperm
- Red blood cells
- Capillaries
7
Q
After Leeuwenhoek died why did further discoveries languish for nearly 100 years?
A
- 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
8
Q
In between the 100 years where no discoveries were made what two controversies sparked debate and experimentation?
A
- Spontaneous Generation
2. Theories of Disease
9
Q
Spontaneous Generation
A
- Living creatures arise from nonliving components
ex: eels from mud - Maggots from rotting foods/dead animals
- Fleas from sweaty cloth/animal fur
10
Q
Theories of Disease
A
- 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)
11
Q
Miasma
A
Gases or fumes rising from diseased or dead individuals…if you got into a miasma you might catch the disease
12
Q
Which two scientists worked on spontaneous generation?
A
-Redi and Pasteur
13
Q
Which scientists worked on causes of disease?
A
- Jenner
- Semmelweiss
- Lister
- Pasteur
- Koch
14
Q
Reid’s Meat/Maggot Experiment
A
-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)
15
Q
What controversy did Redi’s Meat/Maggot experiment settle?
A
Spontaneous generation for macroorganisms
16
Q
What method was developed with Redi’s Meat/Maggot experiment?
A
Use of a control group
17
Q
Jenner’s Smallpox Experiments
-what two observations did he make?
A
- 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
18
Q
Jenner developed the first _____
A
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
19
Q
Semmelweiss
A
- 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
20
Q
Lister
A
- 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
21
Q
Lister’s Aseptic Surgery
A
- Heat sterilization of instruments
- Disinfection of wounds and dressings
- Disinfection of air during surgery
- “father of aseptic surgery”
22
Q
Louis Pasteur Wine Experiment
A
-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)
23
Q
What procedure did Pasteur develop that is still used today?
A
Pasteurization
24
Q
Pasteur’s wine Results
*3 things
A
- 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
25
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
26
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).
27
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
28
Koch's anthrax results
- Proved, "Germ Theory of Disease"
| - -anthrax caused bacillus anthraces
29
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
30
Pasteur's Attenuation
Late 1800's
| -Method of making vaccines by weakening a pathogen to inject into a subject
31
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
32
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)
33
The Golden Age
1850-1900 (Koch v. Pasteur)
34
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
35
Who studied fermentation
- Spallanzani
- Gram
- Pasteur
- Koch
Pasteur
36
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
37
Robert Koch sought a "magic bullet" for the treatment of disease caused by bacteria
T/F
False
38
Which of the following individuals pioneered the use of chemicals to reduce the incidence of infections during surgery?
- Semmelweis
- Nightingale
- Snow
- Lister
Lister
39
Semmelweis advocated hand washing as a method of preventing which of the following diseases?
- Anthrax
- Puerperal fever
- Cholera
- Smallpox
- Syphilis
Puerperal fever
40
The first true vaccine protected against diseased cause by a(n) ____ pathogen
- Archaeal
- Bacterial
- Protozoal
- Viral
- Fungal
Viral
41
Which of the following types of microbe was NOT observed by Leeuwenhoek?
- Prokaryote
- Protozoan
- Fungus
- Virus
- Alga
Virus
42
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
43
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
44
What was the first disease shown to be bacterial in origin?
- yellow fever
- malaria
- cholera
- tuberculosis
- anthrax
Anthrax
45
Who discovered penicillin?
- Fleming
- Ehrlich
- Kitasato
- Pasteur
- Domagk
Fleming
46
Koch's postulates can be used only to determine the cause of infections diseases
T/F
True
47
Morphology of bacteria
| hint - 3 types
1. Cocci - round (coccus=singular)
2. Bacilli - rods (bacillus = singular)
3. Spirilli - spirals/curved cells (spirillus - singular)
48
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
49
All bacterial cells have...
