EXAAAM1 Flashcards
surfaces of microbes are negatively charged and attract basic dyes
Positive staining
Proponent for and lended support for Spontaneous Generation
John Needham
single flagellum at one end
small bunches emerging from the same site
flagella at both ends of the cell
flagella dispersed all over the cell
monotrichous lophotrichous amphitrichous peritrichous Flagellar Arrangements
- has outer membrane of lipopolysaccharide/phospholipid bilayer found outside peptidoglycan portion
- Two periplasmic spaces
- thin peptidoglycan layer
G- cell wall
iv. tough endospore coat of keratin makes it resistant to chemicals and radiation
Endospore
irregular clusters
staph
i. bad internally (neosporin)
ii. only used topically
cell wall
narrow G+
Bacitracin
curved rod
vibrio
i. high toxicity index
ii. need pick line to adimnistrate
iii. only used topically
narrow G+
cell wall
Vancomycin
rods laying side by side
palisade
- Apply crystal violet for 1 minute
a. primary stain = crystal violet - Wash off stain with distilled water
- Apply Gram’s iodine for 1 minute
a. iodine = mordant = combiens with primary stain to form insoluble crystalline compound. crystals get trapped in thick peptidoglycan but fail to be so where it is thin. - Wash off iodine with distilled water
- Apply 95% alcohol, drop by drop until alcohol runs clear (no more than 3-4)
a. crystal violet is washed out of cells with thin peptidoglycan; destroys outer membrane of gram negatives. - Wash off the alcohol with distilled water
- Apply safranin for 20 seconds.
a. safranin is the counterstain. - Wash off the stain with distilled water.
- Blot dry with bibulous paper
Gram Stain
E coli belongs to hich domain
B
which domains includes organisms with prokaryotic cell type?
A and B
i. Nutrition and physical environment
1. body temperature?
ii. Growth Characteristics
1. Color, Texture
iii. Metabolism
1. H2S - anaerobe
2. aerobic?
iv. Staining
1. G staining
2. capsule
3. endospore
v. Cell Morphology
1. Cell shape
2. arrangement
3. flagella?
Diagnostic techniques to classify bacteria
i. demonstrated thatif dust removed from the air, bacteria don’t grow
ii. demonstrated the presence of heat resistant forms of some microbes
iii. Developed Tyndallization, intermitten boiling that eliminates what we now know to be the endospores that caused Pasteur to have inconsistent results
iv. Explaiining Pasteur’s results (which were sprouting endospores) end belief in spontaneous generation.
i. John Tyndall England 1859
inert, resting cells produced by G+ Clostridium, Bacillus (the two that cause disease)
Endospores
- Talk about why microbes are essential
They're everywher producers decomposers drugs/chemicals recyclers damage understand higher forms of life
i. metabolism
ii. temperature
iii. nutrient requirements
Bacterial physiology
Heat fixing a smear
helps bacteria absorb the stain
kills the bacteria
helps the bacteria stick to the slide
which bacteria shapes are always solitary
vibrio, spirillum, spirochete
i. shape,
ii. appearance,
iii. flagella
Microscopic morphology
- Small intracellular parasites
- G- cell wall
- Nonmotile rods or coccobacilli
- Ticks, fleas, lice involved in life cycle
- Bacteria enter endothelial cells –>necrosis of vascular lining - vasculitis, vascular leakage, and thrombosis
ii. The Rickettsia Genus
which scientist boiled and seaked flask of broth failed to grow microbes, yet failed to still generate support for B.G. since vegtative force couldn’t get into the flask?
Lazzaro Spallanzani
which domain was first to appear?
A
d. Germination - return to vegetative growth
Endospores
Branched apart 3.5 bya
prokaryotes
The most important stain
Gram
Heat-dried
Capsule stain
Gram stain
acid fast stain
endospore stain
capsule stain
are examples of ____ stain
Differential Stain
Which scientists contributed the most to the development of the growth media and pure culture techniques we used in class?