- Cell membrane
- Cytoplasm
- Genome
- Ribosomes
- Cell wall
50
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
51
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
52
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)
53
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
54
Drug Targets
- DNA gyrase
- Ribosomes
- Cell wall
- Production of folic acid
55
Bacterial cell wall
Made of peptidoglycan (NAG & NAM with tetrapeptide cross linkages
Function: to prevent cells from overextending in a hypotonic solution (plain water)
-allows bacteria to survive in many different environments without expanding and dying
56
What is peptidoglycan made of
2 alternating sugars: NAG and NAM with cross linkages called tetra peptides
57
Two types of bacterial cell wall
Gram positive and Gram negative
58
Gram Positive cell wall
-Cell wall organized in a thick peptidoglycan (multiple layers)
-More sensitive to drugs that target peptidoglycan specifically
Teichoic acids - can be used as identification, anchor, and transport
59
Gram Negative cell wall
-cell wall organized in a thin peptidoglycan layer with outer LPS (lipopolysaccharide) inside of a lipid bilayer
60
LPS (lipopolysaccharide)
- Characteristic of gram negative cell walls
- Easily destroyed
- Lipid A - part of lipopolysaccharide layer
- LPS layer can neutralize some drugs making them harder to kill
61
Lipid A
Part of LPS
-toxin - if your immune system is killing bacteria cells, then lipid A can be a toxin (endotoxin) that can kill a patient
62
DNA Gyrase and how it is used as a drug target
DNA Gyrase is normally used to unwind the DNA double helix to use/reproduce via replication and transcription
- DNA Gyrase is UNIQUE to bacterial cells
- Ex: Drug: Ciprofloxacin, & metronidazole block DNA gyros which prevents DNA from unwinding and thus reproducing
63
Nucleoid Region
Part of the cytoplasm where DNA double helix is floating freely
64
Ribosomes and how they are used as a drug target
Drugs that attack ribosomes: Kanamycin, tetracycline, erythromycin
- Some drugs can prevent tRNA's from docking, no amino acid chains, some keep 2 subunits from coming together at all
* *drugs can attack ribosomes in many ways
65
Drugs that attack peptidoglycan
-Stronger effect on gram +
-All "-cillin" drugs
ex- penecillin, cephalosporins, vancomycin,, bacitracin
--attack cross linkages causing over expanding
66
Bacterial optional parts:
If bacteria have these it has to be something that gives them an advantage
-they are NOT required by the bacteria to have
-plasmids, sex pilli, fimbrae, flagella, glycoalyx, endospores,
67
Plasmids
Small "extra" segments of DNA, don't code for day to day activity enzymes
- Generic = bacteria can share them with each other
- Self replicating
- Easily passed back and forth
68
R Plasmids
-Resistance plasmids - code for proteins that allow drug resistance
69
3 Common mechanisms of antibiotic resistance coded for on r plasmids:
1. Efflux pump - pumps out drugs
2. Enzymes break down drug (into harmless parts)
3. Enzymes change drug (bind to active sites on the drug so that it can't do anything)
70
f plasmids
- fertility genes
- allow bacteria to initiate conjugation
- f+ makes sex pill, which protrudes to attach to f-
71
Virulence (t) plasmids
Codes for production of toxins or enzymes that then attack you
72
Bacteriocin plasmids
Production of proteins that kill other bacteria
73
Sex Pilli
- Small, temporary; only made when potential partner is detected
- Tubular pilin protein contracts
- Connects to allow DNA transfer
*Cell with the F plasmid is initiator bc f plasmid has directions to make sex pili
74
Fimbrae
- Short, numerous projections
- not contractile
- permanent
- main function: for adhesion to surfaces (deli meat, rocks)
- also made of pilin protein
75
Flagella
- only means of motility
- hairlike structures
- bacterial flagella are stiff, rigid, and are a curved S shape
- rotates - more like a propeller than a whip seen in sperm
76
Flagella counterclockwise turn
Movement in a straight line "runs" (cell moves in a straight line in one direction)
77
Flagella clockwise turn
Cell tumbles and changes direction
78
Pattern that bacterial cells move in
run, tumble, run, tumble
79
Taxis
Movement in response to a stimulus (series of runs and tumbles)
80
What type of taxis occurs when a bacteria encounters a positive stimulus ahead
More runs and fewer tumbles
81
What type of taxis occurs when a bacteria encounters a negative stimulus ahead
Fewer runs and more tumbles
82
4 Common Arrangements of flagella
- Lophotrichous
- Monotrichous
- Peritrichous
- Amphitrichous
83
Lophotrichous
- Flagellar arrangement
| - Tufts (a lot of flagella coming out of the same end) "pony tail like"
84
Monotrichous
Flagellar arrangement:
| One
85
Peritrichous
Flagellar arrangement:
| -surrounding
86
Amphitrichous
Flagellar arrangement:
-both ends
"-amphi" means "both"
87
Glycocalyx
-Slimey layer that is sugar rich
88
Type of Glycocalyx
Mucoid layer:
| -polysaccharide/glycoprotein (carb rich)
89
Slime layer
Mucoid layer:
| Loose layer
90
Capsules
Mucoid layer:
| Dense thick layer
91
Shared layer, many cells
Mucoid layer:
| Biofilm
92
Advantages of Capsules
1. Confer increased
- Neutralize drugs (i.e. protect against antibacterial)
- Fool/delay immune response (capsule gets picked off first by immune system)
- Adhere to surfaces (even without fimbrae)
- Avoid phagocytosis (WBC eating of cell)
- --WBC can't digest/kill pathogens ass quickly if they have the glycocalyx layer
93
Advantages of Capsules
2. Help pathogen survive
- Because carbohydrate rich provides nutrient source during starvation
- storage of toxic waste products (in capsule)
94
Endospore
- Spores that form inside a bacterial cell in bad conditions