Koch
one
singular
i. Negative stain + gentle heat fix + adding crystal violet –> differential stain
ii. uses ink to smear/colorb ackground + stain to color the background itself.
iii. Differentiates the capsule from rest of cell
Capsule stain = negative + simple positive stain
i. Disadvantages: not selective
ii. only used topically
iii. neosporin
Narrow G-
cell membrane
Polymyxin
usually have cell walls of petidoglycan
B
All cells have cell membrane with sterols
E
Flagella has flagellin, powered by ATP
Archaea
stains bacteria itself
positive stain
i. FIne, hairlike bristles emerging from cell surface of _ domain
ii. Function in adhesion to other cells/surfaces
iii. contribute to virulence
Bacteria G+ G-
- Chlamydia Trachomatis
i. Trachoma - attacks mucous membrane of eyes, genitourinary tract, and lungs
- Ocular trachoma - severe infection, deforms eyelid and cornea, preveted by prophylaxis
- Inclusion conjuncitivitis - occurs as baby passes through birth canal
ii. STD - second most prevalent STD; urethritis, cervicitis, salpingitis (PID), infertiligy, scarring
Chlamydia Trachomatis
provides the surface where your smear will be located.
Glass Slide
packets
cubical packets
Cells have nucleoid that consists of single chromosome
A & B
Cells have 80s ribosomes
E
GI upset
Narrow G+
Aminoglycosides
Erythromycin
Cells often use undulipodia to move from place to place
E
i. deafness; kidney damage
Broad
Aminoglycoside
70s ribosome
Streptomycin
Flagella powered by ion channels
Bacteria
i. Boiled the broth longer, sealed the flask, nobacteria grew.
ii. argued that he destroyed the “vegetative force” of the broth and degraded the small amount of air that was there.
iii. Gravy boiled + lid –> w/o lid? bacteria growth. w/lid? no growth.
g. Lazzaro Spallanzani 1765 Italian
flagella on inside
spirochete
i. supported spontaneous generation
ii. assumed boiling kills everything
iii. when boiled mutton brother produced large quantities of bacteria he concluded that they spontaneously generated from the broth
iv. also left the lid open for awhile.
f. John Needham 1748 England
Most of cells in this domain use plasmids to exchance DNA
B+A
euk only yeast
Antibodies
Serological Analysis
- Free swimming cells settle on the surface and remain there
- Cells synthesize sticky matrix that holds them tightly to the substrate
- When biofilm grows to certain density (quorum), the cells release inducer molecules that can coordinate a response.
- Enlargement of one cell to show genetic induction, inducer molecule stimulates expression of a particular gene and synthesis of a protein product such as digestive enzymes or toxins.
- Cells secrete their enzymes in unison to digest food particles; survive
Biofilm synthesis
- weak sexually transmitted pathogens
ii. mycoplasma genitalium/ureplasma urealyticum
When you’ve finished applying stain, what colorshould the endospore be?
Green
vegetative will be pink.
a. detected; contains lipid A endotoxin
b. has porins controls entrance of nutrients and antibiotics (which are too big to pass through pores)
G- outer membrane
Which cell wall has outer membrane?
G-
i. improve definition
ii. negative stains background
iii. positive stains bacteria itself
staining
Aplastic anemia - loss of red bonoe marrow w/LT use
Broad
Aminoglycosides
70s riboosomes
Chloramphenicol
- protect cells from dehydration
- nutrient source
- allows for attachment to surfaces (biofilms)
- inhibits killing by white blood cells by phagocytosis, contributing to pathogenicity
- considered a virulence factor (plays a role in causing diseases)
Glycocalyx
Sedimentation Rate
70s
80s
Prokaryotic ribosome
Eukaryotic
Cells in this domain wrap DNA around histones
E
i. Allowed heated air to enter abroth filled flask through a coiled tube
ii. Broth stayed clear, he concluded that microbes can not spontaneously generate from broth.
iii. Opponents claimed he killed the “vegetative force” in the air by heating it.
iv. Air inlet - flame heated air - previously sterilized infusions remain sterile.
Schultze & Schwann, 1839
What makes an endospore resistant to chemicals and radiation?