- Not reproductive structures, DORMANT bacterial genome that forms inside a living cell - when the living cell deteriorates endospore forms and stays dormant until conditions improve
95
Sporulation
Becoming a spore
- Layers of peptidoglycan + protein = spore coat
- Water removed from inside of spore (makes cytoplasm more heat stable)
- Dipicolinic acid added - heat stability (keeps proteins from being denatured)
96
Characteristics of endospores
- Highly resistant to harsh environmental conditions
| - Germination (in favorable conditions to normal vegetative cells)
97
Characteristics of endospores: resistant to harsh enviro conditions
- heat (survive boiling)
- harsh chemicals (alcohol etc. - cannot get through hard spore coat)
- Drying
- Lack of nutrients (don't need food bc not metabolizing)
98
Endospore structure & type
Bacterial spores are used to help identify the species by using 3 characteristics:
1. Location of spore (central, subterminal, terminal)
2. Size
3. Shape (circular, oval)
99
Drug target: folic acid
- Unique to bacteria bc humans have to ingest folic acid whereas bacterial cells need to make it to survive
- "Sulf-" drugs target production of folic acid precursor
100
Unusual bacteria
1. Mycoplasma
2. Rickettsia/Chlamydia
3. Spirochaetes
4. Archaea
101
Mycoplasma
- cause some pneumonias (ex "walking" pneumonia)
| - have no cell wall - have to stay in warm, isotonic solution at all times
102
Rickettsia/Chlamydia
-Rocky Mountain Spotted Fever
Chlamydia:
-eye or general disease (STD)
Both are obligate intracellular parasites
- replicate only inside host cell, burst out to infect new cells
- hard for immune system to kill since its inside host cells
103
Spirochaetes
```
Genus:
-Borrelia = lyme disease
-Treponema = Syphilis
Both are:
-huge spiral cells
-use axial filament - internal flagellar arrangement that runs the length of the entire cell for motility, and penetration (can corkscrew right through cells)
```
104
Archaea
- Prokaryotic, but not true bacteria (cell wall has no peptidoglycan)
- Are very ancient
- Simpler than bacteria
- Methanogens
- Extremophiles
- -Thermophiles
- -Halophiles (salty)
- Hard to find because they wouldn't grow in a typical lab setting/culture medium
- Potential source of new antibacterial chemicals***
105
Bacterial growth
Bacteria reproduce by cloning:
- binary fission = splitting right in half to form 2 daughter cells that are identical
- -genome is copied (fast) in a bidirectional way
- -cell elongates
- -New cell wall and membrane separate the new cells
106
Generation time
Amount of time it takes a cell to carry out binary fission
107
Bacterial growth phase
1. Lag phase
2. Exponential growth phase
3. Maximum stationary phase
4. Death phase
* after death phase either... will occur:
1. Crash or
2. Minimum stationary phase
108
Lag phase:
Adaptation (turn genes on, produce enzymes)
| -bacteria observing their environment and are adjusting to it and figuring out what enzymes they need
109
Exponential growth phase
Actively doubling of bacteria as long as conditions are good
110
Maximum stationary phase
Carrying capacity of environment has been reached
111
Death phase
Halving (opp. of exponential growth)
| -only strongly selected members survive
112
2 things that could happen at end of death phase
1. Crash = all nutrients depleted, everything dies
| 2. Minimum stationary stage = a few hardy cells remain
113
Pasteur (things he did)
- attenuation methods
- vaccination for rabies
- proposal that bacteria metabolize like other living things, are not static
- wrote germ theory of disease
114
Leeuwenhoek (things he did)
-discovery of all 3 shapes of microorganisms
115
Jenner (things he did)
-first vaccination
116
Koch (things he did)
- proved germ theory of disease
- petri dish
- vaccination for tuberculosis
- creation of solid medium for isolation of pure cultures
- perfected bacterial stains
117
Redi (things he did)
-disproved spontaneous generation for macroscopic organisms
118
Lister (things he did)
-introduction of aseptic surgery techniques
119
Flemming
-discovery of first antibiotic
120
Hooke (what he did)
-published book "micrographic" and coined the word "cell"
121
Chronological order of scientists discoveries
Harry Really Likes Jane's Super Lively Perfect Kind Friends
| Hooke, Redi, Leeuwenhoek, Jenner, Simmelweiss, Lister, Pasteur, Koch, Flemming
122
What new discovery caused an increase of deaths, rather than the expected decrease of deaths, which led Lister to try these expanded techniques taken from Semmelweiss?
Anesthesia
123
Who wrote the germ theory of disease?
Pasteur
| -had an institution dedicated to him
124
What disease (found in both humans and animals) did Koch use to prove the germ theory of disease ?
Anthrax
125
What kind of “materials” did Koch have that Pasteur lacked?
- staining methods
- agar
- solid culture medium
126
In four words, sum up Pasteur's failure at proving germ theory of disease?
Chickens inoculated, not sickened...discovered attenuation
127
The vaccine against which disease led to Koch having a huge failure and leaving Europe?
Tuberculosis
128
Teichoic acids:
Protrude from the surface of gram + cells
129
Which of the following is an accurate description of the mucoid layers surrounding bacteria?
The term “glycocalyx” describes thick, thin, or shared mucoid layers
130
Which of the following is NOT a common characteristic of bacterial capsules
a. Resistance to phagocytosis by white blood cells
b. Delay immune response to bacterial cell
c. Resistance to heat, harsh chemicals, drying
d. Serve as a food source
e. Serve to store toxins
C
131
What drug (s) used to target DNA gyrase/circular genome
Cipro
132
What drug (s) is used to target ribosomes?
Tetracycline
133
What drug (s) is used to target peptidoglycan
-cillin drugs
134
What drug (s) is used to target folic acid synthesis
-sulfa drugs