Spore coat
- Gram negative have thin peptidoglycan surrounded by outer membrane with phospholipids and lipopolysaccharide RED/PINK
- Gram positive has thick layer of peptidoglycan and no outer membrane. PURPLE
Gram Stain
i. Ribosomal RNA analysis
ii. protein analysis
g. Genetics and molecular analysis
i. Used whenever you are transferring bacteria from solid media.
Inoculating Needle
3 parts
filament
hook
basal body
flagella components
capsule stain is
combination of negative and simple stain
differential stain
What does mordant do?
combines with crystal violet to form crystalline structure
i. Target cell components common to most pathogens (ribosomes)
d. Broad spectrum - greatest range of activity
i. Vegetative cell: metabolically active and growing
ii. Endospore - When exposed to adverse environmental conditions
iii. Capable of high resistance and very long term survival
iv. Hardiest of all life forms
Endospores
- no infectious
2. but responsible for the O2 explosion. booyah.
Cyanobacteria
little shrinkage and bacterial shape/size can be more reliably interpreted.
benefits of air-dry
- G-
- Intracellular parsites
- Polymorphic - its life cycle includes two different forms
a. elementary bodies
i. time infectious agent that’s taken into cell where it grows inside vacuole into reticulate body
ii. infectious form
b. reticulate bodies
i. the form that multiplies inside cell; turning back into elementary bodies before escaping from the hos cell via lysis.
Chlamydiaceae Family
Bacteria spread out in ink
Negative and Capsule
Coat is made of keratin and spore specific proteins makes acid/radiation/chemical/disinfectants/dyes/antibiotics difficult to penetrate
Endospores
preparing a smear for a negative stain involves
air drying the smear
effective on a small range of microbes
i. Target specific cell component that is found only in certain microbes
Narrow Spectrum
bacteria spread out in water, then air dried
Positive Stain
i. narrow for G+
ii. downside: allergies
Cell wall
methicilin
Determined that microbes in dust and air were resistant to boiling and came up with the technique of intermittent boiling to eliminate what was later to be confirmed to be endospores?
John Tyndall
i. early belief that some forms of life could arise from vita forces present in nonliving or decomposing matter (flies from manure)
a. Spontaneous Generation
i. Phospholipids contain backwards glycerol, and no fatty acids - isoprene chain - helps them to resist heat.
Archaea Cell Membrane
a. Vectors
i. body lice
b. Reservoirs
i. humans
c. Transmissions
i. inoculation + feces –> human skin –> no soap or water –> scratch the microbe into skin –> flu-like symptoms + rash
ii. Reactivation with stress or weakened immuine system
d. Symptoms
i. flu-like + rash
- Rickettsia Prowazekii - Typhus - Worse
Heat Fixed
Positive Stain
i. discovered first antibiotic, penicillin
ii. isolated in 1939 by Ernest Chain and Howard Florey
iii. Extracted from Penicillum mold
Alexander Fleming 1929
Sizes of bacteria
1 um to 200 nm -ish
- Take one of heat fixed smears and place it on screen over steaming water
- Put small piece of paper towel on top of the smear and add enough malachite green to saturate the paper.
a. malachite green primary stain - Steam for 5 minutes while keeping the paper moist with additional stain as needed.
a. since spores resistant to staining. - To avoid stain get on bottom of slide, hold slide with clothespin over steam rather than let the slide sit there.
- remove slide from screen and let it cool; rinse with distilled water for 30 seconds.
- Place the slide on staining rack and counterstain with sfranin for 20 seconds
a. This is the counterstain that stains the vegetative cells. - Rinse the slide and blot dry.
a. Endospores should be green; vegetative cells should be red/pink.
Endospore Stain
i. Used swan-necked flask to demonstrate the dust is associated with microbes in the air
ii. 1861 paper tried to persuade readers that mcirobes do not spontaneously generate
iii. still had some results that were contrary to the idea.
iv. Developed pasteurization
v. Demonstrated what is now known as the Germ Theory of Disease
h. Louis Pasteur, 1859 Frenchman
- Place heat fixed smear on staining rack over your sink.
- Flood with methylene blue for 1 minute
- Rinse slide with distilled water
- Blot with bibulous paper
- View with oil immersion.
Simple stain